1 00:00:12,950 --> 00:00:11,350 nasa's jet propulsion laboratory 2 00:00:15,669 --> 00:00:12,960 presents 3 00:00:17,590 --> 00:00:15,679 the von carmen lecture a series of talks 4 00:00:20,950 --> 00:00:17,600 by scientists and engineers who are 5 00:00:34,389 --> 00:00:20,960 exploring our planet our solar system 6 00:00:38,310 --> 00:00:36,310 hey good evening ladies and gentlemen 7 00:00:39,830 --> 00:00:38,320 how's everyone tonight 8 00:00:41,270 --> 00:00:39,840 good well thanks for coming out to join 9 00:00:43,270 --> 00:00:41,280 us this evening 10 00:00:45,270 --> 00:00:43,280 as humans drive earth's climate into a 11 00:00:47,270 --> 00:00:45,280 new regime it is critical to keep our 12 00:00:49,430 --> 00:00:47,280 fingers on the pulse of the planet 13 00:00:51,190 --> 00:00:49,440 sea level rise is both a stark reminder 14 00:00:52,790 --> 00:00:51,200 of our impact on the climate and its 15 00:00:54,790 --> 00:00:52,800 impact on us 16 00:00:56,869 --> 00:00:54,800 the oceans capture over 90 percent of 17 00:00:59,430 --> 00:00:56,879 the heat trapped by greenhouse gases 18 00:01:01,189 --> 00:00:59,440 expanding as they warm they also collect 19 00:01:03,510 --> 00:01:01,199 water from melting glaciers and ice 20 00:01:05,750 --> 00:01:03,520 sheets making sea level rise a doubly 21 00:01:07,910 --> 00:01:05,760 important indicator of global warming 22 00:01:10,830 --> 00:01:07,920 without adaptation a two meter rise 23 00:01:12,870 --> 00:01:10,840 would displace 187 million people 24 00:01:13,990 --> 00:01:12,880 worldwide sea level will continue to 25 00:01:15,910 --> 00:01:14,000 rise 26 00:01:17,749 --> 00:01:15,920 but we don't know how fast 27 00:01:19,670 --> 00:01:17,759 like its predecessors the jason-3 28 00:01:21,190 --> 00:01:19,680 mission will serve as our eyes on sea 29 00:01:23,190 --> 00:01:21,200 level rise 30 00:01:24,950 --> 00:01:23,200 measuring global sea level once every 10 31 00:01:26,870 --> 00:01:24,960 days it will chart out the global rise 32 00:01:29,350 --> 00:01:26,880 of the oceans a rise that is unlikely to 33 00:01:31,990 --> 00:01:29,360 subside or reverse for generations 34 00:01:34,149 --> 00:01:32,000 but jason 3 will be more than a senten a 35 00:01:35,670 --> 00:01:34,159 sentinel of climate change as it will 36 00:01:37,429 --> 00:01:35,680 also measure the tilt of the ocean's 37 00:01:39,590 --> 00:01:37,439 surface providing oceanographers with 38 00:01:41,109 --> 00:01:39,600 information about ocean currents 39 00:01:43,510 --> 00:01:41,119 measure wind and waves helping 40 00:01:45,670 --> 00:01:43,520 forecasters predict marine weather and 41 00:01:48,310 --> 00:01:45,680 even find local warm spots 42 00:01:50,789 --> 00:01:48,320 that can intensify hurricanes in short 43 00:01:52,830 --> 00:01:50,799 jason 3 will be pretty cool 44 00:01:55,350 --> 00:01:52,840 our guest tonight has been at jpl since 45 00:01:57,190 --> 00:01:55,360 2004 and is now the nasa project 46 00:01:58,709 --> 00:01:57,200 scientist for the soon to be launched 47 00:02:00,789 --> 00:01:58,719 jason 3 mission 48 00:02:02,630 --> 00:02:00,799 in 2010 he was awarded a presidential 49 00:02:04,870 --> 00:02:02,640 early career award for scientists and 50 00:02:06,630 --> 00:02:04,880 engineers by president obama for his 51 00:02:08,949 --> 00:02:06,640 pioneering research on understanding the 52 00:02:10,790 --> 00:02:08,959 causes of sea level rise and the ocean's 53 00:02:13,270 --> 00:02:10,800 role in a warming climate 54 00:02:16,869 --> 00:02:13,280 most recently his project ocean's 55 00:02:18,790 --> 00:02:16,879 melting greenland or omg for short 56 00:02:20,710 --> 00:02:18,800 was selected by nasa as an earth 57 00:02:22,470 --> 00:02:20,720 ventures mission to study how the oceans 58 00:02:23,510 --> 00:02:22,480 are melting the greenland ice sheet from 59 00:02:25,589 --> 00:02:23,520 below 60 00:02:27,830 --> 00:02:25,599 in his spare time he studies comedy and 61 00:02:29,589 --> 00:02:27,840 improvisational theater last year he 62 00:02:31,350 --> 00:02:29,599 graduated from the second city improv 63 00:02:32,949 --> 00:02:31,360 program in hollywood we learned to 64 00:02:34,150 --> 00:02:32,959 communicate about climate change through 65 00:02:36,150 --> 00:02:34,160 comedy 66 00:02:38,550 --> 00:02:36,160 despite his love of laughter though he 67 00:02:39,910 --> 00:02:38,560 has not yet quit his day job 68 00:02:41,110 --> 00:02:39,920 ladies and gentlemen please help me 69 00:02:45,750 --> 00:02:41,120 welcome tonight's guest and a good 70 00:02:45,760 --> 00:02:50,550 thanks 71 00:02:53,990 --> 00:02:52,630 wow thank you mark that was uh 72 00:02:57,030 --> 00:02:54,000 incredibly 73 00:03:00,229 --> 00:02:57,040 erudite and well written um 74 00:03:01,670 --> 00:03:00,239 so i just will end there uh 75 00:03:03,750 --> 00:03:01,680 see you guys 76 00:03:05,509 --> 00:03:03,760 no i really appreciate the uh the warm 77 00:03:06,790 --> 00:03:05,519 welcome and i really appreciate 78 00:03:09,110 --> 00:03:06,800 everybody coming out tonight and 79 00:03:12,390 --> 00:03:09,120 everybody who's watching us streaming on 80 00:03:16,070 --> 00:03:12,400 the interwebs and uh on nasa tv when it 81 00:03:17,430 --> 00:03:16,080 airs tomorrow night uh so uh why am i 82 00:03:21,430 --> 00:03:17,440 here 83 00:03:24,070 --> 00:03:21,440 which is 84 00:03:25,270 --> 00:03:24,080 the successor to the successor to the 85 00:03:27,670 --> 00:03:25,280 successor 86 00:03:29,670 --> 00:03:27,680 to the mission that got me my phd back 87 00:03:32,149 --> 00:03:29,680 in graduate school and that mission was 88 00:03:33,350 --> 00:03:32,159 called topex poseidon and it was our 89 00:03:35,990 --> 00:03:33,360 very first 90 00:03:37,830 --> 00:03:36,000 look at the oceans from space in a way 91 00:03:39,509 --> 00:03:37,840 that we could really measure them well 92 00:03:41,190 --> 00:03:39,519 enough to tell us something incredibly 93 00:03:42,390 --> 00:03:41,200 useful to oceanographers and i'll talk a 94 00:03:43,350 --> 00:03:42,400 little bit more about that as we go 95 00:03:45,350 --> 00:03:43,360 along 96 00:03:46,869 --> 00:03:45,360 but i also want to really drive home the 97 00:03:49,910 --> 00:03:46,879 theme tonight 98 00:03:52,229 --> 00:03:49,920 that this is one of the fundamental ways 99 00:03:55,270 --> 00:03:52,239 in which we measure human-caused climate 100 00:03:56,869 --> 00:03:55,280 change or global warming really 101 00:03:59,910 --> 00:03:56,879 two-thirds of the planet are covered 102 00:04:02,390 --> 00:03:59,920 with ocean and as we look at our 103 00:04:04,229 --> 00:04:02,400 changing climate and our changing planet 104 00:04:06,070 --> 00:04:04,239 uh really we need to be looking to the 105 00:04:06,949 --> 00:04:06,080 oceans because that's where the action 106 00:04:09,110 --> 00:04:06,959 is 107 00:04:10,789 --> 00:04:09,120 so uh you guys look like a really nice 108 00:04:12,550 --> 00:04:10,799 crowd so hopefully i'm not gonna say 109 00:04:14,070 --> 00:04:12,560 anything uh that will get me beat up 110 00:04:15,990 --> 00:04:14,080 later 111 00:04:19,189 --> 00:04:16,000 i ask you know because 112 00:04:23,909 --> 00:04:20,629 so i am going to say global warming is 113 00:04:25,990 --> 00:04:23,919 real so so please don't beat me up 114 00:04:28,070 --> 00:04:26,000 and i want to start off with this slide 115 00:04:29,909 --> 00:04:28,080 i like to start with this slide because 116 00:04:31,350 --> 00:04:29,919 it's a reminder of just how big the 117 00:04:33,909 --> 00:04:31,360 oceans are 118 00:04:36,310 --> 00:04:33,919 the pacific ocean covers about one third 119 00:04:38,390 --> 00:04:36,320 of the planet's surface all by itself if 120 00:04:40,390 --> 00:04:38,400 you were to rotate this globe just a 121 00:04:42,550 --> 00:04:40,400 little bit to the east and look at it 122 00:04:45,270 --> 00:04:42,560 from this same view almost the only 123 00:04:47,110 --> 00:04:45,280 thing you would see is the pacific ocean 124 00:04:48,469 --> 00:04:47,120 the oceans cover two-thirds of our 125 00:04:50,469 --> 00:04:48,479 planet's surface 126 00:04:54,710 --> 00:04:50,479 and they play an incredibly important 127 00:04:57,030 --> 00:04:54,720 role in our overall changing climate so 128 00:04:59,590 --> 00:04:57,040 in this sense um you might not be 129 00:05:01,590 --> 00:04:59,600 surprised that it's an ocean mission 130 00:05:05,110 --> 00:05:01,600 that's really measuring uh the most 131 00:05:07,990 --> 00:05:05,120 fundamental aspect of climate change 132 00:05:10,550 --> 00:05:08,000 so uh as uh mark kind of set up a little 133 00:05:13,029 --> 00:05:10,560 bit here uh this is the uh 134 00:05:15,749 --> 00:05:13,039 actual fourth mission in a long line of 135 00:05:17,110 --> 00:05:15,759 missions that have measured sea level 136 00:05:18,710 --> 00:05:17,120 from space 137 00:05:20,629 --> 00:05:18,720 starting with topex poseidon which was 138 00:05:23,270 --> 00:05:20,639 launched in 1992 139 00:05:26,469 --> 00:05:23,280 jason won in 2001 and this graphics a 140 00:05:29,110 --> 00:05:26,479 little old actually we lost jason one 141 00:05:30,550 --> 00:05:29,120 just a little under two years ago 142 00:05:33,029 --> 00:05:30,560 and jason two which is still in 143 00:05:35,029 --> 00:05:33,039 operation and of course jason three 144 00:05:37,830 --> 00:05:35,039 which we hope to launch this summer uh 145 00:05:39,510 --> 00:05:37,840 if all goes well 146 00:05:41,029 --> 00:05:39,520 why do we need to keep measuring the 147 00:05:43,830 --> 00:05:41,039 oceans like this 148 00:05:45,270 --> 00:05:43,840 uh well if we take a look at how jason 149 00:05:47,590 --> 00:05:45,280 works just to give you kind of a 150 00:05:49,590 --> 00:05:47,600 fundamental idea of what's going on with 151 00:05:51,510 --> 00:05:49,600 this satellite it looks something like 152 00:05:53,350 --> 00:05:51,520 this and in a sense it's one of the 153 00:05:55,189 --> 00:05:53,360 simplest measurements we can make from 154 00:05:57,510 --> 00:05:55,199 space it doesn't require a whole lot of 155 00:05:58,790 --> 00:05:57,520 interpretation or guesswork to kind of 156 00:06:01,029 --> 00:05:58,800 figure out what it is you're really 157 00:06:03,110 --> 00:06:01,039 measuring all you do is you bounce a 158 00:06:05,830 --> 00:06:03,120 radar wave off the surface of the ocean 159 00:06:07,830 --> 00:06:05,840 from your satellite so we shoot a radar 160 00:06:09,510 --> 00:06:07,840 wave down it comes back up 161 00:06:11,350 --> 00:06:09,520 it travels through the atmosphere and 162 00:06:13,510 --> 00:06:11,360 the ionosphere and some other things and 163 00:06:16,309 --> 00:06:13,520 we have to do some corrections in order 164 00:06:17,749 --> 00:06:16,319 to uh in order to understand this real 165 00:06:19,430 --> 00:06:17,759 distance but essentially we're just 166 00:06:20,629 --> 00:06:19,440 measuring how long it takes for this 167 00:06:22,629 --> 00:06:20,639 wave 168 00:06:24,950 --> 00:06:22,639 of electromagnetic energy essentially a 169 00:06:26,230 --> 00:06:24,960 radio wave to go down to the surface of 170 00:06:28,309 --> 00:06:26,240 the earth and 171 00:06:30,150 --> 00:06:28,319 come back up and that tells us the 172 00:06:31,590 --> 00:06:30,160 distance between the satellite and the 173 00:06:34,390 --> 00:06:31,600 surface of the ocean 174 00:06:36,870 --> 00:06:34,400 so if we know where the satellite is 175 00:06:39,430 --> 00:06:36,880 then we can figure out how tall the 176 00:06:41,430 --> 00:06:39,440 ocean is and essentially this 177 00:06:42,309 --> 00:06:41,440 mission flies about 800 miles out in 178 00:06:45,029 --> 00:06:42,319 space 179 00:06:48,309 --> 00:06:45,039 and it can measure the accuracy of about 180 00:06:49,590 --> 00:06:48,319 a 10 kilometer square on the ocean it 181 00:06:51,909 --> 00:06:49,600 can measure the sea level with an 182 00:06:54,309 --> 00:06:51,919 accuracy of about one inch from 800 183 00:06:55,110 --> 00:06:54,319 miles up so it's really an amazing piece 184 00:06:57,510 --> 00:06:55,120 of 185 00:06:59,909 --> 00:06:57,520 engineering and an amazing technological 186 00:07:00,790 --> 00:06:59,919 feat and when you do this 187 00:07:02,870 --> 00:07:00,800 once 188 00:07:05,110 --> 00:07:02,880 every few every second really for 10 189 00:07:08,150 --> 00:07:05,120 days you cover the entire surface of the 190 00:07:10,629 --> 00:07:08,160 earth earth's oceans uh or almost the 191 00:07:13,029 --> 00:07:10,639 entire surface once every 10 days you 192 00:07:14,710 --> 00:07:13,039 can see not only changes in the ocean 193 00:07:16,790 --> 00:07:14,720 that have to do with changes in ocean 194 00:07:18,870 --> 00:07:16,800 currents but you can also also see the 195 00:07:19,990 --> 00:07:18,880 increasing volume of the ocean as a 196 00:07:21,670 --> 00:07:20,000 whole 197 00:07:23,510 --> 00:07:21,680 so this is the way in which it really is 198 00:07:25,189 --> 00:07:23,520 one of the most fundamental tools for 199 00:07:27,990 --> 00:07:25,199 measuring climate change 200 00:07:29,189 --> 00:07:28,000 so uh uh just to give you an idea uh you 201 00:07:31,189 --> 00:07:29,199 know we keep talking about ocean 202 00:07:33,270 --> 00:07:31,199 currents and essentially whenever a 203 00:07:36,150 --> 00:07:33,280 large current happens in the ocean and 204 00:07:38,390 --> 00:07:36,160 it persists for several days or weeks 205 00:07:40,469 --> 00:07:38,400 then it literally tilts the surface of 206 00:07:41,909 --> 00:07:40,479 the ocean and we can measure that tilt 207 00:07:43,830 --> 00:07:41,919 with this satellite we can figure out 208 00:07:45,430 --> 00:07:43,840 what the currents are and how they're 209 00:07:46,710 --> 00:07:45,440 changing especially 210 00:07:48,629 --> 00:07:46,720 but when you average over the whole 211 00:07:49,830 --> 00:07:48,639 planet you really see this other signal 212 00:07:51,350 --> 00:07:49,840 which i'll talk more about as we go 213 00:07:52,390 --> 00:07:51,360 along 214 00:07:53,990 --> 00:07:52,400 now 215 00:07:59,110 --> 00:07:54,000 the 216 00:08:01,029 --> 00:07:59,120 all kinds of important uses and in april 217 00:08:03,189 --> 00:08:01,039 of 2010 218 00:08:04,390 --> 00:08:03,199 there was an explosion aboard the 219 00:08:07,670 --> 00:08:04,400 deepwater 220 00:08:10,390 --> 00:08:07,680 horizon oil rig in the gulf of mexico 221 00:08:13,430 --> 00:08:10,400 11 people were killed during the 222 00:08:15,909 --> 00:08:13,440 eventual sinking of this uh of this 223 00:08:18,710 --> 00:08:15,919 platform and many others were injured 224 00:08:21,029 --> 00:08:18,720 and eventually uh the platform uh was 225 00:08:22,790 --> 00:08:21,039 lost completely and 226 00:08:25,510 --> 00:08:22,800 the well it had been drilling began to 227 00:08:26,390 --> 00:08:25,520 spew oil into the gulf of mexico 228 00:08:28,710 --> 00:08:26,400 and 229 00:08:30,550 --> 00:08:28,720 it was because of satellites like the 230 00:08:32,709 --> 00:08:30,560 jason missions that we were really able 231 00:08:35,350 --> 00:08:32,719 to understand and predict 232 00:08:36,870 --> 00:08:35,360 the currents that would carry this oil 233 00:08:38,870 --> 00:08:36,880 around in the gulf stream eventually 234 00:08:41,029 --> 00:08:38,880 mixing it up and dispersing it 235 00:08:42,070 --> 00:08:41,039 some of it eventually probably even left 236 00:08:42,949 --> 00:08:42,080 the gulf 237 00:08:44,630 --> 00:08:42,959 through 238 00:08:46,310 --> 00:08:44,640 the gulf stream which runs around the 239 00:08:48,070 --> 00:08:46,320 southern tip of florida and heads out 240 00:08:50,150 --> 00:08:48,080 into the atlantic ocean 241 00:08:51,990 --> 00:08:50,160 so this is really an incredibly powerful 242 00:08:54,870 --> 00:08:52,000 tool for for understanding ocean 243 00:08:57,110 --> 00:08:54,880 currents and the json mission both one 244 00:08:59,030 --> 00:08:57,120 and two were in operation at this time 245 00:09:00,230 --> 00:08:59,040 and another satellite which measures sea 246 00:09:01,509 --> 00:09:00,240 surface height but in a slightly 247 00:09:04,389 --> 00:09:01,519 different way 248 00:09:07,110 --> 00:09:04,399 envysat was also used to 249 00:09:08,790 --> 00:09:07,120 map this oil slick so 250 00:09:10,710 --> 00:09:08,800 measuring the ocean currents from space 251 00:09:12,150 --> 00:09:10,720 has long been important to people like 252 00:09:14,790 --> 00:09:12,160 the navy 253 00:09:17,110 --> 00:09:14,800 and and other users of of data that 254 00:09:20,150 --> 00:09:17,120 tells you how the currents are are 255 00:09:21,990 --> 00:09:20,160 moving in the ocean fishermen as well 256 00:09:24,470 --> 00:09:22,000 another thing that measuring how tall 257 00:09:26,550 --> 00:09:24,480 the ocean tells you is how how warm the 258 00:09:30,150 --> 00:09:26,560 water is this is a really fundamental 259 00:09:32,470 --> 00:09:30,160 piece of uh how the oceans change warm 260 00:09:35,269 --> 00:09:32,480 water literally expands 261 00:09:38,389 --> 00:09:35,279 so a blob of warm water in the ocean 262 00:09:39,829 --> 00:09:38,399 stands taller than a blob of cold water 263 00:09:42,389 --> 00:09:39,839 and this is incredibly important for 264 00:09:44,790 --> 00:09:42,399 things like hurricanes which suck their 265 00:09:47,350 --> 00:09:44,800 energy out of the ocean in order to 266 00:09:49,590 --> 00:09:47,360 survive so these massive storms are 267 00:09:51,110 --> 00:09:49,600 skating over the surface of the ocean 268 00:09:54,070 --> 00:09:51,120 sucking up heat out of it and putting it 269 00:09:56,070 --> 00:09:54,080 into the atmosphere and as they do 270 00:09:57,590 --> 00:09:56,080 they mix up the ocean 271 00:10:00,070 --> 00:09:57,600 but what's really amazing about the 272 00:10:01,670 --> 00:10:00,080 satellite altimetry is it tells you not 273 00:10:03,990 --> 00:10:01,680 just that the ocean's warm right at the 274 00:10:07,030 --> 00:10:04,000 surface but that it's warm over depth 275 00:10:10,310 --> 00:10:07,040 too and so uh this is a plot showing the 276 00:10:12,630 --> 00:10:10,320 path of hurricane katrina where um 277 00:10:14,949 --> 00:10:12,640 uh essentially the the hurricane was 278 00:10:16,710 --> 00:10:14,959 fairly small as it had uh passed over 279 00:10:18,949 --> 00:10:16,720 the uh 280 00:10:20,790 --> 00:10:18,959 the southern tip of florida entered the 281 00:10:23,910 --> 00:10:20,800 gulf and as it started to turn north it 282 00:10:27,350 --> 00:10:23,920 hit this huge blob of warm water that 283 00:10:29,509 --> 00:10:27,360 was a giant eddy uh and this pool of 284 00:10:32,470 --> 00:10:29,519 warm water fueled it into the category 285 00:10:34,150 --> 00:10:32,480 four and eventually five hurricane which 286 00:10:36,310 --> 00:10:34,160 you which sped up and eventually made 287 00:10:38,870 --> 00:10:36,320 landfall very close to new orleans as 288 00:10:40,230 --> 00:10:38,880 you all know with disastrous results but 289 00:10:41,910 --> 00:10:40,240 if you only looked at the surface 290 00:10:44,470 --> 00:10:41,920 temperature of the oceans you wouldn't 291 00:10:46,389 --> 00:10:44,480 have been able to tell why the hurricane 292 00:10:49,509 --> 00:10:46,399 sped up right as it went across this big 293 00:10:52,550 --> 00:10:49,519 blob of warm water so it turns out that 294 00:10:54,550 --> 00:10:52,560 satellite altimeters also tell us about 295 00:10:56,790 --> 00:10:54,560 hurricanes and and how and where they 296 00:10:58,790 --> 00:10:56,800 might speed up due to the presence of 297 00:11:01,910 --> 00:10:58,800 extra warm water that's really hidden 298 00:11:05,910 --> 00:11:04,150 another trick that we can do with our 299 00:11:08,230 --> 00:11:05,920 altimeter data you know i said at the 300 00:11:10,710 --> 00:11:08,240 beginning that this is a follow-on 301 00:11:11,829 --> 00:11:10,720 mission to a series of satellites that's 302 00:11:14,150 --> 00:11:11,839 been flying 303 00:11:15,590 --> 00:11:14,160 since the early 90s so we now have over 304 00:11:17,910 --> 00:11:15,600 20 years 305 00:11:19,829 --> 00:11:17,920 of an incredibly accurate record of how 306 00:11:21,190 --> 00:11:19,839 the sea levels have changed all around 307 00:11:22,870 --> 00:11:21,200 the world 308 00:11:24,949 --> 00:11:22,880 and what's interesting is that we're 309 00:11:25,670 --> 00:11:24,959 slowly now starting to be able to tease 310 00:11:28,389 --> 00:11:25,680 out 311 00:11:31,910 --> 00:11:28,399 the part of sea level change 312 00:11:34,069 --> 00:11:31,920 local sea level change that's caused by 313 00:11:36,069 --> 00:11:34,079 human-caused climate change from the 314 00:11:37,910 --> 00:11:36,079 kind of natural fluctuations that happen 315 00:11:40,310 --> 00:11:37,920 in the ocean now if we look at the ocean 316 00:11:42,389 --> 00:11:40,320 as a whole if we average over the entire 317 00:11:45,030 --> 00:11:42,399 planet it's easy to see the human-caused 318 00:11:47,590 --> 00:11:45,040 component the long-term trend of global 319 00:11:49,910 --> 00:11:47,600 warming but if you look locally it can 320 00:11:51,910 --> 00:11:49,920 be swamped for a period of 20 years or 321 00:11:53,990 --> 00:11:51,920 so as a matter of fact on our coast 322 00:11:56,150 --> 00:11:54,000 right here in southern california we've 323 00:11:59,350 --> 00:11:56,160 had almost zero sea level rise for the 324 00:12:02,069 --> 00:11:59,360 last 20 years that's despite the fact 325 00:12:03,750 --> 00:12:02,079 that the entire planet has seen a couple 326 00:12:05,750 --> 00:12:03,760 inches of sea level rise 327 00:12:07,590 --> 00:12:05,760 so where did our sea level rise go well 328 00:12:09,350 --> 00:12:07,600 it turns out it went into the western 329 00:12:11,829 --> 00:12:09,360 pacific ocean 330 00:12:14,629 --> 00:12:11,839 due to a sort of natural cycle which we 331 00:12:16,629 --> 00:12:14,639 call the pacific decadal oscillation and 332 00:12:19,509 --> 00:12:16,639 finally now that we have this 20-year 333 00:12:22,310 --> 00:12:19,519 record of how the ocean levels are 334 00:12:24,550 --> 00:12:22,320 changing we can begin to tease apart the 335 00:12:25,509 --> 00:12:24,560 natural cycle which looks something like 336 00:12:28,870 --> 00:12:25,519 this 337 00:12:30,949 --> 00:12:28,880 from the part that's caused by uh that's 338 00:12:33,509 --> 00:12:30,959 really driven by human-caused climate 339 00:12:35,910 --> 00:12:33,519 change so this is a very recent study 340 00:12:37,829 --> 00:12:35,920 which was really exciting because it was 341 00:12:39,430 --> 00:12:37,839 the first one to really say look some of 342 00:12:41,190 --> 00:12:39,440 this warming in the western pacific 343 00:12:44,069 --> 00:12:41,200 which we used to think was just a 344 00:12:45,590 --> 00:12:44,079 natural cycle and would eventually 345 00:12:47,670 --> 00:12:45,600 cool back down 346 00:12:49,190 --> 00:12:47,680 maybe kind of permanent it may stick 347 00:12:51,509 --> 00:12:49,200 around and if we look in our climate 348 00:12:53,829 --> 00:12:51,519 models we see very similar patterns 349 00:12:56,310 --> 00:12:53,839 to where these things are warming so so 350 00:12:57,750 --> 00:12:56,320 this altimeter data is really helping us 351 00:13:01,110 --> 00:12:57,760 tease apart 352 00:13:02,389 --> 00:13:01,120 the human caused changes in our oceans 353 00:13:03,509 --> 00:13:02,399 from the 354 00:13:05,350 --> 00:13:03,519 kind of 355 00:13:07,509 --> 00:13:05,360 natural cycles that have always been 356 00:13:09,190 --> 00:13:07,519 there and will continue to be there so 357 00:13:10,949 --> 00:13:09,200 it's really an incredibly powerful data 358 00:13:13,030 --> 00:13:10,959 set and there's one last quick result i 359 00:13:13,910 --> 00:13:13,040 want to show you that's sort of new and 360 00:13:15,910 --> 00:13:13,920 fun 361 00:13:18,150 --> 00:13:15,920 i've been working with my colleague 362 00:13:20,790 --> 00:13:18,160 veronica neves to 363 00:13:23,430 --> 00:13:20,800 look at the recent global warming hiatus 364 00:13:24,790 --> 00:13:23,440 as it's been called now uh you may have 365 00:13:26,230 --> 00:13:24,800 heard something about this in the news 366 00:13:28,710 --> 00:13:26,240 scientists have been kind of puzzling 367 00:13:31,350 --> 00:13:28,720 over what's going on with uh global 368 00:13:33,350 --> 00:13:31,360 warming in the last 10 or 20 years um 369 00:13:34,389 --> 00:13:33,360 and it turns out that's actually a 370 00:13:35,990 --> 00:13:34,399 misnomer 371 00:13:38,470 --> 00:13:36,000 you shouldn't really be calling it the 372 00:13:41,030 --> 00:13:38,480 global warming hiatus because if we look 373 00:13:43,030 --> 00:13:41,040 at the surface temperature in the last 374 00:13:45,110 --> 00:13:43,040 20 years 375 00:13:48,550 --> 00:13:45,120 it was rising pretty fast in the 80s and 376 00:13:50,150 --> 00:13:48,560 90s and then in the last decade 377 00:13:51,350 --> 00:13:50,160 global surface temperature kind of 378 00:13:53,269 --> 00:13:51,360 flattened out 379 00:13:55,269 --> 00:13:53,279 and we didn't have a very fast rise in 380 00:13:57,189 --> 00:13:55,279 global surface temperature 381 00:13:58,949 --> 00:13:57,199 and it turns out if you look at the 382 00:14:01,269 --> 00:13:58,959 different places in the ocean that are 383 00:14:02,870 --> 00:14:01,279 either warming or cooling in the pacific 384 00:14:05,350 --> 00:14:02,880 ocean right at the surface we've had 385 00:14:07,670 --> 00:14:05,360 this enormous cooling 386 00:14:10,069 --> 00:14:07,680 so you know what's going on this cooling 387 00:14:12,870 --> 00:14:10,079 was big enough to kind of hide the 388 00:14:14,629 --> 00:14:12,880 increase in global surface temperature 389 00:14:16,389 --> 00:14:14,639 for the last 10 years 390 00:14:18,629 --> 00:14:16,399 um but 391 00:14:20,310 --> 00:14:18,639 as i probably already mentioned as we'll 392 00:14:22,710 --> 00:14:20,320 get to in a little bit 393 00:14:24,550 --> 00:14:22,720 global warming didn't really stop 394 00:14:28,150 --> 00:14:24,560 the surface temperature stopped 395 00:14:30,310 --> 00:14:28,160 increasing but the warming as a whole 396 00:14:31,590 --> 00:14:30,320 continued and it turns out that even 397 00:14:33,590 --> 00:14:31,600 though there wasn't much warming at the 398 00:14:35,750 --> 00:14:33,600 surface there was a lot of warming going 399 00:14:38,470 --> 00:14:35,760 on just below the surface in the pacific 400 00:14:41,590 --> 00:14:38,480 so a lot of this heat was hiding in what 401 00:14:44,470 --> 00:14:41,600 we call the pacific warm pool so really 402 00:14:46,470 --> 00:14:44,480 there is no hiatus in global warming 403 00:14:47,750 --> 00:14:46,480 there was a bit of a hiatus in surface 404 00:14:49,910 --> 00:14:47,760 temperature 405 00:14:51,750 --> 00:14:49,920 but in terms of global warming we're 406 00:14:54,550 --> 00:14:51,760 still chugging right along as you'll see 407 00:14:56,150 --> 00:14:54,560 in some slides a little bit later 408 00:14:57,350 --> 00:14:56,160 so you know i want to talk about global 409 00:14:58,870 --> 00:14:57,360 warming but you can't really talk about 410 00:15:00,790 --> 00:14:58,880 global warming without talking about the 411 00:15:02,389 --> 00:15:00,800 weather a little bit and it's important 412 00:15:04,470 --> 00:15:02,399 to remember that the weather is 413 00:15:07,030 --> 00:15:04,480 different than climate so you know right 414 00:15:08,949 --> 00:15:07,040 now we're having a heat wave it's hot 415 00:15:10,870 --> 00:15:08,959 you know i got in my car 416 00:15:13,269 --> 00:15:10,880 on the lab this afternoon and the little 417 00:15:14,230 --> 00:15:13,279 thermometer read 91 degrees 418 00:15:15,509 --> 00:15:14,240 so 419 00:15:17,910 --> 00:15:15,519 it's been a heatwave we've had a little 420 00:15:19,670 --> 00:15:17,920 mini heat wave here in in california and 421 00:15:22,710 --> 00:15:19,680 of course on the east coast they're 422 00:15:24,230 --> 00:15:22,720 getting blasted with huge snowstorms 423 00:15:25,670 --> 00:15:24,240 but you got to remember that not 424 00:15:28,230 --> 00:15:25,680 everything 425 00:15:30,710 --> 00:15:28,240 is related to global warming we get 426 00:15:32,230 --> 00:15:30,720 these warm spells and cold spells and 427 00:15:34,629 --> 00:15:32,240 they come and go and this is just part 428 00:15:37,269 --> 00:15:34,639 of the natural weather that we've had 429 00:15:38,710 --> 00:15:37,279 for for decades for millennia 430 00:15:41,509 --> 00:15:38,720 so you know 431 00:15:43,189 --> 00:15:41,519 sometimes we try and we go wait uh 432 00:15:45,269 --> 00:15:43,199 tonight's lecture is cancelled on global 433 00:15:46,949 --> 00:15:45,279 warming because we're snowed out right 434 00:15:48,949 --> 00:15:46,959 so global warming must not be real but 435 00:15:51,189 --> 00:15:48,959 but hold on you know you got to remember 436 00:15:52,949 --> 00:15:51,199 this is really a weather phenomenon it's 437 00:15:54,389 --> 00:15:52,959 not a climate phenomenon this is 438 00:15:56,389 --> 00:15:54,399 something that comes and goes in the 439 00:15:59,030 --> 00:15:56,399 matter of a week or two 440 00:16:00,790 --> 00:15:59,040 and it can take us on an awful wild ride 441 00:16:02,230 --> 00:16:00,800 but it's really not human-caused climate 442 00:16:03,749 --> 00:16:02,240 change it's important to keep that in 443 00:16:05,749 --> 00:16:03,759 mind 444 00:16:09,030 --> 00:16:05,759 the climate you could define as the 445 00:16:12,470 --> 00:16:09,040 long-term usual weather conditions of an 446 00:16:14,150 --> 00:16:12,480 area a country or a planet so 447 00:16:15,749 --> 00:16:14,160 you have to keep in mind that climate is 448 00:16:18,470 --> 00:16:15,759 something that changes over the course 449 00:16:20,230 --> 00:16:18,480 of decades or a century 450 00:16:22,710 --> 00:16:20,240 but not two weeks 451 00:16:24,550 --> 00:16:22,720 that's not climate change 452 00:16:26,389 --> 00:16:24,560 but what is climate change when i talk 453 00:16:28,069 --> 00:16:26,399 about global warming we often look at 454 00:16:31,829 --> 00:16:28,079 this curve this is the temperature curve 455 00:16:33,910 --> 00:16:31,839 for the last 120 or 30 years 456 00:16:36,069 --> 00:16:33,920 and it's the surface temperature this is 457 00:16:37,829 --> 00:16:36,079 again how the surface temperature has 458 00:16:39,910 --> 00:16:37,839 changed and you can see right at the end 459 00:16:41,350 --> 00:16:39,920 of this this is not a this is not 460 00:16:43,910 --> 00:16:41,360 totally up to date but right at the end 461 00:16:45,430 --> 00:16:43,920 here's our hiatus right this tiny little 462 00:16:46,230 --> 00:16:45,440 flat plateau 463 00:16:47,590 --> 00:16:46,240 but 464 00:16:48,870 --> 00:16:47,600 what's global warming well global 465 00:16:50,790 --> 00:16:48,880 warming is this 466 00:16:52,949 --> 00:16:50,800 degree and a half fahrenheit of increase 467 00:16:55,829 --> 00:16:52,959 that we've seen over the last 100 years 468 00:16:58,310 --> 00:16:55,839 and that's actually not stopping 469 00:16:59,590 --> 00:16:58,320 if uh if we look at at climate change 470 00:17:02,790 --> 00:16:59,600 and global warming and kind of the 471 00:17:05,110 --> 00:17:02,800 context of the last 10 000 years it 472 00:17:07,189 --> 00:17:05,120 really brings to light why this is such 473 00:17:09,429 --> 00:17:07,199 an important issue and one we we can't 474 00:17:11,029 --> 00:17:09,439 really afford to just ignore 475 00:17:13,350 --> 00:17:11,039 or blow off 476 00:17:15,909 --> 00:17:13,360 for the last 10 000 years 477 00:17:17,510 --> 00:17:15,919 human beings have enjoyed a very stable 478 00:17:19,590 --> 00:17:17,520 climate 479 00:17:21,750 --> 00:17:19,600 prior to this 480 00:17:23,110 --> 00:17:21,760 people were more or less evolved into 481 00:17:25,189 --> 00:17:23,120 what they are today 482 00:17:28,230 --> 00:17:25,199 but we were nomadic we would 483 00:17:30,630 --> 00:17:28,240 not settle in single places and 484 00:17:33,190 --> 00:17:30,640 farming was not really developed until 485 00:17:35,350 --> 00:17:33,200 the climate stabilized about 10 000 486 00:17:37,830 --> 00:17:35,360 years ago and it stabilized into this 487 00:17:39,750 --> 00:17:37,840 relatively warm climate now that's not 488 00:17:41,750 --> 00:17:39,760 to say nothing was going on in terms of 489 00:17:44,630 --> 00:17:41,760 climate you guys might have heard about 490 00:17:46,630 --> 00:17:44,640 the little ice age uh well 491 00:17:48,310 --> 00:17:46,640 the little ice age followed what was 492 00:17:50,230 --> 00:17:48,320 called the medieval warm period which 493 00:17:52,470 --> 00:17:50,240 was a little warm period right here this 494 00:17:54,070 --> 00:17:52,480 is surface temperature over the last 20 495 00:17:55,909 --> 00:17:54,080 000 years 496 00:17:58,150 --> 00:17:55,919 and the scale gets a little finer as you 497 00:18:00,630 --> 00:17:58,160 go to the right but 20 000 years ago we 498 00:18:01,830 --> 00:18:00,640 were in the middle of an enormous 499 00:18:03,350 --> 00:18:01,840 ice age 500 00:18:04,549 --> 00:18:03,360 excuse me 501 00:18:07,029 --> 00:18:04,559 and this 502 00:18:09,590 --> 00:18:07,039 was a period of time when glaciers 503 00:18:11,830 --> 00:18:09,600 covered much of north america chicago 504 00:18:14,230 --> 00:18:11,840 was buried under two miles of ice 505 00:18:16,230 --> 00:18:14,240 the great lakes were being formed and it 506 00:18:19,270 --> 00:18:16,240 was an incredibly different climate and 507 00:18:20,710 --> 00:18:19,280 human beings didn't really settle down 508 00:18:21,669 --> 00:18:20,720 and begin to 509 00:18:25,029 --> 00:18:21,679 develop 510 00:18:28,630 --> 00:18:25,039 farming techniques and eventually 511 00:18:30,789 --> 00:18:28,640 cities and states and technology and 512 00:18:31,669 --> 00:18:30,799 iphones right we didn't get iphones 513 00:18:34,630 --> 00:18:31,679 until 514 00:18:37,270 --> 00:18:34,640 10 000 years of a stable climate 515 00:18:39,590 --> 00:18:37,280 so if we look out into the future 516 00:18:41,830 --> 00:18:39,600 this was the change out of the last ice 517 00:18:43,750 --> 00:18:41,840 age into the stable period it's about 518 00:18:46,070 --> 00:18:43,760 five degrees celsius in the global 519 00:18:48,789 --> 00:18:46,080 average and what we're looking at in the 520 00:18:50,710 --> 00:18:48,799 next 100 years relatively short time 521 00:18:52,070 --> 00:18:50,720 period compared to the last 10 000 in 522 00:18:54,789 --> 00:18:52,080 the next 100 years we're looking at 523 00:18:58,390 --> 00:18:54,799 something between two and five degrees 524 00:19:00,230 --> 00:18:58,400 celsius of warming so this is a major 525 00:19:02,870 --> 00:19:00,240 change in our climate we're looking at 526 00:19:05,110 --> 00:19:02,880 an incredibly different planet compared 527 00:19:07,029 --> 00:19:05,120 to the one we've had and enjoyed for ten 528 00:19:08,710 --> 00:19:07,039 thousand years the one we've built our 529 00:19:11,350 --> 00:19:08,720 civilization on 530 00:19:13,190 --> 00:19:11,360 so it's a pretty major change now i'm 531 00:19:14,630 --> 00:19:13,200 not saying it's the end of the world 532 00:19:16,789 --> 00:19:14,640 but it's definitely something we're 533 00:19:18,870 --> 00:19:16,799 going to have to deal with 534 00:19:21,510 --> 00:19:18,880 so uh what do you think causes climate 535 00:19:24,710 --> 00:19:23,190 this is the interactive portion so feel 536 00:19:26,789 --> 00:19:24,720 free to 537 00:19:29,270 --> 00:19:26,799 just yell it out 538 00:19:31,669 --> 00:19:29,280 co2 somebody said uh some would say 539 00:19:33,029 --> 00:19:31,679 democrats 540 00:19:36,310 --> 00:19:33,039 um 541 00:19:38,549 --> 00:19:36,320 it's not al gore's fault uh you know 542 00:19:39,669 --> 00:19:38,559 not everybody loves al but uh but you 543 00:19:41,190 --> 00:19:39,679 know it's not his fault that we're 544 00:19:43,830 --> 00:19:41,200 heating up the planet he was really just 545 00:19:45,190 --> 00:19:43,840 the messenger or one of them um but what 546 00:19:48,549 --> 00:19:45,200 what really causes climate change you 547 00:19:50,549 --> 00:19:48,559 guys got it it's co2 um if we look back 548 00:19:53,990 --> 00:19:50,559 over the last hundred thousand years of 549 00:19:56,549 --> 00:19:54,000 the planet's history we see these rises 550 00:19:59,350 --> 00:19:56,559 and falls in co2 and these actually 551 00:20:02,070 --> 00:19:59,360 track the rises and falls in the 552 00:20:02,870 --> 00:20:02,080 temperature of uh the 553 00:20:07,430 --> 00:20:02,880 the 554 00:20:09,029 --> 00:20:07,440 sort of 555 00:20:11,590 --> 00:20:09,039 ten thousand years of warming in a 556 00:20:14,070 --> 00:20:11,600 hundred thousand years of cooling 557 00:20:15,510 --> 00:20:14,080 go back for millions of years and what 558 00:20:17,029 --> 00:20:15,520 had happened was you know we talked 559 00:20:19,590 --> 00:20:17,039 about twenty thousand years ago that was 560 00:20:21,750 --> 00:20:19,600 the end of this last cold period 561 00:20:24,549 --> 00:20:21,760 and then we warmed up out of this 562 00:20:27,350 --> 00:20:24,559 cold period into the holocene that 10 563 00:20:28,870 --> 00:20:27,360 000 years of sweet climate 564 00:20:30,950 --> 00:20:28,880 and now what we're doing is we're 565 00:20:34,390 --> 00:20:30,960 looking at putting carbon dioxide up to 566 00:20:36,070 --> 00:20:34,400 levels that haven't been seen for 567 00:20:37,190 --> 00:20:36,080 hundreds of thousands probably millions 568 00:20:39,110 --> 00:20:37,200 of years 569 00:20:40,390 --> 00:20:39,120 so we're changing our 570 00:20:42,789 --> 00:20:40,400 composition we're changing the 571 00:20:45,270 --> 00:20:42,799 composition of our atmosphere in a way 572 00:20:48,149 --> 00:20:45,280 we've now pushed past the 400 parts per 573 00:20:49,350 --> 00:20:48,159 million mark which is about right here 574 00:20:51,590 --> 00:20:49,360 and we've done it in the last hundred 575 00:20:53,350 --> 00:20:51,600 years so this is a major change in the 576 00:20:55,830 --> 00:20:53,360 composition of our atmosphere now often 577 00:20:57,350 --> 00:20:55,840 people ask me how do you know that and 578 00:20:59,590 --> 00:20:57,360 we have all kinds of techniques i like 579 00:21:00,870 --> 00:20:59,600 to talk a little bit about how we know 580 00:21:02,470 --> 00:21:00,880 the information we know because i think 581 00:21:03,909 --> 00:21:02,480 it's important 582 00:21:05,909 --> 00:21:03,919 you know if you drill down through the 583 00:21:07,110 --> 00:21:05,919 ice cores uh if you drill down through 584 00:21:10,390 --> 00:21:07,120 glaciers 585 00:21:11,270 --> 00:21:10,400 for the moment 586 00:21:13,029 --> 00:21:11,280 where 587 00:21:15,029 --> 00:21:13,039 the snow doesn't melt completely every 588 00:21:17,190 --> 00:21:15,039 year and it stacks on top of each other 589 00:21:19,110 --> 00:21:17,200 and you can see these annual layers and 590 00:21:21,190 --> 00:21:19,120 if you drill down through that through 591 00:21:23,190 --> 00:21:21,200 these annual layers you can find tiny 592 00:21:25,669 --> 00:21:23,200 little bubbles where the air has been 593 00:21:27,430 --> 00:21:25,679 captured and you can measure the old 594 00:21:29,350 --> 00:21:27,440 atmosphere 595 00:21:31,270 --> 00:21:29,360 all the way back hundreds of thousands 596 00:21:33,510 --> 00:21:31,280 of years and that's how we build these 597 00:21:35,350 --> 00:21:33,520 records of carbon dioxide and you can 598 00:21:37,270 --> 00:21:35,360 actually measure temperature separately 599 00:21:39,590 --> 00:21:37,280 so you can measure both carbon dioxide 600 00:21:41,510 --> 00:21:39,600 and temperature based on the isotopes 601 00:21:43,909 --> 00:21:41,520 that get taken up 602 00:21:45,110 --> 00:21:43,919 and the amount of actual co2 trapped in 603 00:21:47,510 --> 00:21:45,120 the little bubbles 604 00:21:48,710 --> 00:21:47,520 so uh we have a pretty good record you 605 00:21:50,310 --> 00:21:48,720 know often people say well there was 606 00:21:52,710 --> 00:21:50,320 nobody around a million years ago how do 607 00:21:55,590 --> 00:21:52,720 you know co2 was what it was well this 608 00:21:57,590 --> 00:21:55,600 is how we know we we dig it up 609 00:22:00,070 --> 00:21:57,600 now every global warming talk has a 610 00:22:01,029 --> 00:22:00,080 slide like this and this is mine 611 00:22:04,549 --> 00:22:01,039 uh 612 00:22:07,190 --> 00:22:04,559 this is a a just a simple schematic 613 00:22:09,990 --> 00:22:07,200 of what causes global warming so all of 614 00:22:12,470 --> 00:22:10,000 the important energy that we get for 615 00:22:14,549 --> 00:22:12,480 our planet's climate comes from the sun 616 00:22:16,149 --> 00:22:14,559 and this energy essentially goes right 617 00:22:17,990 --> 00:22:16,159 through the atmosphere 618 00:22:19,990 --> 00:22:18,000 you can see the sunlight when you walk 619 00:22:21,430 --> 00:22:20,000 outside and even though it's gone all 620 00:22:23,270 --> 00:22:21,440 the way through the atmosphere and the 621 00:22:25,270 --> 00:22:23,280 reason is because the sunlight is 622 00:22:26,390 --> 00:22:25,280 basically uh the atmosphere is 623 00:22:28,230 --> 00:22:26,400 transparent 624 00:22:29,750 --> 00:22:28,240 when it comes to sunlight sunlight goes 625 00:22:31,990 --> 00:22:29,760 right through now some bounces off 626 00:22:33,669 --> 00:22:32,000 clouds and other things yes but by and 627 00:22:35,510 --> 00:22:33,679 large most of the energy goes right 628 00:22:38,230 --> 00:22:35,520 through the atmosphere and it gets 629 00:22:39,750 --> 00:22:38,240 absorbed at the surface and remember 630 00:22:42,310 --> 00:22:39,760 two-thirds of the ocean two-thirds of 631 00:22:43,830 --> 00:22:42,320 the surfaces i gave it away 632 00:22:47,190 --> 00:22:43,840 ocean right 633 00:22:48,470 --> 00:22:47,200 so by and large this energy is heating 634 00:22:51,909 --> 00:22:48,480 up the oceans 635 00:22:54,630 --> 00:22:51,919 and that warm uh ocean 636 00:22:56,950 --> 00:22:54,640 radiates energy back out towards space 637 00:22:58,630 --> 00:22:56,960 so we've got the energy coming in gets 638 00:23:00,710 --> 00:22:58,640 sucked up by the ocean and gets spit 639 00:23:03,029 --> 00:23:00,720 back out toward the atmosphere now the 640 00:23:03,990 --> 00:23:03,039 problem is that the energy going out is 641 00:23:08,230 --> 00:23:04,000 different 642 00:23:10,549 --> 00:23:08,240 it's long wave radiation what we call uh 643 00:23:13,510 --> 00:23:10,559 infrared radiation and the atmosphere 644 00:23:15,430 --> 00:23:13,520 actually absorbs that and the amount 645 00:23:18,630 --> 00:23:15,440 that it absorbs it depends on how much 646 00:23:20,390 --> 00:23:18,640 carbon dioxide there is so very simply 647 00:23:23,669 --> 00:23:20,400 if we change the composition of the 648 00:23:27,029 --> 00:23:23,679 atmosphere we're trapping extra heat on 649 00:23:28,710 --> 00:23:27,039 the planet right so the question is 650 00:23:31,750 --> 00:23:28,720 where does the heat go 651 00:23:33,830 --> 00:23:31,760 well mark ruined the answer already 652 00:23:37,750 --> 00:23:33,840 by telling you in the beginning 653 00:23:40,470 --> 00:23:37,760 but anybody want to guess 654 00:23:43,110 --> 00:23:40,480 the oceans yes i heard somebody say it 655 00:23:45,830 --> 00:23:43,120 that counts you get extra credit 656 00:23:47,669 --> 00:23:45,840 uh yeah over 90 percent of the heat 657 00:23:49,590 --> 00:23:47,679 trapped by global warming is going into 658 00:23:51,350 --> 00:23:49,600 the oceans so if you're not really 659 00:23:54,230 --> 00:23:51,360 looking in the oceans you're not really 660 00:23:57,190 --> 00:23:54,240 seeing the signal so even though we 661 00:23:58,789 --> 00:23:57,200 think of global warming as global 662 00:24:01,830 --> 00:23:58,799 temperature increase 663 00:24:03,510 --> 00:24:01,840 really it's here it's global heating 664 00:24:05,830 --> 00:24:03,520 it's that extra heat that's trapped in 665 00:24:07,990 --> 00:24:05,840 the ocean that's really important that's 666 00:24:09,510 --> 00:24:08,000 really changing our climate so almost 667 00:24:11,830 --> 00:24:09,520 all of the action in terms of global 668 00:24:14,230 --> 00:24:11,840 warming is really in the oceans now why 669 00:24:16,149 --> 00:24:14,240 is that now you can do a simple 670 00:24:18,630 --> 00:24:16,159 experiment if you take a a simple 671 00:24:22,310 --> 00:24:18,640 balloon and you fill it with air and you 672 00:24:24,470 --> 00:24:22,320 hold a lighter to it what happens 673 00:24:26,710 --> 00:24:24,480 it pops yes someone on the internet said 674 00:24:28,549 --> 00:24:26,720 it pops 675 00:24:30,710 --> 00:24:28,559 if you take a balloon filled with water 676 00:24:33,590 --> 00:24:30,720 and you do the same trick 677 00:24:35,909 --> 00:24:33,600 what happens 678 00:24:36,870 --> 00:24:35,919 it doesn't pop that's right somebody 679 00:24:39,830 --> 00:24:36,880 said it 680 00:24:41,190 --> 00:24:39,840 in fact the water is so good at sucking 681 00:24:43,350 --> 00:24:41,200 up the heat 682 00:24:45,669 --> 00:24:43,360 that the skin on the balloon the rubber 683 00:24:47,190 --> 00:24:45,679 doesn't have time to melt so 684 00:24:48,390 --> 00:24:47,200 this is an experiment you can try at 685 00:24:49,909 --> 00:24:48,400 home 686 00:24:53,590 --> 00:24:49,919 or it's an experiment you can try in 687 00:24:56,630 --> 00:24:53,600 about about a room full of 100 people 688 00:25:00,390 --> 00:24:57,909 since i'm in a room filled with 100 689 00:25:03,510 --> 00:25:00,400 people i figured i'll try it 690 00:25:06,470 --> 00:25:03,520 so some of you in the front row 691 00:25:07,909 --> 00:25:06,480 may be in harm's way 692 00:25:09,830 --> 00:25:07,919 so 693 00:25:13,029 --> 00:25:09,840 trust me 694 00:25:21,029 --> 00:25:14,630 all right so this is a balloon that's 695 00:25:25,269 --> 00:25:22,310 and i could keep going and fill it with 696 00:25:25,279 --> 00:25:29,750 you guys want to keep going 697 00:25:32,789 --> 00:25:30,630 and 698 00:25:34,310 --> 00:25:32,799 if i tie it off 699 00:25:35,750 --> 00:25:34,320 which i'm going to make a big production 700 00:25:36,789 --> 00:25:35,760 of 701 00:25:37,990 --> 00:25:36,799 um 702 00:25:40,310 --> 00:25:38,000 no i'm not i'm just going to hold the 703 00:25:41,990 --> 00:25:40,320 flame to it if i tie it off 704 00:25:44,310 --> 00:25:42,000 and hold the flame to it you guys can 705 00:25:46,390 --> 00:25:44,320 guess that it's going to pop so let's 706 00:25:48,710 --> 00:25:46,400 see how long it takes to pop the balloon 707 00:25:50,870 --> 00:25:48,720 filled with air with a lighter 708 00:25:52,390 --> 00:25:50,880 are you guys ready 709 00:25:53,990 --> 00:25:52,400 are you sure you're ready 710 00:25:55,669 --> 00:25:54,000 all right here we go 711 00:25:57,669 --> 00:25:55,679 you should close your eyes and your ears 712 00:25:59,350 --> 00:25:57,679 and anyone with a pacemaker heart 713 00:26:00,789 --> 00:25:59,360 condition 714 00:26:04,149 --> 00:26:00,799 now would be the time to leave the room 715 00:26:10,630 --> 00:26:05,430 boom 716 00:26:14,470 --> 00:26:12,950 um so there's only one thing left to do 717 00:26:16,630 --> 00:26:14,480 and that's try it with a water balloon 718 00:26:19,029 --> 00:26:16,640 so we're gonna do that um the water 719 00:26:21,110 --> 00:26:19,039 balloon won't pop either uh 720 00:26:22,870 --> 00:26:21,120 just like in the video 721 00:26:29,510 --> 00:26:22,880 and i know this because i'm a scientist 722 00:26:31,990 --> 00:26:30,630 all right 723 00:26:35,830 --> 00:26:32,000 you people in the front row are in 724 00:26:41,269 --> 00:26:38,789 this is strictly the policy of uh the 725 00:26:42,390 --> 00:26:41,279 auditorium that i use this bucket 726 00:26:44,630 --> 00:26:42,400 um because there's all kinds of 727 00:26:47,669 --> 00:26:44,640 sensitive electronic equipment you guys 728 00:26:50,230 --> 00:26:47,679 are fine that would be great um in honor 729 00:26:52,070 --> 00:26:50,240 because it's valentine's day 730 00:26:53,269 --> 00:26:52,080 i decided it should be a pink ocean 731 00:26:57,190 --> 00:26:53,279 today 732 00:26:59,909 --> 00:26:58,149 okay 733 00:27:01,909 --> 00:26:59,919 uh we're gonna try this and and just see 734 00:27:03,590 --> 00:27:01,919 what happens what i want you guys to do 735 00:27:06,230 --> 00:27:03,600 is count how long 736 00:27:07,590 --> 00:27:06,240 it takes for me to pop the balloon okay 737 00:27:10,230 --> 00:27:07,600 filled with water 738 00:27:11,909 --> 00:27:10,240 you're gonna be fine 739 00:27:14,549 --> 00:27:11,919 um 740 00:27:23,990 --> 00:27:14,559 this almost always works 741 00:27:24,000 --> 00:27:27,669 getting kind of nervous guys 742 00:27:27,679 --> 00:27:35,029 you guys are good at counting 743 00:27:35,039 --> 00:27:40,630 getting hot in here 744 00:27:45,190 --> 00:27:42,230 20 is good right 745 00:27:47,269 --> 00:27:45,200 yay we can stop at 20. look 746 00:27:49,190 --> 00:27:47,279 look um and actually if you want to feel 747 00:27:50,870 --> 00:27:49,200 it uh 748 00:27:53,909 --> 00:27:50,880 it's not even hot right 749 00:27:55,350 --> 00:27:53,919 yeah it's because 750 00:27:56,950 --> 00:27:55,360 it's because the balloon is so good at 751 00:27:58,149 --> 00:27:56,960 taking up heat and the water sucks up 752 00:28:02,389 --> 00:27:58,159 all the heat and that's that's why it 753 00:28:05,269 --> 00:28:03,590 ah 754 00:28:06,630 --> 00:28:05,279 all right 755 00:28:08,230 --> 00:28:06,640 so 756 00:28:10,950 --> 00:28:08,240 that was the scariest part for me i know 757 00:28:12,710 --> 00:28:10,960 it was for you too 758 00:28:15,029 --> 00:28:12,720 that's why i got to drink some water so 759 00:28:17,350 --> 00:28:15,039 uh what did we learn 760 00:28:18,149 --> 00:28:17,360 nothing i knew it great 761 00:28:20,470 --> 00:28:18,159 um 762 00:28:22,389 --> 00:28:20,480 so uh really the point here is that 763 00:28:23,190 --> 00:28:22,399 water is kind of an amazing substance 764 00:28:25,350 --> 00:28:23,200 and 765 00:28:26,149 --> 00:28:25,360 two-thirds of our planet is covered by 766 00:28:29,110 --> 00:28:26,159 it 767 00:28:30,549 --> 00:28:29,120 to a depth of about four kilometers 768 00:28:33,909 --> 00:28:30,559 couple of miles 769 00:28:35,350 --> 00:28:33,919 so this is a huge volume of water and 770 00:28:37,590 --> 00:28:35,360 essentially what we're doing with 771 00:28:40,630 --> 00:28:37,600 climate change is holding a great big 772 00:28:45,669 --> 00:28:40,640 lighter to it and waiting for sea level 773 00:28:48,310 --> 00:28:47,430 on that happy note 774 00:28:50,149 --> 00:28:48,320 um 775 00:28:52,389 --> 00:28:50,159 just to kind of revisit what's going on 776 00:28:53,990 --> 00:28:52,399 uh you know if we imagine our sun again 777 00:28:56,310 --> 00:28:54,000 and our atmosphere 778 00:28:59,110 --> 00:28:56,320 before climate change started so say 779 00:29:01,430 --> 00:28:59,120 during that 10 000 year period of 780 00:29:02,789 --> 00:29:01,440 climate happiness um 781 00:29:05,029 --> 00:29:02,799 essentially we were getting the same 782 00:29:07,350 --> 00:29:05,039 amount of energy coming in from the sun 783 00:29:09,909 --> 00:29:07,360 as was going back out into space 784 00:29:13,110 --> 00:29:09,919 and what happened in the last 150 years 785 00:29:14,549 --> 00:29:13,120 is we reshaped the atmosphere we changed 786 00:29:17,029 --> 00:29:14,559 the composition of the atmosphere and we 787 00:29:18,549 --> 00:29:17,039 started keeping more of this heat on the 788 00:29:20,389 --> 00:29:18,559 planet 789 00:29:21,990 --> 00:29:20,399 so if you look at our our little happy 790 00:29:23,510 --> 00:29:22,000 earth what's happening is he's getting 791 00:29:26,870 --> 00:29:23,520 warmer right 792 00:29:29,350 --> 00:29:26,880 he's turning into hot earth now uh 793 00:29:31,029 --> 00:29:29,360 eventually this heat goes somewhere it 794 00:29:32,149 --> 00:29:31,039 warms up the oceans it warms up the 795 00:29:33,590 --> 00:29:32,159 atmosphere 796 00:29:35,350 --> 00:29:33,600 eventually 797 00:29:38,149 --> 00:29:35,360 you get a warm enough 798 00:29:40,710 --> 00:29:38,159 atmosphere that it starts sending more 799 00:29:43,669 --> 00:29:40,720 radiation back out into space so you 800 00:29:46,470 --> 00:29:43,679 achieve a new balance a new 801 00:29:48,870 --> 00:29:46,480 earth a new climate but the penalty for 802 00:29:50,870 --> 00:29:48,880 that new balance is that now you've got 803 00:29:52,310 --> 00:29:50,880 a warmer earth you've heated up your 804 00:29:54,789 --> 00:29:52,320 planet 805 00:29:56,950 --> 00:29:54,799 but remember i said that global warming 806 00:29:59,990 --> 00:29:56,960 is all happening in the oceans 807 00:30:02,230 --> 00:30:00,000 so in order to get from the left earth 808 00:30:04,789 --> 00:30:02,240 that's normal and cool to the right 809 00:30:06,630 --> 00:30:04,799 earth that's hot and sweaty you have to 810 00:30:09,430 --> 00:30:06,640 first heat up the oceans 811 00:30:10,870 --> 00:30:09,440 and heating up the oceans is a huge task 812 00:30:12,789 --> 00:30:10,880 because they're so big 813 00:30:14,310 --> 00:30:12,799 in fact it takes something like a 814 00:30:16,310 --> 00:30:14,320 thousand years 815 00:30:19,190 --> 00:30:16,320 for the heat we put in the ocean today 816 00:30:21,590 --> 00:30:19,200 to spread through the entire oceans uh 817 00:30:24,230 --> 00:30:21,600 and eventually circulate back up 818 00:30:26,310 --> 00:30:24,240 to the surface so we're setting in 819 00:30:27,909 --> 00:30:26,320 motion changes by changing this 820 00:30:29,750 --> 00:30:27,919 composition the atmosphere that are 821 00:30:31,190 --> 00:30:29,760 going to be with us for something like a 822 00:30:33,510 --> 00:30:31,200 thousand years 823 00:30:37,110 --> 00:30:33,520 so if you go back to my title about 824 00:30:39,590 --> 00:30:37,120 irreversibility no way back um you know 825 00:30:41,510 --> 00:30:39,600 in terms of a human scale in terms of 826 00:30:43,510 --> 00:30:41,520 people alive today our children our 827 00:30:44,950 --> 00:30:43,520 grandchildren our great grandchildren 828 00:30:47,110 --> 00:30:44,960 we're really looking at changes that 829 00:30:49,110 --> 00:30:47,120 we're not going to be able to undo in 830 00:30:51,190 --> 00:30:49,120 any easy way 831 00:30:53,269 --> 00:30:51,200 for thousands of years 832 00:30:55,269 --> 00:30:53,279 sea level rise will continue to happen 833 00:30:57,350 --> 00:30:55,279 even after we stop putting carbon 834 00:31:00,230 --> 00:30:57,360 dioxide in the atmosphere because it 835 00:31:03,669 --> 00:31:00,240 takes the oceans so long to absorb and 836 00:31:04,710 --> 00:31:03,679 eventually redistribute this heat 837 00:31:07,909 --> 00:31:04,720 so 838 00:31:09,990 --> 00:31:07,919 is global warming really happening um 839 00:31:11,830 --> 00:31:10,000 i say yes um 840 00:31:12,950 --> 00:31:11,840 my friends say yes 841 00:31:15,110 --> 00:31:12,960 uh 842 00:31:16,710 --> 00:31:15,120 if you haven't seen ice age two global 843 00:31:18,230 --> 00:31:16,720 warming is like the bad guy and sea 844 00:31:20,310 --> 00:31:18,240 level rise is happening it's a great 845 00:31:22,070 --> 00:31:20,320 movie anyway 846 00:31:24,310 --> 00:31:22,080 but not everybody believes that global 847 00:31:26,070 --> 00:31:24,320 warming is real some of our 848 00:31:29,590 --> 00:31:26,080 some of our friends on the radio 849 00:31:31,590 --> 00:31:29,600 still don't uh don't agree and in fact 850 00:31:33,750 --> 00:31:31,600 also since valentine's day is coming up 851 00:31:35,990 --> 00:31:33,760 i thought i'd just take a second and 852 00:31:38,630 --> 00:31:36,000 tell this little story a couple years 853 00:31:40,549 --> 00:31:38,640 ago i wrote a paper about 854 00:31:42,070 --> 00:31:40,559 about climate change 855 00:31:44,070 --> 00:31:42,080 suggesting that the oceans had actually 856 00:31:46,549 --> 00:31:44,080 cooled off a little bit 857 00:31:49,509 --> 00:31:46,559 and rush limbaugh actually mentioned it 858 00:31:51,990 --> 00:31:49,519 on his show uh he 859 00:31:54,149 --> 00:31:52,000 had this fantastic quote he said you 860 00:31:55,830 --> 00:31:54,159 know this paper by josh willis and john 861 00:31:57,190 --> 00:31:55,840 lymon these other guys 862 00:31:58,950 --> 00:31:57,200 is uh 863 00:32:01,029 --> 00:31:58,960 totally crazy they have no idea what's 864 00:32:03,430 --> 00:32:01,039 happening in the climate it doesn't make 865 00:32:05,669 --> 00:32:03,440 any sense and he said 866 00:32:08,230 --> 00:32:05,679 to overturn the world economy based on 867 00:32:10,149 --> 00:32:08,240 the musings of a few idiot leftist 868 00:32:12,230 --> 00:32:10,159 scientists 869 00:32:14,389 --> 00:32:12,240 is just stupid and that's what global 870 00:32:15,909 --> 00:32:14,399 warming is actually all 871 00:32:18,549 --> 00:32:15,919 about 872 00:32:19,350 --> 00:32:18,559 thank you rush and uh 873 00:32:21,430 --> 00:32:19,360 uh 874 00:32:23,110 --> 00:32:21,440 so it was you know some of my colleagues 875 00:32:25,029 --> 00:32:23,120 that wrote the paper with me were of 876 00:32:28,310 --> 00:32:25,039 course horrified that rush limbaugh had 877 00:32:30,310 --> 00:32:28,320 talked about us on the radio um and uh 878 00:32:32,230 --> 00:32:30,320 it turned out that um i kept looking at 879 00:32:34,070 --> 00:32:32,240 this data and this the signal of ocean 880 00:32:36,470 --> 00:32:34,080 cooling which actually in a sense really 881 00:32:39,110 --> 00:32:36,480 didn't even make sense to me um and i 882 00:32:41,110 --> 00:32:39,120 dug a little further and um it was uh 883 00:32:42,710 --> 00:32:41,120 february of i think 884 00:32:44,310 --> 00:32:42,720 2008 885 00:32:45,509 --> 00:32:44,320 i want to say 886 00:32:47,190 --> 00:32:45,519 and i was 887 00:32:49,430 --> 00:32:47,200 standing with my wife in the kitchen and 888 00:32:51,990 --> 00:32:49,440 i was looking over a talk about ocean 889 00:32:53,669 --> 00:32:52,000 cooling that i was supposed to give at a 890 00:32:55,590 --> 00:32:53,679 big climate center in colorado the 891 00:32:57,029 --> 00:32:55,600 following weekend and 892 00:32:58,789 --> 00:32:57,039 i uh 893 00:33:00,470 --> 00:32:58,799 i found this result and i i thought it 894 00:33:02,789 --> 00:33:00,480 was really surprising 895 00:33:04,549 --> 00:33:02,799 um some of the data that was going into 896 00:33:07,190 --> 00:33:04,559 it looked like it had been flawed like 897 00:33:09,110 --> 00:33:07,200 it was too cold and i wrote a friend of 898 00:33:10,310 --> 00:33:09,120 mine an email and he wrote back kind of 899 00:33:11,830 --> 00:33:10,320 quickly and said yeah you know 900 00:33:13,269 --> 00:33:11,840 something's definitely wrong with that 901 00:33:15,669 --> 00:33:13,279 data 902 00:33:18,230 --> 00:33:15,679 and i turned to my wife uh 903 00:33:19,909 --> 00:33:18,240 um it was actually valentine's day and 904 00:33:21,909 --> 00:33:19,919 we were getting ready to go out for a 905 00:33:22,710 --> 00:33:21,919 nice dinner and i said i think i'm wrong 906 00:33:25,590 --> 00:33:22,720 about 907 00:33:28,789 --> 00:33:25,600 ocean cooling 908 00:33:30,549 --> 00:33:28,799 and she said okay let's go get dinner 909 00:33:31,990 --> 00:33:30,559 but dinner was kind of ruined because i 910 00:33:34,389 --> 00:33:32,000 was really worried i had to give a talk 911 00:33:36,389 --> 00:33:34,399 literally the next day 912 00:33:37,990 --> 00:33:36,399 at a big climate center and so i was 913 00:33:40,389 --> 00:33:38,000 just worrying the whole time and dinner 914 00:33:42,070 --> 00:33:40,399 was completely ruined 915 00:33:43,750 --> 00:33:42,080 and 916 00:33:45,590 --> 00:33:43,760 as a reminder 917 00:33:48,549 --> 00:33:45,600 my wife actually 918 00:33:51,190 --> 00:33:48,559 had a small business card made for me 919 00:33:53,110 --> 00:33:51,200 which has my job title listed as idiot 920 00:33:54,870 --> 00:33:53,120 leftist scientist so 921 00:33:56,470 --> 00:33:54,880 if anybody wants one you can see me 922 00:33:59,110 --> 00:33:56,480 after the show 923 00:34:00,950 --> 00:33:59,120 um yeah so uh you know but i think this 924 00:34:02,789 --> 00:34:00,960 is an important lesson in how science 925 00:34:06,070 --> 00:34:02,799 works because you know we don't get the 926 00:34:08,950 --> 00:34:06,080 answer right the first time every time 927 00:34:10,230 --> 00:34:08,960 but we keep hacking away at it and so uh 928 00:34:12,149 --> 00:34:10,240 you know eventually i wrote another 929 00:34:14,470 --> 00:34:12,159 paper and said okay i was wrong about 930 00:34:16,950 --> 00:34:14,480 ocean cooling and rush was right i am a 931 00:34:17,750 --> 00:34:16,960 big fat idiot 932 00:34:21,990 --> 00:34:17,760 but 933 00:34:24,869 --> 00:34:22,000 certain about and stands on a whole lot 934 00:34:27,190 --> 00:34:24,879 more uh research and papers than uh just 935 00:34:28,790 --> 00:34:27,200 my one bad one that rush uh mocked me 936 00:34:31,909 --> 00:34:28,800 for um 937 00:34:33,510 --> 00:34:31,919 is the rise of sea levels over time 938 00:34:35,669 --> 00:34:33,520 you know i mentioned a little while ago 939 00:34:38,389 --> 00:34:35,679 that temperatures went up and down with 940 00:34:41,190 --> 00:34:38,399 the cycles of the ice ages and co2 941 00:34:43,510 --> 00:34:41,200 followed those as well and uh 942 00:34:45,990 --> 00:34:43,520 sea level actually also went up and down 943 00:34:48,950 --> 00:34:46,000 with the ice ages because as you build a 944 00:34:50,470 --> 00:34:48,960 gigantic ice sheet over north america 945 00:34:52,149 --> 00:34:50,480 the water has to come from somewhere and 946 00:34:54,950 --> 00:34:52,159 it comes from the oceans 947 00:34:58,310 --> 00:34:54,960 so during that period 20 000 years ago 948 00:35:00,470 --> 00:34:58,320 the oceans were 120 meters lower than 949 00:35:02,870 --> 00:35:00,480 they were today so this is when you had 950 00:35:05,670 --> 00:35:02,880 things like a land bridge across the 951 00:35:07,829 --> 00:35:05,680 bering strait and north america and 952 00:35:08,790 --> 00:35:07,839 siberia were essentially connected and 953 00:35:11,670 --> 00:35:08,800 so 954 00:35:13,670 --> 00:35:11,680 as we warmed up out of that period 955 00:35:15,270 --> 00:35:13,680 sea levels began to rise and those ice 956 00:35:17,589 --> 00:35:15,280 sheets began to melt and we had 957 00:35:19,109 --> 00:35:17,599 incredibly fast sea level rise about ten 958 00:35:21,430 --> 00:35:19,119 thousand years ago 959 00:35:23,510 --> 00:35:21,440 and then it really started to level out 960 00:35:25,589 --> 00:35:23,520 and if you look at just the last couple 961 00:35:27,510 --> 00:35:25,599 thousand years we have a very new very 962 00:35:29,430 --> 00:35:27,520 exciting record of this 963 00:35:32,150 --> 00:35:29,440 incredibly accurate from 964 00:35:35,750 --> 00:35:32,160 of all places north carolina 965 00:35:37,910 --> 00:35:35,760 and in north carolina the land itself 966 00:35:41,990 --> 00:35:37,920 is sinking a little bit 967 00:35:43,910 --> 00:35:42,000 and as it does the ocean crawls up these 968 00:35:46,630 --> 00:35:43,920 salt marshes the sea level crawls up 969 00:35:48,550 --> 00:35:46,640 these salt marshes and you can it leaves 970 00:35:50,230 --> 00:35:48,560 behind a record because 971 00:35:53,030 --> 00:35:50,240 they're little critters that like to 972 00:35:55,829 --> 00:35:53,040 live in very specific levels 973 00:35:56,790 --> 00:35:55,839 in the tidal range you can dig a core in 974 00:35:59,109 --> 00:35:56,800 these 975 00:36:02,310 --> 00:35:59,119 salt marshes or a number of cores and 976 00:36:03,910 --> 00:36:02,320 you can reconstruct sea level back two 977 00:36:05,750 --> 00:36:03,920 thousand years 978 00:36:07,270 --> 00:36:05,760 and when you do that 979 00:36:08,870 --> 00:36:07,280 and you account for the local land 980 00:36:10,710 --> 00:36:08,880 motion what you see 981 00:36:12,790 --> 00:36:10,720 is that we essentially had two thousand 982 00:36:15,270 --> 00:36:12,800 years or at least a thousand years a 983 00:36:17,670 --> 00:36:15,280 very stable sea level sea levels were 984 00:36:19,430 --> 00:36:17,680 not changing hardly at all 985 00:36:21,589 --> 00:36:19,440 then during what was called the medieval 986 00:36:23,510 --> 00:36:21,599 warm period we had a little bit of rise 987 00:36:25,750 --> 00:36:23,520 right through here and during what was 988 00:36:27,990 --> 00:36:25,760 called the little ice age we had maybe a 989 00:36:29,910 --> 00:36:28,000 little bit of decline but what's really 990 00:36:32,550 --> 00:36:29,920 striking about this picture what's 991 00:36:34,790 --> 00:36:32,560 really the amazing part the last 150 992 00:36:37,030 --> 00:36:34,800 years where sea levels rising at two 993 00:36:38,950 --> 00:36:37,040 millimeters per year in agreement with 994 00:36:41,109 --> 00:36:38,960 local tide gauges by the way these data 995 00:36:43,829 --> 00:36:41,119 have been verified by nearby actual 996 00:36:46,790 --> 00:36:43,839 instruments and uh 997 00:36:48,150 --> 00:36:46,800 incredibly this rate of sea level rise 998 00:36:50,150 --> 00:36:48,160 is different than anything we've seen in 999 00:36:51,750 --> 00:36:50,160 the last two thousand years 1000 00:36:53,750 --> 00:36:51,760 so you know remember we've been through 1001 00:36:55,990 --> 00:36:53,760 these ice ages little ice ages and 1002 00:36:57,670 --> 00:36:56,000 little warm periods cycles of the sun 1003 00:37:00,150 --> 00:36:57,680 coming and going and tilt of the earth's 1004 00:37:01,910 --> 00:37:00,160 axis and so forth but nothing until the 1005 00:37:04,550 --> 00:37:01,920 industrial revolution 1006 00:37:06,470 --> 00:37:04,560 until the rise of co2 put there in the 1007 00:37:09,430 --> 00:37:06,480 atmosphere by people 1008 00:37:11,430 --> 00:37:09,440 can really explain the warming and the 1009 00:37:13,589 --> 00:37:11,440 incredible rate of sea level rise we've 1010 00:37:15,750 --> 00:37:13,599 seen in the last hundred years 1011 00:37:18,390 --> 00:37:15,760 so to me this is really the nail in the 1012 00:37:19,990 --> 00:37:18,400 coffin in terms of the deniers argument 1013 00:37:22,150 --> 00:37:20,000 that global warming is not happening or 1014 00:37:24,550 --> 00:37:22,160 that it's not caused by people because 1015 00:37:27,670 --> 00:37:24,560 you can't really explain this rise in 1016 00:37:28,470 --> 00:37:27,680 the last 100 years without it 1017 00:37:29,829 --> 00:37:28,480 so 1018 00:37:31,589 --> 00:37:29,839 i like to 1019 00:37:33,829 --> 00:37:31,599 drone on about this but i'll move on and 1020 00:37:35,430 --> 00:37:33,839 look at just the last hundred years and 1021 00:37:37,750 --> 00:37:35,440 this is the period where we kind of have 1022 00:37:40,630 --> 00:37:37,760 enough actual tide gauges in different 1023 00:37:42,470 --> 00:37:40,640 places in the planet to get a good sense 1024 00:37:46,150 --> 00:37:42,480 of how sea levels have changed in the 1025 00:37:48,710 --> 00:37:46,160 last 150 years 130 years and if you look 1026 00:37:51,270 --> 00:37:48,720 they haven't increased at a stable rate 1027 00:37:52,790 --> 00:37:51,280 in fact if you look at the first 1028 00:37:53,990 --> 00:37:52,800 50 years 1029 00:37:56,390 --> 00:37:54,000 they were going up at about one 1030 00:37:59,430 --> 00:37:56,400 millimeter per year in the second 50 1031 00:38:01,430 --> 00:37:59,440 years about two in the last 20 years 1032 00:38:03,910 --> 00:38:01,440 about three so there's actually been an 1033 00:38:05,510 --> 00:38:03,920 acceleration in the last hundred years 1034 00:38:07,349 --> 00:38:05,520 and even 1035 00:38:08,710 --> 00:38:07,359 more recent research than this suggests 1036 00:38:10,550 --> 00:38:08,720 that that acceleration might even be a 1037 00:38:12,230 --> 00:38:10,560 little bit bigger than what we show here 1038 00:38:14,470 --> 00:38:12,240 because the early part might have been 1039 00:38:16,310 --> 00:38:14,480 overestimated we see a little less sea 1040 00:38:18,550 --> 00:38:16,320 level rise in that first hundred first 1041 00:38:20,230 --> 00:38:18,560 50 years than is shown here 1042 00:38:23,190 --> 00:38:20,240 so 1043 00:38:25,270 --> 00:38:23,200 this seems small it's only about 1044 00:38:26,310 --> 00:38:25,280 20 centimeters about eight inches and 1045 00:38:28,710 --> 00:38:26,320 when you're standing on the beach 1046 00:38:30,870 --> 00:38:28,720 watching the waves crash in that seems 1047 00:38:33,270 --> 00:38:30,880 like a small number but remember 1048 00:38:35,349 --> 00:38:33,280 two-thirds of the planet's surface right 1049 00:38:37,510 --> 00:38:35,359 so this is a huge area and this turns 1050 00:38:40,150 --> 00:38:37,520 out to be an enormous volume sixteen 1051 00:38:42,950 --> 00:38:40,160 thousand cubic miles of extra ocean in 1052 00:38:45,349 --> 00:38:42,960 the last 130 years so finally we get to 1053 00:38:47,030 --> 00:38:45,359 kind of the more recent stuff the 1054 00:38:49,510 --> 00:38:47,040 altimeter period the period where 1055 00:38:51,030 --> 00:38:49,520 satellites really dominate our record of 1056 00:38:54,790 --> 00:38:51,040 sea level rise 1057 00:38:57,030 --> 00:38:54,800 and we look in the last 20 years 1058 00:38:59,430 --> 00:38:57,040 my phd was 1059 00:39:01,510 --> 00:38:59,440 somewhere in here and rush was making 1060 00:39:03,750 --> 00:39:01,520 fun of me somewhere in here 1061 00:39:05,829 --> 00:39:03,760 and finally we're out here but what's 1062 00:39:07,589 --> 00:39:05,839 striking about this and if you think 1063 00:39:09,190 --> 00:39:07,599 back to my earlier discussion about the 1064 00:39:13,829 --> 00:39:09,200 hiatus 1065 00:39:15,670 --> 00:39:13,839 this is the global warming curve and 1066 00:39:17,349 --> 00:39:15,680 there's really no hiatus in it anywhere 1067 00:39:19,670 --> 00:39:17,359 to be found a few small bumps and 1068 00:39:21,670 --> 00:39:19,680 wiggles but nothing like what you see in 1069 00:39:23,270 --> 00:39:21,680 the temperature record 1070 00:39:26,310 --> 00:39:23,280 but if you're not convinced by satellite 1071 00:39:28,790 --> 00:39:26,320 data of sea level rise you can look at 1072 00:39:31,030 --> 00:39:28,800 satellite data of the arctic um this is 1073 00:39:33,430 --> 00:39:31,040 the minimum amount of sea ice we had in 1074 00:39:35,750 --> 00:39:33,440 1979 the first year we had a satellite 1075 00:39:38,310 --> 00:39:35,760 to really look at the top of the planet 1076 00:39:39,910 --> 00:39:38,320 and this is the minimum in 2008 1077 00:39:42,550 --> 00:39:39,920 and so you go back and forth and you see 1078 00:39:45,030 --> 00:39:42,560 really it's an incredible 1079 00:39:47,349 --> 00:39:45,040 wastage of floating ice at the top of 1080 00:39:48,790 --> 00:39:47,359 the planet and i didn't just cherry pick 1081 00:39:51,109 --> 00:39:48,800 two years if you 1082 00:39:51,829 --> 00:39:51,119 plot the time series it looks like this 1083 00:39:54,550 --> 00:39:51,839 so 1084 00:39:57,430 --> 00:39:54,560 we've lost about half of the area of the 1085 00:39:59,349 --> 00:39:57,440 ice that's floating on the arctic ocean 1086 00:40:01,430 --> 00:39:59,359 and in fact actually that ice is thinned 1087 00:40:02,950 --> 00:40:01,440 by about a factor of two so if you're 1088 00:40:05,589 --> 00:40:02,960 thinking about the volume of ice 1089 00:40:08,230 --> 00:40:05,599 floating in the arctic it's decreased by 1090 00:40:11,670 --> 00:40:08,240 a factor of four in the last 20 or 30 1091 00:40:13,349 --> 00:40:11,680 years so it's a pretty major change 1092 00:40:15,430 --> 00:40:13,359 but nothing says global warming like a 1093 00:40:18,470 --> 00:40:15,440 polar bear right 1094 00:40:20,470 --> 00:40:18,480 so in 2007 we had this major minimum and 1095 00:40:23,030 --> 00:40:20,480 you know the ice was being blown north 1096 00:40:24,870 --> 00:40:23,040 away from canada and the polar bears are 1097 00:40:27,030 --> 00:40:24,880 hunters they use the ice to try and 1098 00:40:29,829 --> 00:40:27,040 catch seals which are better swimmers 1099 00:40:32,870 --> 00:40:29,839 than they are uh but the ice gives them 1100 00:40:34,390 --> 00:40:32,880 a kind of tactical advantage uh so polar 1101 00:40:36,950 --> 00:40:34,400 bears were literally starving to death 1102 00:40:39,750 --> 00:40:36,960 because they couldn't find enough ice uh 1103 00:40:42,310 --> 00:40:39,760 to hunt on hunt seals with now i'm not a 1104 00:40:43,910 --> 00:40:42,320 biologist but my guess is the polar 1105 00:40:45,829 --> 00:40:43,920 bears will survive global warming 1106 00:40:48,950 --> 00:40:45,839 because they can always just move south 1107 00:40:52,870 --> 00:40:49,910 but 1108 00:40:54,630 --> 00:40:52,880 at the same time this is a reminder that 1109 00:40:57,510 --> 00:40:54,640 some of really the world's top level 1110 00:41:01,030 --> 00:40:57,520 predators besides people are beginning 1111 00:41:02,550 --> 00:41:01,040 to feel the pressure of our changing 1112 00:41:04,390 --> 00:41:02,560 climate 1113 00:41:06,630 --> 00:41:04,400 and and so they do serve as an important 1114 00:41:07,910 --> 00:41:06,640 reminder kind of an iconic one i think 1115 00:41:09,270 --> 00:41:07,920 but of course you don't have to take the 1116 00:41:11,190 --> 00:41:09,280 polar bear's word we have another 1117 00:41:12,710 --> 00:41:11,200 satellite called grace 1118 00:41:15,510 --> 00:41:12,720 this is a fun satellite because it 1119 00:41:17,750 --> 00:41:15,520 literally weighs the continents 1120 00:41:19,190 --> 00:41:17,760 one satellite flies ahead of the other 1121 00:41:21,510 --> 00:41:19,200 and whenever it goes over something 1122 00:41:23,510 --> 00:41:21,520 heavy the pull of gravity literally 1123 00:41:25,270 --> 00:41:23,520 causes it to speed up then when the 1124 00:41:27,589 --> 00:41:25,280 second one follows it eventually catches 1125 00:41:29,589 --> 00:41:27,599 up and by measuring the distance between 1126 00:41:31,349 --> 00:41:29,599 the two satellites you can actually 1127 00:41:33,190 --> 00:41:31,359 infer the weight of the thing you're 1128 00:41:35,990 --> 00:41:33,200 flying over so if you're flying over 1129 00:41:39,430 --> 00:41:36,000 something like greenland you can chart 1130 00:41:41,190 --> 00:41:39,440 its uh its ice loss over time this is a 1131 00:41:45,990 --> 00:41:41,200 little bit older 1132 00:41:47,829 --> 00:41:46,000 continued through the present period 1133 00:41:50,309 --> 00:41:47,839 and greenland has been on jenny craig 1134 00:41:51,270 --> 00:41:50,319 it's lost uh a couple trillion tons 1135 00:41:53,270 --> 00:41:51,280 already 1136 00:41:56,309 --> 00:41:53,280 so um uh 1137 00:41:58,150 --> 00:41:56,319 go jenny um anyway uh the point here is 1138 00:42:00,390 --> 00:41:58,160 that we're really 1139 00:42:02,309 --> 00:42:00,400 seeing these huge changes in the ice 1140 00:42:03,670 --> 00:42:02,319 sheets that are unlike anything that's 1141 00:42:05,190 --> 00:42:03,680 been happening in the last several 1142 00:42:07,349 --> 00:42:05,200 thousand years if this had been going on 1143 00:42:09,430 --> 00:42:07,359 in greenland for two or three thousand 1144 00:42:12,790 --> 00:42:09,440 years sea levels would be 1145 00:42:14,790 --> 00:42:12,800 many feet higher than they are today 1146 00:42:17,750 --> 00:42:14,800 it's interesting too because greenland 1147 00:42:19,190 --> 00:42:17,760 is kind of melting in an interesting way 1148 00:42:21,349 --> 00:42:19,200 it starts 1149 00:42:23,910 --> 00:42:21,359 with the most melting the most ice loss 1150 00:42:25,109 --> 00:42:23,920 in the southeast sector but actually 1151 00:42:26,470 --> 00:42:25,119 there's also 1152 00:42:28,230 --> 00:42:26,480 ice loss 1153 00:42:29,750 --> 00:42:28,240 further to the north up up on the 1154 00:42:31,750 --> 00:42:29,760 western coast 1155 00:42:33,349 --> 00:42:31,760 and if you start asking 1156 00:42:34,950 --> 00:42:33,359 why is that 1157 00:42:36,150 --> 00:42:34,960 you immediately start 1158 00:42:38,150 --> 00:42:36,160 well i'll come back to this in a little 1159 00:42:40,309 --> 00:42:38,160 bit immediately start looking toward the 1160 00:42:41,990 --> 00:42:40,319 oceans it turns out the oceans are kind 1161 00:42:44,470 --> 00:42:42,000 of eating away at the edges of the 1162 00:42:45,990 --> 00:42:44,480 glaciers here and causing the ice loss 1163 00:42:48,150 --> 00:42:46,000 to accelerate 1164 00:42:51,589 --> 00:42:48,160 but again a picture is worth a thousand 1165 00:42:53,349 --> 00:42:51,599 words and a picture of a glacier is 1166 00:42:54,550 --> 00:42:53,359 worth at least a couple of satellites i 1167 00:42:56,069 --> 00:42:54,560 think 1168 00:42:58,630 --> 00:42:56,079 and this is a picture of a glacier in 1169 00:43:00,870 --> 00:42:58,640 alaska now some of the glaciers were in 1170 00:43:03,589 --> 00:43:00,880 retreat before global warming started in 1171 00:43:05,990 --> 00:43:03,599 alaska but not like they are today and 1172 00:43:08,150 --> 00:43:06,000 and the fact is that over 90 percent of 1173 00:43:11,030 --> 00:43:08,160 all the glaciers everywhere in the world 1174 00:43:12,710 --> 00:43:11,040 today are retreating so this is a global 1175 00:43:14,710 --> 00:43:12,720 signal that we're seeing all over the 1176 00:43:17,109 --> 00:43:14,720 place but this glacier is retreated 1177 00:43:19,349 --> 00:43:17,119 miles this was a night picture in 1941 1178 00:43:20,390 --> 00:43:19,359 this was 2004 1179 00:43:22,710 --> 00:43:20,400 and 1180 00:43:25,109 --> 00:43:22,720 many of the glaciers there in retreat in 1181 00:43:26,550 --> 00:43:25,119 really quite a spectacular fashion 1182 00:43:27,829 --> 00:43:26,560 but one of my favorite pieces of 1183 00:43:30,390 --> 00:43:27,839 evidence for 1184 00:43:32,550 --> 00:43:30,400 human-caused climate change 1185 00:43:35,670 --> 00:43:32,560 was the breakup of the larsen b ice 1186 00:43:37,270 --> 00:43:35,680 shelf in 2002 and this was interesting 1187 00:43:40,630 --> 00:43:37,280 this was a couple of images captured 1188 00:43:41,750 --> 00:43:40,640 again by nasa satellites and in january 1189 00:43:44,309 --> 00:43:41,760 which is summer in the southern 1190 00:43:46,230 --> 00:43:44,319 hemisphere this is um the continent of 1191 00:43:48,550 --> 00:43:46,240 antarctica is below here and this is 1192 00:43:52,069 --> 00:43:48,560 part of the big peninsula that sticks up 1193 00:43:53,990 --> 00:43:52,079 uh into the in the oceans and um this 1194 00:43:57,829 --> 00:43:54,000 region of this ice shelf is essentially 1195 00:43:59,829 --> 00:43:57,839 a giant floating pillow of ice that lays 1196 00:44:02,069 --> 00:43:59,839 out over the surface of the ocean that 1197 00:44:04,069 --> 00:44:02,079 comes from the flow of glaciers which 1198 00:44:06,069 --> 00:44:04,079 cut down through the mountains and then 1199 00:44:07,750 --> 00:44:06,079 spread out over the water so this is a 1200 00:44:08,790 --> 00:44:07,760 piece of floating ice 1201 00:44:11,349 --> 00:44:08,800 and 1202 00:44:12,630 --> 00:44:11,359 in january 2002 they saw these puddles 1203 00:44:14,470 --> 00:44:12,640 appear 1204 00:44:15,990 --> 00:44:14,480 these are little dark spots where the 1205 00:44:17,510 --> 00:44:16,000 sunlight's being 1206 00:44:19,270 --> 00:44:17,520 taken up instead of getting reflected 1207 00:44:20,550 --> 00:44:19,280 back out into space 1208 00:44:22,230 --> 00:44:20,560 and then in march when they flew back 1209 00:44:25,589 --> 00:44:22,240 over and took another picture this 1210 00:44:27,510 --> 00:44:25,599 entire shelf had broken up and collapsed 1211 00:44:30,309 --> 00:44:27,520 so all this fuzzy stuff are little 1212 00:44:32,309 --> 00:44:30,319 icebergs which are what is left of this 1213 00:44:34,150 --> 00:44:32,319 enormous ice shelf 1214 00:44:36,710 --> 00:44:34,160 now what's interesting to me is not so 1215 00:44:38,230 --> 00:44:36,720 much that a giant ice shelf broke up but 1216 00:44:41,190 --> 00:44:38,240 oceanographers went back and they 1217 00:44:42,870 --> 00:44:41,200 drilled a sediment cores where the ice 1218 00:44:44,950 --> 00:44:42,880 shelf had been and they found that the 1219 00:44:46,069 --> 00:44:44,960 ice shelf had been there for 10 000 1220 00:44:48,069 --> 00:44:46,079 years old 1221 00:44:49,510 --> 00:44:48,079 so through the little ice age and the 1222 00:44:51,510 --> 00:44:49,520 medieval warm period and all these 1223 00:44:53,829 --> 00:44:51,520 things that we think of all the way back 1224 00:44:55,349 --> 00:44:53,839 to when there was way more ice in the 1225 00:44:57,270 --> 00:44:55,359 world than there is today so these ice 1226 00:44:58,630 --> 00:44:57,280 shelves go way way back 1227 00:45:00,230 --> 00:44:58,640 they're the only thing older than hugh 1228 00:45:03,990 --> 00:45:00,240 hefner to break up in the last hundred 1229 00:45:07,829 --> 00:45:05,750 um i really need a rim shot anybody got 1230 00:45:10,870 --> 00:45:07,839 one of those anyways um 1231 00:45:12,630 --> 00:45:10,880 but the larson bi shelf uh i think um is 1232 00:45:14,390 --> 00:45:12,640 is another really striking piece of 1233 00:45:16,870 --> 00:45:14,400 evidence that something's happening 1234 00:45:18,470 --> 00:45:16,880 today in this hundred years that really 1235 00:45:21,750 --> 00:45:18,480 hasn't been happening for the last 1236 00:45:23,190 --> 00:45:21,760 several thousand and that's us um 1237 00:45:25,750 --> 00:45:23,200 you know if you ask where's global 1238 00:45:27,430 --> 00:45:25,760 warming uh and and you you still think 1239 00:45:29,829 --> 00:45:27,440 you can't see it i think then you're 1240 00:45:31,990 --> 00:45:29,839 really just not looking for it 1241 00:45:33,589 --> 00:45:32,000 so i want to come back really quick to 1242 00:45:34,870 --> 00:45:33,599 greenland with just the last couple of 1243 00:45:36,630 --> 00:45:34,880 minutes here and 1244 00:45:39,349 --> 00:45:36,640 talk about 1245 00:45:40,790 --> 00:45:39,359 the ice loss there 1246 00:45:43,670 --> 00:45:40,800 i'm going to skip ahead 1247 00:45:49,190 --> 00:45:46,790 mark mentioned my new uh uh mission 1248 00:45:51,910 --> 00:45:49,200 coming up which is called omg ocean's 1249 00:45:53,829 --> 00:45:51,920 melting greenland and uh 1250 00:45:55,910 --> 00:45:53,839 that was the best omg picture i found in 1251 00:45:57,349 --> 00:45:55,920 all the internet so if you have a better 1252 00:45:58,870 --> 00:45:57,359 one please send it to me see me after 1253 00:46:00,710 --> 00:45:58,880 the talk but i want to talk just for a 1254 00:46:03,030 --> 00:46:00,720 second about this because i talked a lot 1255 00:46:05,030 --> 00:46:03,040 about sea level rise but what's really 1256 00:46:07,109 --> 00:46:05,040 amazing is the cause of sea level rise 1257 00:46:08,150 --> 00:46:07,119 so if you look at greenland and i talked 1258 00:46:10,069 --> 00:46:08,160 about how 1259 00:46:12,150 --> 00:46:10,079 this south eastern quadrant and the 1260 00:46:13,030 --> 00:46:12,160 northwestern quadrant are both warming 1261 00:46:16,150 --> 00:46:13,040 what's 1262 00:46:17,750 --> 00:46:16,160 this is the place where the oceans are 1263 00:46:19,270 --> 00:46:17,760 warming the fastest 1264 00:46:20,950 --> 00:46:19,280 and so when we started to look when 1265 00:46:24,470 --> 00:46:20,960 researchers started to go up close to 1266 00:46:26,309 --> 00:46:24,480 these uh ice shelves or glaciers 1267 00:46:28,790 --> 00:46:26,319 the glaciers here literally run right 1268 00:46:30,150 --> 00:46:28,800 off of the continent and into the ocean 1269 00:46:31,670 --> 00:46:30,160 so they're 1270 00:46:33,589 --> 00:46:31,680 they're literally sticking right into 1271 00:46:35,349 --> 00:46:33,599 the water and that means ocean water can 1272 00:46:37,670 --> 00:46:35,359 come right up to the face 1273 00:46:40,069 --> 00:46:37,680 and melt away the face and as they do 1274 00:46:42,150 --> 00:46:40,079 that then the glacier itself is free to 1275 00:46:44,390 --> 00:46:42,160 speed up and dump more ice into the 1276 00:46:46,150 --> 00:46:44,400 ocean more quickly and that's what 1277 00:46:48,069 --> 00:46:46,160 causes the sea level rise and the 1278 00:46:50,950 --> 00:46:48,079 acceleration so 1279 00:46:53,109 --> 00:46:50,960 we proposed this a couple years ago to 1280 00:46:55,030 --> 00:46:53,119 do an aircraft mission to essentially 1281 00:46:56,470 --> 00:46:55,040 fly around greenland 1282 00:46:58,710 --> 00:46:56,480 and drop little sensors that would 1283 00:47:00,150 --> 00:46:58,720 measure the ocean temperatures and you 1284 00:47:02,230 --> 00:47:00,160 can't just measure the ocean temperature 1285 00:47:05,349 --> 00:47:02,240 at the surface because it turns out that 1286 00:47:08,230 --> 00:47:05,359 the oceans here have a cold fresh layer 1287 00:47:10,069 --> 00:47:08,240 that caps this warm salty layer which is 1288 00:47:11,589 --> 00:47:10,079 climbing up into the fjords and into 1289 00:47:14,470 --> 00:47:11,599 these trenches to eat away at the 1290 00:47:16,150 --> 00:47:14,480 glaciers so we designed an aircraft 1291 00:47:18,470 --> 00:47:16,160 mission to drop little sensors and 1292 00:47:19,670 --> 00:47:18,480 measure these things uh directly in the 1293 00:47:21,829 --> 00:47:19,680 ocean 1294 00:47:24,390 --> 00:47:21,839 another aircraft mission to fly over the 1295 00:47:26,870 --> 00:47:24,400 ice and measure it with a radar 1296 00:47:28,950 --> 00:47:26,880 and over the next five years we're 1297 00:47:31,030 --> 00:47:28,960 hoping to 1298 00:47:33,430 --> 00:47:31,040 literally kind of shower greenland with 1299 00:47:35,670 --> 00:47:33,440 observations new observations of 1300 00:47:38,390 --> 00:47:35,680 how the ocean is changing 1301 00:47:40,950 --> 00:47:38,400 in the in the region right up close 1302 00:47:43,349 --> 00:47:40,960 uh to the land and also to fly over all 1303 00:47:45,349 --> 00:47:43,359 the all the places where we know 1304 00:47:47,750 --> 00:47:45,359 glaciers are literally sitting right 1305 00:47:49,030 --> 00:47:47,760 into the water and feeling the impact of 1306 00:47:50,950 --> 00:47:49,040 these currents 1307 00:47:54,150 --> 00:47:50,960 and try to answer the question 1308 00:47:56,550 --> 00:47:54,160 how much of the ice loss here is really 1309 00:47:59,030 --> 00:47:56,560 because of the oceans and how much of 1310 00:48:00,710 --> 00:47:59,040 the ocean's really threatening the ice 1311 00:48:02,790 --> 00:48:00,720 sheet in the future 1312 00:48:06,470 --> 00:48:02,800 so we're really excited about 1313 00:48:08,790 --> 00:48:06,480 excuse me omg and hopefully in a year or 1314 00:48:10,630 --> 00:48:08,800 so i'll come back and give you a talk 1315 00:48:12,950 --> 00:48:10,640 all about this one and say all kinds of 1316 00:48:15,270 --> 00:48:12,960 crazy stuff about greenland um but in 1317 00:48:25,109 --> 00:48:15,280 the meantime i'll stop and answer 1318 00:48:27,990 --> 00:48:26,390 so we're going to do a little question 1319 00:48:29,589 --> 00:48:28,000 and answer session here so if you have a 1320 00:48:31,510 --> 00:48:29,599 question please come up to the 1321 00:48:32,870 --> 00:48:31,520 microphone and ask me through the 1322 00:48:34,470 --> 00:48:32,880 microphone 1323 00:48:36,790 --> 00:48:34,480 so that everybody can hear 1324 00:48:39,030 --> 00:48:36,800 even people on the internets 1325 00:48:41,430 --> 00:48:39,040 and uh i think we may also get some 1326 00:48:43,510 --> 00:48:41,440 questions from uh online 1327 00:48:45,990 --> 00:48:43,520 uh if we have any so uh 1328 00:48:49,750 --> 00:48:46,000 please thanks 1329 00:48:51,750 --> 00:48:49,760 how long is uh florida going to uh 1330 00:48:54,069 --> 00:48:51,760 going to be but by the time florida 1331 00:48:56,230 --> 00:48:54,079 sinks into the ocean 1332 00:48:57,990 --> 00:48:56,240 um when do we finally get rid of florida 1333 00:49:00,710 --> 00:48:58,000 is that what you're asking 1334 00:49:02,309 --> 00:49:00,720 yeah that's a great question well 1335 00:49:04,150 --> 00:49:02,319 florida's already beginning to feel the 1336 00:49:06,390 --> 00:49:04,160 impact of sea level rise they've had 1337 00:49:08,230 --> 00:49:06,400 about that same eight inches that we've 1338 00:49:09,190 --> 00:49:08,240 had pretty much everywhere else in the 1339 00:49:11,109 --> 00:49:09,200 world 1340 00:49:13,430 --> 00:49:11,119 and 1341 00:49:15,670 --> 00:49:13,440 they're beginning to have to protect 1342 00:49:18,710 --> 00:49:15,680 areas that they want to keep and decide 1343 00:49:20,790 --> 00:49:18,720 which areas they want to lose but in the 1344 00:49:23,030 --> 00:49:20,800 next hundred years 1345 00:49:24,390 --> 00:49:23,040 excuse me we face somewhere between 1346 00:49:26,870 --> 00:49:24,400 one foot 1347 00:49:28,870 --> 00:49:26,880 which is probably unlikely and six feet 1348 00:49:31,190 --> 00:49:28,880 of sea level rise 1349 00:49:34,549 --> 00:49:31,200 if it's six feet then 1350 00:49:35,510 --> 00:49:34,559 really a whole lot of florida is gonna 1351 00:49:38,150 --> 00:49:35,520 be 1352 00:49:40,150 --> 00:49:38,160 underwater um and it doesn't happen sort 1353 00:49:41,430 --> 00:49:40,160 of all you know like one day you walk 1354 00:49:44,309 --> 00:49:41,440 out and 1355 00:49:46,069 --> 00:49:44,319 your backyard is flooded um you know 1356 00:49:47,829 --> 00:49:46,079 it's that storm that didn't used to get 1357 00:49:48,710 --> 00:49:47,839 you now it gets you 1358 00:49:50,790 --> 00:49:48,720 uh 1359 00:49:52,390 --> 00:49:50,800 it's that high tide that didn't use to 1360 00:49:54,390 --> 00:49:52,400 get you now it gets you 1361 00:49:55,990 --> 00:49:54,400 and so it's kind of this creeping thing 1362 00:49:56,829 --> 00:49:56,000 and one that that people are going to 1363 00:49:59,109 --> 00:49:56,839 have to 1364 00:50:01,030 --> 00:49:59,119 decide what kind of stuff they want to 1365 00:50:04,230 --> 00:50:01,040 protect and what kind of stuff they want 1366 00:50:06,390 --> 00:50:04,240 to let the oceans reclaim so 1367 00:50:08,069 --> 00:50:06,400 so you know florida is going to face 1368 00:50:10,069 --> 00:50:08,079 some tough decisions in the next hundred 1369 00:50:12,870 --> 00:50:10,079 years now is it all going to be at 1370 00:50:14,790 --> 00:50:12,880 underwater by the end of the 21st 1371 00:50:17,030 --> 00:50:14,800 century no 1372 00:50:19,030 --> 00:50:17,040 but major cities 1373 00:50:21,270 --> 00:50:19,040 along the coast of florida will face 1374 00:50:23,349 --> 00:50:21,280 trouble from sea level rise 1375 00:50:26,549 --> 00:50:23,359 the question is how much 1376 00:50:28,950 --> 00:50:26,559 and um part of it is we don't know the 1377 00:50:30,630 --> 00:50:28,960 answer entirely we we have some idea 1378 00:50:32,710 --> 00:50:30,640 like i said between one foot and six 1379 00:50:34,470 --> 00:50:32,720 feet but these things like the oceans 1380 00:50:36,150 --> 00:50:34,480 eating away the glaciers 1381 00:50:38,549 --> 00:50:36,160 uh there's a whole lot that we really 1382 00:50:41,670 --> 00:50:38,559 don't understand about that so 1383 00:50:44,069 --> 00:50:41,680 our ability to say one foot or six feet 1384 00:50:45,990 --> 00:50:44,079 is limited at this point 1385 00:50:47,349 --> 00:50:46,000 and in a way that's a bigger risk than 1386 00:50:48,790 --> 00:50:47,359 if we already knew 1387 00:50:51,349 --> 00:50:48,800 if i could tell you it's definitely 1388 00:50:53,589 --> 00:50:51,359 going to be 2.5 feet by the middle of 1389 00:50:55,109 --> 00:50:53,599 the century then you could say okay well 1390 00:50:57,670 --> 00:50:55,119 it's time to abandon this city in this 1391 00:50:59,430 --> 00:50:57,680 city and and move on 1392 00:51:02,150 --> 00:50:59,440 but because there's this uncertainty in 1393 00:51:04,630 --> 00:51:02,160 a way we face bigger risk because we 1394 00:51:06,549 --> 00:51:04,640 might choose to ignore it 1395 00:51:08,790 --> 00:51:06,559 and then you know then you really have 1396 00:51:10,390 --> 00:51:08,800 troubles well i used to be stationed on 1397 00:51:12,230 --> 00:51:10,400 kwajalein 1398 00:51:13,750 --> 00:51:12,240 in the pacific 1399 00:51:16,870 --> 00:51:13,760 and just a foot 1400 00:51:19,750 --> 00:51:16,880 rise would sink that entire island 1401 00:51:20,870 --> 00:51:19,760 and a lot of islands in the pacific 1402 00:51:23,270 --> 00:51:20,880 now my 1403 00:51:24,950 --> 00:51:23,280 other my question is 1404 00:51:29,670 --> 00:51:24,960 how do we 1405 00:51:32,390 --> 00:51:29,680 all our fault 1406 00:51:34,710 --> 00:51:32,400 do we ruin our economy do we stop 1407 00:51:37,589 --> 00:51:34,720 putting our you know we got to watch the 1408 00:51:39,829 --> 00:51:37,599 way we are our light bulbs what we use 1409 00:51:42,950 --> 00:51:39,839 what kind of cars we drive 1410 00:51:43,750 --> 00:51:42,960 our whole life becomes all screwed up 1411 00:51:48,549 --> 00:51:43,760 or 1412 00:51:51,030 --> 00:51:48,559 cause of global warming besides me 1413 00:51:54,470 --> 00:51:51,040 and us individuals that are being 1414 00:51:56,150 --> 00:51:54,480 hounded by the left yeah well uh oh some 1415 00:51:59,589 --> 00:51:56,160 applause 1416 00:52:01,270 --> 00:51:59,599 um well you know i think uh uh i think 1417 00:52:03,030 --> 00:52:01,280 the fact is that we're gonna pay the 1418 00:52:04,950 --> 00:52:03,040 costs of global warming whether it's 1419 00:52:06,710 --> 00:52:04,960 today or tomorrow 1420 00:52:08,549 --> 00:52:06,720 and 1421 00:52:11,109 --> 00:52:08,559 we 1422 00:52:13,589 --> 00:52:11,119 human activity is definitely the cause 1423 00:52:16,470 --> 00:52:13,599 of modern day sea level rise 1424 00:52:18,950 --> 00:52:16,480 it's the burning of fossil fuels 1425 00:52:21,990 --> 00:52:18,960 and um but that's not to say that it's 1426 00:52:23,510 --> 00:52:22,000 hopeless uh i think there's uh plenty of 1427 00:52:27,109 --> 00:52:23,520 opportunity to 1428 00:52:29,589 --> 00:52:27,119 innovate new forms of energy and to wean 1429 00:52:31,829 --> 00:52:29,599 ourselves off of our addiction to oil 1430 00:52:33,829 --> 00:52:31,839 and if we do then i think we can stave 1431 00:52:35,589 --> 00:52:33,839 off some of the biggest 1432 00:52:37,910 --> 00:52:35,599 consequences 1433 00:52:39,910 --> 00:52:37,920 but if we don't we'll eventually pay for 1434 00:52:41,349 --> 00:52:39,920 them one way or another 1435 00:52:42,470 --> 00:52:41,359 well the way it looks to me like it's 1436 00:52:45,030 --> 00:52:42,480 just 1437 00:52:47,030 --> 00:52:45,040 global pollution 1438 00:52:49,190 --> 00:52:47,040 basically yeah pollutions yeah we don't 1439 00:52:51,589 --> 00:52:49,200 do nothing with china or india they just 1440 00:52:52,950 --> 00:52:51,599 going wild with it and we are the one in 1441 00:52:55,349 --> 00:52:52,960 america they get 1442 00:52:56,870 --> 00:52:55,359 uh always told that we're the bad guys 1443 00:52:58,470 --> 00:52:56,880 well of course uh there's plenty of 1444 00:53:01,190 --> 00:52:58,480 blame to go around 1445 00:53:03,589 --> 00:53:01,200 um but you know uh china and india are 1446 00:53:05,589 --> 00:53:03,599 trying to innovate solutions uh just 1447 00:53:07,990 --> 00:53:05,599 like we are in fact china is better at 1448 00:53:09,990 --> 00:53:08,000 building solar panels than we are so you 1449 00:53:11,270 --> 00:53:10,000 know uh we got to pick up the pace a 1450 00:53:15,990 --> 00:53:11,280 little bit 1451 00:53:19,990 --> 00:53:17,270 oh hello 1452 00:53:22,549 --> 00:53:20,000 uh is jason 3 equipped with the 1453 00:53:25,589 --> 00:53:22,559 microwave and a rodometer 1454 00:53:27,589 --> 00:53:25,599 uh there's a uh there is a radiometer on 1455 00:53:30,870 --> 00:53:27,599 board jason 3 1456 00:53:32,870 --> 00:53:30,880 that will measure how much 1457 00:53:35,030 --> 00:53:32,880 water the 1458 00:53:37,990 --> 00:53:35,040 signal has to travel through when it 1459 00:53:39,829 --> 00:53:38,000 travels down through the atmosphere 1460 00:53:42,150 --> 00:53:39,839 if it goes through water and clouds then 1461 00:53:44,309 --> 00:53:42,160 it it changes the travel time a little 1462 00:53:46,950 --> 00:53:44,319 bit so the radiometer essentially 1463 00:53:49,030 --> 00:53:46,960 measures that separately uh so that you 1464 00:53:51,829 --> 00:53:49,040 can correct for it but yes it does have 1465 00:53:54,549 --> 00:53:51,839 a radiometer in addition to 1466 00:53:56,710 --> 00:53:54,559 the actual radar instrument itself which 1467 00:53:58,390 --> 00:53:56,720 is measuring the the travel time and 1468 00:54:00,790 --> 00:53:58,400 telling us the height 1469 00:54:03,109 --> 00:54:00,800 when is the launch going to occur 1470 00:54:05,430 --> 00:54:03,119 well uh right now 1471 00:54:08,549 --> 00:54:05,440 the launch has slipped past its original 1472 00:54:11,190 --> 00:54:08,559 march 31st date uh we don't yet have a 1473 00:54:14,230 --> 00:54:11,200 firm date for a new launch but we're 1474 00:54:15,829 --> 00:54:14,240 looking at the summer maybe july 1475 00:54:17,910 --> 00:54:15,839 sometime around there 1476 00:54:19,589 --> 00:54:17,920 but we haven't been given a firm launch 1477 00:54:21,589 --> 00:54:19,599 date yet so 1478 00:54:24,069 --> 00:54:21,599 we're still they're still 1479 00:54:27,430 --> 00:54:24,079 looking at issues with the uh 1480 00:54:29,510 --> 00:54:27,440 trying to qualify the spacex rocket 1481 00:54:31,030 --> 00:54:29,520 which is going to be our ride to space 1482 00:54:32,790 --> 00:54:31,040 you know nasa makes you jump through a 1483 00:54:34,069 --> 00:54:32,800 bunch of hoops before you uh before 1484 00:54:34,950 --> 00:54:34,079 they'll put one of their babies on your 1485 00:54:37,270 --> 00:54:34,960 rocket 1486 00:54:40,790 --> 00:54:37,280 and uh so uh 1487 00:54:41,589 --> 00:54:40,800 but uh we are uh excited that um you 1488 00:54:43,829 --> 00:54:41,599 know 1489 00:54:45,910 --> 00:54:43,839 uh a lot of the waiting is is hopefully 1490 00:54:46,630 --> 00:54:45,920 behind us and we're hopeful that it'll 1491 00:54:48,630 --> 00:54:46,640 be 1492 00:54:49,589 --> 00:54:48,640 this summer we we really got our fingers 1493 00:54:53,030 --> 00:54:49,599 crossed 1494 00:54:55,750 --> 00:54:53,040 oftentimes uh lodges are 1495 00:54:57,750 --> 00:54:55,760 delayed due to high winds or something 1496 00:54:59,270 --> 00:54:57,760 like the launch of the discover every 1497 00:55:01,589 --> 00:54:59,280 day it's supposed to be launched and 1498 00:55:02,630 --> 00:55:01,599 then the window opens and closes and 1499 00:55:06,150 --> 00:55:02,640 whatever 1500 00:55:08,950 --> 00:55:06,160 and yet it's so inept because it's 1501 00:55:10,630 --> 00:55:08,960 dependent upon like data from 1502 00:55:13,589 --> 00:55:10,640 soho 1503 00:55:18,069 --> 00:55:13,599 with the uh actual measurements that can 1504 00:55:19,750 --> 00:55:18,079 be passed on to a dragon and discovered 1505 00:55:21,270 --> 00:55:19,760 right well you know we we we want the 1506 00:55:24,069 --> 00:55:21,280 good weather and a good window so that 1507 00:55:27,270 --> 00:55:24,079 we can hit the right target right uh so 1508 00:55:28,870 --> 00:55:27,280 uh but uh you know i i we've had a 1509 00:55:31,430 --> 00:55:28,880 couple of successful launches out of 1510 00:55:33,670 --> 00:55:31,440 vandenberg on previous missions and uh 1511 00:55:36,069 --> 00:55:33,680 you know we're we're really excited so 1512 00:55:38,630 --> 00:55:36,079 uh we're optimistic and and looking 1513 00:55:40,549 --> 00:55:38,640 forward to a launch this summer so keep 1514 00:55:44,710 --> 00:55:40,559 your fingers crossed for us i certainly 1515 00:55:48,549 --> 00:55:46,710 hi my name is ben i'm from redmond 1516 00:55:50,470 --> 00:55:48,559 washington um 1517 00:55:52,710 --> 00:55:50,480 and i'm a huge fan of the earth 1518 00:55:55,109 --> 00:55:52,720 observation satellite program so don't 1519 00:55:57,670 --> 00:55:55,119 take this as criticism but uh what is 1520 00:55:59,910 --> 00:55:57,680 the advantage to having multiple json 1521 00:56:02,230 --> 00:55:59,920 missions active at the same time is it 1522 00:56:03,670 --> 00:56:02,240 just that the new ones have better or 1523 00:56:05,990 --> 00:56:03,680 newer instruments 1524 00:56:07,670 --> 00:56:06,000 oh that's a great question uh there's a 1525 00:56:08,950 --> 00:56:07,680 couple reasons you want them to operate 1526 00:56:10,870 --> 00:56:08,960 at the same time 1527 00:56:12,150 --> 00:56:10,880 one is so that you have this unbroken 1528 00:56:14,230 --> 00:56:12,160 record 1529 00:56:18,549 --> 00:56:14,240 you know all of our missions so far 1530 00:56:21,349 --> 00:56:18,559 topex jason one jason one jason ii 1531 00:56:23,750 --> 00:56:21,359 have had some overlap and that overlap 1532 00:56:26,470 --> 00:56:23,760 has really allowed us to get an unbroken 1533 00:56:27,829 --> 00:56:26,480 record of sea level rise for 20 years so 1534 00:56:29,829 --> 00:56:27,839 part of the reason we want to fly them 1535 00:56:31,430 --> 00:56:29,839 both at the same time is so we can make 1536 00:56:33,589 --> 00:56:31,440 sure we really understand the new 1537 00:56:35,670 --> 00:56:33,599 instrument before we turn over the main 1538 00:56:37,829 --> 00:56:35,680 mission to it but there's other reasons 1539 00:56:38,630 --> 00:56:37,839 to fly them both at the same time too if 1540 00:56:41,109 --> 00:56:38,640 you 1541 00:56:43,270 --> 00:56:41,119 move one over into a slightly adjacent 1542 00:56:45,910 --> 00:56:43,280 orbit which is what we did between jason 1543 00:56:48,870 --> 00:56:45,920 1 and jason ii then you can essentially 1544 00:56:50,710 --> 00:56:48,880 double the resolution you get these 1545 00:56:52,870 --> 00:56:50,720 missions look straight down and they 1546 00:56:54,470 --> 00:56:52,880 give you a single point and they fly in 1547 00:56:56,789 --> 00:56:54,480 a pattern to kind of cover the whole 1548 00:56:59,270 --> 00:56:56,799 earth in 10 days but if you have two of 1549 00:57:01,510 --> 00:56:59,280 them you can uh essentially double your 1550 00:57:03,510 --> 00:57:01,520 resolution and you can see smaller scale 1551 00:57:04,870 --> 00:57:03,520 stuff in the ocean things like the 1552 00:57:06,789 --> 00:57:04,880 eddies that 1553 00:57:11,030 --> 00:57:06,799 push the oil slick around in the gulf of 1554 00:57:15,510 --> 00:57:12,549 catastrophe 1555 00:57:18,069 --> 00:57:15,520 those things uh are smaller and the more 1556 00:57:20,150 --> 00:57:18,079 satellites you have looking uh the finer 1557 00:57:22,710 --> 00:57:20,160 the resolution of things you can see 1558 00:57:24,789 --> 00:57:22,720 um a final reason which is something we 1559 00:57:26,870 --> 00:57:24,799 did with jason one is eventually we 1560 00:57:29,910 --> 00:57:26,880 might repurpose the mission and instead 1561 00:57:33,030 --> 00:57:29,920 of trying to do oceanography 1562 00:57:35,829 --> 00:57:33,040 really try and look at marine gravity so 1563 00:57:37,670 --> 00:57:35,839 it turns out that little mountains and 1564 00:57:40,230 --> 00:57:37,680 troughs and ridges on the bottom of the 1565 00:57:42,789 --> 00:57:40,240 ocean actually bend the shape of the sea 1566 00:57:45,030 --> 00:57:42,799 surface also from the pull of gravity 1567 00:57:47,030 --> 00:57:45,040 now this is a something they don't move 1568 00:57:50,470 --> 00:57:47,040 around the the mountains stay pretty 1569 00:57:52,069 --> 00:57:50,480 still so if you subtract out the time 1570 00:57:54,069 --> 00:57:52,079 average signal you can really look at 1571 00:57:57,349 --> 00:57:54,079 the oceanography but if you look at the 1572 00:57:59,190 --> 00:57:57,359 actual complete signal then those 1573 00:58:00,630 --> 00:57:59,200 little bumps and wiggles tell you where 1574 00:58:03,190 --> 00:58:00,640 the sea mounts are they tell you where 1575 00:58:05,030 --> 00:58:03,200 the under water mountains are so what we 1576 00:58:06,950 --> 00:58:05,040 actually did with jason one was move it 1577 00:58:08,390 --> 00:58:06,960 into a slightly different orbit where it 1578 00:58:10,150 --> 00:58:08,400 didn't really repeat 1579 00:58:12,069 --> 00:58:10,160 and it 1580 00:58:13,510 --> 00:58:12,079 you know measured a small swath that 1581 00:58:15,270 --> 00:58:13,520 traced along 1582 00:58:18,150 --> 00:58:15,280 the equator and covered the entire 1583 00:58:20,470 --> 00:58:18,160 oceans in a much finer mesh and that's 1584 00:58:22,710 --> 00:58:20,480 how they began to really improve the the 1585 00:58:24,710 --> 00:58:22,720 knowledge of the shape of the sea floor 1586 00:58:27,589 --> 00:58:24,720 so we might do something like that with 1587 00:58:29,750 --> 00:58:27,599 jason ii uh in a couple of years as it 1588 00:58:32,230 --> 00:58:29,760 starts to age and becomes more likely to 1589 00:58:36,150 --> 00:58:32,240 uh to eventually 1590 00:58:40,230 --> 00:58:38,470 your response just uh partly answered my 1591 00:58:41,990 --> 00:58:40,240 question but i was curious what kind of 1592 00:58:44,150 --> 00:58:42,000 techniques do you use to validate the 1593 00:58:45,589 --> 00:58:44,160 accuracy of your measurements 1594 00:58:48,150 --> 00:58:45,599 for example you mentioned about that 1595 00:58:51,190 --> 00:58:48,160 valentine's day episode 1596 00:58:53,270 --> 00:58:51,200 where you realize i don't know if it was 1597 00:58:55,349 --> 00:58:53,280 by intuition that that 1598 00:58:57,430 --> 00:58:55,359 you understood the data wrong like what 1599 00:58:59,510 --> 00:58:57,440 was the thought process um going into 1600 00:59:01,430 --> 00:58:59,520 that oh yeah what's what's keeping rush 1601 00:59:03,030 --> 00:59:01,440 off my back with the satellites 1602 00:59:04,470 --> 00:59:03,040 yeah that's a great question well we 1603 00:59:06,150 --> 00:59:04,480 have a lot of ways to 1604 00:59:08,069 --> 00:59:06,160 we have a lot of other things to compare 1605 00:59:10,309 --> 00:59:08,079 our satellite mission with so we have 1606 00:59:13,109 --> 00:59:10,319 tide gauges that are spread all across 1607 00:59:14,950 --> 00:59:13,119 the planet on coasts everywhere that 1608 00:59:16,870 --> 00:59:14,960 measure how the sea level changes and we 1609 00:59:18,470 --> 00:59:16,880 compare those with how the satellite's 1610 00:59:20,789 --> 00:59:18,480 telling us it changes 1611 00:59:22,950 --> 00:59:20,799 we also have a few dedicated places that 1612 00:59:25,109 --> 00:59:22,960 the satellite flies directly over 1613 00:59:27,829 --> 00:59:25,119 there's one right off the coast of santa 1614 00:59:29,910 --> 00:59:27,839 barbara called the harvest oil platform 1615 00:59:32,230 --> 00:59:29,920 it's just off the coast and it's had a 1616 00:59:33,990 --> 00:59:32,240 continuous sea level measurement right 1617 00:59:36,470 --> 00:59:34,000 there on the platform 1618 00:59:38,789 --> 00:59:36,480 and our satellite flies right over it so 1619 00:59:40,870 --> 00:59:38,799 we get a direct look and we can compare 1620 00:59:43,270 --> 00:59:40,880 directly and see just how good the 1621 00:59:44,870 --> 00:59:43,280 satellite is doing so 1622 00:59:47,510 --> 00:59:44,880 we also have a whole other suite of 1623 00:59:50,390 --> 00:59:47,520 satellites and and an entire team of 1624 00:59:52,549 --> 00:59:50,400 about 200 people who every year all the 1625 00:59:54,230 --> 00:59:52,559 time are just looking at this data 1626 00:59:56,150 --> 00:59:54,240 trying to uh make sure that it's 1627 00:59:58,309 --> 00:59:56,160 accurate and and agrees with other 1628 01:00:00,150 --> 00:59:58,319 things we're measuring uh that that are 1629 01:00:03,270 --> 01:00:00,160 consistent 1630 01:00:06,069 --> 01:00:03,280 what happened to me on my phd was 1631 01:00:08,470 --> 01:00:06,079 a different story and um that was a 1632 01:00:10,309 --> 01:00:08,480 actually a symptom of changing to a new 1633 01:00:13,109 --> 01:00:10,319 kind of data we had been measuring the 1634 01:00:14,870 --> 01:00:13,119 temperatures of the ocean with a 1635 01:00:17,109 --> 01:00:14,880 small probes 1636 01:00:18,789 --> 01:00:17,119 for decades and we switched over to a 1637 01:00:20,069 --> 01:00:18,799 new system and there were some 1638 01:00:21,910 --> 01:00:20,079 differences 1639 01:00:23,270 --> 01:00:21,920 that was part of the problem and then 1640 01:00:25,270 --> 01:00:23,280 part of the problem was that some of the 1641 01:00:27,750 --> 01:00:25,280 new floats just weren't some of the new 1642 01:00:28,390 --> 01:00:27,760 instruments just weren't working right 1643 01:00:30,870 --> 01:00:28,400 but 1644 01:00:32,789 --> 01:00:30,880 what eventually allowed us to tease out 1645 01:00:36,870 --> 01:00:32,799 the difference between the new and old 1646 01:00:39,510 --> 01:00:36,880 data was actually satellites like json 1647 01:00:41,349 --> 01:00:39,520 because as the bad data accumulated and 1648 01:00:42,950 --> 01:00:41,359 you got enough of it you begin to look 1649 01:00:44,789 --> 01:00:42,960 at the difference between what the 1650 01:00:47,750 --> 01:00:44,799 satellite was telling us and and what 1651 01:00:49,430 --> 01:00:47,760 the floats were telling us so uh 1652 01:00:51,030 --> 01:00:49,440 it's really a 1653 01:00:52,630 --> 01:00:51,040 an ongoing it's always a work in 1654 01:00:53,990 --> 01:00:52,640 progress we're always double checking 1655 01:00:55,589 --> 01:00:54,000 the data we're always looking back at 1656 01:00:57,109 --> 01:00:55,599 the results trying to make sure that 1657 01:00:59,829 --> 01:00:57,119 we're getting it really right and you 1658 01:01:01,430 --> 01:00:59,839 know science is a it's not a 1659 01:01:03,430 --> 01:01:01,440 you know 1660 01:01:05,270 --> 01:01:03,440 one big discovery after another kind of 1661 01:01:07,990 --> 01:01:05,280 thing it's a kind of a three steps 1662 01:01:09,589 --> 01:01:08,000 forward two steps back process um and 1663 01:01:11,510 --> 01:01:09,599 that's really part of what makes it so 1664 01:01:14,630 --> 01:01:11,520 accurate in the long run so we're always 1665 01:01:16,230 --> 01:01:14,640 checking ourselves but uh uh you know 1666 01:01:18,069 --> 01:01:16,240 you're still left with those occasional 1667 01:01:20,710 --> 01:01:18,079 moments where rush limbaugh's making fun 1668 01:01:24,950 --> 01:01:22,309 i think you said the precision of the 1669 01:01:27,910 --> 01:01:24,960 radio altimeter is about one inch that's 1670 01:01:29,750 --> 01:01:27,920 right yeah so for a sea level rise of a 1671 01:01:32,069 --> 01:01:29,760 few millimeters per year obviously 1672 01:01:33,750 --> 01:01:32,079 that's not particularly precise so how 1673 01:01:35,670 --> 01:01:33,760 do you actually tease it out do you just 1674 01:01:37,829 --> 01:01:35,680 take lots of measurements and 1675 01:01:39,670 --> 01:01:37,839 statistically yeah that's exactly it 1676 01:01:41,030 --> 01:01:39,680 that's a that's a great question that's 1677 01:01:42,870 --> 01:01:41,040 really good what'd he tell you that was 1678 01:01:45,750 --> 01:01:42,880 a great question i said no that's right 1679 01:01:51,349 --> 01:01:48,230 and yeah you said um you also measure 1680 01:01:52,870 --> 01:01:51,359 something else tilt or something yeah so 1681 01:01:54,549 --> 01:01:52,880 so essentially if i measure the height 1682 01:01:55,589 --> 01:01:54,559 over here yeah okay and the height over 1683 01:01:57,430 --> 01:01:55,599 here 1684 01:01:59,910 --> 01:01:57,440 and they go like this 1685 01:02:01,990 --> 01:01:59,920 then um the reason they went like this 1686 01:02:04,789 --> 01:02:02,000 is probably because there was a current 1687 01:02:07,510 --> 01:02:04,799 uh an ocean current at the surface so 1688 01:02:09,829 --> 01:02:07,520 literally when when the water's moving 1689 01:02:12,789 --> 01:02:09,839 it feels the rotation of the earth 1690 01:02:16,069 --> 01:02:12,799 and it winds up causing a tilt 1691 01:02:17,750 --> 01:02:16,079 in the surface of the ocean so 1692 01:02:19,670 --> 01:02:17,760 originally these satellites were 1693 01:02:22,390 --> 01:02:19,680 designed just to measure that tilt we 1694 01:02:23,829 --> 01:02:22,400 weren't thinking about global warming 1695 01:02:25,190 --> 01:02:23,839 the guy sitting next to you by the way 1696 01:02:27,349 --> 01:02:25,200 is one of the uh 1697 01:02:29,829 --> 01:02:27,359 one of the guys who made this first 1698 01:02:32,390 --> 01:02:29,839 mission topex poseidon happened so 1699 01:02:33,589 --> 01:02:32,400 uh any questions that uh yeah there he 1700 01:02:36,549 --> 01:02:33,599 goes 1701 01:02:38,390 --> 01:02:36,559 bill i can answer but uh 1702 01:02:39,990 --> 01:02:38,400 you know essentially it was designed to 1703 01:02:41,990 --> 01:02:40,000 measure that tilt we were really looking 1704 01:02:44,470 --> 01:02:42,000 for the currents but it turned out that 1705 01:02:46,710 --> 01:02:44,480 it was so accurate and and you know by 1706 01:02:48,069 --> 01:02:46,720 averaging over the whole globe 1707 01:02:50,150 --> 01:02:48,079 and really looking at the kind of 1708 01:02:51,829 --> 01:02:50,160 biggest scales you get millions and 1709 01:02:53,910 --> 01:02:51,839 millions of measurements every time 1710 01:02:55,190 --> 01:02:53,920 every 10 days and you average them all 1711 01:02:56,630 --> 01:02:55,200 together and you average a bunch of 1712 01:02:59,430 --> 01:02:56,640 10-day periods together and you can 1713 01:03:01,030 --> 01:02:59,440 really see this long-term change it's 1714 01:03:03,670 --> 01:03:01,040 like looking for an exoplanet just that 1715 01:03:07,510 --> 01:03:03,680 little bulge in the star motion yeah 1716 01:03:11,030 --> 01:03:09,750 my question is about the pacific decal 1717 01:03:13,030 --> 01:03:11,040 oscillation 1718 01:03:15,109 --> 01:03:13,040 and my impression is that we don't 1719 01:03:17,430 --> 01:03:15,119 really understand it very well 1720 01:03:19,670 --> 01:03:17,440 and so my question is to what extent 1721 01:03:21,190 --> 01:03:19,680 json data and maybe 1722 01:03:23,510 --> 01:03:21,200 data from 1723 01:03:25,589 --> 01:03:23,520 from probes that flowed up and down in 1724 01:03:27,589 --> 01:03:25,599 the ocean to what extent do we think 1725 01:03:29,430 --> 01:03:27,599 that that oscillation is chaotic and 1726 01:03:31,270 --> 01:03:29,440 really can't be predicted or what extent 1727 01:03:33,750 --> 01:03:31,280 do you think you'll you'll be able to 1728 01:03:35,109 --> 01:03:33,760 understand it better so because my 1729 01:03:38,069 --> 01:03:35,119 impression is we've only sort of seen 1730 01:03:40,150 --> 01:03:38,079 one cycle right 20 or 20 years or so 1731 01:03:42,549 --> 01:03:40,160 we don't have any way of knowing what it 1732 01:03:45,190 --> 01:03:42,559 was on previous cycles yeah it's a great 1733 01:03:47,029 --> 01:03:45,200 question um you know uh 1734 01:03:49,750 --> 01:03:47,039 just like you said the pacific decadal 1735 01:03:52,470 --> 01:03:49,760 oscillation is something that's decadal 1736 01:03:54,950 --> 01:03:52,480 takes a decade or two to change from one 1737 01:03:57,029 --> 01:03:54,960 sign to another one phase to another and 1738 01:03:59,750 --> 01:03:57,039 we've only had our satellite for two 1739 01:04:01,829 --> 01:03:59,760 decades so we don't have an especially 1740 01:04:03,750 --> 01:04:01,839 long look at the pacific decatal 1741 01:04:06,230 --> 01:04:03,760 oscillation but what's interesting is 1742 01:04:08,069 --> 01:04:06,240 that over those last two decades it's 1743 01:04:10,789 --> 01:04:08,079 really changed a lot it's changed a lot 1744 01:04:12,710 --> 01:04:10,799 from a very positive phase 1745 01:04:15,510 --> 01:04:12,720 which is associated here in california 1746 01:04:17,990 --> 01:04:15,520 with more rain to a very negative phase 1747 01:04:19,829 --> 01:04:18,000 which is associated with more drought 1748 01:04:21,430 --> 01:04:19,839 here in california 1749 01:04:23,990 --> 01:04:21,440 and it's interesting that there are 1750 01:04:26,069 --> 01:04:24,000 these weather connections because those 1751 01:04:27,430 --> 01:04:26,079 actually allow you to trace back over 1752 01:04:29,270 --> 01:04:27,440 time 1753 01:04:31,349 --> 01:04:29,280 things like the pacific decatal 1754 01:04:33,589 --> 01:04:31,359 oscillation by looking at the growth of 1755 01:04:36,150 --> 01:04:33,599 trees from tree rings and and other 1756 01:04:38,230 --> 01:04:36,160 proxies so our satellites only go back 1757 01:04:40,870 --> 01:04:38,240 20 years but we have a few other data 1758 01:04:43,190 --> 01:04:40,880 sets surface temperature goes back maybe 1759 01:04:45,109 --> 01:04:43,200 40 50 years 1760 01:04:47,270 --> 01:04:45,119 some surface pressure measurements maybe 1761 01:04:48,710 --> 01:04:47,280 go back farther than that and when you 1762 01:04:50,950 --> 01:04:48,720 get into longer time series you're 1763 01:04:53,349 --> 01:04:50,960 really looking at these tree rings 1764 01:04:56,150 --> 01:04:53,359 and and proxies 1765 01:04:57,910 --> 01:04:56,160 for the pacific decadal oscillation 1766 01:04:59,750 --> 01:04:57,920 but you're right in that our ability to 1767 01:05:02,230 --> 01:04:59,760 really tease all that apart we've only 1768 01:05:03,990 --> 01:05:02,240 got about 10 or 20 years worth of data 1769 01:05:05,670 --> 01:05:04,000 so we really are we really do have a lot 1770 01:05:08,390 --> 01:05:05,680 to learn about the pacific decatal 1771 01:05:09,750 --> 01:05:08,400 oscillation but at the very least we can 1772 01:05:11,829 --> 01:05:09,760 say that 1773 01:05:13,990 --> 01:05:11,839 it kind of goes back and forth between a 1774 01:05:16,309 --> 01:05:14,000 range a certain range 1775 01:05:17,190 --> 01:05:16,319 and that at least over the last say 50 1776 01:05:20,230 --> 01:05:17,200 years 1777 01:05:22,789 --> 01:05:20,240 it probably takes somewhere between 5 1778 01:05:24,789 --> 01:05:22,799 and 20 years to change 1779 01:05:28,069 --> 01:05:24,799 so we have some sense that it's kind of 1780 01:05:29,829 --> 01:05:28,079 these decades-long time scales but uh 1781 01:05:31,750 --> 01:05:29,839 but you're right the real 1782 01:05:33,270 --> 01:05:31,760 underlying cause 1783 01:05:35,270 --> 01:05:33,280 probably has something to do with the 1784 01:05:37,670 --> 01:05:35,280 ocean probably has something to do with 1785 01:05:39,829 --> 01:05:37,680 the way it interacts back and forth with 1786 01:05:42,630 --> 01:05:39,839 the atmosphere but what's really driving 1787 01:05:43,589 --> 01:05:42,640 this oscillation i think um is still 1788 01:05:47,109 --> 01:05:43,599 unknown 1789 01:05:52,309 --> 01:05:50,150 oh we have questions from people out in 1790 01:05:54,950 --> 01:05:52,319 interspace 1791 01:05:57,829 --> 01:05:54,960 great um so uh how long you want me to 1792 01:05:59,589 --> 01:05:57,839 drone on up here mark 1793 01:06:00,789 --> 01:05:59,599 as long as it takes to answer all of 1794 01:06:02,870 --> 01:06:00,799 these 1795 01:06:04,950 --> 01:06:02,880 um 1796 01:06:06,230 --> 01:06:04,960 okay so uh i'll just if you have other 1797 01:06:08,309 --> 01:06:06,240 questions feel free to go ahead and line 1798 01:06:09,510 --> 01:06:08,319 up at the mic but i'll um 1799 01:06:10,630 --> 01:06:09,520 i'll just go through a couple of these 1800 01:06:12,069 --> 01:06:10,640 really fun really quick because i think 1801 01:06:15,349 --> 01:06:12,079 they'll be fun so 1802 01:06:17,510 --> 01:06:15,359 elijah michael asks how long will jason 1803 01:06:21,349 --> 01:06:17,520 3 be active 1804 01:06:22,150 --> 01:06:21,359 we hope uh longer than rush limbaugh 1805 01:06:26,630 --> 01:06:22,160 but 1806 01:06:29,750 --> 01:06:26,640 between three and five years 1807 01:06:33,190 --> 01:06:29,760 so the they have a 1808 01:06:35,270 --> 01:06:33,200 must live for three-year kind of design 1809 01:06:37,349 --> 01:06:35,280 and we really hope they live for five 1810 01:06:39,349 --> 01:06:37,359 years and we kind of expect them to but 1811 01:06:41,510 --> 01:06:39,359 of course its predecessors have done 1812 01:06:43,349 --> 01:06:41,520 fantastic topex 1813 01:06:46,710 --> 01:06:43,359 lasted 13 years 1814 01:06:47,589 --> 01:06:46,720 jason lasted 11. jason one jason two is 1815 01:06:50,150 --> 01:06:47,599 now 1816 01:06:53,349 --> 01:06:50,160 let's see 2008 what year is it 1817 01:06:55,750 --> 01:06:53,359 it's getting up to seven years old so um 1818 01:06:58,470 --> 01:06:55,760 we're uh we're optimistic that it will 1819 01:07:00,789 --> 01:06:58,480 outlast the five-year life expectancy 1820 01:07:03,349 --> 01:07:00,799 and maybe it'll go 10 if we're lucky 1821 01:07:06,230 --> 01:07:03,359 but but we can't really plan on longer 1822 01:07:10,470 --> 01:07:09,109 uh jeffrey b boy lizard 1823 01:07:13,190 --> 01:07:10,480 asks 1824 01:07:15,750 --> 01:07:13,200 are there other things besides co2 1825 01:07:19,430 --> 01:07:15,760 affecting global warming well jeffrey b 1826 01:07:23,670 --> 01:07:21,589 co2 is the big dog when it comes to 1827 01:07:26,710 --> 01:07:23,680 causing global warming 1828 01:07:28,630 --> 01:07:26,720 there are other things that we do like 1829 01:07:30,309 --> 01:07:28,640 things that emit methane there are other 1830 01:07:32,150 --> 01:07:30,319 greenhouse gases 1831 01:07:33,670 --> 01:07:32,160 there are some other effects like 1832 01:07:36,150 --> 01:07:33,680 reshaping 1833 01:07:37,750 --> 01:07:36,160 the surface of the planet turning 1834 01:07:39,829 --> 01:07:37,760 the desert like we used to live in 1835 01:07:41,510 --> 01:07:39,839 around here into parking lots and golf 1836 01:07:43,349 --> 01:07:41,520 courses 1837 01:07:45,510 --> 01:07:43,359 these things all affect the climate but 1838 01:07:46,230 --> 01:07:45,520 in terms of the global climate in terms 1839 01:07:49,190 --> 01:07:46,240 of 1840 01:07:51,270 --> 01:07:49,200 the whole planet's heating up really co2 1841 01:07:52,870 --> 01:07:51,280 is the major cause 1842 01:07:54,710 --> 01:07:52,880 it's definitely 1843 01:07:57,270 --> 01:07:54,720 the biggest dog and it's the one that 1844 01:07:59,430 --> 01:07:57,280 lives the longest in the atmosphere so 1845 01:08:01,829 --> 01:07:59,440 co2 has an expected lifetime in the 1846 01:08:04,150 --> 01:08:01,839 atmosphere of hundreds if not thousands 1847 01:08:05,190 --> 01:08:04,160 of years the ocean sucks up a little bit 1848 01:08:07,349 --> 01:08:05,200 of it but 1849 01:08:10,630 --> 01:08:07,359 but by and large what we put there we're 1850 01:08:11,430 --> 01:08:10,640 stuck with for a long time 1851 01:08:13,990 --> 01:08:11,440 oh 1852 01:08:15,109 --> 01:08:14,000 this last one's from marvin the martian 1853 01:08:17,430 --> 01:08:15,119 um 1854 01:08:19,510 --> 01:08:17,440 what effect would a large volcanic 1855 01:08:20,950 --> 01:08:19,520 eruption or asteroid strike have on our 1856 01:08:22,309 --> 01:08:20,960 climate 1857 01:08:27,749 --> 01:08:22,319 uh 1858 01:08:29,990 --> 01:08:27,759 blow up the earth um 1859 01:08:33,349 --> 01:08:30,000 but uh 1860 01:08:35,030 --> 01:08:33,359 and uh you know an asteroid or a giant 1861 01:08:36,950 --> 01:08:35,040 volcanic eruption could have a pretty 1862 01:08:39,749 --> 01:08:36,960 major impact on the climate 1863 01:08:42,309 --> 01:08:39,759 in fact it's been suggested that this 1864 01:08:46,070 --> 01:08:42,319 was partly the cause for extinctions in 1865 01:08:47,510 --> 01:08:46,080 the past a big meteor would hit the 1866 01:08:50,070 --> 01:08:47,520 hit the 1867 01:08:52,550 --> 01:08:50,080 planet and blow dust up into the 1868 01:08:54,550 --> 01:08:52,560 stratosphere and effectively you know a 1869 01:08:57,269 --> 01:08:54,560 volcano can do the same thing it can put 1870 01:08:59,269 --> 01:08:57,279 all this soot into the stratosphere and 1871 01:09:02,550 --> 01:08:59,279 this can actually cool off the planet so 1872 01:09:03,669 --> 01:09:02,560 you can get a little ice age or a little 1873 01:09:05,030 --> 01:09:03,679 winter 1874 01:09:06,950 --> 01:09:05,040 in fact 1875 01:09:09,669 --> 01:09:06,960 we've seen this in the not too distant 1876 01:09:12,630 --> 01:09:09,679 past mount pinatubo was a major eruption 1877 01:09:14,789 --> 01:09:12,640 in the early 1990s interestingly right 1878 01:09:17,749 --> 01:09:14,799 at the launch of jason or of topex 1879 01:09:19,189 --> 01:09:17,759 poseidon and um it's been suggested that 1880 01:09:22,870 --> 01:09:19,199 it cooled off the earth just a little 1881 01:09:25,510 --> 01:09:22,880 bit for a couple of years so these kinds 1882 01:09:28,070 --> 01:09:25,520 of things can have a big impact 1883 01:09:29,910 --> 01:09:28,080 but of course soot eventually settles 1884 01:09:32,229 --> 01:09:29,920 out of the atmosphere 1885 01:09:34,390 --> 01:09:32,239 and these things eventually 1886 01:09:37,110 --> 01:09:34,400 kind of go back to the way they were 1887 01:09:38,950 --> 01:09:37,120 whereas co2 can really last uh hundreds 1888 01:09:40,709 --> 01:09:38,960 if if not thousands of years like i said 1889 01:09:42,470 --> 01:09:40,719 so um 1890 01:09:46,070 --> 01:09:42,480 uh keep working at it marvin but we're