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there's a controversy about earth it's a

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controversy about a process that may

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affect the quality of life in the United

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States and in every other nation

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scientists don't agree on its impact

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because it's evidence is complex

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disturbing and filled with conflicting

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information that process is called

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global warming your national and

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international initiative is needed to

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seek new solutions for ozone depletion

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in global warming and acid rain and this

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initiative global warming is the phrase

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used to describe the heating up of the

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Earth's atmosphere why is this an

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important issue if the atmosphere heats

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up by only a few degrees wind rain and

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heat patterns change damaging vital

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agricultural areas the impact natural

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resources would alter the geopolitical

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assets of the earth would shift a

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different climate would change the

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forestry food and water supply of each

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nation dr. Anthony del genio from NASA's

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Goddard Institute for Space Studies New

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York by the time we get into the middle

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of the next century a magnitude of heat

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wave or drought that we might have only

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experienced once in the 20th century we

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might be experiencing once every 10

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years in order to acquire the

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information necessary to answer global

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warming issues a number of scientific

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instruments are needed including an

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imaging instrument called SAR synthetic

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aperture radar SAR as planned as a part

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of a mission to Planet Earth NASA's

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series of Earth observing satellites in

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1981 and 1984 dr. Charles elachi and his

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colleagues sent an imaging radar into

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space

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they received astonishing data the radar

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penetrated the dry sands of the Sahara

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and discovered ancient riverbeds this is

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the most arid region on earth and it

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trains once every 40 to 60 years however

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when we look at the radar image which is

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moving in front of you you see what

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seemed to be drainage channels and these

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are the remnant rivers which have dried

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up because of climatic change at so we

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know that as recent as a time of the

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pyramids that region was not as drawing

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as arid as it is at the present time

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radar can see through vegetation as well

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as through clouds it's as if we could

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take an x-ray of the inaccessible areas

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of the earth the belts of rain forests

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around the earth are critical

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storehouses of vegetation and thus

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carbon some researchers believe that

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deforestation is causing significant

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damage to the Earth's biosphere however

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rain forests are difficult to measure

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they are difficult to access and the

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great bulk of their biomass is hidden by

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their canopy of tall trees dr. Joe bway

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from nasa's jet propulsion laboratory

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scientists know very well today that

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atmospheric carbon dioxide is increasing

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very significantly and we have

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successfully been able to map the areal

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extent of deforestation we have never

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attempted to measure anything about the

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forest itself biomass or its water

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properties that will disappear when you

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get into the account view pressure the

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radar however can penetrate the entire

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biomass of in the lower understory you

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see as you look behind here that there's

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quite a bit of action going on below

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this canopy raid art may be tuned to

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look at different levels of the biomass

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thus electronically penetrating tree

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tops that have veiled the rainforests

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at the other extreme of the earth the

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icy oceans of the planet are powerful

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drivers of global climate the exchange

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of heat gases and energy at the polar

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regions is immense essentially all of

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the uncertainties in predicting future

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climate have to do in one way or another

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with the hydrologic cycle anything that

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involves water and how it changes phase

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and goes from one form to another is

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something that we need to know

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desperately to predict future climate

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and for which we don't have adequate

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data sets right now sea ice is an

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important modifier of the Earth's energy

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it insulates the warmer ocean below from

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the freezing winter atmosphere in cloud

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free seasons it dramatically increases

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the amount of solar energy reflected

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back to space the heat flux through an

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open area of Arctic Ocean is 100 times

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more than in an ice-covered area we know

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that the polar masses are laced with

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cracks that expose ocean areas of the

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air however there's a problem at the

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poles how do we monitor an area that is

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obscured with clouds and in darkness for

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six months of the year SAR can

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investigate ice concentration and motion

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during the long polar night period and

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through extensive cloud cover being able

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to get that continuous monitoring and

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the extent of the ice cover and the age

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of the ice and possibly the thickness of

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it is a key scientific parameter in that

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heat exchange between the ocean and the

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atmosphere we know with certainty that

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the burning of fossil fuels is causing

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significant damage to the Earth's

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biosphere the concentration of carbon

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dioxide in the air has increased by over

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ten percent since nineteen fifty eight

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and by nearly twenty five percent since

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the Industrial Revolution

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heat from the Sun flows past nitrogen

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and oxygen molecules but is absorbed by

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co2 heat from the earth is also kept in

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by co2 creating an atmospheric blanket

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the result the greenhouse effect the

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increased warming of the earth however

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scientists disagree on whether it will

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get warmer because global processes are

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complex sunshine land masses vegetation

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the oceans and the atmosphere are

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intricately bound in a climatological

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dance the earth is a closed system a

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huge global system

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NASA's mission to Planet Earth a program

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to use satellites for the analysis of

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our own environment will address

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questions of potentially great impact to

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our future is global warming occurring

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how fast is it occurring how do man's

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actions today relate to our past and

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future climate yasar will explore the

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dynamics of the earth as a fragile

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system in a search for answers to