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since instrumental measurements began in

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the 1880s the past decade is officially

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the warmest on record previous research

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suggested that in the 1980s and 90s

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warmer temperatures and higher levels of

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precipitation factors associated with

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climate change were generally good for

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plant growth but it is possible we've

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had too much of a good thing an updated

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analysis published this week in the

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journal Science indicates that as

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temperatures have continued to rise the

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benefits to plant growth are now

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overwhelmed by longer and more frequent

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droughts scientists from the University

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of Montana investigated global net

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primary production of land plants using

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satellite data from the past three

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decades an instrument on NASA's Terra

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satellite provides insight as to whether

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plants are actually benefiting from a

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changing climate high-resolution data

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from the moderate resolution imaging

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spectroradiometer or modus indicate a

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net decrease in primary production from

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2000 through 2009 as compared to the

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previous two decades primary production

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is a measure of plant growth and the

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first step in the carbon cycle carbon

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enters the atmosphere from a variety of

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sources including deforestation fossil

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fuel-burning and wildfires plants absorb

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carbon from the atmosphere and use it to

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grow as they continue to grow they pull

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down more carbon and slow the increasing

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concentration of carbon dioxide in the

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air it is important for scientists to

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monitor changes of primary production as

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changes in plant growth affect the

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balance of carbon between the atmosphere

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and terrestrial ecosystems this

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visualization represents the amount of

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carbon that was removed from the

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atmosphere by plants during the warmest

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decade on record an increase in primary

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production as indicated in green tells

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us that plants are removing carbon

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dioxide faster than they usually do

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while a decrease in primary production

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in red means that carbon died

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oxide is being removed more slowly

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higher temperatures led to longer

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growing seasons and increased amounts of

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water and sunlight in the northern

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hemisphere causing a net increase in

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atmospheric primary production but it

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was not enough to offset the decrease in

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carbon absorption in the southern

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hemisphere leading to more carbon

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dioxide in the atmosphere Africa for

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instance suffered a severe drought in

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2005 crops suffered major losses and

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with less green vegetation to fix the

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carbon there was more of it left in the

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atmosphere the planet as a whole

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experienced a net decrease in primary

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production over the past ten years but

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it was a modest decrease this research

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reinforces the idea that climate

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variability is complex with increasing

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demands on our natural resources of

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growing population and expansion of

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biofuel production it is critical to