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forest, far</title></head><body>
<div><font face="Times" size="-1">THE UNIVERSITY OF MONTANA PUBLIC
RELEASE: 9-DEC-2015</font></div>
<div><font face="Times" size="+1">UM study: Plants absorb less carbon
dioxide than models show</font></div>
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<div><font face="Verdana">Running said the study could help
researchers understand how Montana forests and crops will respond to
the changing climate.</font></div>
<div><font face="Verdana"><br></font></div>
<div><font face="Verdana">"While increasing CO2 does aid
photosynthesis, the changing climate is reducing growing season water
supplies," he said.</font></div>
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<div><font face="Verdana">While global plant growth has increased
slightly during the past 30 years, researchers at the University of
Montana found it hasn't increased as much as some scientists
predicted.</font></div>
<div><font face="Verdana"><br></font></div>
<div><font face="Verdana">Former UM doctoral student Bill Smith and
current UM Professors Cory Cleveland, Ashley Ballantyne and Steve
Running studied the relationship between atmospheric carbon dioxide
from human emissions and a corresponding growth in plant life, and
they compared their results with existing models. The study was
published this month in the journal<i> Nature Climate Change</i>.
Abstract of article is available free online at</font></div>
<div><font face="Verdana"
color="#0075C2"
>http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate28<span
></span>79.htm</font></div>
<div><font face="Verdana"><br>
Carbon dioxide enhances plant growth, and plants absorb atmospheric
carbon dioxide. Smith and the study co-authors compared measurements
of plant productivity estimated by models with those measured by
satellites. They concluded that current models unrealistically
overpredict the ability of plants to offset growing greenhouse gas
emissions, suggesting that the earth's capacity to take up future
carbon dioxide emissions may be less than previously
thought.</font></div>
<div><font face="Verdana"><br>
"Current earth-system models assume that global plant growth will
provide the tremendous benefit of offsetting a significant portion of
humanity's CO2 emissions, thus buying us much-needed time to curb
emissions," Smith said. "Unfortunately, our
observation-based estimates of global vegetation growth indicate that
plant growth may not buy us as much time as expected, [so] action to
curb emissions is all the more urgent."</font></div>
<div><font face="Verdana"><br>
The authors identify two important factors that could drive the
divergence between satellite-based results and model-based results:
availability of water and availability of nutrients. Satellite data
indicate warmer climate conditions resulting from rising atmospheric
carbon dioxide may increase stress in plant water, counteracting any
positive effect of carbon dioxide. Additionally, limited availability
of nitrogen and phosphorus in the environment also could limit the
ability of plants to soak up additional carbon dioxide.</font></div>
<div><font face="Verdana"><br></font></div>
<div><font face="Verdana">These findings indicate that current climate
models do not accurately predict future plant growth and suggest that
allowable emissions targets based on these models may need
re-evaluation. The authors recommend better integration among model,
satellite and on-the-ground measurement approaches to improve our
understanding of the effects of rising atmospheric carbon dioxide on
plant growth</font></div>
<div><font face="Verdana"><br></font></div>
<div><font face="Verdana">The work provides an important step toward
understanding how plants may respond (or not respond) to rising
atmospheric carbon dioxide, as well as highlights ways scientists from
different specialties can work together to reach a deeper
understanding of how ecosystems will respond to global change, says
Sasha Reed, a U.S. Geological Survey scientist and a co-author of the
paper.</font></div>
<div><font face="Verdana"><br></font></div>
<div><font face="Verdana">"We have many scientific tools in our
toolbox," Reed said, "and bringing them together is a
powerful approach to asking questions and to solving
problems."</font></div>
<div><font face="Verdana"><br></font></div>
<div><font face="Verdana">Running said the study could help
researchers understand how Montana forests and crops will respond to
the changing climate.</font></div>
<div><font face="Verdana"><br></font></div>
<div><font face="Verdana">"While increasing CO2 does aid
photosynthesis, the changing climate is reducing growing season water
supplies," he said. "The result will help form policies for
forest, range and water management."</font></div>
<div><font face="Verdana"><br>
Running suggests that satellite-derived measurements might, for now,
be a more accurate way to measure how carbon dioxide fertilization
impacts global terrestrial ecosystems.</font></div>
<div><font face="Verdana">###</font></div>
<div><font face="Times" size="-1" color="#262626">Abstract of article
is available free online at</font><font face="Times" size="-1"
color="#0075C2">
http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate287<span
></span>9.html</font><font face="Times" size="-1"
color="#262626">.</font></div>
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<div><font face="Bookman Old Style"
color="#000000"
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<div><font face="Bookman Old Style" color="#000000">"The most
painful and expensive way to deal with global climate change will be
to ignore it until something happens that elicits powerful public
demands for immediate and Draconian action."<br>
<br>
Jonathan Lash. <br>
"As the earth heats up. " <br>
<i>Journal of Commerce </i> August 16, 1996.</font></div>
<div><font face="Geneva" size="-1"
color="#000000"
>====================================================================<span
></span>=========</font></div>
<div><font face="Geneva" size="-1" color="#000000">"Š the race
between climate dynamics and climate policy will be a close one
Š." and " Š requires an industrial revolution for
sustainability starting now." </font></div>
<div><font face="Geneva" size="-1" color="#000000"><br></font></div>
<div><font face="Geneva" size="-1" color="#000000">Hans Joachim
Schellenhuber.<br>
Global warming: Stop worrying, start panicking?</font></div>
<div><font face="Geneva" size="-1" color="#000000"><i>Proceedings of
the National Academy of Sciences</i> September 23, 2008 vol.
105 no. 38</font></div>
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