Title: Earth's plant growth fell because of climate change, study finds
[New York Times Aug 23, 2010] -- Drought linked to climate change
has reversed a decades-long trend of increased global plant growth, according to
a new
analysis of NASA satellite data. "Earth has done an ecological
about-face," a NASA
statement said. "Global plant productivity that once flourished under
warming temperatures and a lengthened growing season is now on the decline,
struck by the stress of drought."
Research over the past two decades had shown terrestrial plant growth on the
rise, with higher temperatures and longer growing seasons linked to a 6 percent
increase in global plant productivity from 1982 to 1999. Between 2000 and 2009,
terrestrial plant growth declined by 1 percent.
"This is a pretty serious warning that warmer temperatures are not going to
endlessly improve plant growth," Steven Running, a biologist at the University
of Montana in Missoula and co-author of the report, said in the NASA
statement.
The researchers found that high latitude ecosystems in the Northern
Hemisphere continued to benefit from longer growing seasons and higher
temperatures, but that this increased productivity was offset by severe
warming-associated drought in the southern hemisphere.
"We see this as a bit of a surprise, and potentially significant on a policy
level because previous interpretations suggested global warming might actually
help plant growth around the world," Dr. Running said.