Global Garden Grows Greener

A NASA-Department of Energy jointly funded study concludes the Earth has been greening over the past 20 years. As climate changed, plants found it easier to grow.

The globally comprehensive, multi-discipline study appears in this week's Science magazine. The article states climate changes have provided extra doses of water, heat and sunlight in areas where one or more of those ingredients may have been lacking. Plants flourished in places where climatic conditions previously limited growth.

"Our study proposes climatic changes as the leading cause for the increases in plant growth over the last two decades, with lesser contribution from carbon dioxide fertilization and forest re-growth," said Ramakrishna Nemani, the study's lead author from the University of Montana, Missoula, Mont.

From 1980 to 2000, changes to the global environment have included two of the warmest decades in the instrumental record; three intense El Niño events in 1982-83, 1987-88 and 1997-98; changes in tropical cloudiness and monsoon dynamics; and a 9.3 percent increase in atmospheric carbon dioxide (CO2), which in turn affects man-made influences on climate. All these changes impact plant growth.

Earlier studies by Ranga Myneni, Boston University (BU), and Compton Tucker, of Goddard also co-authors of the study, reported increased growing seasons and woody biomass in northern high-latitude forests.

For more information visit: http://www.gsfc.nasa.gov/topstory/2003/0530earthgreen.html