Higher CO2 levels will increase plant growth and mitigate global warming.
ScienceDaily (Dec. 9, 2010) — A new NASA computer modeling effort has found that additional growth of plants and trees in a world with doubled atmospheric carbon dioxide levels would create a new negative feedback -- a cooling effect -- in the Earth's climate system that could work to reduce future global warming.
The cooling effect would be -0.3 degrees Celsius (C) (-0.5 Fahrenheit (F)) globally and -0.6 degrees C (-1.1 F) over land, compared to simulations where the feedback was not included, said Lahouari Bounoua, of Goddard Space Flight Center, Greenbelt, Md. Bounoua is lead author on a paper detailing the results published Dec. 7 in the journal Geophysical Research Letters.
Without the negative feedback included, the model found a warming of 1.94 degrees C globally when carbon dioxide was doubled.
Bounoua stressed that while the model's results showed a negative feedback, it is not a strong enough response to alter the global warming trend that is expected. In fact, the present work is an example of how, over time, scientists will create more sophisticated models that will chip away at the uncertainty range of climate change and allow more accurate projections of future climate.
"This feedback slows but does not alleviate the projected warming," Bounoua said.