Acting as natural air conditioners for the environment, plants and trees normally release water vapor through their tiny leaf pores in a process called evapo-transpiration. However, increasing amounts of carbon dioxide in the atmosphere cause the pores to shrink. This reduces their absorption of CO2 as well as their cooling ability.

A recent study from the Carnegie Institution for Science in the USA has shown that such decreased evaporative capacity actually amplifies surrounding temperatures, increasing the warming effect of the CO2 itself.  Study co-authors Drs. Long Cao and Ken Caldeira found that when the concentration of CO2 in the atmosphere was doubled, the diminished evapo-transpiration of plants accounted for 16% of land surface warming, averaged over the entire globe.

In regions such as parts of North America and eastern Asia, the warming effect could exceed 25% of the total caused by CO2 alone. Dr. Caldeira stated, “…The kind of vegetation that's on the surface of our planet and what that vegetation is doing is very important in determining our climate. We need to take great care in considering what kind of changes we make to forests and other ecosystems, because they are likely to have important climate consequences.”

Drs. Long Cao, Ken Caldeira and Carnegie Institute associates, we appreciate your work that reveals how the beneficial vegetation can be so adversely affected by human-caused global warming.
Let us swiftly act in unison to adopt sustainable living practices that protect the forests and our Earthly abode. Supreme Master Ching Hai has frequently spoken of our need to value the irreplaceable components of our planet’s ecosystems, including the flora, as during this 2001 lecture in Florida, USA.

http://www.physorg.com/news192120859.html
http://www.ciw.edu/news/co2_effects_plants_increases_global_warming
http://www.ciw.edu/news/how_avoid_severe_climate_change_discussed_co2_conference