The implications of the findings are worrying: on a global scale, Keppler estimated, methane emissions from plants and trees could amount to hundreds of millions of tonnes a year, throwing scientists' understanding of the greenhouse gas's sources and sinks way off kilter.
Full story here
http://www.earthtimes.org/articles/show/62336.html
[Proofreader's note: this article was edited for spelling and typos on May 16, 2007]
Note: http://www.earthtimes.o...

Why wasn't there any greenhouse effect, when trees covered most of the Earth ?
Who is funding this guy's research and what political party is he connected with ?
Ed Deak.
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The two most common things in the universe are apparently Hydrogen and stupidity.
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You must know that there always is a greenhouse effect going on of some kind or another, and that there need not be any devastating effects from it.<br />
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"Who is funding this guy's research and what political party is he connected with ?"<br />
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Keppler is funded by the European Science Foundation where he is employed.<br />
<a href="http://www.esf.org/home.html">http://www.esf.org/home.html</a><br />
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I did the usual digging into this story before posting it, but I did not find a political or corporate link behind Keppler's work, or that of the ESF. The ESF has been around for a long time, yet there's nothing in the way of "dirt" that I could find after performing a cursory search.<br />
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It seems the research in this area is still being contested and is definitely not conclusive one way or the other.<br />
“….the major sink is the breakdown of methane by the following phytochemical reaction: CH4+O2+sunlight yields CO2+2H2.”<br />
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As trees and other green plants are also generators of O2 (the stuff we need), I would hazard a guess that further delving into this “anomaly” will show that trees emit CH4 because they cannot immediately absorb all the CO2 they take in, in respiration. I would suggest that trees also take in more sunlight energy than they can reasonably use at any given time. So they emit CH4 [CO2 + 2H2O + sunlight = CH4 + 2O2 ] and these products then re-react in sunlight to produce CO2+2H2 . You will note that, in comparing this reaction with that in the parentheses above, there is a net release of O2 (Yay!). Also, the article dwells on the air over tropical forest cover “…the imbalance in the methane budget noticed above tropical evergreens….” which doesn’t mean the methane STAYS there (Winds will ensure its disbursement).<br />
(Hey! Just because WE don’t know it, doesn’t mean ol’ Mother Nature doesn’t know it!)<br />
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Like Ed points out, Earth was just about covered in trees at one time, because SOMETHING had to act as a carbon sink, to get rid of the excess carbon dioxide that resulted in the end of the Ice Age, and trees are quite efficient at this sort of thing over millennia……..<br />
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<p>---<br>"When you change the way you look at things, the things you look at change." <br />
-Max Planck<br />
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But wait, we're already doing our best to combat this "problem" by clear-cutting....problem solved....where is the next forest that requires denuding to save the world?
H.F. Wolff
Just wait 'til they find out one of those compounds is cyanide............
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"When you change the way you look at things, the things you look at change."
-Max Planck