Re:What's the proportions? (Score 1)

While it is true that on an absolute basis, methane is the second largest contributor to climate change, it has a very low global warming potential compared to most other GHGs. Even so, CH4 is 21 times as potent as CO2. So, if the CH4 to CO2 proportion (tons CH4 emitted:tons CO2 stored) from a tree (over its lifecycle) is greater than 1:21, then trees are part of the problem (rather than part of the solution). According to Tufts: a tree stores 671 lbs of CO2 over its lifetime (presumably, lifetime excludes decomposition). Source http://www.tufts.edu/tie/tci/seques tration.htm So, if the CH4 emitted per tree is 32 lbs or more, we'z in a heap o' trouble. The Nature study's coauthor, Thomas Röckmann, stated, "Rough estimates suggest the positive effect of storing carbon far outweighs a plant's emissions of methane . . . ." Source: http://www.philly.com/mld/inquirer/living/health/1 3636155.htm Sounds like Röckmann has already done an estimate of the proportions. I suppose that Röckmann et al did not make the estimated proportions available to the press since the proportions were not covered. Was the "rough" estimate enough to conclude that a more detailed estimate was not necessary? One might ask, why wasn't a per tree comparison included in the report? The omission of the estimated emission proportions seems to me to be a major weakness. I have a hard time believing the findings when something so obvious seems not to have made its way into the hands of the press. How does the rate of methane emission change over time? At what stage in its lifecycle does a tree cease producing methane? How does the methane emission rate change between species? The report summaries suggest that the conclusions were based on lab studies of rye grass. It seems to be a bit of a stretch to go from lab rye grass to the entire Amazon. Who funded the work? Röckmann has the answers. Greg