Forests and methane - at the intersection of science and politics, experimentation and extrapolation, objectivity and subjectivity

According to recent information, vegetation is thought to be a major source of methane. This phenomenon had not been contemplated until now and still remains to be explained. According to the authors and on the basis of rough extrapolations, it may cast light on some missing pieces in the global methane balance. The initial reaction by commentators following this discovery was to discuss its consequences on the strategy to fight the greenhouse effect considering methane's considerable impact on global warming. However, a preliminary analysis based on opinions from a range of experts underscores three aspects - the experimental discovery needs to be confirmed and explained before drawing any hasty conclusions; extrapolations performed so far on a global scale are highly inadequate and probably overestimated; implications for fighting the greenhouse effect are limited because the phenomenon in question is a natural one and not extensive enough to offset the benefits of forests as a sink for carbon dioxide. (authors)