Trees worsen greenhouse effect!(?)

<q>Hamburg- A leading expert in
Germany has spawned a major scientific debate by claiming that trees
put millions of tons of methane into the atmosphere every year
exacerbating the greenhouse effect. Amid controversy, Dr Frank Keppler
of the Max Planck Institute for Chemistry has reaffirmed findings by
his team in Mainz, Germany, in January 2006 that they had detected
methane exhaled from living



plants.



"I am 100 per cent confident that plants emit methane," he told
Chemistry World magazine, insisting that as yet unpublished research
would confirm his findings once and for all.



Keppler's unexpected discovery has caused heated debate among
biologists and atmospheric chemists. Though bacteria in soil or
decaying matter produce methane in anaerobic conditions, there seems to
be no reason or mechanism for living plants to emit the gas in an
oxygen-rich environment.



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.




But many researchers have queried the global impact, suggesting that
Keppler's scale-up calculations, based on methane emission per unit of
metabolically active mass of plant, were a gross overestimate.



Yet until recently, no published research has questioned Keppler's
central discovery that plants can emit methane in the first place. </q>