Montag, 24. Mai 2010

Megafauna Methane collapse

There are lots of hypothesis dealing with the extinction of the Pleistocene Megafauna. Now a research team of the University of New Mexico in Albuquerque adds a something different approach to the problem of climate change as extinction cause. SMITH et al. published a paper where they compared the production of methane of modern farm animals to extinct herbivores. Methane is a very effective green house gas. The research team observed in the geological record strong variations of the concentration of methane between the last glacial maximum, 18.000 years ago, and the Younger Dryas (13.000 years ago). Especially at the beginning of the temperature drop of the Younger Dryas the concentration of methane diminished considerable fast. The research team speculates that with the beginning extinction of large herbivores an important source of methane was removed from the climate system, destabilizing climate and environment end enforcing the extinction rate. The fast changes observed, faster than previously known variations, maybe are also related to human activity, disproving precedent research that excluded humans as triggers for the Pleistocene extinction.

References

SMITH, F.A.; ELLIOTT, S.M.. & YONS, K. (2010): Methane emissions from extinct megafauna. Nature Geoscience. Published online: 23. May 2010: doi:10.1038/ngeo877

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