Methane Released by Northern Peat Lands Might Have Kickstarted past Global Warming
17.10.2006 - Other
Methane gas released by peat bogs in the northern-most third of the globe probably helped fuel the last major round of global warming, which drew the ice age to a close between 11,000 and 12,000 years ago, according to scientists from University of California, Los Angeles (UCLA) and the Russian Academy of Sciences.
Methane is a very potent greenhouse gas (23 times more potent than CO2), released by bogs as a by product of plant decomposition taking place without oxygen (anaerobic decomposition). Scientists knew from past samples that atmospheric levels of methane rose dramatically some 12,000 years ago, but they couldn't explain why.
Previously, although bogs are well known methane producers, northern bogs were dismissed as the main source of the massive amount of methane released in the atmosphere at the end of the last ice age because they were thought to have formed too slowly and too late to be a factor.
By radiocarbon dating 1,500 samples taken from northern peat bogs, scientists were able to reconstruct the timing of their development. They found out that northern peat bogs developed far earlier than previously thought. Moreover the amount of methane they released in the atmosphere vastly contributed to the more than doubling of atmospheric methane that trigger a global warming trend ending the last ice age.
It is worth noting that current methane levels (in 2004), have reached more than 1750 parts per billion.
