Methane and the risk of runaway global warming
By Andrew Glikson
Research was published this week showing the financial cost of methane being released from Earth’s permafrosts. But the risks go beyond financial – Earth’s history shows that releasing these stores could set off a series of events with calamitous consequences.
The sediments and bottom water beneath the world’s shallow oceans and lakes contain vast amounts of greenhouse gases: methane hydrates and methane clathrates (see Figure 1). In particular methane is concentrated in Arctic permafrost where the accumulation of organic matter in frozen soils covers about 24% of northern hemisphere continents (see Figure 2a) and is estimated to contain more than 900 billion tons of carbon.
Methane, a greenhouse gas more than 30 times more potent than CO2, is released from previously frozen soils when organic matter thaws and decomposes under anaerobic conditions (that is, without oxygen present).
