Rainforests have turned to desert, ice sheets have vanished from both poles, rising seas are pouring into continental basins.

When temperatures were at a simlar level 55 million years ago following a sudden period of global warming in the early Eocene, it is believed that the increase was caused by Methane Hydrate.

Methane Hydrate is a combination of methane and water that forms under the intense cold and pressure of the deep sea and which escapes with explosive force when disturbed. Evidence of ancient submarine landslides off Florida and huge volcanic eruptions under the North Atlantic suggests the possibility of the release of trapped methane, a greenhouse gas 20 times more potent than carbon dioxide, released in one giant belch and pushing global temperatures through the roof.

Although the total amount of carbon dioxide during the Eocene exceeded today's, the present rate of increase is still the fastest the world has ever seen, faster than the episodes which caused mass extinctions like the Permian extinction, when global temperatures rose by 6 degrees and 95% of species were wiped out.