warming also accelerates tectonic activity: earthquakes, volcanoes,
landslides. It is not simply a matter of a combustible atmosphere,
the land itself would no longer be stable.
The Earth's crust
responds to the changing mass of water and ice that weighs on it
as it is moved around the planet's surface constantly, but which
escalates during periods of global warming. The pressure is considerable:
1 cubic metre of water weighs 1 ton, while the same volume of ice
weighs less - 0.9 tons. As ice sheets that had pinned down volcanoes
and active fault lines melt away, the Earth's crust bounces back
in a process called 'isostatic uplift'. As it does so faults are
reactivated and seismic activity increases.
This is well
illustrated by the Sumatran Earthquake and ensuing Indian Ocean
Tsumani of 2004.