Examples of such risks include crop yields which could decline gradually in response to global warming, and then lurch over a cliff and the possibility that swathes of Siberia might warm, releasing huge stocks of methane that lie locked up in the permafrost.
Permafrost thaw could trigger what some have dubbed "catastrophic climate change," a cyclical process in which the earth's warming releases stored greenhouse gases, further warming the earth.
As the level of energy and temperature of the atmosphere increased, irreversible tipping points were reached where the synergy of feedback processes – ice melt, warming water, released methane, droughts and fires - combined to shift the climate from one state to the next.
The jetstream, weakened and slowed by Arctic warming, has released its normally strong hold on the Arctic polar air mass, allowing much of it to "wander drunkenly" into the US.
Nicholas D. Kristof (column, April 18) points out a scary scenario of warming oceans releasing gigatons of global-warming pollution.
The consequences could be a catastrophic circular reaction, as warming temperatures release more methane, which in turn raises temperatures further.
And then there was Damon Hill, his Williams FW18 attended by three of the team's mechanics who worked with him in his championship year of 1996: Dickie Stanford, Bob Davis and Colin Watts, observing the old protocols of start-up procedures and tyre warming before releasing him on to the track.
After they have extracted the water, the gels can be regenerated by warming to release the absorbed water.
