August 7, 2008
Time to Prepare for Abrupt 4°C Warming

Trends in population and consumption ensure abrupt warmingBob Watson [search], former IPCC chief and leading climate scientist, has advised the UK government to start preparing [ark] for massive 4°C in warming. While not backing away from urgent policies to limit warming to 2°C warming, the sheer momentum of warming trends makes flood protection, agriculture and coastal erosion adaptations necessary. Chances for abrupt, run-away warming [search] have traditionally been given short-thrift in politically compromised international climate negotiations. Yet, even with a comprehensive global carbon deal, it is suggested there is at least a 50% probability that temperatures would exceed 2°C and a 20% probability they would exceed 3.5°C. And if trends in failed climate policy continue, and pollution goes unchecked for decades and even centuries, we can expect much worse.

Every day of delay by governments and individuals in reducing greenhouse gas emissions makes it increasingly likely the Earth will experience rapid, scorching heat and "global weirding" [search] where climate patterns chaotically break down. By definition predictions are guesses based upon the best available information. I would not be surprised if given continued surging global population and gross consumption, the atmosphere and other key ecosystems collapse making the Earth incapable of supporting advanced life. Or that the current climate and global change ecological science is significantly wrong in still unknown manners. Yet what choice do we have but to act upon the best knowledge currently available while seeking more, and what outcome other than catastrophe can result from destruction of ecological systems which we know are a requirement for all life?

Posted by Dr. Glen Barry on August 7, 2008 11:38 AM | More on abrupt run-away climate change
http://www.climateark.org/blog/2008/08/time_to_prepare_for_abrupt_4c.asp

Climate change: Prepare for global temperature rise of 4C, warns top scientist
Defra's chief adviser says we need strategy to adapt to potential catastrophic increase


The UK should take active steps to prepare for dangerous climate change of perhaps 4C according to one of the government's chief scientific advisers.

In policy areas such as flood protection, agriculture and coastal erosion Professor Bob Watson said the country should plan for the effects of a 4C global average rise on pre-industrial levels. The EU is committed to limiting emissions globally so that temperatures do not rise more than 2C.

"There is no doubt that we should aim to limit changes in the global mean surface temperature to 2C above pre-industrial," Watson, the chief scientific adviser to the Department for the Environment, Food and Rural Affairs, told the Guardian. "But given this is an ambitious target, and we don't know in detail how to limit greenhouse gas emissions to realise a 2 degree target, we should be prepared to adapt to 4C."
Link to this audio
James Randerson: 'Massive shifts in Earth's systems'

Globally, a 4C temperature rise would have a catastrophic impact.

According to the government's 2006 Stern review on the economics of climate change, between 7 million and 300 million more people would be affected by coastal flooding each year, there would be a 30-50% reduction in water availability in Southern Africa and the Mediterranean, agricultural yields would decline 15 to 35% in Africa and 20 to 50% of animal and plant species would face extinction.

More at:
http://www.guardian.co.uk/environment/2008/aug/06/climatechange.scienceofclimatechange