Future Global Temperature? Scenario CO 2 Even eventual CO 2 decreases lead to global warming
The regional picture in 2070- 2100 compared to 1961-90 Annual mean temperature change averaged across all models (colour; o C) Range of uncertainty (blue line; o C) Range/(standard deviation) (green)
Polar Bears in 2050? Depend on sea-ice for hunting seals and land for winter dens There could be no summer sea-ice by 2050 Interval of post-den starvation gets longer – is it sustainable?
Great Barrier Reef in 2050? Major bleachings (coral dieback) have occurred every few years during periods of high sea temperature A permanent temperature rise of 1-2 o C could kill the coral permanently 2002
The UK in 2100? Very Likely ~ 2-4 o C warmer Very Likely 2-7% wetter, concentrated in stormier autumn and winter Very Likely a sea level rise of 0.11-0.77 m Very Likely a rise in oceanic pH But less warming than similar latitudes in the Northern Hemisphere because of a predicted slowdown in the Gulf Stream, which has a very small probability of being abrupt
Global warming at the end of the last glaciation was the spark for civilisation But facing unprecedentedly rapid change, with a global population perhaps 1000 times greater Predictions will improve – next IPCC report out this month! But some change is now inevitable so the challenge is to mitigate change and adapt