The Earth in Climate change – will humanity follow the Polar Bear and the Great Barrier Reef?
Global Warming – the measurements Global surface air temperature
Pattern of change
Local Change No data
Global Warming – context over last 1000 years Global surface air temperature reconstructions over the last millennium
…. And longer
Other changes Arctic sea-ice extent
The Climate System
(Naturally)
The Climate System (anthropogenically)
Solar variability Relative Sunspot number Solar Constant (scaled to satellite observation)
Volcanic Record from Greenland Ice Core
Monthly average atmospheric CO 2 (Mauna Loa observatory, Hawaii) Atmospheric gases Monthly average values of atmospheric methane, California
The Greenhouse Effect
Land Cover Post-glacial maximum forest cover (similar to pre-industrial) Current forest cover
Model “hindcast” of climate change since 1890
Norway USA France UK Brazil Russia India China Wealth and energy consumption are related- as individuals get richer their lifestyles have increased energy demand.
Future Global Temperature?
And Rainfall
Future Global Temperature? A2 B2
Future Global Temperature? Scenario CO 2 Even eventual CO 2 decreases lead to global warming
The regional picture in compared to 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 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