The Earth in 2050. Climate change – will humanity follow the Polar Bear and the Great Barrier...
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The Earth in 2050. Climate change – will humanity follow the Polar Bear and the Great Barrier Reef?
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Transcript of The Earth in 2050. Climate change – will humanity follow the Polar Bear and the Great Barrier...
The Earth in 2050.
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
Sheffield annual mean temperature
7
8
9
10
11
year
tem
per
atu
re (
C)
annual meant
No data
Global Warming – context over last 1000 years
Global surface air temperature reconstructions over the last millennium
…. And longer
Other changesArctic sea-ice extent
The Climate System
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 CO2 (Mauna Loa observatory, Hawaii)
Atmospheric gasesMonthly 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
0.01
0.1
1
10
100
100 1000 10000 100000
GDP ($/person/year)
Pri
ma
ry E
ne
rgy
Co
ns
um
pti
on
(k
W/p
ers
on
)
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?
Future Global Temperature?
And Rainfall
Future Global Temperature?
Scenario CO2
Even eventual CO2 decreases lead to global warming
The regional picture in 2070-2100 compared to 1961-90
Annual mean temperature change averaged across all models (colour;oC)Range of uncertainty (blue line; oC)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 1-2oC could kill the coral permanently
2002
The UK in 2100?• Very Likely ~ 2-4oC 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
