Global Warming Effects of increase CO2

Carbon dioxide Can we be completely sure that the climate changes we observe are caused by anthropogenic emissions of carbon dioxide? Not completely sure But it is likely:

Climate Models Predictions What do climate models lead us to expect?

Climate Models What is the current effect of CO2 A net extra ‘forcing’ of around 2 watts per square metre… Average 240 W/m2 Average 240 W/m2 150 W/m2 On Average 390 W/m2 + 2 W/m2

An additional 2 watts per square metre of ‘radiative forcing’ Scientific American March 2004 From Scientific American

Contributions to Climate Forcing Climate Forcing (W/m2) -1 +1 Greenhouse gases Carbon Dioxide Methane Chlorofluorocarbons Nitrous Oxide Ozone Aerosols Black Carbon Reflective aerosols Cloud droplet changes Land cover changes Sun

Increased Climate Forcing Increased Water Vapour Negative Positive Feedback Increased Climate Forcing Increased Water Vapour Negative Positive Climate Forcing Global Temperature More Evaporation Decreased Climate Forcing Increased Cloud Cover

Probably the best we can hope for in the next century. The Future… CO2 levels will rise Very roughly, If we make a 50% cut in GLOBAL emissions CO2 will stabilise at twice historical levels Probably the best we can hope for in the next century.

IPCC Predictions…