THE world’s top climate scientists have cut their worst-case forecast for global warming over the next 100 years.
A draft report by the Intergovernmental Panel on Climate Change, obtained exclusively by The Weekend Australian, offers a more certain projection of climate change than the body’s forecasts five years ago.
For the first time, scientists are confident enough to project a 3C rise on the average global daily temperature by the end of this century if no action is taken to cut greenhouse gas emissions.
The Draft Fourth Assessment Report says the temperature increase could be contained to 2C by 2100 if greenhouse gas emissions are held at current levels.
Did the newspaper get it wrong, or does the report really say that there is only 1 degree Centigrade’s difference between doing nothing, and doing lot of very expensive things? Given the uncertainties of forecasting, is a 1 degree difference significant?
The Australian also reports sceptical climate scientists as saying,
…man-made increases in carbon dioxide levels are tiny compared with the Earth’s natural exchanges: about 5.5 gigatonnes of carbon a year from human activity compared with about 750 gigatonnes in the atmosphere, another 1000 gigatonnes in the surface oceans and 2000 gigatonnes in vegetation and soils. The deep oceans, they say, contain 38,000 gigatonnes.