In the Daily Telegraph, Lord Rees, President of the Royal Society, argues that even if other factors than greenhouse gases might play a role in global warming, that’s beside the point:
In a system as complex as the global climate we cannot predict with certainty what will happen in future. However, the risks are potentially so high and evidence that CO2 emissions are interfering with the climate is so strong that delaying action to reduce our emissions until we have absolute certainty would be foolish.
Of course, the judgment about potential risks and foolishness is most emphatically not a scientific one. In a world of trade-offs, other considerations must be assessed, such as the dangers of a global cutback in energy use.
The Director of the Scientific Alliance and the former science editor of BBC News respond.