We must make difficult choices
It will soon be too late to stop global warming
We are -- at the same time -- thrillingly close and sickeningly far from solving our planetary fever. The world's leaders huddled in New York City yesterday to discuss man-made global warming, in a United Nations building that will soon be underwater if they fail. They all know what has to happen: their scientists have told them, plainly and urgently.
As man-made warming rises by up to 2.4C, all sorts of awful things happen -- whole island states in the South Pacific will drown, for example -- but we can stop it. If we turn off the warming gases, the temperature will stabilise. But if we go beyond 2.4C, global warming will run away from us, and we will have lost the "Stop" button.
To stay the right side of this climatic Point of No Return, global emissions need to start falling by 2015 -- just six years from now -- and drop by 85pc by 2050. Our leaders need to agree this at the climate talks in Copenhagen in December. The scientific debate is over. The answer is in sight.