“If we do not reach a deal at this time, let us be in no doubt: once the damage from unchecked emissions growth is done, no retrospective global agreement in some future period can undo that choice. By then it will be irretrievably too late.”
Brown said that, according to estimates from the intergovernmental panel on climate change, an extra 1.8bn people – a quarter of the world’s population – could be short of water by 2080 as a result of climate change.
And the threat was not confined to people in the developing world, Brown said.
“The extraordinary summer heatwave of 2003 in Europe resulted in over 35,000 extra deaths. On current trends, such an event could become quite routine in Britain in just a few decades’ time,” he said.
“And within the lifetime of our children and grandchildren the intense temperatures of 2003 could become the average temperature experienced throughout much of Europe. In Britain we face the prospect of more frequent droughts and a rising wave of floods.”
Brown said that he thought a deal at Copenhagen was possible. But negotiators were “not getting to agreement quickly enough”, Brown went on, which was why he was appealing for leaders to get involved personally.
“We cannot compromise with the earth, we cannot compromise with the catastrophe of unchecked climate change, so we must compromise with one another,” he said.
“I urge my fellow leaders to work together to reach agreement amongst us, recognising both our common and our differentiated responsibilities – and the dire consequences of failure.”
Ed Miliband, the climate change secretary, yesterday highlighted signs of movement, pointing out that last month India said it was ready to set itself non-binding targets for cutting carbon emissions, while China said it would curb the growth of its emissions by a “notable margin” by 2020, although it did not specify further.
The US special envoy for climate change, Todd Stern, said developing economies must boost their efforts to curb emissions, warning it was “certainly possible” that no deal would be agreed in Copenhagen. “What we need to have happen is for China and India and Brazil and South Africa and others to be willing to take what they’re doing, boost it up some, and then be willing to put it into an international agreement,” he said.