Tony Blair has urged Barack Obama not to allow the economic crisis overshadow efforts to tackle climate change.
By Tom Leonard in New York Last Updated: 7:50AM GMT 04 Mar 2009
Warning of the danger of putting environmental concerns "to one side", the former Prime Minister argued that the current economic problems "provide us not with an excuse for inaction but a reason for acting" on global warming.
Writing on The Daily Beast website just as his former Labour party rival met the US president in Washington, Mr Blair said that 2009 should be the year when the world - including America - agreed a new treaty on climate change.
"Some say that due to the economic crisis, action on the environment should be postponed. But either the climate is changing or it isn't," he said.
"If it is - and the scientific consensus on this is now vast - we cannot ignore it. To do so would be to multiply the risks to our future economy as well as the environment."
Welcoming the president's support for cleaner energy in his stimulus plan, Mr Blair said economic growth could be stimulated by investing in alternative energy and energy efficiency.
The world would be ready to cope when oil prices rose once more, he added.