One by one, prominent US lawmakers stepped up to the microphone this week and promised to rectify their country's lack of leadership on global warming. Yesterday the unglamorously named G8 plus 5 legislators' forum on climate change - a group of global parliamentarians sponsored by the World Bank - concluded a two-day meeting on Capitol Hill that coincided with Washington's severest ice snap this winter.

But in other respects, the forum - designed to exploit what is widely seen to be a tipping point in American attitudes towards climate change since mid-term elections last November - received the warmest of responses.