Tony Blair appeared last night to undermine more than 15 years of climate change negotiations when he signalled a shift away from a target-based approach to cutting greenhouse emissions. Speaking at the end of the first day of a summit in London of environment and energy ministers, the prime minister said that legally binding targets to reduce pollution made people "very nervous and very worried". He said when the Kyoto protocol expires in 2012, the world would need a more sensitive framework for tackling global warming. "People fear some external force is going to impose some internal target on you ... to restrict your economic growth," he said. "I think in the world after 2012 we need to find a better, more sensitive set of mechanisms to deal with this problem." His words come in the build-up to UN talks in Montreal this month on how to combat global warming after Kyoto. "The blunt truth about the politics of climate change is that no country will want to sacrifice its economy in order to meet this challenge," he said.