Angela Merkel sounded a pessimistic note yesterday on the chances of securing a deal on climate change at the G8 summit next month, as her Environment Minister accused the US of narrow-mindedness over global warming.

Outlining her goals for the meeting in Heiligendamm, the German Chancellor said that leading industrial nations had to cut greenhouse gas emissions or they would not be able to combat climate change. But last week’s EU-Russia meeting and recent talks among G8 environment ministers had proved so difficult that she was not sure the summit would yield the necessary progress.

Berlin wants a G8 commitment to limit global warming to a rise of 2C (3.6F) this century and to cut greenhouse gas emissions to half of 1990 levels by 2050.

“Only if we stride ahead will we be able to convince the emerging economies to commit to appropriate measures, without of course destroying their right to economic growth,” Ms Merkel said.

Sigmar Gabriel, her Environment Minister, added that Germany was prepared to block decisions on other issues unless the US and other G8 members made concessions on the environment.

He said that this issue was the toughest nut to crack.

“America doesn’t want to commit to firm goals. We can’t put the global future of our children at risk because of the narrow-mindedness of individual negotiating partners.”

German officials have said that, despite lobbying from Ms Merkel and Tony Blair, President Bush does not appear likely to agree to any of the German climate aims. The EU believes that there should be penalties for carbon emissions to promote clean energy technologies. Washington thinks public spending and incentives would be a better approach.

As diplomats prepared for the negotiations, Ms Merkel defended the massive security operation under way before the summit, which is expected to draw up to 100,000 protesters.

There was a public outcry broke yesterday after police took scent traces from suspected antiglobalisation activists – a method once used by the Stasi to hunt dissidents in communist East Germany.

Police investigating a wave of arson attacks on buildings and luxury vehicles have taken samples of the body odour of five suspects by making them hold metal tubes in their hands. The aim is to compare the odours with scent traces on anonymous letters left at the scenes of the attacks in Berlin and Hamburg. Sniffer dogs have been trained to match human scents, which are said to be as identifiable and unique as fingerprints.

Ms Merkel said: “Those who are loudly criticising our security measures would be the first to accuse the authorities of neglect if violence does break out.” G8 leaders would listen to protesters if they demonstrated peacefully.

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