The Bush Administration has made one of its most significant concessions on the dangers of global warming, proposing protection for the polar bear, whose habitat is threatened by the melting Arctic sea ice.

The recommendation by the Interior Secretary, Dick Kempthorne, that the bears be added to the list of endangered species, marks a reversal by the Administration from its reluctance to acknowledge the consequences of climate change. It would bar US Government agencies from any activity that would jeopardise polar bears or their hunting grounds - such as oil and gas exploration - and could require US industries to curb their carbon dioxide output.