The United States has listed the polar bear as a threatened species, because its Arctic sea ice habitat is melting due to climate change. US government scientists predict that two-thirds of the polar bear population of 25,000 could disappear by 2050. However, the government stressed the listing would not lead to measures to prevent global warming. Environmentalists have expressed disappointment that more will not be done to protect the bear’s habitat. US Interior Secretary Dirk Kempthorne said the government had made the decision on the advice of scientists, but he suggested the impact of the move would be limited. ‘While the legal standards under the Endangered Species Act compel me to list the polar bear as threatened,’ he said, ‘I want to make clear that this listing will not stop global climate change or prevent any sea ice from melting.’ He said that could only be achieved through action by all of the world’s major economies. Mr Kempthorne also said he was taking measures to make sure the listing was not ‘abused’ to make policies on climate change which would cause ‘harm to the society and the economy of the United States’. […]