Five industry groups are disputing the US decision to list the polar bear as a threatened species. Last week, they filed suit in federal court to attempt to change the text of the listing that says business projects in Alaska — but no other state — must undergo reviews of their greenhouse-gas emissions.

The American Petroleum Institute, the US Chamber of Commerce, the National Mining Association, the National Association of Manufacturers and the American Iron and Steel Institute say the listing unfairly singles out Alaskan businesses.

It is the latest legal challenge to the May listing of the polar bear. The state of Alaska, led by governor and presumptive vice-presidential candidate Sarah Palin, has sued the government over the decision, saying it harms oil and gas exploration in the state. For its part, the environmental group the Center for Biological Diversity, which pushed for the original listing, is suing to get the polar bear upgraded from 'threatened' to 'endangered'.