In the final months of the Bush administration two bipartisan diplomatic missions headed to Beijing to negotiate a US-China deal on carbon emissions.

According to the Guardian's report, John Holdren, now the White House science adviser, and other members of the current administration were involved in the initiative.

A memorandum of understanding has been drafted but not yet signed. Bill Chandler, director of the energy and climate programme at the Carnegie Endowment for International Peace, is confident a deal can be struck by the fall.