Attempts to extract long-term carbon emissions targets from large developing countries would fail to lead to a global consensus over how best to tackle climate change, Michael Spence, the chairman of the World Bank-backed Commission on Growth and Development, said on Monday.

Considerable lobbying is under way to persuade fast-growing emerging economies such as India and China to embrace a low-carbon future and implement caps, or even cuts, on greenhouse gas emissions. Pressure to agree action has intensified in the run up to United Nations talks on climate change in Copenhagen in December.

Professor Spence, a respected economist and Nobel laureate, warned that an attempt to force emerging economies into stringent action could backfire and produce “ugly” and “terrifying” consequences in terms of carbon tariffs and a rise in protectionism. He said the consequences of a failure to reach an agreement in Copenhagen could be “far reaching and long term”.