Governments must switch from fossil fuels to nuclear, wind and solar energy to avoid a global warming catastrophe in a move costing about 300 billion ($578 billion) a year, a United Nations report warns today.

The study by the UN's Intergovernmental Panel on Climate Change lays out the pressing need for the world to ditch coal and oil and switch to green energy.

The report is likely to spark a new row over the cost of countering global warming, as climate change sceptics urge governments not to succumb to a green agenda, alleging it would drive up living costs for the rest of the century.

A leaked draft of the report provides a blueprint on how to tackle climate change, including not only the switch to green energy but even what people should eat. It claims:


• An estimated 300 billion a year is needed for investment in low-carbon sources of electricity such as nuclear, wind and solar energy over the next 20 years;

• Gas should replace coal-fired power stations as soon as possible to reduce carbon emissions, although gas should eventually be phased out too;

• Nuclear power is an established method for producing low-carbon electricity, although the report notes its use has waned since 1993;

• Experts estimate that by 2030, global gross domestic product could be as much as 4 per cent lower through measures to combat global warming;

• Western diets need to become more sustainable and environmentally friendly. This is likely to include a call to eat less meat.

The change of lifestyle is not detailed but the UN suggests people living in the richest countries should eat less.

The central thrust of the report is a call for "large-scale changes in the global energy system" and increased subsidy for green energy to help countries switch from fossil fuels.

World leaders will gather at a UN conference in New York in September before approving new international agreements on carbon emissions in Paris next year. The report will form the basis for those talks.