More efficient energy use and investments in greener cities are among 10 measures that can help the world to slow global warming while also spurring economic growth, an international report said on Tuesday.

Action across the 10 areas could achieve between 59 and 96 per cent of the cuts in greenhouse gas emissions needed by 2030 to keep global warming below a U.N. maximum of 2 degrees Celsius (3.6 Fahrenheit) above pre-industrial levels, it said.

"We've identified some of the most promising opportunities," Felipe Calderon, a former Mexican president who chairs the Global Commission on the Economy and Climate, told Reuters of the 10 goals.

"The most profitable ... is energy efficiency," he said of the report, drawn up by former heads of government, business leaders, economists and other experts.

It urged the Group of 20 major economies to set high global energy efficiency standards in sectors such as lighting, vehicles and buildings, estimating that curbs on energy waste could boost world economic output by up to $18 trillion by 2035.

Investments by cities in cleaner public transport, building insulation and better management of waste could cut greenhouse gas emissions and air pollution and bring savings worth $16.6 trillion by 2050, the report said.

Last year, the Commission said action to combat climate change, mainly shifting from fossil fuels to renewable energies such as solar and wind power, could lift economic growth rather than depress it as many governments fear.

WEIGHING THE COSTS

Apart from energy efficiency and cities, Tuesday's report recommended greater focus on forestry, $1 trillion a year in clean energy investment, carbon pricing, infrastructure, low-carbon innovation, business and investor action, limits on aviation and shipping emissions and curbs on hydrofluorocarbons, which are potent greenhouse gases.

The report did not estimate dollar benefits for each sector, some of which overlap. Benefits hinge on assumptions about the cost of damage from greenhouse gases, which are now emitted without penalty in many nations.

Last year's report estimated, for instance, that air pollution, largely from burning coal or oil, was equivalent to a 4.4 per cent brake on annual world gross domestic product. Such pollution causes 3.7 million premature deaths a year, it said.

Tuesday's report urged governments to step up action before a U.N. summit in Paris in December that will try to agree a global deal to limit emissions, blamed by almost all experts for causing more heat waves, downpours and rising seas. – Reuters