Global energy use to rise fast if no CO2 deal - IEA

By Muriel Boselli and Barbara Lewis

PARIS/LONDON (Reuters) - World energy use will rise rapidly over the next 20 years, increasing costs and greenhouse gases unless a deal is reached to curb carbon dioxide emissions, the International Energy Agency (IEA) said on Tuesday.

Arguing strongly for a global deal at the U.N. Climate Change Conference in Copenhagen in December to limit greenhouse gases, the IEA said use of carbon emitting fossil fuels would increase quickly if policies remained unchanged.

The world would have to spend an extra $500 billion to cut carbon emissions for each year it delayed implementing a deal on global warming, the IEA said in its annual World Energy Outlook.

Without an international agreement on climate change, the ratio of energy spending to gross domestic product for the largest consumer countries would double by 2030.

IEA Chief Economist Fatih Birol told Reuters in an interview the world needed to stabilise the concentration of greenhouse gas emissions in the atmosphere at 450 ppm of CO2 equivalent.

"The world needs to go to the 450 part per million (ppm) target, not only because of climate change but because of growing problems within our energy system and its possible implications again on the economy," Birol said.

The IEA said global energy demand would rise by an average of 2.5 percent per year over the next five years if governments made no changes to their existing policies and measures.