The IEA, energy adviser to 28 industrialized countries, said the world must act urgently to put greenhouse gases on a track to limit global warming to no more than 2 degrees Celsius. Every year's delay beyond 2010 would add another $500 billion to the extra investment of $10,500 billion needed from 2010-2030 to curb carbon emissions, for example to improve energy efficiency and boost low-carbon renewable energy.