“If the world continues on the basis of today's energy and climate policies, the consequences of climate change will be severe,” explains IEA executive director Nobuo Tanaka in a special early excerpt of the World Energy Outlook 2009. “Energy is at the heart of the problem, and so must form the core of the solution.”

The world economic crisis has forced investments in polluting energy technologies to be deferred and CO2 emissions this year could fall by three percent, steeper than at any time in the last 40 years, the study notes.

Even in the absence of additional policies, GHG emissions in 2020 could be 5% lower than the IEA estimated 12 months ago, and the economic downturn “has thereby created an opportunity to put the global energy system on a trajectory to stabilise GHG emissions at 450 parts per million of CO2-equivalent” which is correlated with a global temperature rise of 2ºC.

“This gives us a chance to make real progress towards a clean-energy future, but only if the right policies are put in place promptly,” says Tanaka. The report was released to influence the climate change summit to be held this December in Copenhagen.

Under IEA’s 450 ppm scenario, GHG emissions by 2030 must decline 13,800 Mt compared with the reference scenario, with the largest percentage coming from reductions in power generation. Renewable energy would account for 2741 Mt of this total, behind energy efficiency at 7880 Mt but ahead of carbon capture (1410 Mt), nuclear (1380 Mt) and biofuels (429 Mt).

The investment needed for renewable energy to achieve this goal would be US$2,787 billion from 2010 to 2030, while efficiency would require US$7,585bn, CCS would need US$702bn, nuclear US$616bn and biofuels would need US$405bn of investment over the 20-year period.

In OECD nations, renewable energy could reduce GHG emissions by 816 Mt with an investment of US$1035, of which the USA could abate 228 Mt from US$366bn of investment, 256 Mt in the European Union with US$381bn and 71 Mt in Japan with US$28bn of investment from 2010 to 2030. Renewable energy in China could reduce 485 Mt with an investment of US$487bn, and 312 Mt in India with US$124bn.

In the power generation sector, wind energy and other renewable energy show the largest gains by 2030 under the 450 scenario, while coal without CCS declines.

“The biggest challenge will be to ensure there is funding to back this energy transformation with substantial support for developing countries,” says Tanaka. “The IEA 450 scenario is the energy pathway to Green Growth, yet we need to act urgently and now. Every year of delay adds an extra US$500bn to the investment needed between 2010 and 2030 in the energy sector.”

The excerpt sets out the energy transformation that key countries must undertake, sector by sector, if the world is to adopt a 450 ppm trajectory. The entire World Energy Outlook 2009 will be launched in London on 10 November and will analyse the impact of the financial crisis on the energy sector.