EU global warming limit may not be possible: IEA

LONDON (Reuters) - A European Union target to limit warming of the planet to no more than 2 degrees Celsius may not be technically achievable, the International Energy Agency said in a report to be published next week.

"Even leaving aside any debate about the political feasibility ... it is uncertain whether the scale of the transformation envisaged is even technically achievable, as the scenario assumes broad development of technologies that have not yet been proven," said the IEA's World Energy Outlook.

That analysis referred to a target to limit global warming to no more than 2 degrees.

The implication is that the world may have to accept higher warming limits than targeted at present, for example by the EU since 1996, and prepare for effects which scientists say will include more droughts, floods and rising seas.

A United Nations climate panel said last year that above 3 degrees "hundreds of millions of people (would be) exposed to increased water stress (shortages)."

Stronger action to fight climate change involves rapidly escalating costs, for example to deploy expensive, untested technologies such as carbon scrubbers and even to leave stranded assets -- where high-carbon coal plants, for example, have to be closed prematurely.

"It will be necessary to face up to the reality of the cost of early capital retirement if radical measures are to be taken ... to deliver deep cuts in emissions," the IEA said in its report, due to be published on November 12. The IEA is energy adviser to 28 industrialized countries.

The IEA analyzed two scenarios to limit warming to 2 degrees and 3 degrees, and estimated that these would cost about $180 and $90 per tonne of carbon dioxide emissions respectively.

The present EU carbon price is about 18 euros ($23.20), and accounts for about one fifth of European consumer electricity prices, say analysts.

"The scale of the challenge ... is immense," the IEA said of a 2 degrees target. "The technology shift, if achievable, would certainly be unprecedented in scale and speed of deployment."

The EU Council of Ministers stated in 1996 that it "believes that global average temperatures should not exceed 2 degrees above pre-industrial level."