The rebound effect...

Yes, initiatives aimed at saving energy sometimes backfire...

Initiatives aimed at saving energy and reducing CO2 emissions could end up damaging the Government's climate policy instead, a new study claims.

Scientists have found that new technologies designed to cut energy use could actually result in an increase.

As an example they say a more fuel-efficient car which is cheaper to run can lead to the driver using it more often or on longer journeys.

Or a householder looking for a new fridge might buy a bigger model because it is more energy efficient.

In both cases some of the energy being saved is lost as a direct consequence of what is known as a 'rebound effect'.

The UK Energy Research Centre (UKERC) says in a new report that the resulting shortfall in energy savings could damage the Government's target of cutting energy use by 20 per cent by 2010.

Scientists are divided over whether the rebound effect is significant but some believe that it can actually result in a net increase in energy use, which is known as 'backfire'.

But the UKERC concludes the rebound effect is significant and cannot be ignored and it warns the Government that it must be factored into its climate strategy.

The report's chief author, Steve Sorrell, a Senior Fellow at UKERC, said the rebound effect had been ignored by experts and policymakers and had not even been mentioned in either the Stern and IPCC climate change reports or in the Government's energy white paper.

"This is a mistake. If we do not make sufficient allowance for rebound effects we will overestimate the contribution that energy efficiency can make to reducing carbon emissions," he said.