SuperFreakonomics 'does not deny climate change'

The authors of SuperFreakonomics have refuted allegations that they are climate-change deniers.

Economist Stephen Levitt and New York Times columnist Stephen Dubner provoked attacks from environmentalists when they suggested that spraying sulphur dioxide into the stratosphere could reduce the effects of solar radiation.

Speaking to Telegraph TV, Levitt claimed that the proposals make environmental and economic sense, because it will be up to 50 years before conventional methods of lowering carbon take full effect.

'How are we going to get seven billion people to come together and change their behaviour when they don't get any benefit directly from it themselves?' he asked.

Levitt also said that current methods of cutting carbon cost 'trillions and trillions of dollars' each year, while geo-engineering techniques such as his suggestion have a lower price tag.

Co-author Dubner wrote on his New York Times blog that geo-engineering is likely to be used to tackle climate change, whether environmentalists 'like it or not'.

Reviewing SuperFreakonomics in the Guardian, The Gods That Failed co-writer Larry Elliot admitted the book includes moments of excellence, but claimed that its overall reasoning is 'so 2005'.