A radical shift from fossil fuels to low-carbon energy would slow world economic growth by only a tiny fraction every year, a new draft U.N. report on tackling global warming said on Friday.

Many governments had complained that an earlier draft was not clear in its estimate of the costs of low-carbon energy, which include solar, wind and nuclear power plus fossil fuels whose emissions of greenhouse gases are captured and buried underground.

The new draft, which is being edited by government officials and scientists in Berlin before publication on Sunday, indicates that world economic losses would be small compared to projected costs of heat waves, floods, storms and rising sea levels.