Air pollution 'masking global warming'

The true threat from global warming may have been masked by air pollution, a leading scientist warned today.

The true threat from global warming may have been masked by air pollution, a leading scientist warned today.

Aerosols - particles of pollution in the air - help to cool the earth but, as they diminish in coming decades, global warming may be found to accelerate, says Meinrat Andreae, of the Max Planck Institute in Mainz, Germany.

Professor Andreae will tell a conference in London today that warming will be especially fast if aerosol "cooling" has hidden a higher climate sensitivity than is generally assumed.

"These arguments suggest that there is a considerable chance that climate change in the 21st century will follow the upper extremes of current... estimates, and may even exceed them.

"This would have truly grave consequences for the Earth environment and human society, and argues for immediate and radical reductions of greenhouse gas emissions."

Professor Andreae says the aerosols, which scatter light back to space, tend on balance to cool the earth.

But because of efforts to stop the particles being emitted, and their short lifetime, this "climate protection" will diminish in the future.

He said: "The only winning strategy is to do as much as possible, as fast as possible, to cut emissions of greenhouse gases."

The 13th World Clean Air and Environmental Protection Congress is taking place at the Hilton Metropole Hotel.