The aviation industry could have an "immense" negative impact on the environment, peers have warned.

A report published by the Lords EU sub-committee on environmental issues on Wednesday slammed ministers for continuing to support the expansion of Britain's airports while also pledging to reduce pollution levels.

At the end of last year, transport secretary Alistair Darling announced plans to build a second runway at Stansted "as soon as possible" and backed the option of a third runway at Heathrow.

He also announced further expansion of Manchester, Edinburgh, Bristol and other regional airports.

But the expansion of air travel will put efforts to meet climate change targets at risk, the peers warned.

Climate change

Action to tackle aircraft pollution is needed to combat the devastating effects of climate change, the committee claimed.

"It is extraordinary that on the one hand the government is concerned with climate change and on the other hand it's encouraging a rapid increase in air travel," said chairman Lord Renton.

"Aviation's impact on the environment could be immense. Jet engines directly emit greenhouse gases by burning kerosene.

"But they also produce powerful - yet little-understood - polluting contrails and high-altitude clouds known as 'radiative forcing'. Their exact effect is uncertain."

Lord Renton said the pollution risks were "alarming when air travel is predicted to grow rapidly throughout the EU and the rest of the world".

"With back-up from UK airlines, the government must try to convince the EU to include aviation in its mandatory emissions trading scheme as soon as possible," he added.

Responding to the report, the Department of Transport said its aviation white paper already set out plans to reduce the environmental impact of aircraft.

"It considers the best means of achieving this is to work with the European Commission and other member states with the aim of including aviation in the EU emissions trading scheme, with effect from 2008," a spokesman said.

He added that this would be a "priority" for the government during its EU presidency next year.

Global action

The committee said that with Britain holding the EU presidency in 2005, the country had an "unprecedented opportunity" to push the international agenda forward.

Climate change could have "devastating" effects unless governments, industries and citizens worldwide take action together, it added.

"The EU can lead by example but the impetus must be on citizens to consider how they contribute to global warming - and make changes," said Lord Renton.

"The Russian Duma's decision to ratify the Kyoto protocol is a momentous step forward but it is only one step towards solving a global problem.

"We now urge the UK government to do everything in its power in 2005 - when it holds the presidencies of the EU and the G8 simultaneously - to persuade reluctant countries to commit to concrete action on climate change."