Forests increase global warming, scientists say

Researchers have predicted that global warming will accelerate because carbon dioxide will be released from soils and decaying forests as the climate warms.

Scientists at the UK Meteorological Office’s Hadley Centre for Climate Prediction and Research said that this meant planting forests to act as ‘carbon sinks’ to absorb the greenhouse gas carbon dioxide could be counterproductive.

Two studies published in science journal Nature used computer models of global warming to show that as temperatures rise, forests – so-called carbon sinks – are likely to release more CO2 into the atmosphere as the temperature rises, speeding up the warming effect.

“Our initial results suggest that vegetation and soils, which currently absorb about a quarter of human-made carbon dioxide emissions, could accelerate future climate change by releasing carbon to the atmosphere as the planet warms,” said Dr Peter Cox.

The second study, by Dr Richard Betts, also showed that planting new forests in cold regions like Siberia and Canada could be causing harm because they absorb more sunlight than the colder ground around them, which would contribute to global warming.

The findings could have important implications for the Kyoto framework meeting in The Hague beginning on 13 November because a number of countries, including the US and Australia (see story in this section), are strongly advocating planting forests or counting existing ones as carbon sinks to set against their contribution towards reducing global warming. The Kyoto treaty allows the planting of forests to offset part of a country’s CO2 emissions. But the Hadley Centre research casts this approach into doubt. Dr Geoff Jenkins, head of the Hadley climate change programme, said there are a “huge amount of uncertainties” if this approach is taken.

European nations are set to advocate cutting emissions of greenhouse gases into the atmosphere as a preferred option, rather than relying on carbon sinks or ‘flexible’ options such as emissions trading (see story in ‘Europe’ section).

Greenpeace and the World Wide Fund for Nature are calling for carbon sinks to be excluded from the Kyoto treaty and for industrialised countries to achieve their targets by curbing emissions.

A statement from Bill Hare, Greenpeace’s International Climate Policy Director warns: “Claiming credit for carbon stored in trees is a blatant attempt by some countries to cheat on their Kyoto commitments.” Referring to a joint report produced with the WWF on a ‘carbon sink’ trial project in Tasmania he added: “This report shows that it is also bad for the environment, leading in some cases to the destruction of old growth forests to make way for carbon sink plantations.”

UK Environment Minister Michael Meacher welcomed the research, calling it a “further wake-up call” to our most serious environmental challenge. He said: “These results add weight to our view that we must achieve real emission reductions to meet Kyoto targets, and confirm our concerns about sinks. We must be cautious about them.”

“The UK is playing a leading role in getting global agreement on cutting greenhouse gases which cause climate change”, he continued. “This new research underlines the need to make the forthcoming international negotiations in the Hague a success, working in partnership to achieve reductions in emissions and to develop global and domestic strategies to combat and adapt to climate change.”

Mr Meacher joined Deputy Prime Minister John Prescott at a special EU Environmental Council in Brussels this week to tackle climate change issues in the run up to the forthcoming UN conference on climate change (CoP6) in The Hague (see story in ‘Europe’ section). Mr Prescott and Mr Meacher will strive to get a deal which ensures that Kyoto targets are in force globally by 2002, the Department of the Environment, Transport and the Regions confirmed.

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