matter in the soil releases a surge of carbon dioxide into the air. This release will exceed the carbon dioxide absorbed by growing trees for at least the first 10 years. Only later will the uptake of carbon by the trees begin to offset the losses from soils. In fact, some new forests planted on wet, peaty soils will never absorb as much carbon as they spit out. Europe’s forests are absorbing up to 400 million tonnes a year, or 30 per cent of the continent’s emissions.

The results also reveal that old forests actually accumulate more carbon than young plantations. This suggests that conservation of old forests is a better policy for tackling global warming than planting new ones.

But the Kyoto Protocol takes none of this into account. "Besides ignoring soils, it has no measures to stop deforestation," says Riccardo Valentini of the University of Tuscia in Vitervo, Italy. Instead, it seems to give countries a perverse incentive to chop down existing natural forests and replace them with plantations.

"They will be able to claim carbon credits for the new planting, while in reality releasing huge amounts of carbon dioxide into the air," says Valentini. "There is nothing in the protocol to stop this." "If the politicians had known in 1997 what we know now, they would never have agreed to its rules on carbon sinks –– at least, I hope they wouldn’t," says CarboEurope chairman Han Dolman.

• http://www.newscientist.com/news

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