European forests carbon sink could shrink: study

Reuters 23 Jun 08;

HELSINKI (Reuters) - Carbon capture by European forests has increased by about 70 percent since the 1950s, but this trend might be coming to an end, a joint European study said on Monday.

The increase was due to favorable climate, raised levels of carbon dioxide in air the and nitrogen fallout, but logging for bioenergy use as well as climate change are threatening carbon sink capacity.

"The European Union (EU) is trying to increase the production of bioenergy, and the target can be reached only if logging is considerably increased," the Finnish Environment Institute said. "As a consequence, the carbon sink may be reduced almost down to zero."

EU targets cutting CO2 emissions by 20 percent below 1990 levels by 2020 and having at least 120 percent of energy demand come from renewable sources. Transport fuels should include 10 percent biofuel by then.

Planting new trees is not going to be as effective for carbon capture as old forests which can capture 100 to 240 tonnes of carbon per hectare, while new tree stands capture about 40 tonnes.

Thus, to maintain the efficiency of the carbon sink, logging rate should be considerably lower than the growth rate, the study said.

Droughts, storms and pest invasions due to climate change will slow forest growth and thus also reduce carbon capture, and the warmer the ground, the more it will release carbon dioxide.

(Reporting by Sakari Suoninen; editing by James Jukwey)