November 22, 2006

Forests: Carbon S(t)inks?

Biopact reports that research on the carbon sequestering capacity of forests is challenging long cherished beliefs that they are 'carbon sinks" that suck more carbon-dioxide out of the atmosphere than they emit. The idea that planting or retaining more trees will automatically compensate for greenhouse gases released elsewhere is apparently a myth.

Still, the net CO2 contribution of forests is far lower than that of simply burning fossil fuels, so planting new energy trees (either as part of a re- or afforestation effort) to use them as bioenergy feedstocks to be used instead of coal, gas or oil, remains a good strategy to tackle climate change.

This means that the real impact of forests on global warming is the risk they pose when consumed in fires - during which they expell huge amounts of carbon, particulate matter, NOx, and SOx into the atmosphere.

For the full story, click the title link below to the Biopact site. Excerpts of their article are below:

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Idea that forests are 'carbon sinks" no longer holds

New research now shows that instead of carbon sinks, some forests emit more carbon than they store. Forests can do little to improve the future climate or to lower the atmosphere's carbon levels. What they can do is make global warming worse.

This is the conclusion of a Canadian and American team of forest scientists that went into the woods in northern Manitoba to measure the carbon cycle of a forest ecosystem. They wanted to measure carbon going into and out of a living forest, to learn how effectively the forest was sucking carbon dioxide out of the atmosphere and storing it.

The results of this scientific work are congruent with research done in other forest types, most notably in tropical forests where the same observation was found: forests contribute more CO2 to the atmosphere than they store.

The consequences of these scientific results are manifold: forest nations will not be able to enjoy the benefits brought by the United Nations Framework on Convention on Climate Change because forests can no longer be filed as 'carbon sinks'. Re- and afforestation efforts are no longer a certain quick fix to climate change (they do have many other benefits, though), and large fossil fuel burning utilities who now often contribute financially to such efforts to appease their conscience, must rethink their strategies.


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