Science

Published on April 16th, 2009 | by ebalkan

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Climate Change and Deforestation Engaging in Vicious Cycle of Destruction


deforestation climate change amazon forest rain precipitation logging biofuel palm oil plantation copenhagen temperature[social_buttons]Most of you know by now that deforestation, and the emissions that cleared forestlands add to the atmosphere, exacerbates climate change. But it may come as a surprise to learn that the opposite is true. New scientific findings suggest that climate change is threatening remaining forests more dramatically than previously suspected.

Until recently, climate scientists thought that trees, and the biodiversity they support, could withstand a temperature rise lower than 3C. New findings, announced at last month’s Copenhagen “Congress” to discuss climate issues, estimate that a 3C temperature rise will result in a 75% loss of forests. The report’s sponsoring organization, the UK Meteorological Office‘s climate change research division, has said that a 4C temperature rise – consistent with current human activities – will cause 85% of trees to disappear.

Under even the most conservative climate change scenario – a 1C temperature jump – will kill off one third of Amazonian forests, which alone contain one tenth of total carbon stored in land ecosystems.

Scientists now estimate that the chance of staying below a 2C temperature rise are only 50%, even if drastic cuts in emissions take place over the next ten years. Already, a .75C temperature rise above pre-industrial has been locked-in, with another .6C expected, based solely upon current levels of greenhouse gases in the atmosphere.

The rise in temperatures so threatens the trees because, as forests warm up, evaporation occurs more quickly and trees dry out. Whether through ensuing forests fires or lack of water, the trees can not survive such conditions.

Some have described rainforests as the “Heart of the Planet,” responsible for generating winds that pump water to all parts of the earth. The implication of compromising the operations of forests – a literal “biotic pump“, according to another recent report by a pair of Russian meteorologists – is increased climate change.

These reports suggest such positive feedback mechanisms are already in place, which may be the most troubling aspect of all. Positive feedback is literally a vicious cycle manifested. As forest coverage decreases, more carbon is released into the atmosphere, which will then decrease forest coverage, and so on.

Tim Lenton, a climate expert at the University of East Anglia, said: “When I was young I thought chopping down the trees would destroy the forest but now it seems that climate change will deliver the killer blow.”

Mmmm, not quite. While climate may pose the most severe long-term threat to forestlands, current deforestation is putting trees at great risk right now, begging the question of whether the forests will even be around once the temperature rises enough to kill them off.

At the moment, clearing trees to plant palm plantations, to produce palm oil – a major biofuel feedstock – represents the greatest threat to tropical forests. Just this week, a new study concluded that it would take 75 years for the carbon emissions saved through the use of biofuels to compensate for the carbon released into the atmosphere when forests are converted into palm plantations.

So, whether it’s the climate or the cutting that is killing the forests, the onus of responsibility remains the same. Either way you slice it, it’s not you [trees], it’s us.

Photo Credit: Tjeerd via Flickr



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  • Zachary Shahan

    Excellent article. Chilling, perhaps. But excellent.

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