Margaret Munro in Canwest News Service: There is more than a 10 per cent chance the planet could undergo dramatic warming even if humanity manages to curb emission in coming decades, according to a survey of leading climate experts. "The possibility of really dramatic climate outcomes is significant," says engineer David Keith, of the University of Calgary, whose survey highlights the large but seldom discussed uncertainty in climate change scenarios.It is known the climate will warm as a result of the billions of tonnes of carbon dioxide bumped into the atmosphere each year through the burning of coal, oil and other fossil fuels. But it is still not clear how much, says Keith, director of the U of C's Institute for Sustainable Energy, Environment and Economy. To gauge the risks Keith and his colleagues canvassed 14 leading climate scientists, including two in Canada. Most are on the United Nations Intergovernmental Panel on Climate Change.
The scientists were asked for their expert advice on how the climate system will respond to different emissions scenarios. Their responses are detailed in a report published Monday in the U.S. Proceedings of the National Academy of Sciences. Keith says the most significant finding is that it is "still very uncertain" how the climate will change.
The "risk of rapid or extreme warming are larger than what you would get by reading the IPCC" reports, he says. The UN reports are used at international talks aimed at reducing global CO2 emissions. But on the flip side, Keith says the survey also found a higher than expected chance of seeing less warming than expected.
In a "medium" emissions scenario, which Keith says will be hard to meet given the increasing global emissions, the level of CO2 in the atmosphere climbs to 550 parts per million by 2200 and stays there. "It's still technically possible but it'd be pretty darn hard," Keith says of the "politically optimistic" scenario….
A burn mark on a cork trivet, shot by Ranveig
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