The Syncrude tar sands mine north of Fort McMurray, Alberta. REUTERS/Todd KorolIt's unlikely protests against the development of Western Canada's immense oil sands reserves will dry up over this, but two scientists' contention that burning coal poses a greater global warming threat is bound to spark debate.
Andrew Weaver, a University of Victoria climate modeller, argues emissions from oil sands crude produced mainly in northern Alberta are unlikely to make a big difference to global warming, The Canadian Press reports.
"I was surprised by the results of our analysis," Weaver, who also has been a lead author on two reports from the United Nations Intergovernmental Panel on Climate Change, told the news service. "I thought [the threat of oil sands emissions] was larger than it was."
The article by Weaver and colleague Neil Stewart was published Sunday in the science journal Nature.
They analyzed how burning all of the earth's stocks of coal, oil and natural gas would affect temperatures. The analysis covers both conventional and unconventional hydrocarbon sources such as oil sands.
If all the hydrocarbons in the oilsands were mined and consumed, they concluded the carbon dioxide released would raise global temperatures by about 0.36 degrees Celsius, roughly half the total amount of warming over the last century. But when only commercially viable oil sands deposits were considered, the temperature increase would be just 0.03 degrees Celsius, according to the scientists.
Burning all the world's vast coal deposits would create a 15-degree rise in the globe's temperature, well above the two-degree limit set by governments hoping to rein in global warming.
"The conventional and unconventional oil is not the problem with global warming," Weaver told The Canadian Press. "The problem is coal and unconventional natural gas [such as shale gas and undersea methane hydrates]."
Oil sands development has become an international issue among environmentalists, bringing out high-profile opposition from the likes of Robert Redford. Opponents saw the U.S. government's rejection of plans for the Keystone XL pipeline to take oil sands crude to American refineries as a major victory.
Weaver said his analysis suggests governments should be more worried about increased dependence on coal, as well as growth in the use of natural gas, which is considered greener than oil.
That doesn't mean giving oil sands carte blanche, he stressed.
"One might argue that the best strategy one might take is to use our oil reserves wisely, but at the same time use them in a way that weans us off our dependence on coal and natural gas," Weaver told The Canadian Press.
"As we become more and more dependent on these massive reserves, we're less and less likely to wean ourselves away from them."
(Reuters photo)
57 comments