01/07/2015 02:45 EST | Updated 03/09/2015 05:59 EDT

Canada's Oilsands Largely Unusable If Global Climate Deals Take Hold: Report

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CANADA - MARCH 06: The Mildred Lake upgrader, on the grounds of The Syncrude Project in Fort McMurray, Alberta, Canada is pictured from the air Monday, March 6, 2006. An upgrader is part of the process in extracting useable oil from oil sands. The Syncrude Project is a joint venture operated by Syncrude Canada Ltd. and owned by Canadian Oil Sands Limited, ConocoPhillips Oilsands Partnership II, Imperial Oil Resources, Mocal Energy Limited, Murphy Oil Company Ltd., Nexen Inc., and Petro-Canada Oil and Gas. (Photo by Norm Betts/Bloomberg via Getty Images)
British researchers have concluded that most of Canada's oilsands will have to be left in the ground if the world gets serious about climate change.

The report, published in the journal Nature, says three-quarters of all Canada's oil reserves and 85 per cent of its oilsands can't be burned if the world wants to limit global warming. The report also concludes that no country's Arctic energy resources can be developed if global temperature increases are to be kept manageable.

It adds that about one-quarter of Canada's natural gas reserves and four-fifths of its coal would also have to be left in the ground.

Report author Christophe McGlade of University College London says the research was undertaken in response to agreement from politicians around the world that global warming should be limited to within 2 C of historic averages. At the same time, said McGlade, most are enthusiastic boosters of their own country's fossil fuels.

"Nearly all politicians across the world would like to develop all domestic sources of oil and gas and coal that they have and also search for new resources," he said in an interview Wednesday.

"What this analysis shows is that those two positions are inconsistent. Every country can't exploit all of their domestic reserves and keep to two degrees."

McGlade and co-author Peter Ekins used a mathematical model that accounted for all the world's oil, natural gas and coal and analyzed demand for each type. They then looked at future demand to 2050, using a model to calculate how much of each resource would be used given constraints such as production costs and distribution.

They used the two-degree figure to provide a global cap on the amount of carbon that could be emitted into the atmosphere. The point at which their estimates of future demand intersected with the cap gave them the amount of how much each fossil fuel reserve could be developed.

"Our results suggest that, globally, a third of oil reserves, half of gas reserves and over 80 per cent of current coal reserves should remain unused," the report says.

Natural Resources Canada declined to provide an expert to discuss the report. The department, noting world energy demand is expected to increase, provided an emailed statement:

"The majority (of that energy) will come from fossil fuels, even under its most stringent greenhouse gas reduction forecast. The choice is whether to use energy from a secure, environmentally responsible, transparent country like Canada, or to seek energy from less stable countries without responsible environmental policies," the email said.

The study is the latest in a growing body of research into the implications of what is being called a "global carbon budget" — the total amount of carbon emissions that can be released and still stay below a two-degree temperature increase.

The Intergovernmental Panel on Climate Change has placed that budget at 1,100 gigatonnes of carbon dioxide.

About two-thirds of that has already been used. Carbon dioxide locked in current fossil fuel reserves totals about three times that budget.

Other studies have looked into financial and political impacts of the carbon budget. Some have warned that energy companies risk stranding billions of dollars in assets if carbon is increasingly restricted or subject to financial penalty.

McGlade said he hopes his research will be used by world leaders when they meet next December in Paris to try again to hammer out an agreement on climate change. It could form the basis for talks on how countries could be compensated for resources left in the ground, he suggested.

"It's further evidence for the policy-makers to use. Hopefully, this will help inform some of the negotiations."