One of NASA's top scientists has told a panel reviewing a proposed oil sands mine in northern Alberta that the resource should simply be left in the ground.
James Hansen of the Goddard Institute for Space Studies says allowing new developments such as Total E&P Canada's $9-billion plan to build the Joslyn North mine would make it too hard to manage the impact of climate change.
"The simple message is the oil sands may appear to be gold. We do need energy and there's a lot of potential energy in the oil sands," Mr. Hansen said Tuesday during a break from public hearings in Sherwood Park, Alta.
"But it is fool's gold because it's going to be clear and understood within a reasonably brief period of time that we cannot exploit unconventional fossil fuels like tar sands and tar shale. If we do, we're going to have to suck the CO2 back out of the atmosphere and the estimated cost of doing that is $200 to $500 a tonne of carbon."
Hollywood director James Cameron came to a similar conclusion when he toured the oil sands last week. He said the resource could be a gift to Alberta and Canada in an energy-starved world, but could become a curse if not handled properly.
But Mr. Hansen, sometimes dubbed the godfather of climate-change science, goes even further. He said that burning the Earth's conventional oil has already contributed to a dangerous level of heat-trapping carbon dioxide. Adding oil sands crude and new coal supplies to the mix would be too much for the atmosphere to bear.
"We should not develop the unconventional fossil fuels. Those fuels - coal and tar sands - are so dirty and have such large regional negative consequences that it only makes sense to leave them in the ground."
Mr. Hansen, who has spoken out on the oil sands before, also said he no longer believes governments have the will or the independence to scale back the fossil fuel industry. He suggested legal action is the best route environmentalists have.
"It's not that the governments don't know [about the consequences] but the governments are not doing anything," he said. "I think we're going to have to get the courts to order the governments to give them a plan for phasing down emissions at a rate that allows a stabilization of climate."
Forging ahead with new developments foists the environmental costs on future generations, he concluded.
"This whole issue - carbon dioxide and climate - is a matter of inter-generational injustice where the current generation is getting the benefit of burning the fossil fuels and the consequences occur primarily with young people and future generations just because ... it takes time for the largest effects to occur."
The Total proposal would see the company develop a 5,400-hectare site adjacent to the community of Fort McKay along the Athabasca River north of Fort McMurray. The mine would eventually produce 100,000 barrels of bitumen a day and employ 1,650 workers during construction and 600 during operation.
Documents filed with the company's application promise the site would be reclaimed.
Mr. Hansen hopes the hearings will lead to at least a delay in the Total project.
"The evidence presented by the other witnesses seemed to me to be very persuasive, that the fossil fuel companies have not done the job at looking at the regional effects of this operation. I would hope that it delays things and gives us time to make clear the overall scientific story that we just can't exploit these unconventional fossil fuels."
The hearings began last month in Fort McMurray and moved to Sherwood Park this week. Total has already received regulatory approval for an upgrader to process the bitumen it hopes to mine.
Company spokeswoman Elizabeth Cordeau-Chatelain has said the company is involved with renewable energy projects, but the oil sands are an important part of its future.
"There needs to be room for all kinds of energy to be able to supply the energy needs of the people on the globe," she said before the hearings began.
Environmentalists calculate that the Total project would emit 1.5 million tonnes of greenhouse gases - the equivalent of putting 270,000 cars on the road.
Ms. Cordeau-Chatelain said the company's plan includes environmental advances for less water use and accelerated reclamation of the land.
No proposal for an oil sands mine has ever been turned down.