The first stage of restoring an oil sands mine into a peat wetland is to gather branches and wood that contain seeds for shrubs like blueberries and cranberries. Image: Photo courtesy of Syncrude Canada Ltd.
Previous studies have vastly underestimated the carbon footprint of the Canadian oil sands by not considering the industry's impact on peatlands, according to new research.
Scientists from the University of Alberta found that 10 operational oil sands mining projects would destroy enough peatlands to release 11.4 million to 47.3 million metric tons of stored carbon into the atmosphere. That release is the equivalent of seven years' worth of emissions from the oil sands mining region.
If the full area currently under lease for future mining had been calculated, as well, the carbon emission numbers could be three times higher, said Rebecca Rooney, a research associate in the biological sciences department at the University of Alberta and a co-author of the study, which appeared yesterday in the Proceedings of the National Academy of Sciences. The carbon emissions numbers also would jump if companies do not fully implement their plans to "reclaim" land by planting carbon-absorbing trees over mined areas, she said.
"The industry can't tell you how much peat they've agreed to have destroyed," Rooney said. "That's quite alarming."
The other authors from the University of Alberta were professors Suzanne Bayley and David Schindler, who is well-known in Canada for publishing a 2010 study about water pollutants from oil sands mining that prompted a national review of the industry.
Rooney said the emission numbers take into consideration the offsetting carbon benefits of existing efforts by industry to reclaim land.
The carbon deficit still occurs because peatlands cannot easily be restored. Additionally, the upland trees like spruce and aspen commonly used as replacement do not have nearly the carbon-absorbing ability of peat, the researchers said.
The study comes amid a fierce debate about the carbon footprint of the oil sands generally. A study released last month in Nature Climate Change found that emissions released from burning oil sands fuel would be minuscule in comparison to those from combusting coal and natural gas.
Rooney said the current study does not contradict that research, since the footprint of the oil sands would still be less than that of coal even with consideration of the peatlands.
The point, she said, is that Canadians are being asked to weigh the economic benefits and the environmental impact of the oil sands without complete information.
'Misleading' notions of restoration
It is also important for people to understand that mined land is not being restored to its original state, despite industry claims, she said. There have been television ads running in Canada showing people walking through reclaimed areas of flowers and trees that are "completely misleading," Schindler said.
Greg Stringham, a vice president at the Canadian Association of Petroleum Producers, said in a statement that "industry's obligation is to restore the land to a sustainable condition, a similar but not identical state. As such, we have not said we will restore peatland, although we are working on it."
Albertan law generally requires all land disturbed by oil sands operations to be reclaimed by an official company plan. The province also does not have a comprehensive wetlands policy, which makes it difficult to craft rules for what to do with disturbed lands, specifically peatlands, according to Bayley, a study co-author.
The study is the first that measures the cumulative effect of reclaimed mines, and not each mine in isolation, Bayley said.
Peat, the mass of decomposed plant matter that has settled in many wetlands in Alberta, is composed of about 50 percent carbon, accumulated over thousands of years. Peatlands are an important component of slowing the onset of climate change, as they absorb carbon dioxide and prevent the release of the gas into the atmosphere.