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Oil Sands' CO2 Emissions Could be Higher Than Thought

A new finding comes amid a debate about the carbon footprint of the oil sands generally. Emissions released from burning them still would be small compared with those from burning coal and natural gas
energy-sustainability, energy-technology, basic-science, physics, society-and-policy



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.

For companies to mine Canadian oil sands crude, or bitumen, they must remove trees, along with approximately 2 meters of peat, sand and gravel, before reaching oil. Part of the large carbon release results from peat's faster decomposition when it is disturbed and drained of water.

The shift from peatlands to uplands also has a long-term effect.

After the initial release of carbon, the altered landscape -- including with "reclaimed" trees -- will continue to absorb carbon at a much lower rate in the mined oil sands region without peat, or about 5,734 to 7,241 metric tons less annually, the three scientists found. Peatlands make up a majority of the fully leased area of the oil sands, a plot about the size of Rhode Island that is expected to be fully developed.

In the 10 mines examined, nearly 30,000 hectares (115 square miles) of peatlands will be lost despite the reclamation efforts and about 3 hectares restored.

"A lot of assumption here have never been tested," Bayley said. "Three hectares is a drop in a bucket."

The industry notes that less than 1 percent of global emissions come from the oil sands.

It also emphasizes that about 80 percent of the oil in Alberta is not attainable by mining but must instead be produced in situ, using natural gas to heat steam to loosen bitumen. The process does not disturb peatlands or wetlands much, but also has a larger greenhouse gas footprint than mining because of the natural gas usage (ClimateWire, Dec. 16, 2010).

Even so, the industry and the government of Alberta have invested heavily in land reclamation amid outcry against industrial "tailings ponds" of waste at oil sands facilities. In 2008 and 2009, the government of Alberta awarded $4.5 million to the School of Energy and the Environment at the University of Alberta to support oil sands reclamation research.

Research on peatlands remains in its infancy
Suncor and Syncrude Canada Ltd. are two oil sands mining companies that have spearheaded mining reclamation projects.

Syncrude Canada has committed $7 million this year to recreate a 54-hectare peat wetland called the Sandhill Fen Watershed project. Once the Sandhill wetland, or fen, is completed this year, it will serve as the site of a 15-year research study on peatland reclamation.

The restoration of wetlands have always played a role in Syncrude's reclamation, said Robert Vassov, a boreal forest researcher in the company's environmental research team. The focus on reclaiming upland forests over peatlands is dependent on timing -- in order to restore peat, the mine basins must be spent of the valuable bitumen.

"Now that we have the basins, we can progress into more wetland reclamation," Vassov said.

The research to recreate wetland or peatland environments is still in its infancy, said Kelman Wieder, a professor of biogeochemistry and ecosystem ecology at Villanova University who studies Canadian peatlands. The current commitment across oil sands companies should be increased at least tenfold, Wieder said.

In the perspective of large-scale landscape projects, the authors of the study are probably right: The reclamation efforts will do little to recoup the greenhouse gas emissions from extracting oil sands and digging out peat. Nevertheless, it is a field that is still evolving.

"I don't think that anyone is saying that reclamation promises to restore the complete systems that were there prior to mining," he said. But "they can get a small carbon sink, which is better than nothing."

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500

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