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