There has been much debate about the environmental damage being done by oil-sands mining in Alberta, Canada, from the carbon emissions to the water pollution produced by the energy-intensive process. Now an Albertan scientist well known for his concerns about the industry weighs in with another factor: the destruction of peatlands.
David Schindler of the University of Alberta and his colleagues note that industry plans for the oil-sands region will eliminate some 29,500 hectares, or 65%, of local peatland habitat — a wet, boggy terrain that is rich in decaying organic matter. This will force the release of 11 million–47 million tonnes of carbon now stored in the peatland (about 7 years’ worth of emissions from the mining process) and the reduction of sequestration potential by 5,700–7,200 tonnes of carbon a year, they calculate in a study published today in Proceedings of the National Academies of Science (PNAS). By comparison, burning all the proven oil-sands reserves would release 22 billion tonnes of carbon, and thawing permafrost could release 30 billion–60 billion tonnes of carbon by 2040.
Schindler points out that the industry and the media often seem to assume that mined land will be returned to its original state: the Canadian Association of Petroleum Producers (CAPP), for example, writes on their website that they aim to help return land “to a sustainable landscape that is equal to or better than how we found it”. Schindler and his colleagues call this “greenwashing” in their PNAS paper, noting that, at present, no industry reclamation plans call for restoring peatlands, but call instead for generally replacing wetlands with drier forests and pit lakes to cover tailing ponds. “Industry’s obligation is to restore the land to a sustainable condition: a similar but not identical state,” wrote CAPP vice-president Greg Stringham to Nature. “We have not said we will restore peatlands, although we are working on it.”
An independent review of the oil-sands operations by the Royal Society of Canada came to a theoretically more optimistic conclusion about land reclamation in 2010 (see Impacts of Canada’s oil-sands operations ‘exaggerated’). That report states: “The potential for successful reclamation of wetlands, particularly peatland, has not been well demonstrated in the research to date although studies elsewhere indicate more feasibility than generally believed.”
Schindler has been a prominent voice calling for improvement of monitoring and regulation in the oil-sands industry (see Tar sands need solid science). “The oil sands reclamation is about the same quality as their monitoring,” says Schindler now. New monitoring programmes have recently been set up (see Oil sands monitoring plan gears up).
Last month, climate scientists startled some observers by saying that theoretical carbon emissions from the oil sands weren’t as big as they had suspected: they estimated that burning all the oil that might reasonably be extracted from Alberta’s sands would raise the global temperature by just 0.02 degrees Celsius (See Canadian oil sands: Defusing the carbon bomb). This estimate has been criticized, however, for not including the fact that the oil sands take a lot of energy to extract in the first place, making it two to three times ‘dirtier’ per barrel than other types of oil production.
Several mining companies are considering steam reforming the oil, which would allow them to extract it without making as much of a dent to the surface landscape. But this process takes yet more energy, so would worsen greenhouse-gas emissions.
Photo credit: Paul Sanborn, University of Northern British Columbia