So little is known about the long-term impacts of extracting gas by fracturing rock beds with high-pressure fluids that scientists and regulators need to start now to understand how to develop the resource safely and cleanly, said co-author Rick Chalaturnyk, an engineering professor at the University of Alberta.
"Perhaps cautionary is the right philosophy," he said. "We really do stand a chance to put in place the regulatory framework to answer the questions around environmental impact."
Chalaturnyk was part of a panel formed by the Council of Canadian Academies, an independent organization that brings together university researchers from across Canada to look at public policy issues. It was asked by Environment Canada in 2012 to examine fracking and drew its conclusions from publicly available, peer-reviewed research.
Its 292-page report says that the economic benefits could be significant across Canada. There are substantial or potential deposits of shale gas in all provinces and territories except Manitoba, Prince Edward Island and Nunavut.
"Canada’s shale gas resources dwarf the 60.4 trillion cubic feet of marketable gas reserves that the National Energy Board estimated
remained in Canada at the end of 2010," says the report.
However, it found significant uncertainty on the risks to the environment and human health, which include possible contamination of ground water as well as exposure to poorly understood mixtures of chemicals.
"The scale and pace at which shale gas resources are being developed are challenging the ability to assess and manage their environmental impacts."
The effects on ground water from fracking water pumped underneath the surface are one concern.
"There is reason to believe that shale gas development poses a risk to water resources, but the extent of that risk, and whether substantial damage has already occurred, cannot be assessed because of a lack of scientific data and understanding," the report says.
Exposure to chemicals is another. A long list of substances must be added to fracking water and their possible effects on human and environmental health are unknown. Some jurisdictions don't even require industry to list what chemicals are being used.
"There is only minimal reference literature and no peer-reviewed literature that assess the potential for the various chemicals in hydraulic fracturing fluids to persist, migrate and impact the various types of subsurface systems or to discharge to surface waters."
Many suggest that increased fracking could help mitigate climate change through the increased use of natural gas, which emits less carbon than fuels such as coal. The council's report notes that natural gas is itself a greenhouse gas more potent than carbon dioxide, and emissions from leaking wells could outweigh the benefit from replacing other fuels.
The report also notes that fracking has only been around for 10 years or so in Canada — not enough time to assess its long-term effects, which could play out over decades.
It warned against being blinded by the lure of big bucks.
"The lessons provided by the history of science and technology concerning all major energy sources and many other industrial initiatives show that substantial environmental impacts were typically not anticipated," the report says.
"What is perhaps more alarming is that where substantial adverse impacts were anticipated, these concerns were dismissed or ignored by those who embraced the expected positive benefits of the economic activities that produced those impacts."
Chalaturnyk said the report should form the basis of a much-needed political, regulatory and public debate about understanding and managing the industry.
"The public needs to be firmly engaged in this conversation."