It's only a matter of time before Canadian corporations are sued over their greenhouse emissions, say experts in the investment field.
Just as tobacco companies have been sued for the health effects of smoking, the argument runs, polluters could be held responsible for contributing to global warming.
Already the State of California has sued six of the biggest automakers, charging that greenhouse gases from their vehicles have caused billions of dollars in damages.
Canada hasn't seen a similar case yet but it's coming, predicts Julie Desjardins, an adviser to the Canadian Institute of Chartered Accountants.
"It's only going to take the first lawsuit to get things going," Desjardins said in an interview. "I think that advocate groups, interest groups, people interested in the environment, will look for a good first case."
A lawsuit wouldn't necessarily be based on direct impacts of emissions.
Shareholders could sue a firm for not disclosing the volume of its emissions or its vulnerability to the effects of climate change, she said.
"Investors in that company are going to be able to claim, 'You did not do your due diligence; you did not communicate to me as an investor the risk that I was taking in buying your shares.' " Even if lawsuits are rejected, they could still have an impact on the company's reputation and drive down the value of its shares, said Desjardins.
Eventually some companies will wind up paying costly settlements, said Martin Whittaker, director of MissionPoint Capital Partners, a private investment company involved in the global carbon market.
"There is a feeling of inevitability about that," he said.
Linking emissions from a certain plant to a specific climate event is impossible, but researchers have suggested methods for quantifying damages and allocating responsibility among polluters.
Tobacco companies have been successfully sued even though the precise mechanisms by which smoking causes cancer aren't fully understood.
Wherever a damage can be linked to a cause, litigation will follow, said Hugh Wilkins, a lawyer with Sierra Legal Defence Fund.
The climate issue poses special challenges because most of the damages will occur in the future, he noted. But some impacts are already being seen.