Anderson said the government's options include a gas tax, although no rate has yet been set, as well as money from tax revenues or a self-financing plan, Anderson said.

The National Post newspaper said in a front-page article last week that senior ministers were mulling a 10-cent tax.

"This is not what the government of Canada proposes," said Anderson. "We do not know the costs of the plan that ultimately will be chosen (to reduce greenhouse gas emissions)."

Canada has little chance of fulfilling its Kyoto commitment to cut emissions of greenhouse gases, blamed for global warming, by 6 percent from 1990 levels by 2010, and it wants extra credits for supplying clean energy to the United States - an idea rejected by the European Union.

Latest estimates show that Canada's emissions actually grew by 20 percent from 1990 to 2000.

Energy producers and some provinces have warned Ottawa that ratifying Kyoto will cost tens of billions of dollars and countless jobs, and they want the government to follow Washington's lead and reject the treaty.

But Anderson said there were costs of not dealing with the problem of climate change as well.