The exhaust fumes coming out of the tailpipes of Yukon cars are the subject of an international agreement Canada helped negotiate last December. So are the plumes of smoke from office buildings in Winnipeg and the clouds of gas belched out of power stations in Ontario.

At the international summit on climate change, held in Kyoto, Japan, the Canadian government helped develop a plan to reduce greenhouse gas emissions worldwide over the next decade.

Greenhouse gases, such as carbon dioxide and methane, are created mainly through the burning of fossil fuels and contribute to a potentially disastrous change in the global climate.

Under the Kyoto Protocol, Canada's job is to reduce its emissions to six percent below 1990 emission levels by 2008 to 2012. Since our emissions would normally increase over the next decade, that commitment means an actual reduction of 21 percent from the emission level we would hit by carrying on business as usual.

The change from "business as usual" will affect all of us. Greenhouse gases are pumped out of everything from motorcycles to factories, says Pat Paslawski, Environmental Protection Analyst with the Yukon Department of Renewable Resources.

In the Yukon, vehicles make a large contribution to greenhouse gases and other forms of air pollution. There are no statistics for the Yukon, says Paslawski. However, since the Yukon has less industry than most parts of the country, vehicles likely contribute a larger proportion of greenhouse gases and air pollution.

Vehicle exhaust contains carbon dioxide, carbon monoxide, nitrogen oxide, hydrocarbons, and fine particles. In a year, an average car or light truck pumps more than four tonnes of pollutants into the air.

In British Columbia, transportation accounts for half the provincial emissions of carbon dioxide, the most common greenhouse gas. Seventy-three percent of the air pollution in the Lower Fraser Valley comes from automobiles, Paslawski says.

"Vehicle emission inspection programs are becoming common practice across Canada," he says. "We're a little bit behind."

In a couple of weeks, some Yukoners will have chance to find out how much their vehicles are contributing to global climate change. An emission testing clinic will be set up in Whitehorse June 26 and 27, sponsored by Environment Canada, Yukon Renewable Resources, and the City of Whitehorse.

The clinic is a free service, available to any motorist who's interested, Paslawski says.

"There's no such thing as passing or failing the test," he adds. "If the vehicle is an emitter, we'll recommend what can be done to improve it."

The test itself takes about five minutes. It includes a visual inspection of the automobile's equipment and two samples of the exhaust, one at idle and one while the engine is being revved. The test equipment produces the analysis almost immediately, says Paslawski.

"We're looking forward to seeing how Yukon vehicles compare to vehicles across Canada," he says. "The data we get will allow us to make that comparison."

Meanwhile, there are ways to reduce the amount of pollution coming out of your car. Driving less and walking or cycling more is one approach. Driving smoothly and at moderate speed reduces the amount of gas you use and the quantity of exhaust the car emits.

Regular maintenance is also important. A badly tuned car might emit 10 times as much pollution as one that is well maintained. Properly inflated tires also reduce gas consumption.

In winter, cars and trucks left idling are major contributors of pollution. Even in extreme cold, just a few minutes of idling produces the maximum warming effect, says Paslawski.

"We've heard cases of people leaving their vehicles running for a whole night."

For information about the Kyoto Protocol or about vehicle emissions, contact Pat Paslawski at Yukon Renewable Resources.