The prime minister's residence at 24 Sussex Drive is 395 metres from the Governor General's front door, right across the street at Rideau Hall.

But when Stephen Harper came calling Sunday to seek the dissolution of Parliament, he didn't walk. He arrived in a four-vehicle motorcade that included a gas-gulping van and SUV.

The environment is among the key issues as leaders embark on the campaign toward an Oct. 14 federal election.

But while talking the talk is one thing, walking it appears to be quite another -- for the prime minister, at least.

The Conservatives are the only party with no plan to offset the environmental costs of criss-crossing the country on planes, buses and automobiles over the next 37 days.

An official in Harper's office recently dismissed any suggestion the Tories might consider buying carbon credits, suggesting the need to get the political message out to Canadians trumps any practical environmental considerations.

"That's fine for (Bloc Leader Gilles) Duceppe who only has to drive his bus around a small fragment of the geography of this country," said the official, who spoke on condition of anonymity.

"But for other campaigns, no. For us, no. We're not going to do that."

Pierre Sadik, a senior policy adviser at the David Suzuki Foundation, acknowledges that a federal election campaign is inherently unfriendly to the environment.

But he says parties can curb the environmental costs of campaigning by limiting personal appearances and using more video links, the Internet and other means to get their messages out.

When travel is necessary, leaders should use the train or hybrid vehicles whenever possible, Sadik said.

"It would send a strong signal to Canadians that you are walking the talk and not just talking it," he said in an interview.

Other federal parties do have plans to limit the environmental impacts of their campaigns:

  • The Liberals plan to run a "carbon-neutral" campaign by puchasing carbon offsets from the firm Carbonzero to neutralize travel-related emissions. Projects include one that, among other things, replaces inefficient gas boilers in Quebec heating systems. Leader Stephane Dion is "walking the talk," said a Liberal release. "Stephen Harper wouldn't even walk across the street to go to Rideau Hall."
  • The New Democrats plan to offset carbon-dioxide emissions from air travel, buses and cars, as well as energy use for events. They've retained ICF Consulting to calculate emissions.
  • The Greens will buy "thousands of dollars" worth of carbon credits, primarily toward renewable energy and energy efficiency programs, to offset each tonne of carbon dioxide emissions as calculated by Carbonzero.

Air travel is already an issue in the campaign.

"Dion is prepared to lecture Canadians about the environment but he won't walk the talk," Tory MP Jason Kenney said Sunday.

Dion will be travelling via a 29-year-old Boeing 737 owned by Air Inuit, which Kenney suggests is far less environmentally friendly than the newer Air Canada Airbus 319s that Harper and NDP Leader Jack Layton are using.

The Liberals rebutted that -- based on methodology used by the International Civil Aviation Organization -- "the Conservative claims fall flat."

"When it comes to air travel, fuel efficiency is not a simple calculation and depends greatly on such factors as payload, length of flight distance, whether the plane is climbing, descending, cruising, or taxiing on the runway," the Liberals said in a release.

"Under certain scenarios ... the Airbus craft can actually be dirtier, or less fuel-efficient, than the plane the Liberals have chartered."

The release says ICAO calculates there is only a zero to 10 per cent fuel-efficiency difference between the two aircraft

A Green party spokesman said Leader Elizabeth May plans to travel by train as much as possible and drive a Toyota Prius hybrid "slowly" around her Pictou County, N.S., riding.