By The Canadian Press ADVERTISEMENT

OTTAWA – Green party Leader Elizabeth May says her whistle-stop campaign tour is the green way to go and it seems she’s right.

May says her cross-country train journey will spew fewer greenhouse-gas emissions into the atmosphere than a plane trip. A carbon offset firm says her claim isn’t just hot air. Jay Goldman of Toronto-based Zerofootprint says May will emit fewer emissions by taking the train from Vancouver to Halifax than by flying.

Via Rail’s website says the rail run between the two cities is 6,300 kilometres.

Zerofootprint – which Air Canada contracts to runs its carbon offset program – says making the trip by train would result in 651 kilograms of carbon dioxide for each passenger.

The calculation for flying is a bit trickier.

The total distance from one coast to the other – as the crow flies – is 4,520 kilometres.

Zerofootprint calculates a flight from Vancouver to Halifax would result in 535 kilograms of carbon dioxide per passenger.

But it’s not quite that straightforward.

The United Nations’ Intergovernmental Panel on Climate Change says emissions spewed by an aircraft flying at high altitudes have 2.7 times the effect on the planet than ground-borne emissions.

The panel says there are several reasons for this.

Emissions released at a high altitude don’t have to travel as far to reach the upper atmosphere and are more concentrated than emissions that waft skyward from the ground.

Aircraft also emit water vapour and nitrogen oxides – both of which can contribute to global warming when released at the altitude at which most passenger planes fly.

Take all that into account and Zerofootprint says a flight from coast-to-coast would produce the equivalent of 1,445 kilograms of carbon dioxide per passenger.

May left Vancouver on Sunday and plans to attend rallies in eight provinces before arriving Friday in Truro, N.S.