Traveling by plane doesn’t get good reviews: this decision is often singled out for its environmental impact.
However, the air transport sector accounts for only about 2% of global greenhouse gas (GHG) emissions compared to 12% for the road transport sector. And on the roads, 60% of emissions come from passenger transport (mostly cars).
Our travel is hurting the planet, and the best option is always to cut back. But, if you have no choice and really need to travel to the other side of Canada, which option is best suited for the climate and under what conditions?
Understanding the Carbon Footprint of Air Travel
Let’s first look at the parameters that need to be taken into account when calculating greenhouse gas emissions from air travel.
The farther an aircraft flies, the more greenhouse gases it emits when it burns fuel. The size of the aircraft is also important to consider: the larger the aircraft, the more fuel it consumes.
It also releases a significant amount of carbon dioxide (CO2) with each takeoff and landing, in proportion to its weight. Thus, the shorter the distance an aircraft travels, the higher its CO2 emissions per kilometer will be. Thus, a connecting flight will have a higher carbon footprint than a direct flight.
Other parameters, such as weather, can cause an aircraft’s fuel consumption to change, but these phenomena, which are very specific to each flight, are usually not taken into account when estimating in-flight emissions.
Once the total emissions from a flight have been calculated, they must be allocated to the passengers in order to obtain the amount of CO2 equivalent per passenger and per trip. This number will depend on the seating configuration of the aircraft: the more seats on the aircraft, the lower the impact per passenger. What’s more, a first class seat takes up about five times as much space as an economy class seat, so traveling in economy class will be less polluting.
Finally, it is important to know how full the plane is (fill factor). Indeed, the fewer passengers on an aircraft, the more the impact attributed to each of those passengers will increase. Thus aircraft flying short flights (300 km), which are often small light aircraft capable of carrying a limited number of passengers, will typically have higher GHG emissions per passenger and per kilometer flown than larger aircraft flying longer flights.
To help us make informed choices, Google Flights now displays CO2 emissions per passenger for each flight offered. However, it is important to understand the limitations of the displayed numbers. On the one hand, Google Flights does not account for per-route occupancy rates (with the exception of flights passing through the US), which can vary greatly from one destination to another and from one country to another, from time of year to another. . On the other hand, the impact of flying in an aircraft is not limited to the emissions generated during the flight. The carbon footprint should take into account GHG emissions throughout the life cycle of a flight, including fuel production (crude oil extraction, refining, etc.) as well as aircraft construction, maintenance, end-of-life, related emissions. with the airport, etc. Therefore, it is necessary to add approximately 25% to the figure displayed by Google Flights in order to get an estimate closer to reality.
For long-distance travel: I prefer the plane
Let’s now compare the same trip by plane (non-stop) or by car, assuming for our scenario that there are two passengers in the car.
For a Montreal-Quebec or Montreal-Ottawa trip, the carbon footprint of an airplane would be 1.5 to 2 times higher than that of a car.
On the other hand, over longer distances, the opposite is true: for a Montreal-Halifax or Montreal-Vancouver trip, the carbon footprint of traveling by plane will be almost half that of a car (unless you travel that distance in an electric car). , which makes both options equivalent in this case).
A car full of passengers is a game changer
If you’re alone in your car, even short trips are less interesting: a Montreal-Quebec or Montreal-Ottawa trip produces the same carbon footprint as flying in an airplane!
But once the number of passengers in a vehicle increases, and the more people on board, the more car travel competes with airplane, even over fairly good distances.
So for long trips like Montreal-Halifax or Montreal-Vancouver, the carbon footprint per passenger becomes the equivalent of an airplane’s emissions if you’re traveling with four people in the car.
In fact, it’s rare to see more than two passengers in a car in Canada…
But still: if you manage to fill your car with as many passengers as possible by combining a trip with family, friends or fellow travelers, then the car becomes less harmful to the climate than an airplane, even over long distances.
However, this comparison does not take into account the travel time, which can be spread over several days, requiring food and sleeping at the hotel during the trip…
And the train? Competitive in some areas
The Quebec-Windsor rail line is one of the most modern and busiest lines in Canada. In particular, it connects Montreal with Quebec, Ottawa and Toronto.
On this line, the carbon footprint per passenger is roughly equivalent to traveling with two passengers in a car. Thus, traveling by train on this line is a good option to avoid traveling alone or as a couple.
On the other hand, according to a recent study, train lines between Toronto-Vancouver and Montreal-Halifax will emit 1.5 to 7 times more greenhouse gases per passenger than the same economy flight.
How can we explain this poor performance when the train is generally considered a good option for reducing our environmental footprint?
First, trains in Canada are only half full. This mode of transport is not very popular, which dramatically increases the carbon footprint per passenger.
On the other hand, long distance locomotives in Canada are diesel locomotives. They date back to the 1980s and are equipped with old technology that is not very energy efficient. They emit more pollutants than the average train in the world.
Long live the modernization of the railways!