Several readers of Courrier de la Planete asked us this question: Does driving your car more slowly reduce your GHG emissions?
The short answer is yes, but not much compared to other gestures.
The province’s household carbon footprint stands at at least 8.1 tonnes of CO2 equivalent per capita, a footprint five times too high to meet the most ambitious target of the Paris Agreement. Road transportation in Quebec represents the main source of greenhouse gas (GHG) emissions, at 34%. This is why experts agree that the government should indeed target automobile transportation.
On the other hand, the transition to an electric vehicle is not always advantageous from an environmental point of view, when considering its entire life cycle. Depending on the model of gasoline car owned and the number of kilometers traveled, the “equivalence point” of the carbon footprint is not the same.
So several of you readers are writing to us to find out if there would not be a greater individual effort to make to drive slower in the car, or to respect the speed limits less. Line Pelletier, for example, calculated that she saves approximately 1 liter of gasoline every 100 kilometers by adopting a speed of 70 to 90 km/h on provincial roads. “I have been repeating this feat for over a year, so at 1 tank per week for 52 weeks, 6760 kg less CO2 per year,” she writes to us.
Another reader, Denis Benoît, also wants Quebec to address tolerance for speeding, since a vehicle traveling at 120 km/h, rather than 100 km/h, would consume 20% more fuel. At least that’s the percentage put forward by Natural Resources Canada.
As in Quebec, a law in Ontario requires heavy vehicles to install a speed limiter of 105 km/h. One study estimated that this measure would have saved 4.6 megatons of CO2 between 2009 and 2020.
Even the Intergovernmental Panel on Climate Change cites a scientific article that includes “eco-driving” as a “consumption option” that allows you to reduce your GHGs. However, its impact would be modest.
This reduction in emissions of course depends on a host of other factors, including the model and age of the vehicle: each car has an optimal speed for minimum consumption, before air resistance changes the equation .
However, the way you drive would also count for a lot. Having a soft pedal, that is to say not accelerating or braking suddenly, would also save gasoline, and thereby control individual GHG emissions. Obviously, opting for a small automobile remains the wisest choice, in the context where sales of sport utility vehicles continue to increase.
This text is taken from our newsletter Le Courrier de la planete.