Canada comes in dead last in the International Energy Agency’s latest ranking of average fuel consumption and carbon dioxide emissions per kilometre travelled, University of Calgary economist Blake Shaffer reports in a commentary for Global News.

Canadian vehicles are also the biggest and second-heaviest in the world, the analysis shows.

“Many point to Canada’s vast land area—often connected with less-than-ideal roads and highways—and our cold climate as reasons for requiring more substantial vehicles,” Shaffer writes. But “more than 80% of Canadians live in urban or suburban areas where a more modest vehicle suffices for most activities.”

He adds that, “in terms of vast distances, that actually calls for better fuel efficiency, not worse. And if cold weather is the excuse for buying an SUV, similarly frigid countries—Sweden, Finland, and Iceland—have all managed to survive with lower-emitting vehicles.”

The difference, Shaffer says, is North American auto manufacturers’ emphasis on SUVs, crossovers, and minivans, a trend that “in part reflects consumer preferences,” but “is also the result of marketing campaigns and economies of scale in production that push buyers towards SUVs.” The resulting shift in vehicle preference “has been phenomenal,” he writes. “And before fingers point at places like Alberta, this is a trend seen across every province in Canada.”

Shaffer acknowledges many Canadians’ belief that a heavier vehicles are safer in a collision, but with an important caveat. “When similar-sized vehicles collide, it makes little difference to safety outcomes whether it is large-on-large or small-on-small,” he writes. “However, when a large vehicle collides with a small one, the results are (unsurprisingly) far worse for the small vehicle’s passengers.”

That results in what the Calgary economist refers to as “vehicle-size externalities: buying a larger car imposes safety costs on drivers of smaller cars. It also raises the prospect of a vehicle arms race, with drivers buying ever-larger cars in order to protect themselves, when safety would be just as effective if everyone drove similar, smaller vehicles.”

But the most basic economic reality shaping Canadians’ vehicle choices connects back to the country’s much wider, currently more fraught conversation about pricing pollution. “Simply put, the cost to purchase and operate a gas guzzler in Canada (or the U.S.) is far less than the rest of the world,” Shaffer explains. European vehicle registration charges are often based on fuel efficiency, and petrol prices are higher.

“While most people focus on the role of carbon taxes to reduce emissions by discouraging driving, higher gas prices can also affect the choice of which vehicle to buy,” Shaffer writes, citing a University of British Columbia study that showed drivers favouring more fuel-efficient cars after the province introduced its carbon tax. The conclusion, he says, is that “carbon taxes may be unpopular with many, but they play an important role in determining what vehicles are on the road now—and in the future.”