Is the era of the gas-guzzling SUV back, and spreading globally?

For the first time ever in the history of car sales in Europe, SUVs were the top sellers in 2015. Is this a bad sign for fuel efficiency?

Fueled by cheaper gasoline, European countries are now buying SUVs at record rates.

For the first time ever, sport utility vehicles, or SUVs, were the best-selling cars in countries including Portugal, Spain, and Denmark last year, growing by 24 percent across Europe from the previous year. The gas guzzlers made up 22.5 percent of all European car sales in 2015, according to auto industry research firm JATO Dynamics, up from 19.8 percent the year before.

"Similar to the shift towards SUVs in the US car market, Europeans are clearly favouring these vehicles," Felipe Munoz, an analyst at JATO, said in a statement. "Both economic and social factors, such as the lower fuel prices and the growing appeal of SUVs' benefits, had a big influence on this sales boom."

For fuel efficiency and environmental advocates, this could be discouraging news, especially coming from a region of the world that historically has been known for driving small, efficient cars. Denmark is often counted among the most environmentally enlightened countries in the world, after all.

But despite a trend that some may think is a setback for hard-won global gains in the overall fuel efficiency of vehicles, there are slivers of progress. Most SUVs today are more fuel efficient than the SUVs of five years ago, for example. 

Plus, says Sam Ori, executive director of the Energy Policy Institute at the University of Chicago, while, yes, there are more SUVs on US roads, there are also more electric vehicles, or EVs. And not just in the US; China surpassed the US and Europe in EV sales last year, says Ori.

 “I’m increasingly very optimistic about global EV trends,” he says in a phone interview with The Christian Science Monitor.

Since EVs hit the market in 2011, four of their five best months for sales have been during this current oil price slump, which started in 2014.

In December 2015, when, at $2.01 per gallon on average, gas prices were lowest since the recession in 2009, US car buyers bought more EVs than they did in any month ever. Overall, however, 2015 EV sales declined by 5 percent from 2014, as The Huffington Post reported.

"Electric vehicle sales are doing extremely well," says Ori. "Much, much better than I would have dreamt in this price environment."

Despite their reputation as gas hogs, new SUVs are becoming more efficient these days thanks to US federal fuel-efficiency standards and carbon emissions limits that have been introduced throughout the administrations of former President George W. Bush and President Obama. The European Union also sets efficiency standards for cars.

In fact, the top-selling, small SUV best-seller in Europe is the Renault Captur, according to car registrations analyzed by Jato, which claims to get almost 60 miles per gallon of driving range. That's better than a Toyota Prius v.

But there are still a lot of gas-guzzling cars on US roads. In the US, SUVs, light trucks and vans today make up 60 percent of car sales, compared to 43 percent in 2008, when oil prices averaged $100 a barrel. Oil is now at about $50 a barrel, as Bloomberg points out.

And fuel economy of the average car sold is expected to decline this year for the first time since 2007, according to Bloomberg, while the US Department of Transportation reports that record numbers of people are traveling by car, taking advantage of an improving economy and cheap gas. Travel by car in the UK is also at record levels, says Ori.

He warns that the days of cheap gas are numbered, though, as high consumer demand is expected to outweigh supply in the next several years.

"Seeds are being sown for higher oil prices in the next four to five years," says Ori. "A lot of people will have a rude awakening by 2020, when prices are up at $100 a barrel."

[Editor's note: This story has been updated from its original version to  clarify a statement made by Sam Ori.]