Germany is one of several countries with aggressive plans to curb transportation-related carbon emissions.
Over the past few years, its large domestic car industry has worked to improve fuel efficiency--and even launched several plug-in electric models.
But a recent study claims the transportation sector in Germany is the only one that hasn't, in fact, seen a drop in greenhouse-gas emissions in the past 25 years.
The study--conducted by Germany's Federal Environment Agency--found the transportation sector accounts for 18 percent of the country's emissions.
It also notes that emissions of particulate matter and nitrogen have fallen, an indication the exhaust from internal-combustion engines in new cars is indeed cleaner.
2016 Volkswagen Touareg
However, that improvement hasn't translated into reductions in carbon dioxide, a greenhouse gas, which are proportional to the amount of fuel consumed.
And that's largely due to the buying habits of German consumers. The study claims there are simply more vehicles on German roads than in previous decades, and that more of them are gas guzzlers.
Germany buyers apparently favor SUVs and larger cars, while sales of smaller, more fuel-efficient greener models remain relatively low.
"We've noticed that many technical improvements and the trend toward more fuel-efficient vehicles have made little difference," Federal Environmental Agency President Maria Krautzberger is reported as saying.
The government agency also views commercial trucks as partially to blame for Germany's high level of transportation-related emissions.
Krautzberger wants to institute emissions standards for heavy-duty trucks--something that's now in place in the U.S.--increase tolls, and shift more freight traffic to ships and trains.
Smart Fortwo Electric Drive and Mercedes-Benz B-Class Electric Drive at driving school.
Stricter European Union emissions standards will soon increase the efficiency of all new cars sold in Germany--regardless of what people are actually buying.
In addition, the country has set its own goal of putting 1 million plug-in cars on its roads by 2020.
That will require a significant uptick in pace from the roughly 19,000 electric cars sold in Germany in 2014.
Yet while the government has discussed electric-car incentives multiple times--and approved tax breaks for owners--it's done relatively little compared to other European countries, and the U.S.
Incentives could very well be key to getting more Germans to trade in their SUVs for more efficient vehicles.