In 2015, more than one million Volkswagen vehicles were caught in an emissions scandal after it was discovered the cars had been fitted with ‘defeat devices’ to deliberately mislead in environmental impact testing. 

But now a new study has revealed that the German automaker is not alone, and claims that diesel cars globally are polluting more than any previous laboratory results would lead us to believe.

Associate Professor, Daven Henze, said: “A lot of attention has been paid to defeat devices, but our work emphasizes the existence of a much larger problem.” 

‘Defeat devices’, that were used by VW, sense when a vehicle is undergoing testing and reduce emissions to comply with government standards, but this is only a fraction of the problem. 

The team at the University of Colorado Boulder state that the phenomenal extent of this means cars, trucks and buses worldwide emit 4.6 million tons more harmful nitrogen oxide, a chemical precursor to particulate matter and ozone, than standards allow.

They found that in 2015, diesel vehicles emitted 13.1 million tonnes. Had the emissions met standards, they would have been closer to 8.6 million tons.

And these excess emissions alone lead to 38,000 premature deaths globally, and 1,100 in the United States.

In fact the study projects that by 2040, 183,600 people will die prematurely each year due to diesel vehicle NOx emissions unless governments act. 

The primary cause of these excess fumes can be traced back to heavy-duty vehicles, such as commercial trucks and buses, which account for 76% of the problem. 

The findings reveal major inconsistencies between what vehicles emit during testing and what they emit in the real world, due to testing inefficiencies, maintenance inadequacies and other factors. 

Susan Anenberg, co-lead author of the study, said: “The consequences of excess diesel NO_x emissions for public health are striking.

“Tighter vehicle emission standards coupled with measures to improve real-world compliance could prevent hundreds of thousands of early deaths from air pollution-related diseases each year,” 

They assessed 30 studies of vehicle markets, representing 80% of new diesel vehicle sales in 2015, including Australia, Brazil, Canada, China, the European Union, India, Japan, Mexico, Russia, South Korea, and the United States.

Air pollution in Europe is causing nearly half a million premature deaths every year, according to a 2016 report from the European Environment Agency. 

The EEA released their annual report in November last year, for the 28 European Union member states, and warned that despite a general trend of improvement, the toxicity of the air is still killing 467,000 people annually.