The European Commission on Thursday fined German automakers BMW and Volkswagen $1 billion (875 million euros) for knowingly collaborating against a technology that could have reduced vehicles' diesel engine’s nitrogen oxide emissions.

Nitrogen oxide contributes to climate change. According to the Environmental Protection Agency, nitrous oxide accounted for about 7% of all U.S. greenhouse gas emissions from human activities in 2019.

The companies agreed to avoid “emissions-reducing AdBlue urea injection technology” during meetings held between 2009-2014 in what has been called “cartel stunt.”

The fine comes after the 2015 Volkswagen emissions scandal, also known as "Dieselgate," which involved the company admitting to rigging diesel engines on vehicles to make the emissions appear less toxic in tests.

Mark Bulgrin, of Norma Group, explained the prevalence of urea solutions for pollution: “This liquid, consisting of one-third urea and two-thirds demineralized water, is injected into the exhaust system by a high-pressure injector. This results in selective catalytic reduction (SCR) – or exhaust gas purification.”

BMW, Volkswagen, and Daimler agreed to share information on tank sizes, ranges, and average consumption to avoid competition, by curbing the use of emissions technology they developed. This took away the full potential of what the emissions technology could have done for cars individually and pollution everywhere.

European Union antitrust chief Margrethe Vestager told a news conference in Brussels that "we have never had a cartel whose purpose was to restrict the use of novel technology."

“The five-car manufacturers Daimler, BMW, Volkswagen, Audi, and Porsche possessed the technology to reduce harmful emissions beyond what was legally required under EU emission standards. But they avoided competing on using this technology’s full potential to clean better than what is required by law.”

Volkswagen Group, which has Audi and Porsche, was fined $595 million (502 million euros) and BMW was fined $442 million (373 million euros). Daimler avoided a $861.5 million (727 million euros) fine for its transparency with the commission.

“In today’s world, polluting less is an important characteristic of any car, and this cartel aimed at restricting competition on this key competition parameter,” said Vestager.