New data from real-world emissions testing shows that diesel cars emit up to 30% more nitrogen oxide at higher summer temperatures. Motorcycles are especially to blame.
Diesel car emissions of nitrogen oxide increase sharply by up to 30% at temperatures above 30 degrees Celsius, according to a new report by The Real Urban Emissions (TRUE) initiative. Its report is based on measurements of real-world nitrogen oxide, particulate and carbon dioxide emissions from over 180,000 vehicles at three sites in Paris in summer 2018.
Its data confirms that nitrogen oxide emissions are much higher from diesel cars, including the newest (Euro6) models, and rise in higher temperatures. As the effects of climate change intensify, the number of days with comparably high or higher temperatures in Europe will rise, especially in urban heat islands such as Paris.
“Dirty diesel vehicles have knowingly been manufactured and sold for decades and these excess emissions alone are responsible for some 38,000 deaths each year,” said Sheila Watson, Deputy Director of the FIA Foundation. “The unacceptable urban health burden caused by diesel vehicles increases as cities get hotter in terms of both the level of emissions and the health impact of those emissions. This poses huge implications for cities all around the world as we face hotter and hotter summers in a climate crisis to which transport it a major contributor.”
The data showed that motorcycles and other two- and three-wheelers have higher emissions per gram of fuel used compared to many other cars, making them “neither the answer to urban air quality nor traffic issues”, added Watson.
Image credit: Neil Howard via Flickr