How do we fix air pollution? It’s simple but it needs political will

Cutting toxic levels of city air pollution to safer levels is simple, but not easy – it requires resolve. Yet, despite the key culprit in the UK being well known – diesel vehicles – the government has been asleep at the wheel for years.

Levels of nitrogen dioxide have been illegally high across much of the UK since 2010. In 2015 86% of major urban areas broke annual limits. Cutting this pollution means choking off diesel emissions and there is a wide range of effective measures available.

Creating zones in city centres where polluting cars are either banned or charged is important, while making cities safe for cycling and walking cuts traffic too.

Cleaner buses and taxis have an important role to play and change to the perverse taxes that encourage people to buy diesel over cleaner cars is needed. There is also some support for a revival of a scrappage scheme which saw dirty old bangers taken off the road.

The environment and transport departments were well aware of all this and proposed many of these measures internally, only for the Treasury to reject most of them, arguing they “would be politically very difficult, especially given the impacts on motorists”.

Motorists happen to be particularly badly exposed to air pollution, but the real political difficulty for the government is two humiliating legal defeats in two years where judges ruled its air pollution plans were so bad they were illegal.

Ministers have now been forced to come up with a third plan, but clean air zones and car tax changes take time to clean up the air. Yet the UK government is also in the slow lane when it comes to emergency measures.

When foul air descended on Paris in December, officials there swung into action. Public transport was made free and the number of cars allowed on roads was restricted, alternately barring those with odd and even licence plates. In the UK, during the same December smog, the government sent a few tweets.

At the root of the problem are diesel cars, which successive governments across Europe have utterly failed to ensure meet legal emissions limits when driving in real-world conditions on the road. The gaming of regulatory tests by carmakers was blown open by the Volkswagen scandal. The scandal of governments prioritising supposed driver freedom over the lungs and health of their citizens is only now playing out.