Sixty six years after The Great Smog claimed the lives of 4,000 Londoners, the air in 44 UK cities exceeds World Health Organisation limits for fine sooty particles known as particulate matter. The main source for particulate matter is car exhaust fumes which also contain high levels of another pollutant, Nitrogen Dioxide (NO2). Among larger cities (Figure 1) the Scots have the cleanest air.
Figure 1: PM 2.5 particulates, micrograms per cubic metre (WHO limit = 10)
This is mostly an urban problem. UK cities are home to 88% of roads with NO2 concentrations above legal limits. Regulation has in the past attempted to reduce pollution, most notably the introduction of unleaded petrol, which was finally banned in the EU in 2000 after 10-15 years of gradual withdrawal. But air quality issues have risen right up the agenda in the last few years, as has the strident political language, with former London mayor Boris Johnson arguing in 2014 that high levels of air pollution on London’s Oxford Street were a ‘ludicrous urban myth’ while his successor began referring to London’s ‘toxic air’ within weeks of being elected.
Meanwhile, the UK Government’s plan to tackle air pollution has been ruled unlawful. The previous approach of urging local governments to act on air pollution was deemed to not go far enough and that local authorities should be forced to do so. 28 local authorities have been tasked with developing local plans by the end of 2018.
Figure 2: Proportion of Air Quality Management Area action plans resulting from various sources of NO2
There are already schemes in place in UK cities that aim to tackle air pollution. Some offer local governments easy wins as they are relatively easy to implement. For example, low-, ultra-low-, and zero-emission zones can be found in London, Sheffield, Leeds, and Birmingham. Sheffield has also introduced anti-idling zones around schools.
The low cost and ease of implementation of these schemes suggests many more of them by 2040. Most major cities are replacing their bus fleets with low-emission vehicles. While this is costly, ease with which such a scheme can be implemented as older vehicles are retired means that we will continue to see low-emission vehicles replace city public transport fleets in the future.
Individual buildings also play a role in improving air quality; they are becoming treatment systems for outdoor air. Through HVAC systems, absorbent materials, and living roofs and walls, buildings expel better quality air than is taken in. Although this is already happening, current policy fails to address the role buildings play in air quality management as they are not under the direct control of authorities. For air quality to improve at scale, collaboration must take place between authorities and landlords.
The public are also increasingly gaining access to real time air quality data through mobile devices, apps such as Google maps, and bus stops. This will allow the public greater ability to make informed decisions about the routes they take and places they visit in 2040.
At the national level, the Government recently released its Road to Zero policy which plans to end the sale of conventional petrol vehicles by 2040. By 2040, the majority of new cars and vans will be completely zero emissions.