The United Kingdom’s journey towards its climate change commitment of net zero emissions by 2050 is also expected to cut air pollution in almost every sector, including transport, electricity generation, and agriculture.
That’s the conclusion of a report released late last month by the country’s Air Quality Expert Group of the Department of Environment, Food and Rural Affairs (DEFRA), which looked at the possible air quality implications of 47 individual actions proposed by the Committee on Climate Change that support a trajectory towards the net zero target.
It found that “virtually all” of these, across 15 different emissions sectors, from agriculture and land use to waste, could bring dramatically improved air quality outcomes — but the devil is in the detail.
It was critical that policymakers paid attention to the “how” of deployment of new technologies and management of novel hazards, as much as they did to the “what”.
Making road and rail transport fleets emissions-free is expected to lead to early and “very significant” air quality gains by reducing nitrogen oxides and volatile organic compounds in cities.
“During the COVID-19 crisis we’ve seen that having fewer petrol and diesel engines on the roads has dramatically reduced nitrogen dioxide levels in cities around the country. If the national fleet was converted to electric, we would expect to see similar improvements,” said Professor Alastair Lewis from the National Centre for Atmospheric Science and University of York, who chairs the Air Quality Expert Group.
“Air pollution has a complicated range of sources though, and there is no guarantee that all types of pollution will fall together. For example, electric vehicles will still create particle pollution from road surface abrasion and brake wear. Because of that, walking, cycling and public transport remain the cleanest options for transitioning to net zero emissions,” Professor Lewis said.
“Likewise, widespread improvements in energy efficiency in buildings should reduce the demand for space heating, but the health benefits are only fully realised if constructors choose materials that do not adversely affect indoor air quality,” he said.
The proposed actions were expected to lead to some “immediate improvements in certain primary air quality parameters”, but would reap major reductions in secondary pollutants (such as particulate matter and ground-level ozone, formed from the reactions of methane, volatile organic compounds and nitrogen oxides) “towards the end” of the transition to net zero emissions.
Significant overlaps exist when it comes to the sources of air pollutants linked to myriad negative impacts on the human body from short- to long-term exposure and of greenhouse gases that cause atmospheric warming (though some emission, a number of short-lived climate pollutants, such as black carbon and ground-level ozone, do both).
The researchers expect that concentrations of air pollutants typically co-emitted with carbon dioxide during fossil fuel combustion, such as nitrogen oxides, black carbon, polycyclic aromatic compounds and carbon monoxide, are likely to fall significantly as fossil fuel use drops.
Just over a year ago, the UK government declared the current target of net zero emissions by 2050, more stringent than its previous target of 80 per cent reduction from 1990 levels and one of the most ambitious in the world.
According to the UK government, air pollution is the biggest environmental threat to health in the country, where long-term exposure to air pollutants account for anywhere between 28,000 and 36,000 deaths a year.