Pollution drops under lockdown

This period of coronavirus lockdown is dramatically changing our outside environment - closed shops, quieter roads, emptier parks. One town in Wales has even been invaded by goats lured in from the surrounding hills by the absence of people! And with fewer cars and buses on the road, and fewer planes overhead, what impact is lockdown having on our air quality? Katie Haylor spoke to BBC science correspondent Victoria Gill, who explained that pollution levels in the UK have dropped sharply, particularly noticeably in cities...

Victoria - We've actually very recently had a measure from some ground based measurements showing reductions in some pollutants that we know are bad for our health, and we know are associated with the kinds of activities that have dropped so sharply since we all were sort of plunged into this coronavirus induced lockdown. So things like transport and industry, so nitrogen dioxide and particulate matter. So that's small particles, and we know that they can do some damage in our lungs. Particularly particles under a certain size can sort of get right down into our lungs. Scientists and public health specialists are really interested to see what will happen as this lockdown continues, because there's not much good news coming out of the coronavirus crisis, but it does seem to be inadvertently improving our air quality.

Katie - How are scientists actually measuring this drop?

Victoria - We've seen a number of different measurements actually, and this is an international effect. We've had some measurements that have come from China and from India. We're also, I should say, seeing a drop off in carbon dioxide, some of those greenhouse gases as well. In Europe we saw a really interesting measurement come from some satellite based spectrometry, measuring the colours that are being reflected from the sunlight that's hitting the Earth, and those different colours represent the reflections from different types of gas. You can see different types of pollutants and take that colour intensity as a measure of the amounts of those gases. We then saw from the National Centre for Atmospheric Science, these city-based ground measurements that really give us a measurement of the air that we're breathing, and we're seeing the same thing across the UK.

Katie - Is it possible to determine what impact this could have?

Victoria - A lot of what will happen in the longer term will depend on how quickly some of those pollution driving sectors bounce back. So for one thing, we've heard from the UK government that they're going to be phasing out the sale of vehicles that have internal combustion engines, and moving to electric vehicles. What we can maybe see over the next however many weeks and months that we are kind of stuck in this lockdown, is a realistic measure of the kind of target that we'd be looking for when we take a lot of those diesel vehicles off the road and replace them with electric vehicles. So there could be some longterm better, more informed targets for air pollution. The worry is that once this immediate crisis is over, there'll be a drive to just restart the economy without any of that in mind. So I think public health specialists and atmospheric chemists will be trying to kind of, build in some good practical advice into how we may be keeping some of these benefits to the air that we're breathing.

Katie - Do you think there are any lessons we can learn in terms of pollution, if we look, you know, to people who are a bit ahead of us?

Victoria - There's something positive that we can take from this unintended consequence of what's happening in so many places. You know, we've seen a quarter of the world under lockdown, and lockdown means less transport, less industry. It means less pollution. Now, if we can monitor the effect that that is having on people's cardiovascular health, on people's ability to kind of, breathe clean air, but also take some lessons from it in terms of what our streets and urban centres could look like, if we can limit that pollution and limit that transport. I think we're all learning lessons about how the world could change. You know, there's been a huge amount of frustration, especially from kind of, the younger generations and activists in the environmental movement, about how slow we've been to respond to the emergency that is climate change. And what this does show us, is that when there's an emergency that is immediate to our public health, we can act and we can put in some really severe measures. And I'm not suggesting that governments are going to do anything along this scale to tackle climate change, but it shows what's possible. Maybe we can take some lessons from this in order to apply it to that bigger global emergency that is, you know, the state of our planet and our warming world.