When Science Finds a Way
Is tackling super pollutants an emergency brake for climate change?
03 Jun 2026
Transcript generated automatically by AI and may contain errors.
Chapter 1: What is the main topic discussed in this episode?
I think one way to put it is it's like the emergency brake that we can pull on climate change.
Chapter 2: What are super pollutants and why should we care about them?
Have you heard of super pollutants? Honestly, I hadn't before I sat down with Tom Grylls for this episode, but it is something we really should be paying attention to. It's a term which helpfully groups together a bunch of short-lived, underexplored pollutants like black carbon, methane, and tropospheric ozone, where scientists have spotted an opportunity an emergency break.
By reducing emissions, we can potentially have a quicker impact on global warming than decarbonization alone, while also bringing health benefits by improving the air we breathe. It sounds like a win-win. In this episode, Tom, head of super pollutants at the Clean Air Fund, is going to break down super pollutants' impact on our health and the climate.
why they are rising up the scientific agenda, and the huge opportunity for joint action.
If we just used all available technology around the world and financed the solutions, we could reduce black carbon emissions globally by 80%.
Welcome back to When Science Finds a Way, a podcast about the science changing the world. I'm your host, Alicia Wainwright.
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Chapter 3: How do super pollutants impact climate change and health?
Let's get into it. Hi, Tom. Thank you so much for joining us today.
Hi, really great to be here.
So, Tom, for something that could have such a big impact, I've never heard of super pollutants. So how long has this been on the scientific agenda and is this a relatively new focus?
So the more technical term, and the grouping and the language around this has been evolving over the last few decades, and in particular over the last few years, is short-lived climate pollutants or short-lived climate forces.
That doesn't have such a fun buzz.
Exactly. And I think that's the key.
That's the reason that this language has really emerged over the last few years is to package up what the science community has been thinking about and has shown up in all of the international panel on climate changes assessment reports over the years into something that we can communicate effectively with different types of stakeholders, be that the public, be that policymakers.
So super pollutants is basically a way to package that up.
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Chapter 4: What opportunities exist for reducing super pollutants?
So let's start there. Why don't you tell me what is a super pollutant?
So super pollutants are the gases and particles in the atmosphere that have a climate effect bigger than carbon dioxide per ton. So that's black carbon, tropospheric ozone, methane, HFCs, and nitrous oxide.
And what that categorization does is it brings together three really important and powerful characteristics of what's going on in the atmosphere and what solutions we can implement to drive climate and health benefits. So super pollutants as a grouping are responsible for half of global warming to date, with the other half attributed to carbon dioxide.
They are responsible for millions of premature deaths per year due to air pollution. Many of them also last in the atmosphere for a much shorter amount of time than carbon dioxide, which means that some of the benefits we can see by tackling these super pollutants can be realized much more quickly.
I feel like that's sort of the PR problem with climate change and climate health is that to fix carbon dioxide, this generation or perhaps the next might not get to see the results. But with something like a super pollutant within someone's lifetime, if you made improvements in this space, you could see some of that gain. Is that kind of a way to think about it?
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Chapter 5: How do black carbon emissions affect our environment?
Yeah, for sure. I think one way to put it is it's like the emergency brake that we can pull on climate change. So by tackling these super pollutants, we can avoid the temperature increase within the next decade. And on the health side, you can immediately and visually see the benefits in tackling these. So from an air pollution perspective,
policies and measures like low emission zones or transitions to cleaner industrial processes. You can sometimes visually see in the city that the amount of pollution coming out the back of a tailpipe or the plume of smoke coming out of the the brick kiln that you might live nearby has reduced.
And so both in terms of how we're seeing the climate change and how much warming happens up to 2040, up to 2050, but also in terms of how our communities feel like safer and cleaner and more enjoyable places to live and those affected by asthma and COPD and other things able to live healthier and longer lives.
Something in my research for this episode I found really interesting, and it might be so obvious to everyone else, but I just didn't put two and two together, is that air quality and air pollution and things that can affect climate change or accelerate global warming, they might not necessarily be the same thing, but that super pollutants do both those things.
So air pollution can have negative impacts on our health, global warming and climate change can have impacts on our health in a very long-term way, but super pollutants fit in this sort of Venn diagram in the middle of doing both of those things. So super, I feel like is fairly accurate because it is really negatively impacting people on both fronts.
Yeah, and I think the Venn diagram is a great way to visualize this. So if you took all the different gases and particles that are in the air, where we are right now, where the listeners are right now, there's different levels of all sorts of different gases and particles, and they're interacting with each other in complex ways.
And if we just set them out into a Venn diagram where in one circle you have the pollutants that are, we know affect climate change. And on the other circle, we have the pollutants that affect air pollution and therefore our health, our crops, our forests. You can see that it doesn't make sense always to kind of separate these into two separate boxes.
So you have, often we talk about it like there's the greenhouse gases, which have these long-term global warming impacts, as you say, and then we have these particles and other toxic pollutants, which We understand that when we breathe them in, they will be detrimental to our health.
But actually, within the chemistry that's happening in the atmosphere, within the sources that are producing these pollutants, there's loads of overlap. One way to put it is that air pollution and climate change share the same sources, so Coming out of the back of a tailpipe of a car, you have carbon dioxide, but you also have black carbon.
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Chapter 6: What successful interventions have been implemented in Nepal?
But then they also share the same species. So in particular, pollutants like black carbon and tropospheric ozone, they're both... harmful air pollutants for humans to breathe in, but also when they're in the atmosphere, they contribute to global warming and they have other complex interactions with the climate system.
So this is one of the key benefits of basically looking at that Venn diagram and overlaying a different filter. And that filter being the definition I mentioned of super pollutants, because it focuses in on what's happening in the atmosphere in a way that doesn't silo climate change and air pollution. And there's loads of different benefits to that.
There's benefits in the way we can communicate about it, in the way that we can talk about local benefits as well as global benefits, which is often an important driver in different parts of the world to take these actions to reduce these emissions. When we think about the economic benefits of taking action, Often the calculations are done saying, this is an air pollution measure.
So we know if we reduce this, okay, we see these health benefits. We might see an increase in productivity, some reduced healthcare costs, some longer lives lived. And that adds up to a big economic benefit.
And then you might do a different calculation with climate change where you're looking at what's happening in terms of temperature, what that means for extreme heat, for flooding and other things. But actually, often these solutions can benefit both. And if you combine the economic benefits of both, suddenly the case to take these actions becomes much more compelling.
And there's one really interesting statistic that came out of a Lancet study in 2019 that says the economic benefits associated with clean air would outweigh the costs of delivering on the Paris Agreement.
So there's a few numbers behind that, but basically the amount it would cost for us to deliver on the Paris Agreement of keeping the world to 1.5 degrees, the way in which that would actually help clean up the air would outweigh those costs over a fairly long period. But it shows that the... economic case can really value from not siloing these two issues.
Can you give us a bit of context about the intersection of air pollution and climate change when it comes to super pollutants?
Sure, so methane, tropospheric ozone, and black carbon all contribute to outdoor air pollution. Black carbon and tropospheric ozone themselves, when we breathe them in, they have different effects.
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Chapter 7: How does air pollution relate to climate change?
And that number really doesn't tell the real human story of the impacts these are having, where in practice, it goes way beyond that 8 million premature deaths to affecting people's day-to-day lives in so many different ways, particularly those who are at risk, such as older people and people with asthma.
it's not just that stat, but also the respiratory issues, the hospital visits that create this burden that we're in almost everywhere in the world, we're exposed to air that exceeds the World Health Organization's guideline limits on air pollution.
So pretty much wherever you are in the world, it's likely that one of these pollutants is above the safe level as deemed by the World Health Organization. So this is a pervasive health problem. And as we've been touching upon is something that we should and could be talking about more in the context of climate change and tackling these two problems together.
Agreed. So coming up, we're going to talk about an intervention focused on tackling black carbon, specifically in the brick kiln industry. But can you tell us a bit about the climate impacts of black carbon?
Black carbon, for me, is probably the pollutant that sits most at the heart of that Venn diagram. So it's a component of fine particulate matter pollution, which is the main form of pollution that is harming our health and that governments are tackling worldwide. And then it's also basically soot. So it's the kind of dark sooty material. Unlike most pollutants, you can literally see it.
There's been campaigns done where people have put sheets alongside busy roads. And over the course of a day, you see the change of the color of the white sheet to a darker color. And that stuff is black carbon. And what that means is it's also on the climate side. of the Venn diagram, because in being a darker color, it has these light-absorbing properties.
So black carbon in the atmosphere, like if you're wearing a black T-shirt or a white T-shirt, it's changing your retention of heat. So in the same way, these black carbon particles are absorbing heat and warming the surrounding air, so contributing both to global warming and also locally to extreme heat.
And then even more interesting, through the same characteristic, they have this forcing on snow and ice. So black carbon emissions that are coming from lots of sources, which I'll get onto later, can be deposited onto glaciers, onto oceans. the Arctic sea ice, they darken the color of the snow and ice.
And therefore, again, they increase its capacity to warm up and therefore increase the rate of melting. So you have this quite distinct forcing on the climate, which is actually different to how greenhouse gases are retaining heat in the atmosphere. But it's also significant and something that generally has kind of fallen between the cracks of air pollution and climate policy.
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Chapter 8: What health impacts are associated with black carbon?
We didn't have just the engineers and architects to rebuild the cleans. We had the bricklin entrepreneurs. So with the practical knowledge and with the engineering design, we made a design book for natural draft, zigzag cleans, and a forced draft. Forced draft is we have a fan to suck the air, to blow the air, and in natural draft, it's the natural wind that blows
uh you know and that would fire the coal and ignites the bricklings to bake this bricks no but as there were some brick entrepreneurs while designing this uh you know overall process so they had the full confidence that okay this brickland would work for us that's why this was so popular and the adoption was so fast What the Bricklin owners said was, you know, they really benefited.
They were not worried about the pollution level because they are all business people. So they were saying that the quality of bricks was really good. Now they got more of the A-grade brick, around 90% and less breakage. So they were really happy with the brick quality. And the other part is that the coal consumption was less. So they were very happy on that front.
But for us, like for the environment itself, it was the black carbon was reducing around 60% and also the particulate matter was reducing around 40%. So that was, and you could visibly see from the smoke itself, it was more of a white smoke coming out. And also in the volume, it was really, really less than the previous one.
So the benefit was win-win to both of the entrepreneurs as well for the environment.
Wow. Bidia's brought so many things to mind in her discussion about the brick kiln project. The first thing it made me think of actually is how incredibly impactful it is to notice when something is different for the better. And I also love that they are able to find a solution in which we're making the environment safer and cleaner.
And the businesses are also happy because that is a long lasting solution if both sides feel like it's a win-win.
It's an amazing story from a really sad starting point. Of course. The resilience and the positive outcome in a small way post that earthquake that they were able to change that industry. And generally, I think coming at the problem from black carbon as a starting point helps to find some of these solutions that we already know how to reduce these emissions.
So looking at like maximum technical feasible reduction pathways, which is like the way of saying, if we just used all available technology around the world and finance the solutions, we could reduce black carbon emissions globally by 80%. So the technology already exists to rapidly reduce black carbon because of this association with inefficient burning and open burning.
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