Skip to Main Content

How is COVID-19 Affecting Air Quality and Climate

  • June 3, 2020

Benjamin Brown-Steiner, Ph.D., a scientist with Atmospheric and Environmental Research at Verisk, puts the pandemic’s impact on air quality and climate into perspective.

Related Article: COVID-19 Pandemic and Air Pollution Emissions

Ben Brown-Steiner

Dr. Brown-Steiner’s research includes atmospheric chemistry, climate science, and emissions modeling with a focus on uncertainty quantification, model and component complexity, and the impact of internal spatial and temporal variability on signal detection capabilities. He has diagnosed structural uncertainties within global climate-chemistry models pertaining to selection of model components, chemical mechanisms, emissions, and climate scenarios, and has utilized different modeling frameworks, and different parameter sets within individual models to analyze, quantify, and aid in the selection of chemical mechanism and model configurations that are both capable of representing tropospheric chemistry and computationally efficient. He is currently is working on emissions inventory development and support, box-model simulations of laboratory and chamber experiments relevant to biomass burning aerosols, and applying supervised and unsupervised learning techniques to tropospheric chemistry applications. He has regularly volunteered in various science communication venues including grade schools, science festivals, rural and interreligious communities, and adult education opportunities. He is currently one of the American Geophysical Union’s Voices for Science 2020 Cohort in the Communications Track.

Doug Topken  0:38 
Hi, I'm Doug Topken, host of the new Verisk podcast series on business issues related to the COVID-19 pandemic. As the pandemic has progressed, we've heard in the news, certain cities and parts of the world, have experienced lower levels of pollution and improved air quality. In today's podcast, we'll be chatting with Benjamin Brown Steiner, PhD, a scientist with Atmospheric and Environmental Research at Verisk, will help us put the pandemics impact on air quality and climate into perspective. Thanks for joining us today, Ben. So from the perspective of atmospheric scientists, what does the coronavirus look like and what are you learning?

Ben Brown Steiner  1:13 
Thanks for having me. We're learning a lot. Largely this is a new experience, not any particular past event has been completely comparable to what we're seeing today, and we get new revelations and new information, every day. One big phrase that I'm hearing a lot in my circles is that we're really conducting a new unintended to global experiment, and we're seeing a dramatic decline in emissions associated with transportation and economic activity. And this is teaching us more about the relationship between economic activity, human behavior, and emissions. Studies are coming out every day, looking at initial interpretations of satellite and other observations, but there hasn't really been enough time to dive into the details and interpret all the data yet. Much of what I've been learning comes from other atmospheric scientists in my social media circles. I have a Twitter account that I use where I'm getting a lot of these, and I see every day new plots and new interpretations of the data, they're getting shared on Twitter. And one important point to make with this is that all of this information is coming out far too quickly to move through the peer review process so a lot of what I'm seeing and hearing is initial data and preliminary data and it's probably going to be months or years until we really understand what we're seeing. But, as I was saying there's new stuff every day. And in the few weeks since I wrote with my co-authors the piece in the blog, new informations come out my Twitter feed is a constant flow and in fact, a podcast called Weather Geeks has had an episode on this very topic on air quality, and air pollution in the coronavirus.

Doug Topken  2:41 
We do appreciate that eventually there will be a peer review process, but give us a sneak preview, are there any trends or patterns that you're seeing emerge?

Ben Brown Steiner  2:48 
Yes. What is clear is that the coronavirus is having severe impacts on local, regional and national economies, right now. These economies have associated emissions of both greenhouse gases and other air pollutants. We say in our terms that the economic activity and emissions are coupled when one changes the other changes along with them, and both scientists and researchers that study these emissions are noting severe impacts across the globe. When we look at these we talk about two main types of pollutants that we're interested in studying. One is greenhouse gases, and the other are shorter term air quality pollutants that impact air quality and our day to day air. The greenhouse gases which include carbon dioxide and methane amongst many others tend to have longer lifetimes in the atmosphere on the order of years two decades to centuries, and they mix globally, and operate at much slower timescales. And so, because of this slower processing it takes a lot longer to notice changes in these emissions, and in their concentrations in our atmosphere. For instance, the Scripps Institute of Oceanography has been monitoring the co2 emissions for decades. In one of their initial Twitter reports that they put out, and they were asked essentially what they would expect to see in the co2 trends due to the coronavirus, and they said we're not seeing much at this point. And in fact to see a change in the background observations, we would essentially need a 10% reduction for at least six months, which we haven't quite hit yet.  So there's not a lot of evidence at this point of severe co2 carbon dioxide changes to the coronavirus. However, carbon reef has estimated that co2 levels will continue to rise, this year. But the increase that they expect to see will be slightly less than it would have been without a pandemic roughly 10 or 11% lower than than otherwise, which is definitely an impact but it's not anything as severe as we're seeing with some of the other pollutants. So shorter  lived pollutants, which includes nitrogen oxides, carbon monoxide, sulfur dioxide, and ammonia, as well as aerosols which are non gaseous pollutants tend to be more local largely due to their shorter lifetimes, they tend to last hours to days in the atmosphere, and thus after they're admitted they only get transported short distances. This we're seeing strong impacts of these short lived pollutants due to the coronavirus, especially in cities. Initially we saw a large nitrogen oxide emission reductions in China and Italy is they were the first to show impacts from the pandemic. But we're also seeing them in large cities in the US, including Washington DC and New York City and others, where there's large amounts of fossil fuel emissions from both transportation of cars and trucks, as well as densely packed humans that tend to emit a lot and burn a fair amount of fossil fuels. One caveat with this is that these shorter term signals can be relatively hard to detect since day to day meteorology has a strong impact on what the chemistry does in the atmosphere. And so a particularly warm day or particularly cold day might impact to the chemistry of that day, and add some noise to this chemistry signal. And then finally, the short lifetimes of these shorter air quality pollutants which are more on the scale of hours to days, means that their emissions will snap back, essentially to their pre-coronavirus levels, given that the economy snaps back to the pre-coronavirus levels.

Doug Topken  6:01 
Okay, so things got better quickly and things may also not snap back or return to where they were rather quickly. If and when the economy comes back, you spoke earlier about the relationship between economic activity, human behavior and emissions. Give me some examples please of behavior changes that are resulting in changes in emissions and the levels of pollutants that we're seeing in the atmosphere?

Ben Brown Steiner  6:22 
One of the most direct impacts that I'm seeing, and I'm sure a lot of people are seeing is that there are far fewer commuters on the roads, fewer cars, in general. Truck behavior, non commuting traffic has not changed that much but for commuting traffic there's been a substantial decrease in both driving itself, the International Energy Agency assumes that right now we're about 50% lower and a lot of areas with miles traveled due to transportation for commuting versus this time last year, and this is resulting directly in less gas and diesel being burned on the roads. This is turning into less NOx and co2 and aerosols due to these transportation sources, and that is ultimately turning into better urban and transportation air quality so if you live in a city or near transportation hub, you're going to have cleaner air largely in the cities, but, but also in many places around the globe that are close to transportation sources. We're also seeing far fewer airplanes flying in the sky. This is one of the bigger impacts that I can see. I live in Boston and planes regularly fly overhead and the amount of planes is significantly less than it was months ago, and this is resulting in less emissions just like with a car transportation fewer emissions up in the upper troposphere where the planes fly, fewer contrails those clouds that are created from emissions from plane fuel burning. A lot of people are seeing bluer skies, and less dramatic sunsets, which is the result from the less pollution from the planes. We're also seeing reduced economic activity, just in general, there's fewer industrial emissions, as a lot of the manufacturing plants and other industries have scaled back their production, and this is seen again largely where people tend to gather in cities, and production centers, again the IEA the agency expects roughly 8% drop in coal demand due to some of these changes and that's translating into roughly an 8% drop in co2 emissions that they're expecting compared to last year. One thing I haven't seen strong indicators of is that this is resulting in increased emissions in homes. Now, there might be some but it's it's likely to be a drop in the bucket compared to the change in emissions from other sources, so that signal is not yet emerged from the noise. And then one final one is there's significant changes in supply chains and other economic shifts that we're seeing. And there's articles coming out pretty much every day about a new shift or a new industry that's been hit, for instance, recently I read a paper on Bloomberg that described the big disruption in the flower industry the plant industry, and how, when the springtime was hitting, they usually have a pretty big global distribution of flowers, but that pretty much grinds to a halt through the coronavirus, and you see it with bread flour, for instance, or hearing articles about meat production and the impact that's having, so there's a lot of other examples of industries and supply chains that are shifting. And there's definitely emissions changes associated with these but I think it's really too early to tell exactly what these impacts will be just because of the fast nature of these these changes and the difficulty in identifying some of these constituents in the signals in the answer.

Doug Topken  9:24 
What about the impact on human health due to reduced emissions and pollutant. Is the air I'm breathing cleaner and, if so, how does that benefit me?

Ben Brown Steiner  9:33 
I would say, due to these changes, you're absolutely breathing cleaner air right now, kind of across the board if you live near city or live near road you're definitely breathing cleaner air. And I think in general, just because people aren't driving as much, the air is cleaner kind of across the board. When we look at studies summarizing air quality related illness and death, these, these studies tend to take a lot of time to, to develop because there's so much data you have to collect and so much interpretation and making sure that all of the factors that can kind of complicate the results you know are dealt with so I expect to see a lot more of these studies in upcoming months and years, but right now I think it's still a bit too early to have super strong conclusions about these impacts. It's also highly regional there's, depending on the country or state or city that you're in, you're going to have different impacts, and so it's it's a highly complicated field at the moment, but overall I would say that yes you're definitely breathing cleaner air. I also want to be clear that that I've seen some of this in some of my Twitter feed and social media that this increase in air quality isn't a silver lining, people are still dying and lives are being severely affected across the globe, and communities that are historically exposed to more pollution, are seeing disproportionate impacts from the coronavirus for many reasons, including some of the systematic underlying inequalities. Just are changing the way that different communities can deal with a virus, and I expect to see a lot more studies from atmospheric chemists and others, reflecting this impact into the future. And one large reason we're seeing these changes is that economic activity as I mentioned, is coupled with emissions and air quality so the more economic activity, the worse the air quality largely because most of our economic activity still uses fossil fuels and this emits balloons, along with it. The air quality community has been studying the impact of emissions and human health for, for decades and so there's a lot of information out there. But what this pandemic is demonstrating right now is really what those emissions are doing in the atmosphere and how quickly they could change with changes in behavior that we're seeing.

Doug Topken  11:37 
Interesting. So Ben, I've heard that you and your colleagues have developed four scenarios laying up potential forms of coronavirus recovery. What are those? Can you share them with us and explain how they might impact emissions?

Ben Brown Steiner  11:49 
So we came up with the four scenarios, largely to cover because we wrote this piece, we didn't really know what was going to happen. This was a few weeks ago and things have changed since then but the scenario is still largely hold I think the first one is what we call a return to business as usual scenario, which essentially assumed that we'd get over the coronavirus impacts quickly. The economic activity that was disrupted would shift back to normal or near normal pretty quickly, and thus the shift in transportation of commuter traffic would return to normal shifts in economic activity we returned to normal, pretty much all the behavior that we know emits pollutants just through energy use, or other processes would be back to normal. How quickly this would be really depends on a lot of factors but I would assume, and we kind of assumed this would be maybe a month's scale to return to normal. That's the first one and that's what I think a lot of us are hoping for is to get back to normal as quickly as we can. But there's other possible scenarios, including the second one which we call the gradual recovery scenario. In this scenario, it's similar the first that the economic activity and behavior returns normal relatively quickly, but the timescale on this might be longer, so maybe instead of weeks to months it's months, maybe even years to get back to pre-coronavirus levels. And this scenario has different impacts based on the different species so those short term air quality related species are likely to snap back quickly once we return to near normal activities. The greenhouse gases and those longer live ones might take longer to get back to pre-coronavirus levels. For instance, in the 2008 recession, we did see a blip, a little kink in the rising CO2 levels in that long term record, and I expect to see something similar to that, for the CO2 levels. The scale and size of that really depends on what happens, and how quickly things change. The third scenario, we called a partial recovery or a restructured recovery scenario. And this scenario activity. Doesn't entirely get back to pre-coronavirus levels maybe something shifts in the mounts and ways things are produced, or maybe a lot of the commuters, work at home more frequently, or a couple days a week or shift the times and ways in which they commute. And there are many other structural changes that can happen to big complicated systems that might shift the way we return, and we might have this partial recovery scenario where missions, don't get back to 100% pre-coronavirus levels, or they're slightly different. There's a lot of different paths that we can go with it in that scenario. And then the fourth one we're calling a new seasonal disruption norm where just like other flu and cold seasons happen seasonally, usually in the fall in winter, this coronavirus might be a regular interruption to our activities and we might have to scale back or shift our behavior some way every fall or every winter, and that might happen, at least until there's a vaccine, or it might continue onwards, if, if the vaccine isn't entirely effective or other scenarios that might keep this as a returning event.

Doug Topken  14:54 
Well thank you, Ben. That's really interesting. Personally I'd love to see if scenario one or scenario two rather than scenario four where we have seasonal disruptions as a new normal so thank you, but no thank you on that one. Any final thoughts?

Ben Brown Steiner  15:08 
I do want to say that the pandemic is shining a light on many of the components of our society and systems that we rely on that are often ignored or sometimes forgotten. I was trained as an engineer as an undergraduate and there's a saying that normally invisible quality of working infrastructure becomes visible when it breaks, and one impact of this coronavirus, and all the impacts that we're seeing from, from it, are cracks in the infrastructure that we rely on that might be more cracked than we'd like. This includes things like supply chains of a bread flour for instance locally, we had trouble with bread flour or toilet paper or other things for instance, we're also seeing cracks and other larger parts of our society that that hopefully we can work on so that as we move through this coronavirus pandemic or experience future ones will be better able to respond to these. And finally, I want to say that we being scientists, researchers but also planners and politicians and health experts and the public will certainly be discussing the lessons we've learned from this coronavirus for some time. And I do hope that these lessons that we do learn will help us continue to build a better world, as we move into the future.

Doug Topken  16:19 
Yeah, same Ben, absolutely. Thanks for being with us today, we covered a lot of ground on a really interesting topic. We certainly appreciate you taking the time to meet with us. To learn more on this and other COVID-19 related topics, be sure to follow us and visit We hope you enjoyed this podcast and invite you to join us again. Until next time, stay healthy everyone.

You will soon be redirected to the 3E website. If the page has not redirected, please visit the 3E site here. Please visit our newsroom to learn more about this agreement: Verisk Announces Sale of 3E Business to New Mountain Capital.