The Case for Action on Short-Lived Climate Pollutants

by CCAC secretariat - 16 November, 2020
A coordinating lead author on two IPCC reports and the chair of the Climate and Clean Air Coalition’s Scientific Advisory Panel explains why short-lived climate pollutants will save lives, money, and spur a recovery from the COVID-19 pandemic.

Without slashing short-lived climate pollutants (SLCPs) and dramatically reducing carbon emissions, staying below 1.5 degrees Celsius of global warming is likely impossible, says Professor Drew Shindell who is the Chair of the Climate and Clean Air Coalition’s (CCAC) Scientific Advisory Panel and a Coordinating Lead Author on the 2018 IPCC Special Report on 1.5°C. This year’s research on methane, he adds, exemplifies the compelling case for action.

One of the fastest-growing short-lived climate pollutants, methane is also one of the most important to reduce, given that it is responsible for about half of the more than 1 degree Celsius the Earth has already warmed. Our understanding of the scale of the problem is also improving rapidly. Research published this year found that the amount emitted by the oil and gas sector has been underestimated by up to 40 percent.

Drew Shindell speaking at a CCAC Science Policy Dialogue

Thanks to new satellites that monitor methane leaks from space, we also found out during recent years that a previously largely unknown fracking accident in Ohio was actually one of the largest methane leaks ever recorded in the United States and that a long-term, unnoticed major leak in Turkmenistan was occuring in an oil/gas field. In addition, research on methane emissions from the American oil and gas sector found that leakage may be 60 percent higher than originally estimated.

These concerning revelations have an upshot: if human-caused methane emissions are much worse than previously thought, reducing them could have dramatic payoffs. Like all short-lived climate pollutants, reductions would have extensive benefits beyond global warming reductions. Methane is a precursor to tropospheric ozone, which causes over a million premature deaths every year and up to 15 percent annual yield losses of many major crops. 

We spoke with Shindell about why reducing SLCPs saves lives— not just in the long term by mitigating climate change but right now by reducing air pollution and hunger— and why the CCAC’s role converting research into action matters now more than ever.

What does the IPCC special report on the impacts of global warming of 1.5 degrees above pre-industrial levels tell us about the role that SLCPs must play in climate change mitigation?

Prof. Shindell: Unfortunately, we’ve put off seriously tackling climate change mitigation for decades now so, at this point, meeting lower warming targets (1.5 degrees and even 2 degrees) means we have to do pretty much everything at our disposal. It’s not an either or question of mitigating long-lived or short-lived pollutants, we have to do both and we have to do it extremely rapidly and as much as possible.

One way to look at it is that you’re taking some of the pressure off of CO2 by tackling short-lived climate pollutants. It will still be really, really difficult to meet the lower warming targets but it will be do-able. Without SLCP reductions it’s not possible in any of the scenarios that we assessed in the Special Report. 

The other thing is that policy makers want to know how to mitigate climate change at the lowest cost. Measures to control short-lived climate pollutants are part of a portfolio of available actions to control climate change and many of them are at the lowest cost end of that portfolio. Especially with methane mitigation, these are measures that have very low or even negative costs. So while they’re essential to meeting the low warming targets, even if they weren’t the economics alone are attractive enough to make them worthwhile.

We’re learning more and more about the importance of cutting methane — and not only for the climate benefits. What makes this such an important tool that we have at our disposal?

Prof. Drew Shindell: Methane is one of the most powerful levers we have to slow the pace of climate change over the next few decades. While we definitely need to decarbonize, it is a slow process and because CO2 is long-lived and cooling compounds are emitted along with it reductions will take a long time to bring climate benefits. Because of its relatively short lifetime in the atmosphere (12 years), methane can bring us climate benefits in the near term and there is enormous potential with existing technology to reduce methane at a very low or even negative cost. 

It also brings us large public health benefits and agricultural benefits. Methane is one of the main precursors to ozone at the surface level and ozone is toxic to plants and people and results in major crop losses and about a million premature deaths a year. This latter value is higher than earlier estimates, as expanded epidemiological studies have shown us that breathing higher levels of ozone is more damaging to human health than we thought. 

Methane and the CCAC's role in catalysing 2030 mitigation ambition
Video: Members of the CCAC Scientific Advisory Panel explain the significant climate change and health benefits of methane migitation, and what can be achieved by 2030.
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You’re a lead author on two IPCC Reports and you’re the Chair of the CCAC’s Scientific Advisory Panel, which means you help the CCAC translate the most cutting edge climate science into actionable policy measures. What makes this role so important?

Prof. Shindell: It can be hard for a scientist to keep up with all of the literature and the studies that come out each month. I think it's even harder for policy makers to keep up with every new development. This often means that people get siloed: one policy maker might be really focused on air pollution, while another looks at climate change or at the medical system.

What the CCAC has done is help link these silos with digestible, comprehensible information so that policy makers can easily see how certain choices will have multiple benefits across sectors. Having that information helps them break down the silos to build stronger, more sustainable networks that are more capable of taking action. The measures that target SLCPs might not be the most important actions if you’re focused on maximizing a single benefit for public health, or for food security, or for climate stabilization, but the CCAC is helping show that SLCPs can deliver substantial multiple benefits across all the sectors simultaneously.

Coalition programmes like those that support national planning are really important for showing that it is most effective to target these things collectively: including climate mitigation policies as part of improving health and improving agriculture is going to be more cost-effective than trying to tackle each issue separately.

Cote d'Ivoire's national action plan to reduce short-lived climate pollutants
Video: Cote d'Ivoire's national action plan to reduce short-lived climate pollutants
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The Coalition seems to play an important integrating role not only across different sectors and ministries within countries but also across countries and regions.

Prof. Shindell: That's a great point. And neither air pollution nor climate change respects political boundaries. Especially if you're from a smaller country, you don't have very much leverage over your own environment or fate. I think that's a really important function for CCAC: facilitating regional cooperation to share knowledge and address climate change and air pollution as a team.

A lot of countries are looking forward right now to rebuilding from the COVID-19 pandemic. What role can short-lived climate pollutant mitigation play in that work?

Prof. Shindell: I think a really crucial one. We're seeing an enormous willingness to spend money on basic infrastructure and a public really interested in what science is telling us about their health. I think this is a time to highlight how we can make intelligent choices about rebuilding our economy and how targeting SLCPs can have an immediate impact on public health.

Climate change is an even larger, long-term crisis and while SLCPs are obviously not the whole solution, they are a critical strategy. Targeting them and moving away from fossil fuels both bring enormous air pollution benefits. I think the way to get public support for both right now is by really stressing how they will lead to major public health benefits. 

There’s also a lot of research which is still fairly nascent but suggests that extra exposure to air pollution increases your risk for the worst impacts of COVID, which makes sense because it's causing many of the same respiratory problems. We have to increase people’s resilience to pandemics and improving air quality is one way to do that.

I think there’s a lot of potential to the idea of building back better and recovering from COVID in a way that helps lots of people who are out of work find good jobs that help with the environmental transition, help public health, and help broad segments of the economy. There’s loads and loads of evidence from countries around the world that the transition to a green economy provides a lot more jobs than it loses. It also means that workers can actually do these jobs long-term, because they’re not home with a respiratory disease from air pollution or taking care of a sick child with asthma triggered by air pollution — or a parent suffering from heat stroke. I think treating the environmental problems as part of the larger discussion of the economy and general public health is a really important way to mainstream environmental consciousness. You don’t want the environment to be a niche issue — it is a critical part of all the things we consistently rank as most important such as health and the economy and the CCAC is extremely useful in helping people realize that.