[Q&A] A groundbreaking new study shows we have the tools to halve the predicted warming rate over the next 40 years.
The Mark sat down with Drew Shindell, a NASA climate scientist and the lead researcher of a new study that proposes cuts to non-carbon emissions as the key to slowing global warming in the short term.
According to your study, we could eliminate half the climactic warming predicted to take place over the next 40 years, a stunning number. How?
To reduce the near-term warming, we would target emissions that lead to two of the most important near-term pollutants: ozone in the lower atmosphere, and black carbon, which is what most people think of as soot. While carbon dioxide lasts for decades to millennia in the atmosphere, these pollutants have lifetimes of a month or less. So if you reduce the emissions that lead to these pollutants, the effects are seen much faster.
How technologically difficult would the reduction of those two pollutants be?
The measures we look at all use proven, existing technologies that have been applied at large scale somewhere in the world already. That doesn’t mean it’s trivial – it requires some effort to actually implement them. But it doesn’t require us inventing anything new, or even learning how to apply anything at commercial scale. It’s all stuff we know how to do and have been doing – we just haven’t been doing it around the world.
Is this a shift away from current international strategy, which has been to mitigate climate change by targeting emissions of carbon dioxide?
I would not say that this should represent a shift away from that goal, but rather a second prong in our effort to limit the damage from climate change. We have a way to reduce the rate of climate change over the next several decades by targeting the fast-acting pollutants. That said, since they’re fast acting, these measures are not going to have much effect at all on climate in the longer term.
Carbon dioxide measures are the flipside of that: It takes a long time for carbon dioxide to respond, so anything we do now is unlikely to have much [immediate] impact, unless we see some wildly draconian change in carbon-dioxide emissions. Any plausible scenario for emissions reductions will really have almost no effect on climate over the next several decades. But what we do with carbon dioxide now will determine everything about what happens with climate change in the latter half of the century.
Since they act on different time scales, I think the most logical strategy is to pursue them as two largely independent parts of a more complicated way to deal with climate change: targeting both the near term and the long term.
What would the implications of targeting non-carbon emissions be for international climate policy, and for the post-Kyoto talks as they’re going on right now?
Some people worry that talking about near-term climate change could cause a distraction from dealing with long-term climate change. To me, that’s not a very realistic possibility, because it’s very clear that they are two separate issues. The current international negotiations are really trying to set up a comprehensive worldwide solution, which is very explicitly targeted at long-term climate. This strategy to deal with the near-term climate doesn’t really have a large direct bearing on what we do about long-term climate, since they’re about different activities leading to different emissions.
What it does have the potential to do, in my opinion, is influence how the negotiations might proceed. We’ve had decades of scientific studies documenting the need to reduce CO2, and politicians and countries around the world are committed to that already, at least in name. Yet, we keep setting CO2 emissions records every year. So we’re really not doing very well. If countries work together on some of these near-term climate measures, maybe there will be some confidence building and bridging of gaps between developed and developing nations, giving us some success to build on. It could be a way to encourage the development of successful methods to deal with long-term climate change.
Do we need a co-ordinated international effort for these measures your study targets, or are these things that countries or other sub-international actors could start doing immediately?
I think there’s a mixture of both. There are plenty of things that can be done at national, state, or local levels. Indeed, that’s why we have data on what measures there are, how well they work, and how they can be implemented – because they have already been done on smaller scales. For example, many of the measures to control soot emissions have already been taken in Europe and the United States, and they have certainly been taken with an eye towards improving public health. There’s no need for a global treaty to deal with these kinds of things.
But the fact is, these measures have not been put in place everywhere. In many of the developing nations where these emissions emerge, there are plenty of pressing needs. So while there is clearly recognition that soot is bad for peoples’ health, there hasn’t really been the recognition that it is also contributing to climate change. I hope the recognition that soot is both a public-health hazard and contributing to climate change will boost it at the national or sub-national levels.
If what the study has found is true, what are the implications for current adaptation strategies that have taken on quite a prominent role in international climate negotiations?
I think it’s very positive news as far as adaptation goes, because we can see that even with pretty aggressive measures to deal with the near term and long term, the temperature still keeps going up (not as fast, but it still keeps going up). So adaptation [to climate change] is going to have to happen. But if the next degree of warming happens within the next 40 years, it’s a lot harder to adapt to than if it happens in 90 years. By reducing that rate of change, we give a lot more time for the adaptation to take place, and for us to really learn how to adapt. The changes will develop more slowly and ecosystems will shift more slowly, and we’ll have more time to see what’s happening and realize what we have to adapt to.
Original Article
Source: the Mark
Author: Drew Shindell
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