It’s difficult to explain and even harder to measure — yet it may be one of our best hopes of tackling climate change. So-called “nature-based solutions” may just be one of our best bets to brace ourselves for the future climate. Climate scientist Dr. David Hole explains why these solutions — known as ecosystem-based adaptation or simply EbA to scientists and climate policy wonks alike — are taking on a greater role in the climate change dialogue and what that means for us.
Question: “Nature-based solutions” — sounds like a win for nature and for people when it comes to addressing climate change. Why don’t we hear more about it?
Answer: In our world of 24-hour media, we tend to go for sound bites, but the truth is EbA is sometimes complicated and always nuanced. Often, the media doesn’t want to deal with nuance, because we assume that the public can’t understand it or doesn’t want the details. When the example is about a mangrove barrier protecting coastal communities, the story is quite easy to tell, but many other EbA stories are a lot more complicated.
For example, just off the east coast of Brazil, we were working to conserve the blue parrot fish, which browses algae and keeps the reef there in better health — which, in turn, helps buffer coastal communities from wave energy that causes erosion. As sea levels rise though, if the reef isn’t healthy, it won’t continue to grow, thereby allowing far more wave energy to reach the coast, eroding tourist beaches and eventually settlements. Can you imagine trying to communicate all of that clearly and in a really small sound bite? The moral of the story is: This stuff can get complicated.
In addition, there’s still limited evidence for how effective EbA may be in different contexts, so we have to be very clear in our work. We have to first understand how climate is going to impact someone. In many cases, it’s a rural community, where they tend to rely more directly on ecosystems. We have to understand what risks they face and then determine if and how ecosystems can be used to help reduce those risks. We’re usually not talking about eliminating risk, but reducing it.
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Q: Given that more than half of the global population lives in cities, and that percentage is predicted to continue to grow, can EbA be applied in metropolitan areas as well?
A: The focus of EbA activities is often on small rural communities, and that’s really important — I think that’s absolutely where it should be. But there’s a good argument to be made that EbA can help cities as well.
Take someplace like New York City, where they’re spending nearly US$ 20 billion on adaptation work. Following Hurricane Sandy, they’re putting in a lot of engineered infrastructure, but they’re also using ecosystem-based solutions — like restoring oyster reefs and sand dunes — because they are the best and, in that case, the most cost-effective way of reducing risk in some areas.
Now, you don’t rely on an oyster reef to protect the whole of downtown Manhattan — it’s worth too much. In that case, you start using built infrastructure such as massive sea walls that are very expensive but offer the protection you need for really expensive assets.
At the end of the day, you have to look at the whole system, and you have to recognize that engineering is not the only solution. EbA is not often going to be the only solution either. It’s about understanding all of your risks and then going with the most appropriate adaptation options.
Q: It sounds like EbA offers some viable solutions to the imminent impacts of climate change, but will it play a role in the climate negotiations in Paris?
A: If you look at where the money is going, adaptation still receives just a fraction of the funding put toward mitigation, but this could be the first COP where adaptation is starting to approach parity with mitigation.
Mitigation is critical. We have to get emissions down. Fortunately, some key EbA approaches — such as protecting and restoring mangroves, which absorb carbon and store it in the soil below — help fight climate change even as they increase community resilience to its impacts.
Adaptation work also has to ramp up, because the reality is that we’re already experiencing climate change impacts. While we can’t say that any single weather disaster was caused by climate change, there’s no doubt that some of the events that have occurred this year alone have been more powerful and more damaging because of climate change. So, if less than 1 degree Celsius of global temperature rise can cause the amount of damage that it’s doing now, then with the 2 or 3 or 4-degree rise that could be in the cards in the coming decades, adaptation is fundamental.
The good news is that there is discussion about a global goal around adaptation. It’s not clear what that would look like because, unlike mitigation, which is measured in gigatons of CO2 or the equivalent, adaptation may be needed in pretty much every aspect of our societies and economies. There’s no single metric for measuring or monitoring it. Whatever happens though, we have to massively increase our focus on climate adaptation work.
David Hole is a scientist and the senior director for global synthesis in CI’s Moore Center for Science. Sarah Hauck is a writer for CI.