Building resilience to climate’s emerging impacts

We all aim to be resilient — to bounce back and move on after something goes wrong. We do it after we get sick, for instance, or after we lose the big game. Cities will need to do it, too, especially as they adapt to Earth’s changing climate.

Resilience is “about bouncing back to conditions after a disruption or after some kind of stress,” explains Adam Parris. He heads the Science and Resilience Institute at Jamaica Bay in New York. And, he adds, sometimes that recovery leads to improvements.

Average sea levels are rising. That endangers coastal areas. Climate change is bringing more severe storms, which cause widespread destruction. Shifts in climate can even threaten people’s health, food supplies and more.

Community leaders, policy makers, scientists, engineers and others are all looking for ways to avoid some of climate’s worst impacts — and adapt to deal with the rest. The more that people plan for resilience, the better they’ll be able to survive what comes.

Building resilience

To better understand how people study and build resilience in a community, consider Jamaica Bay.

This body of water borders Brooklyn, New York. About 400,000 people live in the flood plain that surrounds it. Hundreds of thousands more people live in the watershed. That land drains water into the bay. Jamaica Bay is made of smaller systems, such as a fresh water pond that supports wildlife in the Jamaica Bay Wildlife Refuge.

Hurricane Sandy caused widespread flooding of land around the bay in 2012. Scientists know that climate change will bring more such severe storms and more sea level rise to this area. Parris and others want to help the region be prepared to bounce back from those events.

Scientists can forecast impacts of climate change globally or in just one local area, such as here. They start by focusing on climate data from the past. They also can do experiments and make projections of future climate by using computer models. Scientists can then use the results of such studies to anticipate what could happen to people, properties, wildlife, infrastructure (such as roads and bridges) and other things people care about. All that work sets the stage for figuring out what can be done to improve resilience.

But Parris and his colleagues didn’t just rush in with big solutions.

Any resilience plan should “start with some notion of what people want from their community,” Parris says. So his team talked with folks about what they like about their communities and what they would change if they could. They also discussed climate change with these people, both as it could affect them now and in the distant future. Along the way, they learned that living near the bay is very much part of the culture of these people.

Recently, Parris and others compared two possible ideas for this area to cope. Neither has been proposed yet as a formal plan. Both focus on Rockaway Inlet. That’s the bottleneck where the Atlantic Ocean meets Jamaica Bay.

One idea calls for a big sea gate to span the inlet. It could rise up to block incoming water during the higher tides or storms. A tiny bit of work would also restore local wetlands. The other approach would narrow the inlet and bring back a lot of marsh.

Each project would cost a lot — maybe close to $3 billion. But each strategy also should reduce how many sites get flooded. One plan could help protect up to one-fourth of those properties. The other might help slightly more. A sea gate would get to the higher rate of protection more quickly. However, the fix based more on nature would lead to less loss of land. The RAND research corporation described these options in a January 2018 report.

Tipping points

If waters rise too high, even very costly plans won’t work as intended, Parris warns. For example, at some point after seas rise some 0.4 to 0.8 meter (15 to 30 inches), the habitat of Jamaica Bay could change in important ways. And more properties would flood no matter what people chose to do.

Scientists say thresholds like that are tipping points. Once such points are reached, things change in ways that may become permanent. A system would eventually have a “new normal” — and may no longer function quite the way it did before.

In terms of sea level rise, for example, people may no longer be able to live safely in areas that now regularly flood. Sewer systems may be damaged beyond repair. Marsh land may be destroyed. And the list goes on.

Finding out about possible tipping points matters. It helps people judge how much time may be left to take steps to try to mitigate, or lessen, the worst impacts. And it lets people compare different ways of adapting to expected changes.

But boosting a region’s resilience is not a one-and-done thing. If people in New York did either of the projects Parris and his team looked at, researchers would likely take another look to see how well the strategy worked. Then they might consider what else might make sense as climate change and sea level rise continue. In other words, resilience science is a process of testing, adapting, evaluating how well that worked — and then doing it all again.

At this point, no one knows whether New Yorkers will carry out either of the proposed ideas for Jamaica Bay. Meanwhile, some people near the Rockaway Inlet have raised their homes or buildings. That helps them get better flood-insurance rates, Parris notes.

It’s also unclear what people will do worldwide to rein in the greenhouse gas emissions that drive climate change. That, more than anything, may determine how well parts of the world can adapt to the stresses that are due to come.