USA: Nature-based solutions can help New York and New Jersey adapt to rising seas and intensifying storms

By Steve Koller 

Are we prepared?

With peak hurricane season upon us and what seems like daily coverage of record storms, floods, and ice melt, climate adaptation solutions should be top of mind for individuals and governments alike. After all, recent data show billion-dollar disaster events continue to take place with increasing frequency. Here in New York, many are wondering whether we’ll be ready when the next big storm hits. An emerging consensus —even among local elected leaders —seems to be: “Nope.”

The ongoing upward trend in global GHG emissions suggests we are far from experiencing the worst impacts of a changed climate. And while swift decarbonization is a first-best solution, we also need to bolster community resilience to prepare for the climate impacts around the corner.

What to expect? 

New York and New Jersey are acutely vulnerable to sea level rise and storm intensification. Roughly 400,000 New York City residents currently live in an area with a 1% annual chance of flooding. The region’s coast has a booming property market, with an estimated $101.5 billion of property value in an area with a 0.5% annual chance of flooding. Like so many coastal communities, a significant number of lives, assets, and locations of priceless social value are at stake.

An intermediate scenario from NOAA anticipates global mean sea level will rise by more than three feet by 2100. The New York City Panel on Climate Change recently introduced a new low-probability, high-impact “Antarctic Rapid Ice Melt” scenario, which considers the triggering of a critical tipping point that would result in 9.5 feet of sea level rise by 2100.

The science is clear: our coastline is going to look very different by the end of the century.

What can we do? 

Superstorm Sandy was a wakeup call. It exposed myriad deficiencies with regard to disaster response, electricity systems, and post-disaster recovery. The storm incurred more than $19 billion in damages in New York City alone, and led to the deaths of 24 people from my home borough of Staten Island.

In the wake of the storm, a number of promising policy responses created momentum toward greater resilience in the region. One major effort is the Army Corps of Engineers’ “New York-New Jersey Harbors and Tributaries Study,” a comprehensive regional assessment spanning 900 miles of shoreline and 25 congressional districts that will prompt the development of large-scale storm risk mitigation infrastructure projects across both states.

This work has massive implications. One of the alternatives includes a five-mile storm surge barrier, stretching from Breezy Point, Queens, to Sandy Hook, New Jersey. The preliminary price tag of the projects in this alternative: $118.8 billion. While this is just one of five alternatives under consideration, it is clear the Corps’ work will be expensive, transformative and serve as the backbone of the region’s storm risk mitigation infrastructure for generations.

Natural infrastructure can play a part

While the vast majority of the infrastructure solutions considered in the NYNJHATS study are grey — i.e., human-engineered structures which often include steel or concrete— nature-based solutions deserve full consideration as well, because they can be economically viable components of our adaptation strategies. For example, earlier this year the Corps released a final report for a smaller civil works project—still expected to cost more than $600 million—in the Rockaways and Jamaica Bay. EDF successfully advocated to include more than nine acres of new and restored wetlands and maritime forests, and they were ultimately included, as they were deemed the most viable and economically justified solutions in those cases.

While by no means a silver bullet, nature-based solutions are sometimes the most cost-effective flood mitigation options at our disposal. Unfortunately, current Corps guidance does not factor certain incidental benefits, including those from ecosystem services, into cost-benefit analyses. This means things like improved water quality, oxygenation, carbon sequestration, and habitat restoration are excluded from the calculation, on the grounds they are difficult to quantify. Even so, the recent release of “Engineering with Nature: An Atlas” suggests the Corps is moving in a direction that will feature natural infrastructure solutions more prominently in future coastal adaptation efforts.

In the face of historic sea level rise and flood risk, natural and nature-based solutions can play a key role to restore ecosystems and serve as additional lines of defense against flooding in New York and New Jersey. Adaptation authorities need to consider the full range of benefits natural and nature-based flood risk mitigation projects can provide, otherwise we run the risk of leaving economic value on the table. Adapting to climate change is going to be a costly endeavor- let’s not make it more expensive than it has to be.