With growing evidence that our planet is warming (record high temperatures, historic droughts, floods and melting Arctic ice), what does “Superstorm” Sandy suggest about global warming?
Dubbed “Frankenstorm” by the weather media, Hurricane Sandy was a massive North Atlantic hurricane in terms of diameter. It spanned about 1,000 miles as it moved up the coast and turned inland instead of out to sea.
We used to think of storms like Sandy as once-in-a-generation weather events, but as New York Governor Cuomo observed, “we have a 100-year flood every two years now.” As these events happen with more regularity, climate change-related impacts are becoming more observable to scientists – not to mention to the rest of us living through these events.
When we burn fossil fuels, carbon dioxide accumulates in the air, which – over time – has been super charging our atmosphere with warmer average temperatures and more moisture, so storms can dump more rainfall and ride higher seas to shore. Climate science indicates this trend of more frequent and extreme weather will continue.
Amidst Sandy’s devastating effect on millions of people, I'm hopeful that some good can come from the impact of this storm. Since New York City is arguably the financial and media capital of the world, Sandy has gotten people’s attention. As a result, there is an opportunity now to raise awareness about the risks of climate change and the need to get serious about disaster preparedness and understanding the value of healthy ecosystems in helping to reduce our risks.
Why was there so much damage from Sandy? And are damaging storms likely to get worse?
Well, the main reason there was so much damage was that we have chosen to build and develop in some of the riskiest coastal areas – often building over our first line of defense – marshes, wetlands and dunes.
One of TNC’s scientists recently had a paper published in a journal called Natural Hazards that shows that if sea levels rise by just 18 inches in New York, a storm like Sandy may affect 50 percent more people and 75 percent more property than what we have just witnessed. We need to reduce those risks with better climate and development decisions now.
We all know that nature can dish out punishing damage from wind, rain and surf. So, if our coastal communities are at risk from natural disasters, how can nature possibly help reduce the impact of severe weather events?
There always have been and always will be natural disasters caused by weather events like hurricanes, blizzards and rainstorms. But, it turns out that nature can also help protect people.
In a recent report, our scientists found that coral reefs can reduce wave energy approaching coasts by more than 85 percent, helping to reduce risks to the nearly 200 million people worldwide that live in low, at-risk coastal areas.
Even inland, natural areas help strengthen the resilience of the landscapes between our homes and communities. Forests and floodplains that remain connected to rivers absorb high water, hold soil in place to minimize erosion, and filter pollutants (like chemicals or sewage overflows) to clean our water supplies for drinking, manufacturing and recreation.
In what ways can conservation strengthen natural defenses? How do we decide where to focus and prioritize?
Our natural defenses – or natural infrastructure – includes, for example, wetlands, coral reefs, oyster reefs, coastal dunes, mangroves and flood plains. When healthy, all of these systems can help absorb the brunt of wind-driven waves, erosion and flooding. These natural buffers can act as a first line of defense to help protect levees or sea walls further inland.
One example is off the coast of Grand Isle, Louisiana. The Conservancy created a series of man-made oyster reefs there to demonstrate how the structures can help reduce coastal erosion, filter and clean water, and help protect people and properties from storm surge. (Editor's note: check out this new video on the Conservancy's oyster reef work in Grand Isle).
And in South Cape May, New Jersey, not far from where Hurricane Sandy made landfall, a project to restore dunes and freshwater wetlands fared well during the storm. In 2006, the Conservancy worked with federal, state and local governments to reconstruct dunes in South Cape May Meadows to enhance flood protection and protect beaches for nesting birds. Those dunes weren’t breached during Sandy. Neighboring towns of Cape May City and Cape May Point, which saw severe flooding in the 1990s, experienced minimal flooding with Sandy.
Could natural infrastructure work in a place like New York, New York – one of the biggest cities in the world?
Sadly, Sandy caused at least 250 deaths in the U.S. and Caribbean and more than $63 billion in economic costs, at last count. It disrupted people’s lives, livelihoods, property, electricity, transportation and commerce. This epic storm may be an "A-ha" moment for many in the U.S. that investing in natural infrastructure near our cities and communities can be a cost-effective solution to help mitigate the effects of future storms.
The traditional approach of engineering flood control structures like levees, sea walls and canals, will certainly be needed in some places. But, not everywhere. In most places – including New York City – we will need to combine approaches. Indeed, risk reduction always involves multiple solutions from natural and built defenses, to smarter and safer development choices, to early storm warning.
By applying our on-the-ground knowledge, The Nature Conservancy is working to identify the places where natural solutions can be effectively applied as part of a portfolio of coastal defenses. This includes some portions of the coast in urban areas like New York City, Bridgeport, Connecticut and Long Island. It’s also important to remember that where we leave wetlands and dunes intact, or restore them, it ensures that we do not build in the most-exposed and riskiest areas, over this first line of defense.
Can the Conservancy help decision-makers in New York identify how and where to apply natural solutions to reduce disaster risks now?
We sure can. Over the past four years we have built an on-line mapping tool, Coastal Resilience, with partners including the National Oceanic and Atmospheric Administration (NOAA) and the Association of State Floodplain Managers. We use the tool with towns throughout New York and Connecticut to help residents and municipal officials visualize their social and economic risks to storms and sea level rise — and identify solutions.
If you use the tool right now, you can see that the actual mapped storm surge from Sandy looks startlingly similar to the Category 2 storm surge we predicted. In the past two weeks, we have quickly added tools to Coastal Resilience to help decision-makers prioritize which wetlands might offer the most risk reduction benefits to people and property. Our staff shares this science to inform development, and current efforts to rebuild smarter and safer, keeping the next storm or disaster in mind.
What are the cost-benefits of using natural infrastructure versus built infrastructure?
We need to better plan and prepare for these expensive disasters – using a suite of options to help make us safer. In 2011, damage from natural disasters reached an all-time high of $380 billion. More than 40 percent of the world’s population lives in coastal areas, and urbanization along coasts is increasing at a higher rate than anywhere else.
Smart planning can better protect our infrastructure, so schools, hospitals, runways and other crucial facilities are further away from the coast. One study (by the Multihazard Mitigation Council) found that for every $1 spent on preventive measures (including both structural and natural defenses), $4 is saved in avoided costs of natural disasters. That figure is $1 to $5 when you isolate flood events.
What’s more, healthy reefs and other natural solutions are a cost-effective way to mitigate this economic risk. The Conservancy has worked with NOAA for 10 years on more than 125 coastal restoration projects around the U.S. In the Gulf of Mexico, for example, the Conservancy is working to restore 100 miles of oyster reefs at a cost of about $1.5 million per mile – comparable to, or cheaper than built breakwater costs. And reefs and marshes offer many additional benefits – such as healthy fisheries and tourism – that sea walls and artificial breakwaters will never provide.
The bottom line is: No barrier, natural or built, can fully protect us from the most severe disasters. But our goal is to work with governments at all levels, communities and the private sector, to show how smart, cost-effective investments in nature can work together with more traditional flood control approaches to maximize our defenses against impacts of future storms.