March 16, 2012 20:09
We were on the front page of the New York Times earlier this week. We wish! Our marketing department has not cracked that nut yet. Not so the folks at Climate Central. Their press release about their report, Surging Seas, got them a front page spot in New York. It also was picked up by papers of record in Miami, Boston, Los Angeles, and Chicago, among others. Internet outlets like the Huffington Post and msnbc.com carried it. Even the UK's Daily Mail has picked it up.
What was so momentous? The researchers in our view did three things. The first is typical. They identified the risk caused by an effect of climate change. It is a serious risk, potentially affecting millions. The second was astute. The two published studies on storm surge and rising sea levels (Modelling sea level rise impacts on storm surges along US coasts, and Tidally adjusted estimates of topographic vulnerability to sea level rise and flooding for the contiguous United States) are dense. Surging Seas converts them to understandable lay terms. The third was their genius. They brought the issue down to zip code specifics.
Let us explain. The first step was accurately to determine the elevation of all the coastal property in the United States. This was done using the National Elevation Dataset established by the US Geological Survey. The next step was to compare the elevations to local high tide levels as ascertained using NOAA information and techniques. Overlaid on that was 2010 census data. Thus the Climate Central researchers had the best data on population and proximity to the sea. What's more, they could show that information visually and with granularity.
What remained was to add storm surge data. This is the 900 pound gorilla. Rising sea levels will add only inches to the level of mean high tide in the next 20 years. The effect of storm surge is not so minor. To quote Surging Seas:
In many places, only inches separate the once-a-decade flood from the once-a-century one; and separate the water level communities have prepared for, from the one no one has seen. Critically, a small change can make a big difference, like the last inch of water that overflows a tub.
This effect is dramatic. According to the authors of the report, for 2/3 of the locations analyzed the risk of a once-in-a-century flood has doubled, for 1/2 the risk has tripled. What this means is that for many storm surge flooding is no longer something one could expect to see once in a lifetime, or not at all. To get specific, the study "found that at over half the sites examined, there is a one-in-two or better chance of water reaching 4 feet higher than the average local high tide by 2030, at least once." Such flooding puts almost 5 million people at risk.
To complete this part of the analysis the researchers looked at local water level gauges, land subsidence rates and global sea level rise to calculate local sea level rise. They then analyzed historical local extreme water level patterns (i.e., storm surges) assumed they would continue to exist, and applied them. The conclusion is ominous: "Sea level rise is raising the launch pad for storms and high tides, and being experienced by the ever-more frequent occurrence of extreme high water levels during these events -- long before the ocean reaches damaging heights permanently."
Which brings us to the meat of the matter. Our in-laws are in South Florida. We can type in their zip code, and query the Climate Central web page as to the likelihood a 4-foot storm surge will invade their home before 2030. And we can blow up the map and look right at their street. We are buying them a canoe.