Important new meta-study of sea level rise in the US.

This is not a peer reviewed meta-study, but a meta-study nonetheless. Reuters has engaged in a major journalistic effort to examine sea level rise and has released the first part (two parts, actually). It is pretty good; I only found one paragraph to object to, and I'll ignore that right now.

There are two reasons this report is important. First, it documents something about sea level rise that I've been trying to impress on people all along. The effects of sea level rise do not end at one's perceived position of a new shoreline. Here's what I mean.

Suppose you are standing on a barrier island, and your feet are on a grassy sandy knoll 10 feet above high tide. You are standing next to a climatologist who says "some projections say that the sea level will rise by one foot more than it already has by 2100. You breath a sigh of relief because you are standing 10 feet above high tide, and you realize that one foot of seal level rise is easily accommodated by the sea you see in front of you.

But you would be a fool to not be worried for several reasons. First, you are standing on a 10 foot high sea cliff. The sea cliff represents erosion that happened since the last bout of sea level rise (and is actually an ongoing process). When the sea rises by one foot that sea cliff will erode away. The land many hundreds of yards behind you may be fine, but the place you are standing will be gone. It is hard to predict how much land will horizontally erode with a given rise in sea level, but it is generally a positive number, rarely zero (there are places where it effectively can be zero but not along the sandy shores). Second, as you stand there looking at the sea, the restaurants and businesses along the road behind you and the residential and commercial properties all across the nearby hinterland are busy lowering the ground water by taking water out for their own use as if it didn't matter. So, while the sea may rise up one foot by 2011, it may also drop a foot because of the groundwater removal. Third, if the sea rises only a little across certain kinds of sediments, the weight of the sea may further suppress the land. Fourth, if this bit of land you are standing on is along the US Atlantic coast, you probably get more than one foot of sea level rise if the global sea level goes up by one foot. This has to do with the shape of the oceans, wind and water currents, etc. Fifth, one foot of sea level rise means many feet of extra storm surge when that rare tropical storm comes along. The chance of a hurricane hitting a given beach along the Atlantic is low. But we're talking about the year 2011. Between now and then a hurricane with enhanced storm surge will come along and remove the land you are standing on. Sixth, the climatologist you are standing next to is an optimist. He is referring to "some estimates." The funny thing about sea level rise estimates, as well as polar ice sheet melt estimates, is that they keep changing over time, always in one direction. Ten years ago the estimate was one foot by 2200. Now, it's 4 feet, and some estimates suggest 6.6 feet. Also, looking at the paleo record, the last time atmospheric carbon dioxide levels were at their present level plus what we expect to put in the air over the next few decades for good measure, sea levels were so high we used meters instead of feet! Figure 25 feet, maybe 40. The town behind you will eventually be gone, buried deeply in the sea, a nice fishing ground. That probably won't be by 2100, but is it really your job to throw every human that exists after 2100 under the climate change bus because it is a nice round number? No. No, it isn't.

The Reuters report deals with most of those issues (though in a different way), chronicling numerous cases of actual current and ongoing encroachment of the sea on the land. And this brings us to the second key thing about this report. Reuters documents that the humans are running around like chickens with their heads cut off. Local business leaders who want to preserve their short term profits are controlling supposedly long-term-thinking state and federal agencies so nothing gets done. Big Science (in the form of NASA) is busy studying glacial melt and sea level rise from rocket-launching bases that are being washed away by the rising ocean, and acting as though they can somehow stop that. Congress. It does nothing. And so on.

This is the first in a series of reports, it is excellent, and I look forward to the rest of them. You can read it here. By the way, a lot of what is documented by Reuters was covered earlier in this book: Hot: Living Through the Next Fifty Years on Earth, worth a look!

(The graphic above is from the National Climate Assessment report of 2014.)