Monday, November 15, 2010

The spectre of the rising seas in our own backyard

(I actually had this largely written before it came out, but the recent New York Times front page treatment of this science motivated me to wrap it up and deserves mention. Though it is not perfect, for a media article it is very good.)

One problem trying to explain the threat of climate change to residents of an area like the Red River Valley is that some may simplistically think something like, 'hey, a little warmer here sounds pretty good.' There are a wide range of counter-responses to that ranging from how that warming will adversely affect agriculture, how that is not considering changes to precipitation, that without action against it most assuredly it will not stop with merely 'a little warming', etc.

Some people may grasp the negative local effects but not appreciate impacts they would not see or feel in their backyards yet nonetheless would matter. Though there is familiarity with seasonal rises of rivers, one thing North Dakotans certainly do not have to worry about directly is rising sea levels. So one can worry that by the out-of-sight/out-of-mind principle folks around here may not give much consideration to rising sea level among the threats of climate change. The experience fighting river flooding here may even make people dismissive of that threat, thinking that the problem can be easily overcome by putting up some levees, dykes, and walls.

The rising of Devils Lake over the last couple decades gives a local illustration of what rising sea level will look like. That costly picture may help motivate people to try to avoid making the problem much worse that to what we are already committed. To be clear, I am only comparing the effects of the rising levels of the oceans and of Devils Lake. I am not comparing their causes nor saying that Devils Lake is rising because of global warming. But I am also not saying that climate change is not a factor - I am simply ignoring here the causes for the rise of Devils Lake.

A factor in dealing with any mess is having the things done in response be effective and minimizing their negative repercussions. With rising seas pumps are not going to be effective for a variety of reasons, not the least of which is the lack of somewhere you could pump ocean water to "get rid" of it. Pumping water away is a response that has been used at Devils Lake, but that has issues with effectiveness (to say nothing of cost-effectiveness) and resulting water quality concerns due to the discharged water. That is just an example of how a seemingly simple answer may not actually be of much good.

The seemingly simple answer for many people on rising sea level again may be levees, dykes, and walls. After all, the Dutch are doing it. There are plenty of problems with the physical practicality of attempting that. Protecting New Orleans or the Netherlands is one thing, but doing that all across the world is another thing, or rather, like the same thing times a thousand. Though efforts may be made to protect many urban areas, not everywhere could be protected and maintained. Maybe you do not care much about Maldives, Bangladesh, or coastal wetlands like southern Louisiana. Yet the combination of what we do and what we do not do will have an extremely high monetary cost, not even mentioning other social and environmental costs.

Over the past 17 years about $700 million dollars have gone toward dealing with the rise of Devils Lake, and that problem is hardly resolved. Now imagine having to spend like that across just the US where people live near the coast. Hardly seems like what a country currently paranoid about too much spending and expensive future obligations would want to deal with.

The costs of inaction are exceedingly high. If we do not simply let Devils Lake overrun whatever in order to save money, obviously we are not going to give up on wide swaths of oceanfront property. Here is a good summary of the situation facing one area in particular, Florida. Conceding ground costs real estate and other pistons of the economic engine such as tourism and recreation in Florida. Also it makes the threat of storms much more severe. At Devils Lake it is when the wind whips up that damaging water is even more sloshed around. Yet spending on walls, sand pumping, moving infrastructure, etc is not cheap. The $7 million for a new Minnewauken school is a drop in the bucket compared to protecting and moving much of, say, Miami.

It cannot be forgotten that protection against rising seas will surely not be 100% successful all of the time, especially in the face of storms which may be packing increasing punches in our warming world. One needs only look as far as New Orleans during Katrina to see an example and the price of failure.

It is also exceedingly important to remember now long of a view we need to take. Even if the lower estimates (from which there has been much retreat) of sea level rise come to pass over the next century - like a foot or two rather than three feet - that is hardly the end of the story. Because of ocean dynamics major cities in the northeast like New York City, Washington DC, and Boston will actually face even larger rises than the global average sea level increase.

And especially critically do not be confused by all the talk of sea level rise by 2100 into thinking that the rise will not be continuing long beyond that. The year 2100 is an arbitrary point widely used to facilitate comparisons in research. Hardly stopping in 2100, this episode of sea level will very likely be going faster than ever at that time. Is being lucking and having "only" 2 feet of rise by 2100 much good if it will be 5 or 6 or ??? feet by 2200 with more to come after that? Do we close our eyes and pretend that is none of our concern?

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