Monday, August 4, 2008

What's happening to Bangladesh?

Hearing climate contrarians called "skeptics" is, to my ears, like nails on a chalkboard. Not only is there a tendency to fumble about looking for evidence or any argument, good or bad, in support of a predetermined conclusion--the opposite of a skeptic's behavior--but when it comes to evidence supposedly in favor of their position, they more often than not act more like simpletons.

Consider the latest fad in the denialosphere, a pop report on land accretion in Bangladesh. (Of course, the buzz is not about a scientific paper. Denialists don't usually read those, and tend to kick and scream when one insists they must!) It has been widely predicted that sea-level rise will inundate low-lying areas of Bangladesh, but, currently, sedimentation is adding 20 km^2 to the country, annually.

To hear it from Paul Biggs on Jennifer Marohasy's 'blog or CLS at Classically Liberal, this is proof that sea-level rise will not inundate Bangladesh at all, that the IPCC and unnamed predictors of "catastrophists" are wrong, wrong, wrong.

This is nonsense, and it's so patently nonsense that one wonders if Biggs and CLS have any shame at all. Sedimentation and sea-level rise are competing effects: that one and not the other currently determines the sign of land-mass growth doesn't mean that it will always determine that sign. Let's take Paul Biggs' number as gospel for a second, that the IPCC predicts that 17% of Bangladesh will be under water by 2050. (What the IPCC predicts--and what it means for the IPCC as opposed to an individual group's paper to predict anything--is, of course, more complicated than this.) Bangladesh has an area equal to 134,000 km^2 according to the CIA World Factbook 17% of this is 22,780 km^2, far more than 20 km^2/year times 42 years, or even the Yahoo report's sanguine 5000 km^2 of "reclaimed" land.

Comparing percentages is not, of course, the way to go about this problem; one needs a model of land accretion during a time of sea level rise. Neither Mahfuzur Rahman nor Maminul Haque Sarker, the scientists/engineers cited in the Yahoo article, are working is not working with one, and neither are the denialists. At worst, I'm being no more flimsy than the wannabe "skeptics"; the comparison is good for a rough estimate and I have better things to do with my time than change field of study.

What's incontrovertible is that Bangladesh is already feeling the effects of rising sea levels, mainly through saltwater pollution of soils an aquafiers. See the IPCC AR4 WGII report for discussion and references. (I'd put 5-1 odds on the denialists not looking at the IPCC report at all!)

But maybe I'm wasting my time even without changing field of study. CLS talks of a "Church of Saint Al" as though the tail is wagging the dog and climate scientists are taking marching orders from a mere popularizer. And he gives hints that, like Ronald Bailey prior to his Road to Damascus moment, he's choosing a position on a scientific question based on what he wishes public policy to be, a dishonest practice. To quote:

Well that technology costs money and that means an improved economy and that means more carbon emissions so that can’t be allowed.

Yep, it's the usual Bircher-esque paranoia, the party line from glibertarians who talk a lot about free markets but lack the imagination to put such markets to use: Improved economies mean more carbon emissions, economic growth can't be carbon-neutral or carbon-negative or happen in a cap-and-trade framework. You can either have economic growth or you can stop fouling the nest. Want prosperity? Then take unlimited global warming and ocean acidification.

Now there's a teenage pinko's dream argument! "Capitalism and economic growth can only survive by fouling the nest."