Sunday, October 26, 2003

Global warming

I've heard conflicting explanations of the causes, but I also keep hearing news reports about melting ice in important areas.

For the moment, never mind the causes. Short term there's not much to be done anyway--if ice packs are warming just stopping CO2 emissions won't do much beyond changing the slope of the warming curve. If this is a warming trend, we're stuck with it for at least a decade or so.

Given that, what is at risk in the short term?

I see three general types of risk:

  • Rising sea levels due to melting Antarctic ice. (Arctic ice is already floating, and won't change sea levels if/when it melts.)
  • Melting Arctic ice change the ocean currents in the north, and the nutrient flows, with possible damage to fishing.
  • Changing ocean currents change the air weather patterns in unpredictable ways. Some regions might get better growing weather, but even if agriculture is easier in some regions we have to deliberately adapt to it. If the wheat belt gets too dry we could have a new dust-bowl/desert if we keep on trying to grow wheat there.

What regions are susceptible to rising sea levels?

I think we ought to write off New Orleans, global warming or no--we're fighting a losing battle there. Plan a 20-year evacuation, with a new Mississippi course (and watch the notoriously corrupt Louisiana politicos swoop on this trough) as a test case. It is the biggest single city-drowning problem I know of in this country: Venice on the Gulf.

There'll be lots of problems, and things that don't work; but

  • It just gets harder the longer we wait
  • The political and legal and engineering lessons we'll learn apply to the partial city drownings elsewhere (and flood plain cities, too; and cities next to active volcanoes)

Moving a city takes bucks, and a lot of political will. There's a lot of voters in N.O. who don't want to move unless somebody can guarantee they'll be better off afterwards. The only really big club the Feds and state have is the Army Corps of Engineers and a new route for the Mississippi. Given that the Mississippi is going to pick a new route on its own in a few decades and kill a lot of people when it does, it makes good public policy sense to try to point it into a convenient channel. And that dries up New Orleans trade.

There'll still be a rump city hanging out to the bitter end, trying to run the pumps and repair the levees on its own, but if we make it clear that insurance companies don't have to insure property in the flood area after 2030 I think most people will get the message.

I wonder if something like the Abu Simbel project might get the ball rolling: condemn the whole French Quarter and move it to 'Newest Orleans.' I'd predict lots of storm and fury, lawsuits, sabotage, and very powerful people making sure they wind up with lots of bucks. And at the end, if it moved successfully, the tourist promoters would make a virtue of necessity and offer combination packages. We might have to move the cemetary too...

Now that I think about it, the collapse in the fishing industry is starting already. A sudden change in ocean currents might be a good thing if it started up a new rich region we didn't find out about for a few years.

The changes in local climate we can prepare for, if we've a mind to. What we need are variants of old crops and new crops with farming procedures to get them growing efficiently in new places.

That's nice and vague. For example, suppose that the Great Plains become substantially drier. We then can't tap the aquafer enough to sustain wheat. (Not that we can do that sustainably now anyway...) So, we give up on wheat there. What instead? (For the sake of argument, we'll assume we can still grow crops of some kind, and don't have to plant grass and pray for rain.) Amaranth? I've never tried it myself, but I understand it is a nice dry weather crop, though not a lot of yield. OK, three problems: nobody knows how to eat it (and people can be very stupid about unfamiliar foods), the yield isn't great, and we don't have any procedures for growing it or tools for harvesting it on a large scale.

Trying to get people to eat new foods isn't something the government is very good at, unless its World War II and everything is in short supply. Waiting for private enterprises to see a need, develop means, and advertise the heck out of the product sounds like a nice, adaptable approach. Unfortunately, the time scale for developing new crops and tools is more like decades than quarters; and very few businesses I know of think that far ahead. So we need federal research funding for new crops--crops for a dry Midwest, for a wet Midwest; for a cooler South, for a hotter South; and so on.

And we try to increase yields slightly. We could breed for greater yields if we could assume a particular climate. I think a shotgun approach works better, though--try a little of everything and hope something works.

No matter what the causes of the ice melting are, these are things that need addressing.

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