Monday, January 30, 2006

First Rant

So here's a good rant for my first post. It's a bit rambling, but hey, it's my blog.

Today it was 60 degrees (Fahrenheit) in NYC, and 30 degrees (also Fahrenheit) in Boston. This is pretty non-standard, given that Boston and NYC are not very far away from each other (especially in latitude). This got me thinking about all the people who are confused about global warming, and who say stuff like "but it's cold here, so there can't be global warming": the whole point is, it's global warming, not necessarily local warming. Some places might be cooler, while the globe as a whole heats up. Especially places like New England, and Old England (and Northern Europe in general) if the Gulf Stream shuts down due to salinity changes in the Atlantic.

I was thinking about the ignornace of people who don't realize how fragile the Arctic is, especially vis-a-vis global warming. This isn't just because the Arctic ecosystems are balanced on the head of a pin (although a lot of them seem to be), or that animals dependent on year-round ice are basically going to be SOL within a few years. It's also because the Arctic is on a steep part of the climate vs. temperature graph. A small amount of temperature change pushes the geographical climate border (permafrost, tundra, whatever) a long distance.

It's like a very shallow beach: a little change in ocean level (e.g. from high to low) exposes (or covers, when the tide comes back in) a lot of beach.

Another piece of this is that even if the climate vs. temperature graph isn't as steep as we fear, we're still talking about a basic phase change: water melting. The most obvious thing that's going to really get people's attention (though I do wonder if it'll make Alaskans vote out Ted Stevens) is that permafrost is going to melt -- and buildings are going to start falling down because of it. It doesn't take much change in the average temperature to push you over the edge of a phase change if you were right at the transition point.

Serendipity handed me this topic as well: I ran across (on slashdot and boingboing) links to this article about research into viruses that push humans toward obesity. In the article they say

"The prevalence of obesity has doubled in adults in the United States in the last 30 years and has tripled in children," the study noted.
-- and while I don't want to pick on them (this is a quote out of context), it triggered the ranting instinct in me. A lot of people look at "the prevalence of obesity has doubled" and think that some actual number (like people's weight) has doubled. That's absurd. What has doubled is the number of people whose weight is now above the threshold for obesity. If ten million people were just below the threshold for obesity ten years ago and now they're just above, then it looks like ten million people just became obese. But in real terms, those ten million people may have just gained a pound or two.

What really happened is that the statistical distribution of human body-weight in the sample (e.g. the US population) shifted higher. It doesn't take much to push a lot of people over the threshold. The same way that it won't take much rise in sea level to overwhelm lots of coastal areas. (Especially since it's not really averages we're worrying about -- it's the extremes, like storm surges.) None of this is to say that Americans aren't getting fatter; they surely are. But it's not like the per-capita mass of Americans has gone up by a factor of two. But whenever you have thresholds (or a high tide line) a small change can have a big effect.

This is just another reason I think that people shouldn't be allowed to graduate from high school unless they can read graphs.

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