Saturday, March 12, 2005

"I'll Grant You Reality." Gee, Thanks.

Nick Kristoff of the NY Times recognizes the nose on his face: "I Have A Nightmare"

I was once an environmental groupie, and I still share the movement's broad aims, but I'm now skeptical of the movement's "I Have a Nightmare" speeches.

In the 1970's, the environmental movement was convinced that the Alaska oil pipeline would devastate the Central Arctic caribou herd. Since then, it has quintupled.

When I first began to worry about climate change, global cooling and nuclear winter seemed the main risks. As Newsweek said in 1975: "Meteorologists disagree about the cause and extent of the cooling trend ... but they are almost unanimous in the view that the trend will reduce agricultural productivity for the rest of the century."

This record should teach environmentalists some humility. The problems are real, but so is the uncertainty. Environmentalists were right about DDT's threat to bald eagles, for example, but blocking all spraying in the third world has led to hundreds of thousands of malaria deaths.

Likewise, environmentalists were right to warn about population pressures, but they overestimated wildly. Paul Ehrlich warned in "The Population Bomb" that "the battle to feed humanity is over. ... Hundreds of millions of people are going to starve to death." On my bookshelf is an even earlier book, "Too Many Asians," with a photo of a mass of Indians on the cover. The book warns that the threat from relentlessly multiplying Asians is "even more grave than that of nuclear warfare."

If it were just these handful of cases I might cut them some slack, but there are dozens of other "nightmare" scenarios that also haven't taken place.

A current one you hear about is that ocean levels will rise dramatically and inundate places like miami and New York by the end of the 21st century. So I went looking for the data on ocean level rise. All over the internet you can see a stat that over the last 100 years ocean levels have risen from 4 to 8 inches. I've tried to find the original souce for that data, but I haven't been all that succesful. I did find this from the Meteorlogical Service of Canada's website:

Tide gauges along the Eurasian coastline suggest a regional mean sea level rise since 1950 of about 1.8 mm/yr, increasing to 5.8 mm/yr since 1980. Much of these variations can be explained by changes in Arctic Ocean circulation and atmospheric pressure patterns, which may in turn be linked to global climate change. Globally, key tidal gauges suggest ocean levels have risen by 1.4 mm/yr over the past 40 years. However, model studies project that sea level rise due to thermal expansion alone during the period should be only about 0.5 mm/yr. One plausible explanation for this difference is that the paucity of tidal gauges in many regions of the world's oceans may be resulting in significant error in the measured data. Recent satellite altimeter data, for example, appear to be much closer to that simulated by models. Changes in ocean circulation and atmospheric pressure patterns may also have a significant influence on regional tide gauge data.

If this is the key information that people are using to predict ocean level rises, I think Manhattan can rest easy. This admits they don't have a lot of data, what data they do have cannot be directly related to global warming as such, and there are a lot of other factors that need to be accounted for in interpreting the data. In other words, there is a lot that isn't known yet.

Is it too much to ask for people to not make hysterical pronouncements until after they have all the scientific information at hand?

1 comment:

Rich Horton said...

I realize that ocean levels are rising now as they have been for the last 6000 years or so. I just take umbrage with the "End of the world as we know it" crowd. Those prophesying sudden catastrophe need to spend more time doing research and less talking to the press.