Gorillas in our Midst

Sometimes the practice of Science (with a capital S, the discipline) bears a striking resemblance to those National Geographic specials of the animal kingdom. You know, the ones where the 300-pound alpha male gorilla marks his territory, then goes bonkers when another alpha male dares to invade his harem.

That reminds us of the latest issue of Nature (with a capital N, the magazine). A few months ago (Vol. 7, No. 13, 3/11/02), we reported on the research of Simon Hay (University of Oxford) and his colleagues related to malaria occurrence in the highlands of East Africa. Basically, they demonstrated that malaria incidences were increasing there but not as a result of climate change. Using weather data to prove it, they showed no correlation between malaria changes and trends (or more accurately, the lack thereof) in temperature or precipitation in those regions.

Now it's important to realize that many millions of international research dollars are dedicated to the proposition that malaria and other diseases tied to insect "vectors" will spread because of global warming. Entire research labs are dependent upon global warming money to fund their disease research infrastructure. So Hay's report did not exactly set the global warming/malaria crowd into a dancing frenzy. A more considered response was necessary to counter this new gorilla.

The reply appeared in the December 12 issue of Nature, written by Jonathan Patz, Mike Hulme, Cynthia Rosenzweig, and several other major players who stand the most to lose by the proliferation of Hays' radical ideas. Here's a summary of their rebuttal:

  1. The Hay weather data were interpolated over mountainous terrain.

  2. Because of mosquitoes' response to climate thresholds, you don't need a significant trend in climate—climate variability is important, too;

  3. Nevertheless, based on a different analysis, regional warming trends do exist that match the increase in malaria.

Those results were covered by the press. For example, Reuters reporter Patricia Reaney wrote that "Climate change could be causing more than higher temperatures—it may also be helping to fuel a rise in Malaria in East Africa...Earlier research had suggested the upsurge was due to drug resistance and population growth, and not global warming. But scientists in the United States and Britain say it may not be just a coincidence that the rise in malaria parallels East African warming trends."

Well, if only Reaney had looked at the rest of the page in her copy of Nature, the same page where Patz and colleagues' comment ended, she would have seen the rebuttal by Hay and his colleagues. (We suspect it's entirely possible that she missed it—we must give her the benefit of the doubt, because otherwise it would be a flagrant case of reporter bias, and we know that all reporters are duty-bound to present both sides of a story, particularly when the counterargument is literally staring them in the face.)

Here's a summary of Simon Hay's (and his coauthors') reply:

  1. On interpolation: "We know of no evidence that climate surfaces interpolated from meteorological stations consistently fail to reveal trends in climate experienced at those locations. Crucially, further work has confirmed a very high degree of correspondence between the climate surfaces and meteorological-station data from Kericho [one of the original stations —Eds.] Moreover, these station data show no significant trend in temperature or rainfall during the 1966–95 period." Here, to support their argument, the cite several papers by Mike Hulme, whom you'll note was second author of the original comment!

  2. On sparse station coverage: "The sparse coverage of meteorological stations in the data set before 1910 in the east African region is problematic, and these data were excluded from our analyses. The full 1901–95 data set was used by one of the correspondents [Hulme again! —Eds.], however, in their trend analyses of African climate." [Oops! —Eds.]

  3. On thresholds: "The more subtle impacts of non-significant long-term changes in climate on malaria incidence deserve to be investigated, but have not been demonstrated, so we cannot attribute significant increases in malaria incidence to non-significant changes in climate."

And they conclude with "Evidence against the epidemiological significance of climate change in the recent malaria resurgences in Africa is mounting and remains unmatched by any contrary evidence."

Yep, that Reuters reporter must have simply forgotten to tell that part of the story.

So there you have it. Much of the vector-borne disease climate hysteria is based upon models that imply certain responses to a projected climate change. Reality shows significant malaria change and no significant climate change. We report...you decide. At any rate, it looks like a big new 400-pound gorilla has moved into this festering corner of the global warming impacts debate.

References:

Hay, S.I., et al., 2002. Climate change and the resurgence of malaria in the East African highlands, Nature, 415, 905–909.

Hay, S.I., et al., 2002. Hay et al. reply, Nature, 420, 628.

Patz, J.S., et al., 2002. Regional warming and malaria resurgence, Nature, 420, 627–628.