Why Global Warming Doesn't Cause Disease

Thomas Gale Moore
Senior Fellow
Hoover Institution
Stanford University

Threats of global warming are bringing on a plague. Some will tell you it's a plague spread by the mosquitoes that thrive in a hotter climate. But we know differently. In fact, infestation we speak of is a plague of misinformation, infecting the public consciousness and blurring the issue of the effects of climate change on human health in a swarm of anxiety and confusion. This plague feasts not on blood but on fear: Officials at the very highest levels of government are doing all they can to scare us, even though some of us know better, and they probably know better themselves.

Both the President and the Vice President continue to emphasize the health hazards of climate change. In setting his goals for Kyoto, President Clinton asserted that "temperatures will rise and will disrupt the climate Disease-bearing insects are moving to areas that used to be too cold for them." In his sermon to the congregation of environmental ministers praying together in Kyoto, Vice President Gore spoke of "disease and pests spreading to new areas." (Like Washington, D.C.?)

Oh, the tangled Website they weave...
In keeping with these high-tech times, the White House's home page also trumpets this theme: Americans better watch out-global warming will make them sick. Going to extremes, the President's Website extrapolates CO2 concentrations to a quadrupled level of 1100 ppm-a scary prophecy-which they claim would boost the average July heat index (combination of humidity and temperature) for Washington, D.C., to 110 degrees! (Some of us have difficulty suppressing the thought that such a climate might provide a great boon: The federal government would shut down during the hot summer months, as it used to do before air-conditioning. Ah, the beauty of human adaptation to climate.)

In truth, promoting such a scenario on the official White House Website constitutes terror-hawking. No one-on either side of this issue-is predicting such a high concentration of greenhouse gases for any time during the next century, or even during the first part of the hundred years to follow. Forecasts for the late 21st century can only come under the heading of "science fiction." And those for the 22nd century are "pulp fiction." No one knows which types of energy humans will be using, or what technology will be available to them. Remember, in the late 19th century, waistcoated forward-thinkers predicted America's major cities would be knee-deep in horse manure by 1920 unless we "did something" like institute a big horse tax.

We cannot predict the climate's future. What we can predict, however, is that people will be richer, have more and better technology, and will be living longer. They will be better equipped to deal with any climate change than are people today.

Moreover, the warmer climate predicted for the next century is unlikely to bring a rise in heat-related deaths. As a recent article in Science magazine points out, "People adapt. One doesn't see large numbers of cases of heat stroke in New Orleans or Phoenix, even though they are much warmer than Chicago." Even so, the Presidential Website goes on to warn that "Diseases that thrive in warmer climates, such as malaria, dengue and yellow fevers, encephalitis, and cholera are likely to spread."

Unfounded, exaggerated, misleading
Even if the White House ignores WCR's frequent, informative messages on global warming and health, these officials should pay attention to the experts on disease. Both the scientific community and the medical establishment say the frightful forecasts are unfounded, exaggerated, or misleading. Further, and more important for policy-makers to note, these rumors of an upsurge in disease and early mortality stemming from climate change do not require action to reduce greenhouse gas emissions. As Science reports: "Predictions that global warming will spark epidemics have little basis, say infectious-disease specialists, who argue that public health measures will inevitably outweigh effects of climate." The article adds: "Many of the researchers behind the dire predictions concede that the scenarios are speculative."

The director of the division of vector-borne infectious diseases at the Centers for Disease Control and Prevention (CDC), Duane Gubler, calls those prophecies "'gloom and doom' based on 'soft data.'" Others attribute them to "simplistic thinking." These experts agree that "breakdowns in public health rather than climate shifts are to blame for the recent disease outbreaks."

Even El Nino, our most recent climate scapegoat, cannot take the blame for recent epidemics. The claim that dengue fever epidemics in Latin America in1994 and 1995 were due in part to El Nino is simply wrong. Science quotes dengue experts at the Pan American Health Organization: "The epidemics resulted from the breakdown of eradication programs aimed at Aedes aegypti in the 1970s and the subsequent return of the mosquito. Once the mosquito was back the dengue followed."

Oh, no! Not U.S.
The CDC's Gubler also dismisses the idea that these diseases may spread into the United States. According to Science, "He calls such predictions 'probably the most blatant disregard for other factors that influence disease transmission.'" Mosquito control programs, implemented decades ago, eliminated the insects that had inflicted these diseases on Americans for centuries. Heat has little, if anything, to do with it. The Gulf Coast states in the United States are warmer now than the Caribbean islands that are currently suffering from dengue fever. As Gubler says, "If temperature was the main factor, we would see epidemics in the Southern U.S. We have the mosquito; we have higher temperatures and constant introduction of viruses, which means we should have epidemics, but we don't."

According to Science, even those who have made these dire predictions agree that the forecasts are speculative, but justify them as playing "a useful role in consciousness-raising." In other words, let's scare people with hobgoblins in order to convince them to do "the right thing": Give up cheap energy.

In search of the healthy truth
Concerned about the health hysteria, the CDC and the National Research Council are putting together a knowledgeable panel to lay out the truth. The American Council on Science and Health (ACSH), a well-known health policy institute, has emphasized that limiting greenhouse gas emissions "would not be prudent. Fossil-fuel combustion is vital to high-yield agriculture and other practices that are fundamental to the well-being of the human population." Says their official statement: "The optimal approach to dealing with the prospect of climate change would include improvement of health infrastructures (especially in developing countries)."

The ACSH lists several goals:

* improvements in emergency responses to extreme weather events
* intensive cost-effective control of insect vectors, especially in developing countries
* improvement in drinking water and sanitation in developing areas.

These measures should be carried out regardless of whether the global climate changes, they say.

Furthermore, the council rejects specifically measures that "would impair economies and limit public-health resources. Implementation of current proposals for mitigation measures-measures to stabilize the concentration of greenhouse gases in the atmosphere-would be both costly and ineffective, the ACSH concludes.

Gubler echoes the organization's viewpoint, maintaining that "the most cost-effective way to mitigate the effect of climate change on infectious disease is to rebuild our public health infrastructure and implement better disease-prevention strategies."

"But," virologist Barry Beaty of Colorado State University told Science, "global warming is not the current problem. It is a collapse in public health measures, an increase in drug resistance in parasites, and an increase in pesticide resistance in vector populations."

Is the White House listening?

Clearly, the U.S. government should not lay waste to our economy with schemes to slash energy use on the flimsy excuse of promoting health. Disease can best be avoided by maintaining our public health facilities while strengthening those in developing countries.


Taubes, G., 1997, Apocalypse not, Science, 278, 1004-1006.

Shindell, S., and J. Raso, 1997, "Global Climate Change and Human Health, A Position Paper of the American Council on Science and Health," American Council on Science and Health, New York, N.Y.