If Climate Overheats, Will You Be Cool?

Be Prepared for Global Warming, Docs Urge

By Daniel J. DeNoon
WebMD Medical News

Reviewed by Dr. Jacqueline Brooks

Ooh, ooh, ooh,
I feel my temperature rising
Help me, I'm flaming
I must be a hundred and nine
Burning, burning, burning
And nothing can cool me
I just might turn into smoke
But I feel fine.

(written by Dennis Linde, performed by Elvis Presley)

April 20, 2001 -- It looks as though the weather will get worse in the next 50 years. And experts are saying that this will have implications for our health, unless we all take action.

"We consider this the major health problem on the globe," Robert K. Musil, PhD, MPH, tells WebMD. "If more extreme weather is happening, we believe people should be looking at the health effects. There is good evidence these changes will be adverse to human health."

To this end, the U.S. Institute of Medicine has convened a group of well-respected experts to consider the possible health effects of global climate change and to make recommendations for possible solutions. Emory University professor Howard Frumkin, MD, PhD, DrPH, is a member of this Roundtable on Environmental Health Sciences, Research, and Medicine.

"I really don't know what is going to happen, and people who issue shrill warnings probably don't have hard facts," Frumkin tells WebMD. "But I think there is a strong case to be made for the precautionary principle: ... If you don't have full scientific knowledge of an impending health or environmental threat, don't let that paralyze you -- don't let it stop you from taking action. It's better [to be] safe than sorry. We do this all the time in medicine. If you have a stiff neck and can't stand bright light, I will treat you for meningitis. I won't wait until there is absolute proof that you have meningitis, because if you do ... have it, you will die without immediate help."

The nonprofit group Physicians for Social Responsibility, a U.S. affiliate of the international physicians group that in 1985 won the Nobel Peace Prize for public education around issues of nuclear war, has begun an aggressive public relations campaign -- called Death by Degrees -- to call attention to the effects of global warming.

"'Death by Degrees' is a cute way of saying that while the planetary climate is shifting only slowly, we rather quickly will be seeing a number of bad health effects," says Musil, who is executive director of Physicians for Social Responsibility.

Scientists generally agree that the extreme temperatures and violent weather of the 20th century are the first of many effects caused by planetary climate changes -- that is, the warming of the earth's air and oceans. But will this trend continue into the new century? That's the big question.

Predicting weather is a very tricky business. Researchers disagree about how much warming to expect; in fact, a small minority even predicts no global warming at all. But even the most moderate predictions -- a rise in average global temperatures of about 2°F by the year 2050 -- would mean drastic weather changes.

The Scenario

The IOM panel notes that the average U.S. temperature rose by 1°F over the last 100 years. This caused more rain -- as much as 10% more, mostly due to increases in heavy downpours.

But the temperature increase over the next 100 years is expected to be much greater: 5-9°F. Because water will evaporate more rapidly, hotter temperatures will lead to more frequent and more violent thunderstorms and to more frequent and severe droughts.

Why is this happening? Most scientists point to human activity -- specifically, the burning of fossil fuels in power plants and automobile engines. Burning these fuels releases carbon dioxide and other invisible gasses into the air that let the warming sunlight through but keep heat from getting out -- the so-called greenhouse effect.

Hot and Hotter -- Heat-Related Health Threats

The most obvious effect of global warming on the U.S. is that summers will be very hot, even in northern states.

"People in cities will be most strongly affected, and ... people in northern cities [who are] not used to heat waves will be more affected than people in southern cities," Frumkin says. "These effects will include heat cramps and heat exhaustion leading up to heat stroke. ... If warming continues at the currently projected rate -- an extra 2°F in average temperature -- we would see a few thousand [additional] heat-related deaths each year by the year 2050."

Nights would bring little relief.

"It is particularly of concern that the average temperatures will continue to rise in the evenings and at night, so there is no relief for people who are stressed," Musil says.

And with heat waves comes an increase in smog. "Even healthy joggers can actually have lung damage [from pollution], and for people not as healthy as joggers it can cause health problems like asthma and cardiovascular disease," Musil says. "These are just a few of the first things that we are likely to see."

This is not mere speculation. Musil notes that the Chicago heat wave of 1985 was linked to some 740 deaths.

Pests and Pestilence -- Infectious Disease

Warmer weather would extend the ranges of mosquitoes and rodents that carry tropical diseases. More frequent violent storms also would increase pools of standing water for mosquitoes to breed in.

"As the tropical climate advances, tropical diseases like malaria will advance," Frumkin says. "The long and short of it is that malaria is a very temperature-sensitive disease, and even a few degrees of extra warmth affects its spread. The mosquitoes that carry malaria breed more and feed more when it's hot, and the malaria germ itself is more active."

More heat doesn't necessarily equal malaria -- but even if the disease doesn't return to the U.S., the conditions would be right for isolated outbreaks. And malaria isn't the only disease to worry about.

"The same is true of dengue fever, yellow fever, and cholera," Frumkin says. "We are already seeing this happen: The cholera pandemic along the pacific coast of South America probably had a lot to do with El Niño warming the water. ... It looks as though many of the conditions will be met for more infectious diseases in the future."

Musil says heat-related diseases already have appeared in New England, where warmer water temperatures permit the growth of toxic bacteria that contaminate lobster and other shellfish.

Stormy Weather

Of course, severe weather itself is a threat to life and limb.

"It is tough to say for sure that the increasing severity of hurricanes and thunderstorms is linked to climate change, but what we are seeing is close to what the scientific models of global warming would predict," Frumkin says. "A good example of another kind of effect is the recent storm-related flooding of the hog lagoons in North Carolina. Flooding can contaminate local water supplies and lead to local increases in diarrheal diseases."

Ironically, climate disruption would also lead to pockets of extremely cold weather.

"As we look at different parts of the country we see extreme weather leading to flooding and droughts and ice storms and blizzards on the one hand and heat waves on the other," Musil says.

Farming and Food

Weather changes are likely to affect the food supply too. In the short term, warmer and wetter weather in some regions would actually help farmers. Some crops, like rice, will thrive in hot and humid conditions. Other foods, like soybeans, will not.

And where crops are grown will shift dramatically -- often across national borders.

"One projection is that the central U.S. will get warmer and dryer, and the bread basket will shift north into Canada," Frumkin says. "Every projection shows pretty substantial food-crop loss across Africa and Asia. That portends a potential disaster. But it's even bad here. If the grain-growing region shifts north year by year, we could adjust. The worry there is that ecosystems sometimes change suddenly and abruptly. So if the change is over one to three years, there is a question of whether we would be able to maintain an adequate supply of food."

Livestock farms and fisheries also would be affected by climate change.

"Cattle grow more slowly and produce less milk and reproduce less successfully when it is very warm, so livestock would decline in warmer areas -- and also veterinary diseases would increase," Frumkin says.

"And as for fish -- well, we've seen from experience that fish populations are pretty sensitive to ecological changes. We've already seen the loss of cod off New England, the sardine fishery off California, and the anchovy fishery off Peru. Lots of things go into that, especially overfishing, but in the case of several of these fisheries, probably there were subtle ecosystem changes and not overfishing. So crops, livestock, and fish -- put that all together and there may be food-supply disruptions regionally if not globally."

What to Do

Both Musil and Frumkin urge reductions in greenhouse gasses as a way to prevent climate change. Frumkin -- and the IOM panel -- also advise taking protective measures.

"Foresee and prepare," Frumkin urges. "For example, emergency rooms in the South should put in cooling tubs to take care of people who are overheated. We'll need civil engineering to prevent the accumulation of water where mosquitoes can breed. And it means training our young physicians about infectious diseases."

But Musil disagrees that preventive measures can help. He calls for immediate efforts to reduce greenhouse-gas emissions.

"We don't buy the notion that this all can be dealt with," he says. "It is true that unlike Africa we have a better infrastructure, but it doesn't' mean that it is OK to let more cases of malaria develop. ... We want citizens to be aware that there are attempts to either deny or not pay attention to these critical public health problems. We are frankly concerned."

Frumkin agrees that most people -- including many political leaders -- simply don't want to think about it.

"I think there is an awful lot of denial, and it is understandable," he says. "These issues are very frightening, and fear stops people from thinking. These are unprecedented events, so it is hard to imagine what to do. ... There is misinformation being disseminated by industries that have an interest in not reducing emissions. And we need to be more cautious in stewarding our resources. We live a very luxurious life here in the U.S.: We have big cars and use lots of electricity. But it is exactly that pattern of energy use that is causing all this."

"For all these reasons it is hard to address these problems," Frumkin says. "This is going to take a lot of leadership and courage by political, social, and religious organizations. Climate change is a huge challenge. We need to pull together and address it as a society."