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Patz of the University of Michigan, malaria has surged since the 1970s, and expanded into areas—like the Colombian high- lands—that were formally off limits to its carrier, the Anophe- les mosquito. Malaria kills between one and two million people, and gener- ates some 300 million to 500 million new cases a year. The malar- ia plasmodium is also increasingly resistant to standard treatment with chloroquine, although a new palette of drugs based on artemisinin extracted from the sweet wormwood bush has been effective. However, while chloroquine costs 10 cents a dose, the new drug from the pharmacology giant, Novartis, runs $2.50 a pop. Artemisinin should also be taken with fatty meals, not normal- ly a part of the developing world's menu. While malaria is the most dangerous of these mosquito-borne diseases, there are other unpleasant beasts out there, including dengue, or "break-bone fever," which infects 20 million people a year and kills more than 24,000. Yellow fever could also spread, as might more exotic diseases like chagus, a trypanosoma that damages the heart and is spread by the nocturnal assassin bug. Chagus, which takes about 50,000 lives a year, is endemic in Latin America, and closely associat- ed with poverty and substandard housing that gives the carrier places to hide during the day. There is a close link between vector-borne diseases and un- stable weather, the latter a major consequence of global warm- ing. According to a 2003 WHO study, "Climate Change and Human Health—Risks and Responses," dengue epidemics are closely associated with El Niño, when the surface of the Pacific Ocean heats up and brings on warm and wet con- ditions. Malaria epidemics increase fivefold as well. The same study found similar patterns with malaria in India when monsoon rains are heavy and humidity high. In a 40-year study of Bangladeshi medical records, Mercedes Pascual of the Universi- ty of Michigan found that climate change increases the incidence of cholera by spreading the disease through either floods or droughts. In the latter case, restricted water supplies are more vulnerable to dis- ease causing organisms. Recent heavy rains in West Africa have seen cholera rates more than double. More than 31,000 have been stricken since June. Flooding and drought also spread water-borne diarrheal diseases like shigella, dysentery, and typhoid, which kill over 2 million people each year, the majority of them children. Flooding also helps rodents disseminate diseases like hantavirus, tularemia, and bubonic plague. STORM SURGE Melting continental ice, coupled with the expan- sion of the oceans through warming, is projected to raise sea levels anywhere from three-and-a-half inches to three feet by 2100. This will not only inundate lowlands where hun- dreds of millions of people presently live, it will generate more powerful storms. According to the Massachusetts Institute of Technology study, tropical storms have increased in intensity by 50 percent in both the Atlantic and the Pacific over the past 30 years. "Future warm- ing may lead to an upward trend in tropical cyclones' destruc- tive potential, and, taking into account an increasing coastal population, lead to a substantial increase in hurricane-related losses in the 21st century," MIT's Kerry Emanuel told Scripps Howard News Service on July 15. Tropical storms all draw their power from warm water. The hotter the water temperature, the stronger the storm. Hurricane Katrina was a case in point. Hurricanes, heat waves, and vector-borne diseases are the most obvious effects of global warming. Other outcomes, like asthma, are hidden in a web of interconnecting events. U.S. asthma rates have increased 40 percent in the last 10 years, afflicting 25 million Americans, nine million of those chil- dren. It is the No. 1 cause for school absenteeism, and between lost workdays and medical care, costs the country about $11 bil- lion a year. Hospitalization for asthma is at record levels, partic- ularly for African-American children. This latter figure, however, may have more to do with social policy than asthma rates among certain populations. "African- American kids are hospitalized at four times the rate as Euro- American kids in Contra Costa County," says Brunner, but says that is because they don't have quality care. "Kids in Walnut Creek and Danville (affluent areas of the County) don't end up in hospitals because they do [have access to care]." There are, however, asthma "triggers" that global warming is accelerating. A major component of air pollution is ozone, and "ozone is definitely a proven asthma trigger," Brunner says. Pollen, which can cause allergies and asthma, is likely to in- crease with climate change. Studies by Dr. Paul Epstein found COURTESY OF THE NATIONAL MUSEUM OF HEALTH AND MEDICINE, ARMED FORCES INSTITUTE OF PATHOLOGY, WASHINGTON, D.C. C A L I F O R N I A N U R S E D E C E M B E R 2 0 0 5 15 A CDC expert warns that warmer temps and wetter climates mean disease-carrying mosquitoes will move north. Heavy rains in West Africa have doubled the rate of cholera (lower left). Hurricane Dennis arrived July 8, well ahead of the August "hurricane season."