Recently a commission run by The Lancet named what they called the biggest global health threat of the 21st century. HIV/AIDS? Nope. Heart disease? Not at all. Cancer? Keep trying. To get your head around the biggest health threat of all, you might have to change how you think about health entirely. That's because the biggest threat of all, in the view of this blue-ribbon panel, was climate change.
In the last few years, leading medical professionals have begun to speak out about the extraordinary threats climate change poses to human well-being. The American Academy of Pediatrics stated in Pediatrics, its professional journal that "children are likely to suffer disproportionately from both direct and indirect adverse health effects of climate change." The American Nurses Association described the challenges of global climate change as "unprecedented in human history" and called for nurses to "speak out and advocate for change." Cecil Wilson, MD, the president of the American Medical Association, stated at a congressional briefing that climate change could cause "devastating events with serious human health implications."
How can our warming climate affect our health? In some surprising ways, as we describe in our new book, Changing Planet, Changing Health.
- Warming temperatures allow disease-carrying mosquitoes to spread out of the tropics and higher into the mountains, bringing malaria, dengue fever, and other currently tropical diseases with them. And we're not immune in North America: Dengue fever (breakbone fever) has moved from central America northern Mexico, and warming climate has brought Lyme disease to New Hampshire and Maine, is more than eight-fold as common than it was a decade ago.
- Devastating heat waves like the one that baked Chicago in 1995 and the one broiled Moscow in 2010 will become more common. Climate models project a blistering heat wave like the one that killed 739 people in Chicago in 1995 every summer, on average, by the 2040s.
- Extreme rains and snows will be even more common, like the deluge in 2010 that swamped Nashville with 13 inches of rain in a day. Health risks of flooding include drowning, respiratory diseases from mold and diarrheal disease from poor sanitation.
- Red tides and other harmful algae blooms in the warming coastal ocean can cause severe nausea, vomiting, and even paralysis and brain damage to swimmers, surfers, and those who eat contaminated shellfish. In 1987, for example, 150 people on Prince Edward Island who ate contaminated mussels were poisoned by domoic acid, an algal toxin that kills brain cells. All suffered vomiting, cramps and diarrhea; some suffered serious memory loss and seizures; nineteen were hospitalized, and four died. In Florida, emergency room visits already rise during red tides.
- A warmer, drier West is melting the snowpack early and turning forests become tinder. Bark beetle infestations that wipe entire stands of trees worsen the risk. Forest fires can kill, and smoke inhalation from forest fires heighten the risk for heart attacks, asthma and respiratory problems in susceptible people. In one study following severe wildfires in Florida, complaints of chest pain increased by 37 percent, asthma by 91 percent and bronchitis by 132 percent.
In Changing Planet, we also describe a full set of technology and policy solutions, each carefully vetted to provide maximum benefit for human health and the environment. We need a smart electrical grid that will increase efficiency, reduce demand and use renewable sources like wind, solar and geothermal at many homes and businesses rather than get power solely from a centralized power station. We need to move away from nuclear, coal, even with carbon capture and storage, and corn-based ethanol, all of which harm human health and the environment. These choices are based on extensive studies called life cycle analyses that look at the true costs of a technology or energy source from cradle to grave.
Policies must change as well. We need to rejigger the international financial system to encourage countries to invest in measures that protect their environment and the health of their citizens. To promote good health in the 21st century, we need to become resilient and adaptable.