You may think that the adverse effects of increasing levels of carbon dioxide and other heat-trapping greenhouse gases in the atmosphere—what we used to call global warming but now more appropriately call climate change—loom far off in future decades. But they are happening already. For example, ocean heat, which is a better measure of climate trends than air temperature, has risen markedly in recent decades. And it’s likely that climate change is contributing to the extreme weather of recent years. This past spring and summer, with their deadly hurricanes, flooding, tornadoes, heat waves, droughts and wildfires, were among the nation’s most severe weather seasons on record.
Climate change will have equally dramatic effects on human health as well, beyond those resulting from extreme weather. I specialize in infectious diseases, so I’m particularly aware of how climate change is contributing to a resurgence and/or redistribution of certain insect-borne diseases such as malaria, dengue fever and West Nile fever throughout the developing world and, more gradually, here. Another result is the emergence of new infectious diseases. Such exotic-sounding infectious diseases may be off the radar for most Americans, but climate change also increases the risks of many common chronic diseases. Heat waves and higher levels of ozone and other air pollutants can cause or worsen respiratory and cardiovascular disease. Higher temperatures can boost airborne allergens, notably pollen, and affect the timing and/or intensity of allergy seasons.
Droughts endanger water supplies, but so do heavier and more violent storms, which can lead to contamination of drinking water because of damage to sewage pipes, overloaded sewer systems and flooding into reservoirs supplying drinking water. And climate change is expected to have mostly negative effects on crops, livestock and fisheries, especially in poorer parts of the world, thus compounding existing food insecurity.
You and I can help reduce climate change by using energy more efficiently and reducing our “carbon footprint” as much as we can (such as by eating less meat or walking or cycling sometimes instead of driving). Many of these actions themselves have direct health benefits— reducing air pollution, for instance, or making us more physically active and reducing the risk of heart disease.
Only by working together, however, can we meet the challenge. This is where government programs and legislation come in. The Environmental Protection Ageny (EPA) is working on standards to reduce heat-trapping pollution from power plants and refineries. Comprehensive legislation is needed, but that won’t happen until politicians take this issue seriously. In the meantime, the least they can do is let EPA do its job. Humans will adapt and survive, but the health consequences are likely to be severe.