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Harvard Commentaries
Harvard Commentaries
Reviewed by the Faculty of Harvard Medical School

Man to Man Man to Man

Climate Change and Your Health

January 24, 2013

By Harvey B. Simon M.D.

Harvard Medical School

Nearly all scientists agree that climate change is real, is here, and that we humans are part of the problem — and part of the solution.

Experts also agree that the effects of global warming are serious. But climate change threatens more than the environment. It also threatens human health — and it's already causing problems here in the United States. Here's what you need to know to protect yourself.

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Weather is the continuously changing condition of the atmosphere, usually considered on a time scale that extends from minutes to weeks.

Climate change refers to any significant change in measures of climate, such as temperature, precipitation, wind, and other weather patterns, that lasts for decades or longer.

Global warming is one type of climate change. It is an average increase in the temperature of the atmosphere near the earth's surface and in the troposphere (lowest layer), which can contribute to changes in global climate patterns.

How Global Warming Affects Health

Climate change can affect our health in many ways.

  • Heat-related illnesses and deaths will increase as the earth warms up.
  • Hurricanes, cyclones, floods and wildfires are expected to increase, causing injury, death, psychological trauma, and damage to the public health infrastructure.
  • Insect-borne diseases, including West Nile virus and viral encephalitis (carried by mosquitoes), and Lyme disease (carried by ticks) will increase, as many insects thrive in warm water.
  • Tropical diseases, such as malaria, dengue and yellow fever may also spread to the United States. These infections may seem exotic and remote, but a 2007 Italian epidemic of a viral infection normally found in the Indian Ocean region reminds us that warming can make our small world even smaller.
  • Human suffering and economic stress are obvious consequences if melting polar ice caps are left unchecked. The sea level will rise, displacing millions of people.

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The Effects of Climate Change in the United States

These worst-case scenarios may make the health consequences of global warming sound like science fiction or Al Gore's bad dream! But climate change has already created health problems in this country.

  • The depletion of the ozone layer has increased exposure to UVB radiation that contributes to skin cancer, cataracts and immune-system problems.
  • Particulate emissions and noxious gases spewed from car tailpipes, smokestacks and burning forests contribute to heart and lung disease. Experts blame poor air quality for our huge increase in asthma since 1980.
  • Global warming may threaten important food crops. It has already boosted some pesky plants: Ragweed plants now produce twice as much pollen as they did 100 years ago. Global warming is another reason for the rise in asthma, hay fever and allergies. That's nothing to sneeze at — nor is the flourishing growth of Toxicodendron radicans, the CO2-loving plant better known as poison ivy.

And just in case you still think climate change is just a problem for polar bears, consider this: The World Health Organization estimates that climate change is already responsible for 150,000 deaths a year worldwide, and the toll is expected to double by 2030.

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Do Your Part

Here are some small steps you can take to help the environment — and your health — today and in the future.

  • Step it up. Walk (or bike) for transportation. You’ll cut your gasoline bill and air pollution. Of equal importance, the exercise will lower your risk of heart disease, high blood pressure, stroke, dementia, depression, colon cancer and osteoporosis.
  • Eat for a cooler planet. If you eat less meat and dairy, you'll reduce the demand for animal products and the amount of energy used to provide your food. You'll also take in less saturated fat, which raises cholesterol, and lower your risk of colon and prostate cancers. Substitute fruits, vegetables, whole grains, beans and fish for the health of your planet and your body.
  • Become a "locavore." One pound of lettuce contains 80 calories. But it takes 4,600 calories of fossil fuel energy to grow and process it in California and transport it to an East Coast market. Choose locally grown and organic foods to save energy used for fertilizer, pesticides, transportation and storage. You may also reduce your exposure to food-borne infections.
  • Ride right. Make your next car a high-mileage model. Keep your tires fully inflated, your car tuned, and your gas pedal off the floor. Drive less by carpooling or taking public transportation.
  • Make home improvements. A healthier home means a healthier you. The Environmental Protection Agency (EPA) is encouraging everyone to "go green" at home and work.
    • Invest in insulation, weather stripping and storm windows. Use a sealant or caulking to close cracks and plug leaks in and around doors and windows.
    • Turn the heat down a few degrees in winter and at night; set the air conditioner a few degrees warmer in summer. (Dress accordingly to make up for the difference.) Adjust curtains and window shades to keep sunlight out on hot summer days, but to let it in when it's cool. Use fans to reduce air conditioner use.
    • Switch to Energy Star appliances. Don't run your washer, dryer or dishwasher unless they're full.
    • Switch to compact fluorescent light bulbs. Turn off lights when you leave the room.
    • Turn off your computer when it's not in use. Unplug TVs, printers, fax machines and other electronics when you're away for more than a day or two; those little green lights mean you're using electricity and generating CO2.
    • Choose renewable energy (wind, solar and water, for example) if it's available to you. Reduce wasteful consumption, reuse whatever you can; recycle whatever you can't reuse.
  • Use the Environmental Protection Agency's personal emission calculator to figure out your personal and household's greenhouse gas emissions (gases that trap heat in the atmosphere). Then do whatever you can to reduce or offset it.

Health is everyone's concern, and climate change is everyone's problem. Do what it takes to reduce your "carbon footprint" and to prod our leaders to reduce global warming. It's the cool and manly thing to do.

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Harvey B. Simon, M.D. is an Associate Professor of Medicine at Harvard Medical School and a member of the Health Sciences Technology Faculty at Massachusetts Institute of Technology. He is the founding editor of the Harvard Men's Health Watch newsletter and author of six consumer health books, including The Harvard Medical School Guide to Men's Health (Simon and Schuster, 2002) and The No Sweat Exercise Plan, Lose Weight, Get Healthy and Live Longer (McGraw-Hill, 2006). Dr. Simon practices at the Massachusetts General Hospital; he received the London Prize for Excellence in Teaching from Harvard and MIT.

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