Photograph by Melanie Stetson Freeman, Christian Science Monitor/Getty Images

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A man wades through water in New Orleans, Louisiana, after Hurricane Katrina in 2005. Extreme weather linked to climate change can leave behind standing water that contains harmful bacteria and other health hazards, one of the near-term impacts President Obama will stress in his new push for policy.

Photograph by Melanie Stetson Freeman, Christian Science Monitor/Getty Images

Five Reasons for Obama to Sell Climate Change as a Health Issue

In a speech to outline a new strategy for action on climate change, Obama will underscore the health impacts and other "social costs" of global warming.

After five years of referring to climate change as a long-term climate and humanitarian problem, President Obama is trying a new strategy. In a speech Tuesday to sell a package of regulations to limit greenhouse gases from power plants, Obama will list the ways a warming planet impacts human health now, White House officials say.

The strategy may have legs. Despite the growing consensus among scientists of how humans are impacting the atmosphere, how to confront climate change—or in some cases, whether it even exists—has deadlocked along party lines. "Framing issues around some of the near-term impacts on families is probably a more effective way to make people understand the benefits of these changes," says Paul Billings, a vice president for the American Lung Association, who was invited by the White House to attend Tuesday's speech. (See related story: "California Tackles Climate Change, But Will Others Follow?")

The administration has directed several government agencies to work together on a wide-ranging effort to try to quantify the "social costs" of climate change, including health effects. (See related story: "Obama Pledges U.S. Action on Climate Change, With or Without Congress.")

Other climate experts are leaning toward the health impacts as well, curious whether reframing the issue could kickstart the national conversation. "As we clean up the energy sector's carbon dioxide, we also clean it up for [other pollutants like] sulfur dioxide and nitrogen oxides," which have been linked to respiratory diseases, says David Hawkins, director of climate programs at the Natural Resources Defense Council.

How is climate change expected to affect human health? The Centers for Disease Control and Prevention and climate experts illuminate the top five ways.

1) More heat waves, more heat-related deaths

Heat waves are the most deadly of any weather related events—more than hurricanes, floods, earthquakes, and tornadoes combined. The CDC expects not just more waves of warm weather, but more record temperatures as well. Currently, things like heat strokes kill 700 people a year in the United States. The CDC says if current emissions hold steady, officials project that number to rise as high as 5,000 by 2050.

The heating has already begun. Last year was the hottest year ever recorded in the United States. The 12 hottest years on record came in the last 15 years. With the urban heat effect—in which dense cities and paved surfaces produce more heat than in rural areas—people in cities may feel greater impacts. (See related: "10 Ways Obama Could Fight Climate Change.")

2) More asthma and worse allergies

Higher average temperatures from climate change have been shown to increase plant metabolism, causing the increased release of pollens, fungi, and spores. More than 20 million Americans are affected by asthma, a number the National Institutes of Health expect to increase exponentially with every degree increase in ambient temperature.

A bigger concern might be the presence of airborne particulates from coal-fired power plants, which are the U.S.'s biggest emitters of carbon dioxide. The administration is likely to argue that cutting CO2 emissions from power plants would also be helping to reduce the release of respiratory irritants sulfur dioxide and nitrogen oxide.

3) More mosquito bites and the diseases they carry

The relationship isn't completely understood and it depends on regional factors, but biologists have noted that as temperatures rise, the reproduction rates of parasites like malaria and West Nile virus also increase.

On top of that, mosquitoes and ticks tend to have larger appetites in warm weather, causing them to take more blood meals from unlucky mammals. The combination, says the CDC, is a scenario with the easier spread of diseases that ticks and mosquitoes spread.

4) Stressed agriculture, questionable nutrition

Longer growing seasons may be good for producing more food, but agriculture economists have warned that drastic fluctuations in year-to-year weather can overstress crops. In some regions, drought has been shown to encourage the reproduction of aphids and locusts, as well as several types of mold, that can hide inside many leafy crops. Those pests, some farmers fear, could lead to increased use of insecticides, fungicides, and herbicides. (See related Quiz: What You Don't Know About Food, Water, and Energy.)

In a study last year, the U.S. Climate Change Science Program indicated that an increase in sea-surface temperatures would lead to a proliferation of ocean bacteria species like Vibrio vulnificus and Vibrio parahaemolyticus that cause seafood-borne diseases. Most at risk, the study said, would be cultures heavily dependent on marine-based diets.

5) Contaminated water spreading pathogens

Climate change has already been linked to more extreme storms. Some of them, like Hurricane Katrina or Superstorm Sandy, have left entire cities underwater for days, allowing standing water to teem with bacteria and other pathogens. The impacts of standing water depend widely on the region's water and sewage treatment practices.

But scientists believe that new regions will be affected by floods and standing water. A 15-inch (38.1-centimeter) rise in sea level, the high end of what some models have suggested, would increase the annual number of people in the United States affected by coastal storm surges. It's now 50 million; by 2080, it could be as high as 250 million.

This story is part of a special series that explores energy issues. For more, visit The Great Energy Challenge.

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