Search climate change news most days and you’ll likely find few references to public health impacts.

So it comes as no surprise that the American public – apparently unlike the public in Western Europe and other industrialized countries – by and large perceives climate change as affecting nature, but not so much their families, health, or own communities.

There are exceptions, of course, and the climate change/public health connections have not been totally absent from the nation’s news pages and broadcasts. A notable example of effective coverage, for example, is a front-page Washington Post article by David Brown, “As Temperatures Rise, Health Could Decline.” Brown provides a thoughtful analytical portrayal of the anticipated human health effects of climate change and measures that could mitigate those effects.

The Majority, but ‘Crude’ View

“The effects of climate change are diverse and sometimes contradictory,” he wrote in the second paragraph of that piece. “In general, they favor instability and extreme events. On balance, they will tend to harm health rather than promote it.”

Brown described that perspective as “the majority view of scientists,” but he wrote also that “predictions of how global warming could affect people’s health are crude.”

Those predictions stem from experiences over the past several decades, during which time “there has been a small, well-documented rise in the temperatures of the planet’s atmosphere and oceans. What that says about the future – a time when warming is expected to accelerate, but people may be able to prepare for it – is quite uncertain.”

Brown’s article is noteworthy in part because of the carefully nuanced treatment of climate change and potential public health impacts. That’s a tightrope effort in most daily newspapers in today’s market, but Brown’s reporting managed nonetheless to give voice to a growing body of scientific literature supporting the link.

Other news reports connecting climate change and public health have dealt primarily with infectious diseases like West Nile Virus and conditions like heat stroke.

Asked if there is more the popular media should be reporting on the subject, Kristie L. Ebi, Ph.D., a lead author for the human health chapter in the Intergovernmental Panel on Climate Change’s Fourth Assessment Report, said “food and waterborne diseases like Salmonella have links to climate change that don’t receive enough attention.”

Salmonella accounts for 10 to 15 percent of the nearly 300,000 cases of food and waterborne illness in the US each year, Ebi said. As temperatures rise, so does the incidence of Salmonella. The late 2007 widespread media coverage of recalls of contaminated food for pets may amount to a missed opportunity for a “teachable moment” to report also on how changes in temperature and precipitation can lead to increased human exposures to diseases caused by organisms like Salmonella, Campylobacter, Vibrio, Rotavirus and Cryptosporidium. These diarrhea-causing bugs are transmitted through contaminated drinking water or food, and they’ve been around for a long time. Scientists predict we’ll see more of them in the future if current projections are accurate.

More Ticks, More Lyme Disease … and More Northerly

An increased tick population is projected to lead to increased incidences of Lyme disease in places where it hasn’t occurred previously. Parts of Canada, for instance, are projected to pass a temperature threshold allowing a tick population to become established, and that threshold line is projected to spread northward over the next decade or so.

The World Health Organization, meanwhile, is expected to release on April 7 – designated by the United Nations as World Health Day – its annual World Health Report, with an emphasis on climate change impacts. The analysis is expected to address an expanding range of disease vectors, animals, and insects that can carry viruses to which humans are susceptible.

Public health experts are increasingly concerned about whether the nation’s drinking water infrastructure will adequately protect the public during extreme precipitation events that are projected to occur more frequently as temperatures climb. Cryptosporidium concentrations, for instance, increase in drinking water sources when heavy rainfall or floods occur. Most drinking water systems are unable to detect, much less adequately filter, these parasites out of drinking water.

Climate change scientists rank waterborne organisms like Salmonella and Cryptosporidium high among the projected climate change related health risks in a warmer world. Diarrhea may not seem like such a critical health issue, but each year many of our elderly, young people, and persons with compromised immune systems die from diarrheal illnesses.

Under-Reporting of Sensitive Population Groups

An important part of the climate change/public health story deserving more attention involves the most sensitive or susceptible population groups. The list here is a familiar one for those used to dealing with environmental pollution and health effects: the young, the elderly, the infirm, and underserved population groups lacking access to amenities such as air conditioning and adequate health care.

Children breathe more rapidly than adults and their lungs are more susceptible to the effects of increasing atmospheric ozone concentrations linked to motor vehicle emissions tied to combustion of fossil fuel and therefore associated also with greenhouse gas emissions. Pregnant women’s lack of access to safe and nutritious food and clean drinking water, health care, and a healthful environment have been linked to these increased rates. It has been well documented that the elderly and people without access to air conditioning or having pre-existing heart and lung disease are more vulnerable to extreme temperature elevations.

Yet at-risk population groups – that is, those same groups most needing access to preventive care health information – often are the groups least likely to be served by mass media reports on climate change and public health.

“One example is people taking psychiatric medications like Prozac who have a decreased ability to sweat,” says climate change/public health expert Ebi. Another vulnerable group includes diabetics, easily dehydrated. Both groups are more vulnerable to the effects of extreme heat.

Given the nation’s aging population and the increasing prevalence of diabetes in the U.S., a growing number and percentage of the population will be vulnerable to climate-related health effects. These groups and the care givers looking out for them will need more access to information on which groups face higher risks and what steps they can take to protect themselves.

Climate Change: Direct or Indirect Link to More Dengue Fever

Climate change, of course, isn’t occurring in a vacuum devoid of other factors taking place globally, regionally, and locally. Even where climate change factors are not directly related to increasing public health risks, they may be contributing to the increased incidence or severity of those risks.

Writing for the Los Angeles Times‘ news service, reporter Ricardo Alonso-Zaldivar reported that “increased travel to and from South America, where a resurgence has made dengue widespread, is thought to be boosting the disease’s spread northward. And some experts suspect climate change is aggravating the problem.”

Catherine Larkin in a Bloomberg News article wrote that “Increases in rainfall, temperature and humidity caused by global warming also favor the spread of mosquitoes. These types of weather changes may more than double the number of people exposed to dengue worldwide by 2080, according to the United Nations’ 2007-2008 Human Development Report.”

“Cases of the sometimes deadly mosquito-borne disease have been reported in Texas and this may be the beginning of a new trend, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, and his senior scientific adviser, Dr. David Morens,” Larkin later reported.

“A warming climate and less-than-stellar efforts to control mosquitoes could accelerate its spread northwards, they cautioned.”

Larkin quoted form a Fauci/Morens commentary published in the Journal of the American Medical Association: “Widespread appearance of dengue in the continental United States is a real possibility.” They described the risk of such an occurrence as being more likely because of “increases in rainfall, temperature and humidity caused by global warming.”

Because atmospheric ozone and urban smog levels are temperature-related, warming could lead also to longer growing seasons and increased growth of pollen-generating vegetation, again increasing air quality respiratory disease risks for the most susceptible population groups. As warmer temperatures expand northward, so too may be the increased allergies, asthma, and other respiratory ailments … and the increased mortality and morbidity rates associated with them.

Impacts to Vary Regionally, and Not All of Them Negative

Not all of the climate change/public health impacts are likely to be negative, of course. Wealthier countries and wealthier population groups may well adapt more readily to a changing climate. Increased access to air conditioning in some societies may be a major factor mitigating heat-related deaths. People with chronic obstructive lung disease find their conditions worsened when they are exposed to extreme cold, so rising temperatures may benefit them in some ways. Similarly, there may be declines in incidences of encephalitis or Lyme disease in some areas.

Reporting local and regional aspects and public health impacts of the climate change story may help the American public better understand implications in their own backyards. In a recent report on regional impacts of climate change, the Pew Center on Global Climate Change highlighted heat waves in the Midwest, frequent and more intense hurricanes in the Gulf Coast, forest fires in the West, and depleted oxygen levels in the Chesapeake Bay, each with their own implications for public health. These regional climactic case study models can help reporters tell compelling stories of how climate and health may interact.

In the West for example, models predict more catastrophic fires with resulting effects on air quality, pest and vegetation distribution, and a long term lack of tree cover. The tree cover effect itself could increase local warming effects and amplify a cycle of events that feeds upon itself. New models of the effects of carbon dioxide on levels of pollutants associated with respiratory illness and cancer lead Stanford University researcher Mark Jacobsen to fear an additional thousand air pollution-related deaths annually in the United States. These effects may be more pronounced in the Southeast, and slightly less so in the Northeast regions.

The report on mitigation pointed to a number of public health benefits that could accrue from efforts to manage climate change impacts and risks, such as “reduced medical/hospital visits, reduced lost working days, reduced acute and chronic respiratory symptoms, reduced asthma attacks, [and] increased life expectancy.”

Reporters are best positioned to seek answers to help the public understand connections between public health and climate change, including issues related to geographical issues and various population sectors. The media can also help policy makers and the public better understand proactive and preventive health care strategies aimed to reduce health risks related to a warmer climate and help ensure that both climate change and public health issues are portrayed holistically and in context.

It’s a responsibility and a challenge facing not just environmental, health, or science beat reporters specifically, but rather the combined media, information, and education communities. And it’s one on which the gains may be greatest if they can somehow work collegially while each maintaining their own independence and focus.


Dr. Phoenix is an Associate Professor in the Department of Environmental and Occupational Health at George Washington University and Executive Director of the nonprofit Coalition for Environmentally Safe Communities. You can reach Dr. Phoenix by e-mail.