Fall 2011

Climate Change May Be Hazardous to Your Health | Catalyst Fall 2011

By Liz Perera

The song says, “Summertime and the livin’ is easy”—but that’s not true for people who suffer from a chronic lung disease. In the United States today, 3.2 million children and more than 9.5 million adults who suffer from asthma live in areas with bad air quality, as do nearly 4.8 million people with chronic bronchitis and nearly 2.3 million with emphysema. Combine air pollution with the record heat waves we experienced this past summer, and the resulting levels of ground-level ozone—a serious respiratory irritant—can lead to major public health concerns.

With temperatures likely to rise in the future due to climate change, ozone pollution—and its associated health and economic burdens—could get much worse. The first report in our “Climate Change and Your Health” series, Rising Temperatures, Worsening Ozone Pollution, explains why.

The Physical and Financial Toll

Bearing the Brunt of Ozone Pollution

Ozone is bad for everyone, but these groups are more susceptible than others.

INFANTS AND CHILDREN have small airways because their respiratory systems are still developing, and their breathing rates are faster. So when they are exposed to ozone, it is harder and more painful for them to breathe compared with adults. Nearly 37 million children aged 18 and under live in counties with unhealthful ozone levels.

SENIORS also face a higher risk of ozone-related hospitalization or death. More than 17.4 million adults aged 65 and over live in counties with poor air quality, and this number is expected to increase dramatically as the “baby boom” generation—estimated at 79 million Americans—enters this age category over the next two to three decades.

LOW-INCOME AND SOME MINORITY GROUPS often have limited access to health care resources and therefore tend to experience worse outcomes than other groups when exposed to ozone pollution.

OUTDOOR WORKERS such as lifeguards, police officers, construction workers, and farmers are vulnerable to ozone-related illness because of their longer exposure to air pollution.

Ground-level ozone is formed when nitrogen oxides (NOx), produced by the burning of fossil fuels, and volatile organic compounds (VOCs), produced by paints and solvents, chemically react in the presence of heat and sunlight. That is why we most often hear warnings of “bad air days” during the summer and on cloud-free days. To analyze the effect of global warming on ozone pollution across large parts of this country, we combined projections of future climate-induced temperature increases with a metric that captures the relationship between temperature and ozone concentrations. The result, which we call the “climate penalty on ozone,” demonstrates the extent to which ozone pollution could rise above current levels by 2020 and 2050, assuming emissions of ozone-forming pollutants remain constant.

For each degree of warming, we determined that an increase in ground-level ozone of up to two parts per billion (ppb) above current levels in 2020 and 7 ppb in 2050 could occur. These increases may seem minuscule, but they translate into significant public health impacts for most of the continental United States. For example, in 2020—little more than eight years from now—a 2 ppb ozone increase could lead to an additional 2.8 million respiratory ailments (e.g., asthma attacks, severe coughing, wheezing, chest tightness), 944,000 missed school days, and 3,700 seniors and 1,400 infants hospitalized for respiratory problems. In 2050, a 7 ppb increase in ozone would cause these impacts to worsen dramatically: an additional 11.8 million respiratory ailments, 4.1 million missed school days, and 24,000 seniors and 5,700 infants hospitalized with respiratory problems. Some regions and populations will bear a greater burden than others.

These additional health impacts will also hurt the finances of individuals, families, and the United States as a whole: we estimate that, in 2020 alone, the 2 ppb climate penalty on ozone could result in $5.4 billion in additional health costs (in 2008 dollars). Modeling limitations prevented us from quantifying the cost impacts in 2050, but we would expect them to be significantly higher.

A Path Forward for Cleaner Air

Both ozone pollution and climate change are caused in large part by the same activities: humans burning fossil fuels to generate electricity and power their vehicles. So the good news is we can address both problems simultaneously. Solutions such as improving vehicle fuel economy, reducing the number of vehicle miles driven, increasing energy efficiency, and generating more electricity from renewable resources will not only reduce emissions of NOx, and heat-trapping carbon dioxide, but save consumers money as well.

We must also ensure that federal air pollution standards are strong enough to be truly protective of public health. In July, the Environmental Protection Agency (EPA) issued a new rule limiting ozone-forming NOx emissions and other pollutants from power plants. Unfortunately, on September 2, the Obama administration announced it would delay issuing a stricter standard for safe ozone levels until at least 2013. UCS has been pushing for such a standard since 2007, when the EPA’s Clean Air Science Advisory Committee, a panel of independent experts, unanimously recommended capping ozone pollution between 60 and 70 ppb. (The existing standard is 84 ppb.)

Less than two weeks later, the EPA announced it would also be delaying its draft rule for reducing heat-trapping carbon emissions from power plants; a similar rule for reducing carbon emissions from refineries is scheduled to be released in December. These standards, which could help reduce ozone pollution in the long term by limiting climate-induced temperature increases, face stiff opposition from industry groups and some members of  Congress, who have already tried to strip the EPA of its authority to reduce carbon emissions (despite the Supreme Court’s earlier confirmation of that authority). UCS is urging the EPA and the administration to stand firm on these standards.

Spreading the Word


In our fight to secure strong ozone and carbon emission standards, UCS has been using a multi-pronged strategy that involves publicizing our report findings, engaging scientific and health experts who can share their knowledge with policy makers, and encouraging the public to call on their elected officials to support standards that will protect public health. When we released Rising Temperatures, Worsening Ozone Pollution in June, we recruited and trained 22 economists, health experts, scientists, and clean-energy business leaders from nine states to deliver the report to Capitol Hill and meet with their legislators. Along with a teleconference for the national press corps, we released the report to journalists in 13 states, and in the weeks that followed, the report’s authors met with local officials, university faculties, hospital staffs, and reporters about how the climate penalty on ozone will affect their communities.


Our message to all of these audiences is that the United States has the know-how and the technology to reduce unhealthful pollution while also potentially saving billions of dollars. The choices we make today about the way we live, the energy we use, and the pollution we emit will make a difference not only for our own health and well-being, but that of our children and their children as well. The sooner we act, the sooner millions of Americans can breathe easier.

Liz Perera is a senior Washington representative in the UCS Climate and Energy Program.


How Will Global Warming Affect Air Quality?

It depends on where you live.

The health impacts of increased ozone pollution will be felt across much of the country, but residents of California and states in the Midwest and mid-Atlantic regions will suffer the most. The table below lists the 10 states that will be hardest-hit; all have large, densely populated urban areas, and thus a greater number of people exposed to ozone pollution. Other high-risk areas are those with large populations of children and seniors, and those with numerous vehicles and power plants (which generate ozone-forming NOx and VOCs).