Why Researchers Are Sounding The Alarm About Climate Change’s Health Impacts


Climate change and air pollution make a dangerous pair.

That’s one of the findings of a report published Monday from the Lancet Commission on Health and Climate Change, a group that represents a collaboration between European and Chinese climate scientists and geographers, social and environmental scientists, biodiversity experts, energy policy and health experts, and other professionals. The report, which laid out the health risks of climate change and makes policy recommendations, called air pollution among the most serious of the indirect health effects of global warming.

Here’s why that is: gases that result from the burning of fossil fuels pollute the air, and cause global warming. At the same time, rising temperatures worsen air pollution by increasing ground level ozone, a chemical reaction between sunlight and emissions and the main component of smog.

The resulting dirty air — a combination of ozone and fine particles — is very bad for humans, especially children whose lungs are still developing, as well as for the elderly and people with asthma, heart disease or chronic obstructive pulmonary disorder (COPD). Experts even believe it hurts healthy people as well.

“Exposure to air pollution has been directly linked to worsening respiratory disease, and not just in asthmatics,’’ said Jeffrey Demain, director of the Allergy, Asthma & Immunology Center of Alaska. “Pollution has a direct impact, there is no question. We’re seeing a rise in childhood asthma and adult onset asthma too, and increases in COPD, which is becoming a tremendous problem in this country. People are developing it who never smoked, or never had family members who smoked.’’

Society already is familiar with the direct health impacts of climate change through extreme weather events like heat waves, drought, floods, and extreme storms, which can cause death and injury. But indirect effects like air pollution can be just as risky, and will worsen in years to come if nothing is done.

“We are seeing the impacts of climate on lung health, and that is a huge concern,’’ said Janice E. Nolen, assistant vice president for national policy at the American Lung Association. “We are very worried about the threat it poses today, and will pose in the future.’’

Climate-related flooding also creates mold, another serious trigger that can impair breathing. And climate-induced drought increases the risk of wildfires, which produce a staggering amount of fine air particles from smoke and ash that damage human lungs.

“A changing climate will increase heat waves and air pollution such as from forest fires and tropospheric ozone,” said Michelle Bell, professor of environmental health at the Yale University school of forestry and environmental studies. “These are not new problems but an exacerbation of existing public health challenges. For instance, over 100 million people in the United States live in areas exceeding EPA’s health-based standards for ozone today.’’

Dangers For The Most Vulnerable

In this Tuesday, March 31, 2015 photo, an elderly Indian woman cooks using firewood at her home at Gobhali village on the outskirts of Gauhati, India.

In this Tuesday, March 31, 2015 photo, an elderly Indian woman cooks using firewood at her home at Gobhali village on the outskirts of Gauhati, India.

CREDIT: AP Photo/ Anupam Nath

Abroad, particularly in low-income countries, an estimated three billion people cook and heat their homes using open fires and simple stoves burning biomass — wood, animal dung and crop waste — and coal. These cooking methods contribute to household air pollution and an estimated 4 million premature deaths, according to the World Health Organization.

Children, both in the United States and abroad, are especially vulnerable to the harmful effects of air pollution, since their young lungs are still developing, according to W. James Gauderman, professor of preventive medicine at the University of Southern California. “Children are outdoors more than adults, they are more physically active and they breathe more per unit size of their bodies, so the impact on them will be greater than on adults,’’ he said.

Gauderman is co-author of a landmark 2004 study showing that children raised in parts of Los Angeles with poor air quality suffered significant losses in lung function. More recently in March, he authored a follow-up study that showed health improvements among children exposed to better air quality.

“Growing up in a polluted area is worse than growing up in a non-polluted area,’’ Gauderman said. “But if the air gets cleaner, lung health improves, although even those who move to less polluted areas during childhood don’t entirely recover. Flash forward: if the air quality gets worse over time, we have sound scientific evidence that you can expect increases in chronic respiratory conditions for kids, including asthma, bronchitis, reduced lung development – and in all children, not just those with existing respiratory conditions. Asthmatic kids would be particularly hard hit. If it gets worse, children’s health will suffer.’’

To be sure, air quality has improved dramatically in many American cities due to the Clean Air Act of 1970. Nevertheless, the effects of climate are impairing continued progress, according to Nolen.

“Climate change is creating conditions making it harder for us to clean up the air and reduce pollution,” she said.

Every year the American Lung Association compiles a “State of the Air’’ report, ranking cities and evaluating whether their air is improving or worsening.

“We found great improvement in year-round particles and ozone, but this year saw an enormous spike of days with high levels,’’ Nolen said. “We had six cities with the worst that we have ever seen, and that is an indicator of high particle levels, especially out West, suffering from heat, drought and wildfires — extreme weather events.’’

While the United States still faces clean air challenges, the situation for other countries is far more daunting, experts say. “We’ve still got a problem, but other countries have a much larger problem,’’ said Norman Edelman, senior consultant for scientific affairs at the American Lung Association. “The big ones are China and India, all of Southeast Asia, in fact, where the health burden of air pollution is absolutely enormous. Air pollution throughout the world is far greater than in the United States and is taking a far greater total on health.’’

Higher pollen levels — another result of climate change, as some pollen-producing plants thrive in increased carbon dioxide — intense storms and flooding that create damp moldy homes, drought that causes wildfires, and the urban heat island effect, in which cities are hotter than surrounding rural areas, “are all playing significant roles in the development of respiratory diseases,’’ Demain said.

An estimated 18.7 million American adults and 6.8 million children suffer from asthma, a number that is steadily increasing, according to the federal Centers for Disease Control and Prevention (CDC), which says cases of asthma grew by 4.3 million people between 2001 and 2009. If there are no changes in regulatory controls, the CDC predicts up to 4,300 additional premature deaths annually in the United States by the year 2050 from combined ozone and particle health effects.

‘Immediate Gains For Society’

In the United Kingdom, air pollution from the power sector accounts for an estimated 3,800 respiratory deaths annually, while air pollution in China results in 7.4 times greater premature deaths from easily inhalable fine particles than in the European Union, according to the Lancet Commission report, which was published in the British medical journal the Lancet. Also, the current concentrations of particulate matter in the air have cut about 40 months from average life expectancy in China, but “this loss could be cut by half by 2050 if climate mitigation strategies were implemented,’’ the Lancet authors write.

Emissions from coal burning power plants, in particular older plants that have not undergone emission-curbing retrofitting, “are the major source of particulate pollution, which is the big killer,’’ Edelman said. “They cause more deaths than any other form of air pollution. They are very, very fine particles that come out of the smokestacks of coal burning power plants, and they cause heart attacks and deaths.’’

The Lancet report calls for a rapid phase out of coal from the global energy mix in order to protect respiratory and cardiovascular health, urging that society replace the 1,200 coal-fired plants currently proposed for construction globally with healthier, cleaner energy alternatives. Targeting air pollution from the transport, agriculture, and energy sectors, with the aim of reducing the health burden of particulate matter and short-lived climate pollutants, would yield “immediate gains for society,’’ according to The Lancet commission.

“Actions that seek to mitigate climate change have the potential to be beneficial to health, both directly and indirectly,’’ The Lancet authors write. “The potential health benefits of switching to low-carbon technologies include a reduction in carbon emissions from power generation, improved indoor air quality through clean household cooking technologies …and lowered particulate matter exposure from low-emission transport.’’

Many lung experts believe climate change already is having an adverse impact on human health. The American Thoracic Society recently conducted a survey among its members, asking about climate change and its effects on their patients. Seventy-seven percent of those responding reported increases in the severity of chronic respiratory disease as a result of climate change-related air pollution.

“How much does climate change make air pollution worse? We believe it does so to a substantial degree,’’ said the American Lung Association’s Edelman. “It’s still conjecture. But it’s rational conjecture. And it’s worth talking about. Climate change is like this huge aircraft carrier. Once you decide to turn it around, it may be too large and too long to be able to do so.’’

Marlene Cimons, a former Los Angeles Times Washington reporter, is a freelance writer who specializes in science, health, and the environment.