Climate change is a pollution problem. Not only does climate change result from carbon pollution in our atmosphere, but climate change will also increase dangerous air pollution. That is one of the messages from last month’s IPCC report. “Locally higher surface temperatures in polluted regions will trigger regional feedbacks in chemistry and local emissions that will increase peak levels of ozone and PM2.5.” – Climate Change 2013, Summary for Policymakers These pollutants cause cancer, according to a new report from the World Health Organization, which classified outdoor air pollution as a Group 1 carcinogen, alongside the known carcinogens tobacco smoke and ultraviolet radiation.
The World Health Organization estimates that outdoor air pollution caused 223,000 lung cancer deaths in 2010, and noted that it also likely increased incidence of bladder cancer. As air pollution increases in a changing climate, cancer incidence will also likely rise. Ground level ozone pollution, or smog, is a serious health concern for other reasons as well. It is a powerful irritant that causes premature mortality, heart failure, increased hospital and emergency room visits, lung damage, and asthma attacks. Ozone forms when certain chemicals interact with heat and sunlight – a chemical reaction that could increase with hotter days. These chemical precursors to ozone, such as volatile organic compounds (VOCs) and methane, result from cars, power plants, and industries that rely on fossil fuels for energy.
Fine particle pollution, or PM 2.5, is also a major health threat, linked to stroke, heart disease, premature birth, and low birth weight. It harms children in particular due to its link to adverse birth outcomes, and targets those living near heavily trafficked roadways – often the poorest among us. In a warming world, the most significant environmental carcinogen – outdoor air pollution – will increase, triggering a host of other health problems alongside lung cancer: asthma attacks, stroke, heart disease, poor birth outcomes.
When we talk about the health effects of climate change, we need to talk about this: The very air we breathe will become more and more dangerous to our health. Another likely impact of our changing climate, according to the new IPCC report: Background surface ozone levels are predicted to increase on average by 8 ppb by 2100. T
his sounds like a small amount, so I asked Dr. Chris Portier, former director of the National Center for Environmental Health and the Agency for Toxic Substances and Disease Registry, and currently senior contributing scientist at EDF, whether this would have an impact on human health. “EPA’s standard for ozone is 75 ppb,” he wrote in an email. “Currently, the EPA is considering a new standard in the range of 60-70 ppb. Either way, an increase of 8ppb will put many communities into non-compliance and increase the number from 46 counties currently to a much larger number. This is a significant issue.”
Dr. Portier also emphasized that some people are particularly vulnerable to even small changes in air chemistry. There are factors that make normal ozone levels dangerous to some people, such as asthmatics. Raising background levels even relatively small amounts could trigger serious health issues among vulnerable populations. The chemistry is complex, and “there is quite a bit of uncertainty in what will happen in any one locale with respect to ozone and PM,” writes Dr. Portier.
But according to the IPCC, climate change will likely lead to increases in background surface ozone levels, and increases in ozone and PM 2.5 in polluted areas. The IPCC, a scientific group under the auspices of the United Nations, compiles authoritative, technical, exhaustive reports on the science of global warming. The new report is authored by hundreds of scientists from dozens of countries. The IPCC is certain humans have caused this process; now it’s up to us to stop it.