How climate change affects your health

How climate change affects your health
August 23, 2017

Rising temperatures, melting ice, extreme weather and rising sea levels are probably the first things that pop into your head when you hear “climate change.” Climate change, however, has some other, less known effects.

Climate change can alter how well certain species grow and reproduce and can pollute both air and water. Now new research from UNC Chapel Hill predicts that increased air pollution that comes with climate change will cause nearly 60,000 deaths by 2030 and 260,000 by 2100.

Forest Fire

UNC environmental sciences professor Jason West led the research team from UNC, which collaborated with climate modeling teams from Europe, Japan and New Zealand to create the predictions. The research was published in journal Nature Climate Change.

The climate change-induced increase in air pollution comes from a few sources: the chemistry of our atmosphere, the physics of changing weather and the biology of local plant life.

While ozone in the stratosphere protects us from UV radiation, ozone at ground level can cause the small muscles in the lungs to constrict and inflame the interior of the lungs, making asthma attacks more frequent and severe and making lung infections more likely.

At ground level, ozone is created when pollutants like carbon monoxide and nitrogen oxides are hit by sunlight. The reactions are driven by light, but with more heat and more pollutants those reactions move more quickly. The models predict that as both pollution and temperature increase due to climate change, ground-level ozone will increase as well. 

Parched Ground

Ozone accounts for a little less than 10 percent of the projected pollution-related deaths in the models. Volatile chemicals released by plants a higher temperatures make up a small slice as well, but fine particulate matter makes up the lion’s share. Fine particles are defined as any smaller than 2.5 micrometers, about a ten-thousandth of an inch. They can come from smoke, dust or any molecules that can clump up and float into the air. Those particles can settle in the tiny air sacs of the lungs, and from there enter the bloodstream causing heart disease and vascular problems. 

Along with rising temperatures and sea level, climate change can also alter weather patterns. Some regions will see more intense storms, some get heavy rains, some will see drought. and it is these dry regions where particulate matter will have the most impact. 

The stereotypical picture of drought is cracked earth and withered plants fluttering in the breeze.  All three of those things contribute to more dust flying in the air. Dry earth and dead plants are very easily eroded by wind, quickly filling the air with small particles. These dry areas are also more susceptible to fires, and as fires spread over parched areas, smoke and the fine particles that come with it billow into the air.

The researchers’ models show that particulate matter could be responsible for more than 55,000 deaths by 2030 and 215,000 by 2100. 

This study is among the first to employ multiple models of atmospheric chemistry to get a clear picture of how air pollution will progress over the next century. West says millions of people already die from air-pollution-related health complications every year, and this study presents some of the most coherent evidence that those complications could increase as a result of climate change.

—Daniel Lane

Daniel Lane covers science, medicine, engineering and the environment in North Carolina.

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