July 19, 2021

Air Pollution and Climate Change are very much related. By Phyllis C. Leppert, MD, PhD

Now, everyone is concerned about the wild fires in the western part of the United States, the very high temperatures in Canada,  and the devasting floods in Germany, Belgium and the Netherlands. There are melting icebergs and glaciers with rising sea levels. It seems apocalyptic with so much happening everywhere. While climate change is by definition long term change in patterns of heat and moisture in either local areas or on the whole earth, air pollution is defined as the presence of toxic material due chemical, physical of biological changes in the air that is harmful to the people, animals and plants on the earth.  They are not exactly the same. However, they are interrelated. There seems to be a negative feedback loop where air pollution both contributes to climate change and climate change can make air pollution worse. The earth’s climate has had cycles of both warming and cooling over its whole existence. For instance, most people know about the Little Ice Age which started somewhere around 1275-1300, CE  and ended sometime between 1860-1870 CE. It was caused by four huge volcanic eruptions over a fifty-year period of time. Many artists of the time depicted cold winter scenes. The Little Ice Age appears to have mostly effected Europe and North America and was not a global phenomenon as best we can tell. Temperatures in the effected places dropped 2 degrees C or 3.5 degrees F on average. Winters were bitterly cold and summers were very cool. Furthermore, the cooling over these centuries appears to have impacted different parts these areas at different times. History also tells of other eras of climate change. In the first centuries of the CE the Roman Warm Period occurred. Then there was the Dark Ages Cold Period from 400-800 CE followed by the Medieval Warm Period of 800-1200 CE. Because of these cyclic events some persons are tempted to say that the earth has always had changes in climate and that the climate changes we see today are just part of that pattern.

But and there is a big but; none of these past climate changes occurred globally and they occurred over long periods of time. What we see today is climate change – global warming that effects at least 98% of the earth’s area. Temperatures are much hotter than temperatures recorded over the past 2000 years. There are hot spots in the United States that have recorded more that 2 degrees C increase in average temperatures over the lifetimes of those living now.  There are very credible and numerous scientific studies demonstrating that our Anthropocene era climate change is due to our burning of fossil fuels, cutting down forests and our modern agriculture methods. The release of green- house gases, particularly CO2 and methane traps heat in our atmosphere and prevents the heat from being reflected away from our planet.  About 81 % of the green- house gases is CO2 and approximately 10% is methane. Global climate change is quite frankly taking off. There is nothing subtle about our climate change.  Climate change affects local air quality which is also a current problem in our society due to our industries as well as air plane and car travel among other causes.

Warming temperatures most likely increases ground level ozone, which is a result of increased methane released into the atmosphere and is serious air pollutant that causes many health problems including still birth. Scientists are still studying how reduction in CO2 will affect emissions of particulate mater and other air pollutants including ground level ozone. Black Carbon (Soot) from forest fires, and industrial emissions is one component of particulate matter, (PM 2.5).  Other pollutants are hydrofluorocarbons or HFCs are released in coolants from refrigerators and air conditioners. How we deal with these pollutants in the face of the need for air conditioning and refrigeration as the world warms is just one of our current challenges due to the interface between air pollution and the climate change of global warming. 

Because global warming and air pollution are intertwined and have serious health consequences for all reproductive processes, scientists are currently studying these effects.  More research is necessary. In addition, science education is vital. One excellent example of excellent science education is a board game developed by US EPA researchers call Generate! This interactive game allows the players to explore energy sources and the environment and involves competition. It helps players to understand the costs and benefits of energy choices and how changes in future energy source mix means for climate, air, water and overall environmental quality.  For more information contact: Gayle Hagler, or Rebecca Dodder,

Further reading:

Neukom, R., Steiger, N., Gómez-Navarro, J.J. et al. No evidence for globally coherent warm and cold periods over the preindustrial Common Era. Nature 571, 550–554 (2019). https://doi.org/10.1038/s41586-019-1401-2

Barbuzano, J. (2019), The Little Ice Age wasn’t global, but current climate change is, Eos, 100, https://doi.org/10.1029/2019EO129331. Published on 24 July 2019.