On November 23, 2018 the U.S. Global Change Research Program released Volume II of the 4th National Climate Assessment. Mandated by Congress, the 4th National Climate Assessment (NCA4) is a periodic review of the science, impacts, and forecasts of climate change in the U.S. The science underlying this report was reviewed in NCA4 Volume I, released in 2017.

The NCA4 report includes chapters by issue and region. The chapters on Air Quality and the Midwest describe the current state-of-the-science on how climate change is impacting, and will impact, air pollution in the LADCO region. Described as the “climate penalty”, current evidence suggests that climate change is leading to a net increase in air pollution in our region. For instance, summertime ozone concentration and ozone-related premature deaths are projected to increase in the 2050s and 2090s (see NCA4 Fig. 13.2 and Fig. 21.9) in the Midwest.

Climate conditions in the LADCO region that are favorable to air pollution are projected to increase in the future. In fact, the significant reductions in air pollution emissions realized in recent years may be attenuated by rising temperatures, increasing energy demands, and increasing wildfires. From the public health and economic standpoints, NCA4 notes that the ozone pollution impacts alone could result in 200-550 premature deaths annually in the Midwest by 2050 with regional costs as high as $4.7 billion.

The NCA4 report is not all doom and gloom. It offers solutions and mitigation strategies, some of which are already in place in the LADCO region. State Departments of Health throughout the LADCO region have been building climate resiliency plans that identify risks to minimize the health impacts to vulnerable communities.  As climate altering pollution and air pollution emissions often share the same sources, there are opportunities to gain co-benefits by reducing the emissions from industrial and traffic sources.  In other words, strategies to reduce air pollution emissions from cars, such as cleaner engine technologies, will also reduce carbon dioxide and help to mitigate climate change. It is also true that some strategies to reduce greenhouse gas emissions will reduce air pollution.

A key message in the NCA4 report is the connection between climate change and air pollution in the LADCO region. As temperature is a primary driver of ozone pollution in our region, forecasts of higher temperatures in the region present an air pollution planning challenge.  Our predictions of the effectiveness of emissions reduction strategies, which are fundamental to State Implementation Plans, will likely become less reliable if we don’t also consider climate forecasts in our planning models.


About Author

Zac is LADCO's Executive Director. He's an environmental scientist with 20+ years experience in emissions and air quality modeling.