Wildfire smoke has undone roughly 25% of U.S. air quality improvements since 2000, study finds

Since 2016, wildfire smoke in the U.S. has reversed roughly 25% of air quality improvements made from the 2000 Clean Air Act, according to a new study published in the journal Nature. That figure doubles to roughly 50% when looking specifically at the impact on many western states. For more on this, CBS News was joined by Marshall Burke, an associate professor at Stanford’s Doerr School of Sustainability and a co-author of the study. Source