Wildfires are making the U.S. smoggy again, reversing progress on cleaner air, study finds For over a decade, the U.S. saw significant reductions in national smog levels. However, since 2015, smoke from increasingly large wildfires has begun to reverse this positive trend. This shift is resulting in dirtier and deadlier air quality across the nation.

• U.S. national smog levels were dramatically reduced for over a decade.
• Since 2015, smoke from larger wildfires has reversed this clean-up trend.
• Wildfire smoke is making the air dirtier and deadlier.
• A new study highlights this concerning reversal in air quality.