A surge in major wildfire events in the U.S. West as a consequence of climate change will expose tens of millions of Americans to high levels of air pollution in the coming decades, according to a new Yale-led study conducted with collaborators from Harvard.The researchers estimated air pollution from past and projected future wildfires in 561 western counties, and found that by mid-century more than 82 million people will experience "smoke waves," or consecutive days with high air pollution related to fires.The regions likely to receive the highest exposure to wildfire smoke in the future include northern California, western Oregon, and the Great Plains.