1 in 4 Americans today breathes unhealthy air because of climate change. And it's getting worse.

CBS News - For more and to sign up click here Expert discusses EPA crackdown on air quality rules Expert discusses EPA crackdown on air quality rules 03:16 Much of the U.S. Northeast was smothered last summer by dense smoke from Canadian wildfires, leading to New York City's worst air quality since the 1960s. Such episodes, once mostly isolated incidents, are increasingly common due to the impact of climate…