Climate change is extending — and intensifying — allergy season in Seattle

It is the season of misery for millions of people in this country who suffer from the runny nose, sneezing, and congestion of allergies. And many people complain its starting earlier and lasting longer. But why is that? Experts point to one overriding cause: climate change. More carbon dioxide means more heat is trapped in the atmosphere, and that extra warmth causes plants and trees to produce more pollen. Tatevik Aprikyan looks into the environmental impact.