Study: Climate Change Lengthens Allergy Season

Climate change is leading to a longer allergy season in northern regions like New England, according to environmental scientists at the University of Massachusetts Amherst.

The ragweed season lasts longer and ends later than it did 15 years ago, said UMass biologist Christine Rogers.

"On average we have found that that has been expanding by about 13 to 27 days at northern latitudes," Rogers said. "So people will be exposed to pollen over a longer period of time."

Rogers said part of the issue is that ragweed now produces more pollen, due to increased levels of carbon dioxide.