Global warming may to be blame for a longer ragweed pollen (read: allergy) season.
Ragweed season is now 27 days longer in the northernmost areas of North America, according to a new peer-reviewed study in the "Proceedings of the National Academy of Sciences."
With warming temperatures taking over more of winter, pollen-bearing plants have more time to thrive, according to the study.
Ragweed season was especially prolonged farther up north, in places like Wisconsin and Minnesota.
