Global warming may lead to more allergies

Due to global warming, tree, grasses and weeds and ragweed produce more pollen over more weeks when temperatures and carbon dioxide levels rise.

Percentage of U.S. population who reported suffering from allergic rhinitis:

Male
4.9% in 2000
6.4% in 2005

Female
7.6% in 2000
8.2% in 2005

Total
6.3% in 2000
7.4% in 2005

Source: Angency for Healthcare Research and Quality


Pollen-producing plants (weeds and trees) in Omaha, Nebraska

References:

Big culprit for allergies? Evidence points to global change. USA Today.

Anthropogenic climate change and allergen exposure: The role of plant biology. JACI, 2011.
Image source: Pollen grains from a variety of common plants, Wikipedia, public domain, Dartmouth Electron Microscope Facility.