Signal: longer ragweed season
RagweedPollen

Ragweed season now longer, more intense in North America

Original study at http://www.pnas.org/content/early/2011/02/11/1014107108.abstract

allergens

Warming temps driving up pollen production and allergies

“Global warming is having an effect on people’s allergies,” Ziska, a Ph.D. plant physiologist with the USDA in Beltsville, Maryland, said in an interview following the CO2 symposium, which was funded by the Environmental Protection Agency. “From the initial data we have, it appears that there is a correlation between latitude and the length of [...]