US allergy season starting earlier due to global temperature rising, scientists say

As the global temperature has increased in recent years due to climate change, allergy season in the US is starting earlier and the amount of pollen during such periods has increased, leading to worse allergy and asthma symptoms for some – and new symptoms altogether for others, according to scientists.

That trend is projected to increase as average temperatures continue to rise, but could be reversed if humans are able to reduce carbon emissions, allergists say.

“The intensity of the symptoms has increased, which means what used to be responsive to maybe just one pill used sporadically now requires absolutely an allergy pill but also maybe a nasal anti-inflammatory steroid spray as well,” said Dr John Costa, medical director of the allergy and clinical immunology division at Brigham and Women’s hospital in Boston.

Across North America, the length of the pollen season increased by 20 days and pollen concentration increased by 21% between 1990 and 2018, according to a study in the Proceedings of the National Academy of Sciences.

That’s largely due to global warming, the…