When Dr. Stanley Fineman started as an allergist in Atlanta, he told patients that they should start taking their medications and prepare for the pollen season around St. Patrick’s Day. That was about 40 years ago. Now he tells them to start around Valentine’s Day.
In the United States and Canada, the pollen season is starting 20 days earlier and pollen loads are 21 percent higher since 1990, and a large part of this is due to global warming, a new study found in Monday’s newspaper, Proceedings of the National Academies of Sciences.
While other studies have shown that the allergy season in North America is getting longer and worse, these are the most comprehensive data with 60 reporting stations and the first to do the necessary and detailed calculations that can attribute what is happening to the changes caused by man, experts said.
“This is a clear example that climate change is here and is in every breath we breathe,” said lead author Bill Anderegg, a biologist and climate scientist at the University of Utah, who also has “really bad allergies.”
Chris Downs, a 32-year-old mechanical engineer in St. Louis, is already having sinus problems, headaches and, worst of all, itchy red eyes – and his Facebook friends in the area say they are feeling the same . He said that allergies, which started 22 years ago, usually attack in March, but this year and last year, they were already around in early February, along with the buds of trees and flowers outside.
“As a child, I never saw anything start to bloom in February, now I see a few years like that,” said Downs.
The hotter the Earth gets, the earlier spring begins for plants and animals, especially those that release pollen. Add to that the fact that trees and plants produce more pollen when they receive carbon dioxide, the study said.
“This is clearly warming temperatures and more carbon dioxide by putting more pollen in the air,” said Anderegg. Trees expel allergy-causing particles earlier than grasses, he said, but scientists are not sure why that is. Just look at the cherry blossoms opening several days earlier in Japan and Washington, DC, he said.
Texas is where some of the biggest changes are happening, Anderegg said. The south and south of the midwest are getting the pollen season about 1.3 days earlier each year, while the season is coming 1.1 days earlier in the west, he said. The northern midwest is having an allergy season about 0.65 days earlier per year, and is coming in 0.33 days ahead of the year in the southeast. In Canada, Alaska and the Northeast, researchers were unable to see a statistically significant trend.
Anderegg said his team found that city parks and plants were getting greener. They did standard detailed calculations that scientists developed to see if changes in nature can be attributed to the increase in gases that retain heat from burning coal, oil and natural gas. They compared what is happening now with computer simulations of an Earth without man-made warming and increased carbon dioxide in the air.
Since 1990, about half of the previous pollen season can be attributed to climate change – mainly due to higher temperatures – but also to the carbon dioxide that feeds plants, Anderegg said. But since the 2000s, about 65% of previous pollen seasons can be attributed to warming, he said. About 8% of the increase in pollen load can be attributed to climate change, he said.
Dr. Fineman, a former president of the American College of Allergy, Asthma and Immunology and who was not part of the study, said that this makes sense and fits with what he sees: “Pollen really does follow the temperature. There is no question. “
Although doctors and scientists knew that the previous allergy season was going on, no one had done formal climate assignment studies to date to help understand why, said Kristie Ebi, professor of environmental health at the University of Washington, who was not part of the study. . This can help scientists estimate how many cases of allergy and asthma “can be caused by climate change,” she said.
It is not just sniffles.
“We must be concerned about the pollen season because pollen is an important risk factor for allergic diseases, such as hay fever and exacerbation of asthma,” said University of Maryland environmental health professor Amir Sapkota, who was not a part of of the study. “Asthma costs the US economy about $ 80 billion a year in terms of treatment and lost productivity. Therefore, a longer pollen season poses a real threat to allergy sufferers as well as to the US economy.
Sapkota recently discovered a correlation between the early onset of spring and the increased risk of hospitalizations for asthma. One study found that students do worse on tests because of pollen levels, Anderegg said.
Gene Longenecker, a hazard geographer who recently returned to Alabama, did not suffer from a pollen allergy until he moved to Atlanta. Then he moved to Colorado: “Every summer, I just had headaches and big things like that and (I) started taking allergy tests and found that, well, I’m allergic to everything in Colorado – at least trees, grasses and pollens, weeds. “
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