Rising temperatures can prolong the pollen season and exacerbate allergies

Updated to ET at 5:15 am on April 14, 2022

Many allergic patients are afraid of the first warm day of spring when the air is filled with pollen that blooms flowers and trees. The hotter the climate, the longer the season of horror.

Higher temperatures can dramatically worsen the allergic season. According to new researchIf the greenhouse gas emissions are high, it will bring about spring flowering as early as 40 days. In the fall, weeds and grasses can continue to release pollen until 19 days later.

As temperatures rise, some plants, such as oak and sugi, release more pollen as a whole, increasing the incidence of allergic attacks and asthma. About 30% of people in the world have pollen-related allergies.

“This is another unintended consequence of less-studied climate change,” said Allison Steiner, a professor of atmospheric science at the University of Michigan and author of the study. “It has a huge impact on human health.”

Spring flowers bloom early

Many trees and other plants use temperature as a signal, waiting for warm spring days to bloom. In autumn, many weeds produce pollen until the cold of winter. Some small grains fill the air and are carried by insects, while others pollinate nearby flowers simply by blowing in the wind. For humans, it can mean allergic attacks, asthma and visits to the emergency room.

Steiner and her colleagues examined a variety of trees, grasses and weeds and calculated how high temperatures would affect them by the end of this century. They found that in high greenhouse gas emissions scenarios, pollen totals could increase by 16% to 40%. Researchers have found that the season of allergies worsens, even if humans reduce emissions.

“Temperature plays a big role,” says Steiner. “Trees, grasses and weeds are essentially responsive to these climate changes and produce more pollen.”

The effect can be particularly bad in the Pacific Northwest, where alder trees are expected to bloom earlier. Late plants can also get an earlier start. This means that it overlaps more with other species. This is a major drawback for people who are sensitive to multiple pollens. The northern states are expected to see the greatest changes during the allergic season due to the rapid rise in temperature.

Some plants can also get boost from higher levels of carbon dioxide that act like fertilizers, causing them to grow larger and release more pollen. Steiner says the effect is more uncertain due to the limited amount of plants affected by higher carbon dioxide.

The allergy season is already getting worse

Other studies have shown that people with allergies already have something to complain about. In North America The pollen season has been extended by 20 days According to one study, pollen levels increased by 20% between 1990 and 2018.

William Anderegg, an associate professor of biology at the University of Utah, said: “Coping with climate change is really important for people’s health.”

Seasonal allergies are not just annoying. In one study Total medical costs will be over $ 3 billion Per year.

“Pollen has a huge health impact on a huge number of people,” says Anderegg. “Millions of children suffer from asthma, which pollen can affect, and there are many non-intuitive effects, such as worker productivity at work. It’s children at school. It can affect their performance in our learning and testing. ”

Climate change can also cause unexpected allergies in some people. As the temperature rises, the plants move and grow in new places. Ragweed is expected to move further north As the environment becomes more appropriate.

This means that not only will the timing of the allergic season change, but the place where it is happening will also change.

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