Seasonal Allergies Getting Worse From Climate Change

16 States Make “Allergen Hotspots” List for Expanding Habitat of Trees with Highly Allergenic Pollen

04-14-2010 // Aileo Weinmann
Yellow Jacket

Spring is in the air, and it’s a mixed blessing for America’s 25 million allergy sufferers. A new report says many allergy triggers are worsening as a result of climate change unless action is taken to curb global warming pollution and prepare communities for the changes to come.

Tree pollen is the most common trigger for spring hay fever allergies. With spring arriving 10 to 14 days earlier than it did just 20 years ago, pollination is already starting sooner. New maps in the report show projected increases in habitat conducive to more allergenic trees. Nine states in the upper Midwest, lower Mississippi Valley, and Northeast are identified as hotspots for large increases in allergenic tree pollen if global warming pollution increases unabated. An additional seven states are at risk of moderate increases (see below).

“Climate change could allow highly allergenic trees like oaks and hickories to start replacing pines, spruces, and firs that generally don’t cause allergies, exposing many more people to springtime allergy triggers,” said Amanda Staudt, Ph.D., National Wildlife Federation climate scientist and lead author of the new report, Extreme Allergies and Global Warming.

Fall allergies, primarily caused by ragweed, are also getting worse. Ragweed plants at today’s carbon dioxide levels likely produce about twice as much pollen as they would have 100 years ago. The pollen production rate could double again if we keep adding carbon dioxide to the atmosphere.

Global warming is especially bad news for the millions of asthmatics in the United States whose asthma attacks are triggered by allergens. They will have to cope with more abundant and severe allergens plus likely increases in ground-level ozone pollution, particularly in urban areas. High ozone concentrations can trigger asthma symptoms and make bronchial airways less able to cope with allergens.

“We can’t afford for allergies and asthma to get worse,” said Mike Tringale, director of External Affairs, Asthma and Allergy Foundation of America. “Allergies and asthma combined already affect about 50 million Americans and cost nearly $27 billion in medical costs and nearly $6 billion in lost productivity and earnings.”

The report warns that fungal spores, poison ivy and even allergic reactions to bee stings could be on the increase. 

  • State “Hotspots” at risk of high increases in allergenic tree pollen: Arkansas, Iowa, Maine, Minnesota, New Hampshire, New York, Pennsylvania, Vermont and West Virginia. 
  • State Hotspots at risk of moderate increases in allergenic tree pollen: Connecticut, Illinois, Kentucky, Massachusetts, Mississippi, Tennessee and Wisconsin.
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