About the SA Blog Network



Opinion, arguments & analyses from the editors of Scientific American
Observations HomeAboutContact

Allergies from Pollen Projected to Intensify with Climate Change

The views expressed are those of the author and are not necessarily those of Scientific American.

Email   PrintPrint

allergies pollen increase climate change

Image courtesy of iStockphoto/mkrberlin

Spring and summer allergy sufferers might already have noticed a slight increase in days spent sneezing each year. And new research suggests that allergies triggered by pollen are set to increase—in both duration and severity—with climate change.

The seasonal scourge ragweed has already been expanding its range in North America, thanks in large part to warming temperatures. “Climate change will increase pollen production considerably in the near future,” Leonard Bielory, a visiting professor at Rutgers University and lead researcher on the new project, said in a prepared statement. In fact, plant-based allergens are expected to nearly double by the year 2040, according to research presented this week at the annual scientific meeting of the American College of Allergy, Asthma and Immunology (ACAAI).

The researchers are studying plants grown in chambers that mimic conditions (including temperature, precipitation and carbon dioxide levels) similar to those projected by the Intergovernmental Panel on Climate Change in coming decades.

Bielory’s findings suggest that while pollen counts (the average number of pollen particles in a cubic yard of air over the course of a day) in the northeastern U.S. averaged at about 8,455 in 2000, they will surpass 11,412 by 2020 and will top 18,285 by 2040—possibly pushing as high as 21,735. In the past 25 years, for example, ragweed pollen has increased from Texas all the way up to Canada.

Not only are the average pollen counts likely to increase dramatically, but the allergy season is also set to start—and reach peak levels—much earlier in the year. In 2000, for example, pollen production began around April 15, but in 2020 it is expected to begin around March 27. Peak pollen production (increasing from 1,684 in 2000 to at least 1,844 in 2020) is likely to move from May 2 in 2000 to April 9 in 2020. And the warm season is not simply shifting its dates, but in most of North America, it is expanding by starting earlier and ending later, bringing more pollen for its duration.

Allergies are affecting an increasing segment of the population. Although there is currently no cure for seasonal allergies—and many people cope simply by using over-the-counter treatments to reduce symptoms—allergy shots can improve the body’s tolerance for the allergen. Allergies occur when the body’s immune system overreacts to a substance, such as tree pollen, grass, mold, dust mites, animal dander or a food. So shots work by slowly exposing the body to small amounts of the culprit substance. The drawback is that shots generally need to be given over time, and the tolerance generally does not last indefinitely. Bielroy recommends that, “allergy sufferers begin long-term treatment, such as immunotherapy, now” to decrease their reaction to increasing pollen levels to come.

Katherine Harmon Courage About the Author: Katherine Harmon Courage is a freelance writer and contributing editor for Scientific American. Her book Octopus! The Most Mysterious Creature In the Sea is out now from Penguin/Current. Follow on Twitter @KHCourage.

The views expressed are those of the author and are not necessarily those of Scientific American.

Rights & Permissions

Comments 5 Comments

Add Comment
  1. 1. geojellyroll 7:10 pm 11/9/2012

    This is getting ridiculous.

    Link to this
  2. 2. Bops 4:54 pm 11/10/2012

    Allergy shot don’t work.

    Link to this
  3. 3. vapur 4:54 pm 11/11/2012

    I thought that more forests were supposed to become deserts. How are allergies supposed to get worse if the plants producing pollen are dying out? According to this study, plants are going into hyperdrive trying to reproduce.

    Agree with geo, this is getting ridiculous. SCIAM is making all kinds of claims to bastardize science. Instead of trying to sell allergy shots, try teaching people to go outside with a face covering. You don’t know what you are doing to your genetics; you are what you eat.

    Link to this
  4. 4. Bird/tree/dinosaur/etc. geek 2:59 pm 11/12/2012

    OK, denialists, how about you do a modicum of research before claiming that AGW is a hoax?

    Link to this
  5. 5. bucketofsquid 6:11 pm 11/15/2012

    Geojellyroll is already ridiculous. Allergy shots do work quite well for most people but as mentioned they wear off unless you are on a maintenance cycle. Those that don’t like Sciam should stop funding them by coming to the web pages and generating revenue via the advertisers.

    B/T/D/E Geek – I neither accept or deny AGW but I am firmly convinced of GW. Indeed wasn’t the previous president GW Bush? I blame him for all climate change (mainly because it will really annoy the Republican right wing). Global Warming Bush! My personal feeling is that we should cut way back on the “greenhouse” gasses because they make the air we breathe quite icky. If it cuts down on global climate changes then so much the better

    Link to this

Add a Comment
You must sign in or register as a member to submit a comment.

More from Scientific American

Email this Article