• Leah Hess

You're Not Crazy - Allergies are Worse this Year and Climate Change May Be the Culprit

It’s that time of year again. The tens of millions of people that are affected by pollen allergies are feeling that familiar springtime itch. However, many people are reporting more severe symptoms (sneezing, sore throats, itchy eyes, runny noses, etc.) this year than usual- and they’re right. This season continues the ongoing trend of higher levels of pollen and longer pollen seasons, according to Dr. Stephanie Leeds of Yale Medicine. Why this trend is occurring is likely multifactorial, but evidence points to climate change playing a major role.

One of the leading factors in worsening allergy seasons is climate change, which is the long-term alteration of temperature and weather patterns. Along with unpredictable weather patterns, tropical storms, agricultural disruptions, winter storms, and abnormal rainfall levels, climate change is often associated with rising global temperatures. Ice sheets and glaciers in polar regions are melting, causing habitat destruction and rising sea levels. Infrastructure is vulnerable to collapse because of failure to predict these abnormal temperatures. Furthermore, these higher temperatures open the door for warmth-loving plants to thrive, growing larger and producing more pollen. Similarly, carbon dioxide (CO2) is both the principal global warming gas and a source of food for these pollen-producing plants. Examples of these plants vary by region and include ragweed, ryegrass, maple, elm, mulberry, oak, and tumbleweed which are native to North America.

These claims are backed by several preliminary studies. Lewis Ziska of the U.S. Department of Agriculture (USDA) explored the link between pollen production and CO2 levels by growing ragweed plants in chambers with different CO2 concentrations. The ragweed plants grown in chambers containing 600 ppm (parts per million) ambient CO2 produced 320% more pollen than those in 370 ppm chambers. Currently, the atmospheric concentration of CO2 is just above 400 ppm, but it is projected to reach 900 ppm by the end of the 21st century. Similarly, the effect of climate change on ragweed’s flowering season was analyzed by measuring airborne pollen levels in 10 sampling stations throughout the U.S. and Canada between 1995 and 2009. The study found that pollen seasons had lengthened by 13-27 days, with greater increases in northern regions. These pollen studies are consistent with health data, which shows that asthma, eczema, and hay fever prevalence are increasing.

Unfortunately, there is no immediate solution to quell the escalating pollen count. However, biological studies are currently being undertaken to gain further understanding into the genome of allergy-inducing pollen and how concentrations of different nutrients- like nitrogen, ozone, and water- can be used to control pollen count and pollen potency (measured via the concentration of their allergic proteins). Geographical analyses are also being conducted to determine how allergies differ between regions (such as urban vs. rural) and how certain populations may be disproportionately affected. This data will, hopefully, allow scientists, government agencies, and medical professionals to curb worsening seasonal allergies.

In the meantime, individuals can take steps to remedy their allergy symptoms. Along with getting advice from a medical professional or taking daily over-the-counter allergy medications, symptoms can be alleviated by staying indoors, wearing protective clothing (hats, masks, and sunglasses) when outside, avoiding activities that stir up pollen (like mowing the lawn, raking leaves, or playing in sports on the grass), and using an air purifier in your home. All of these methods are proven preventative measures against seasonal allergies and may be enough to ease symptoms as research persists.


Speaking Plainly:

  • People who suffer from springtime allergies are complaining of worse symptoms with each coming year, a trend which is consistent with pollen count data.

  • This phenomenon is due in part to climate change, as rising temperatures and heightened atmospheric CO2 allow flowering plants to produce more pollen and have longer growing seasons.

  • Researchers are exploring the ins-and-outs of climate change’s effect on allergies, including biological and geographical studies that aim to counteract pollen count and potency, as well as how to approach the problem in differing regions.