The Impact of Climate Change on Allergy Seasons
If you suffer from seasonal allergies, it’s essential to visit a board-certified allergist. He or she can conduct testing and provide immunotherapy which gradually desensitizes your immune system over time.
Keep an eye on local pollen forecasts and limit outdoor exposure during high-pollen days, enhancing indoor air quality to help manage allergy symptoms more effectively.
Longer Growing Seasons
Once spring has sprung, tree pollen and ragweed unleash their full fury upon allergy sufferers throughout the country, leaving millions – including 19% of children – itchy eyes and runny noses behind them.
Our changing climate is encouraging plants to begin producing pollen much earlier each year; thus far this year, freeze-free growing seasons have already increased on average by 31 days since 1970.
Higher temperatures enable plant spores to survive longer in the air, increasing allergenicity further. Heavy rainfall, such as that predicted for parts of Southeast and Northeast this week, only compounds matters by breaking pollen particles down further into tiny particles that enter our lungs more readily.
Carbon pollution — which contributes to global warming — must be reduced as rapidly as possible to help ease allergy seasons, which we explain further in our fact sheet, Climate Change & Children’s Health: Seasonal Allergies.
Increased Pollen Production
Allergens like tree pollen, mold spores and ragweed thrive in warmer temperatures due to climate change. Their production increases accordingly leading to itchy eyes and runny noses caused by allergic rhinitis; which affects 26% of adults in the US and 19% of children.
Researchers conducted an examination of pollen emissions to forecast future emissions, and discovered that temperature has an impact on phenology in three ways. First, temperatures increased the simulated maximum daily pollen emissions (Epol,max; grains m-2 d-1) for Category 1 vegetation taxa with strong temperature-dependency such as Acacia, Early Flowering Oaks, and Larch (see “Methods” for further details).
Second, temperatures increase simulated flowering season start and end dates (sDOY and eDOY) across most vegetation types, driving changes that primarily impact pollen levels (see Fig 1). Temperature changes account for around half the lengthening in future pollen seasons as well as 8 percent of increases (see Fig 1). By comparison, land cover changes have minimal impacts on these simulated phenological trends.
Increased Asthma Attacks
An extended allergy season also means higher pollen concentrations for longer, which can irritate people living with allergies or asthma, worsening their symptoms.
As our climate warms, it becomes easier for plants to flourish and produce allergen-inducing pollen due to lengthened freeze-free growing seasons in all nine U.S. climate zones – an expected trend.
As the climate continues to warm, more Americans will face worsening allergy and asthma symptoms as climate change takes effect. These changes pose unique challenges for children, the elderly and vulnerable communities with higher rates of asthma and allergic-immunologic disease as well as additional barriers such as natural disasters or poor air quality – compounding disparate impacts of climate change on respiratory health even further.
Increased Symptoms
Pollen can be an enormous source of irritation for those suffering seasonal allergies (hay fever). Not only can it trigger annoying symptoms like sneezing, itchy eyes and stuffy nose, it can also trigger asthma attacks – making the double hit particularly hazardous for children, people with preexisting respiratory conditions and low-income communities.
Studies show that allergies are worsening with climate change. Studies have confirmed this trend by documenting pollen seasons growing longer and an increase in airborne pollen counts due to factors like warmer temperatures and more frequent droughts that increase tree pollen production; extended frost-free seasons that promote weed growth; and rising levels of greenhouse gases warming the atmosphere.
Impact may depend on where one lives. According to a recent study, while overall allergy seasons tend to extend further north than elsewhere, their severity seems more acute at northern latitudes due to water vapor and pollen interactions: When it rains, pollen grains can break apart into smaller particles more easily inhaled into one’s lungs.