From ClimateRealism

By Anthony Watts

WESA Radio in Pittsburgh ran a story titled, “Sneezing, runny nose, itchy eyes: Allergy symptoms start earlier with climate change,” claiming that allergy seasons are beginning earlier and becoming more intense because of climate change. This is false. Year-to-year changes in pollen timing and severity are overwhelmingly driven by short-term weather variability, regional conditions, landscaping choices, and natural biological cycles, not gradual global temperature trends.

The article states that “allergy season starts earlier than past seasons because of the effects of climate change,” and that “temperature and precipitation pattern changes mean trees are blooming earlier and vegetation is growing more rapidly, producing more pollen in the atmosphere.” That is a broad attribution claim. It assumes that earlier blooms in a given year reflect long-term climate forcing rather than ordinary seasonal variability.

But plant phenology, the timing of leaf-out and pollen release, has always varied from year to year depending on winter chill, spring temperature swings, soil moisture, late frosts, and regional precipitation patterns. A mild February followed by a warm March can advance tree pollen season by weeks. A cold or wet spring can delay it. That is weather, not climate.

The physicians quoted in the story acknowledge that pollen allergy season “typically begins in the beginning of March,” with grass allergens in summer and ragweed in fall. That seasonal progression has been consistent for decades. The intensity of any given season depends heavily on rainfall, wind patterns, and local vegetation density.

In Pennsylvania and surrounding states, spring temperature variability from one year to the next routinely swings by several degrees. Those swings have an immediate effect on bloom timing. A single warm spell can trigger early budding. Extra precipitation can speed up plant growth. A subsequent cold snap can halt or damage growth. None of that requires invoking global climate change. It is the normal interplay of regional weather patterns.

For example, regional map data from the Northeast Regional Climate Center show that for the month of March, Pennsylvania has had above normal precipitation:

Similarly, Pennsylvania’s March temperature has been above normal:

Anybody who has a home garden can tell you that’s a double-booster for plant growth, and by extension results in more pollen causing spring allergies. March next year could be exactly the opposite, cold and dry, with a delayed allergy season. That’s normal year-to-year weather variability. Plants respond to immediate temperature thresholds, not abstract global averages. A warm week in late February can advance budding regardless of whether the long-term global mean temperature has increased by one degree over a century. Year-to-year variability in spring onset can easily exceed the magnitude of the long-term warming trend itself.

Moreover, increased pollen exposure can result from non-weather factors. Urban and suburban landscaping choices matter. The widespread planting of male ornamental trees, which produce pollen but no fruit, has increased airborne pollen in many communities. The widespread planting of male ornamental trees is a phenomenon often referred to as “botanical sexism,” a term coined by horticulturist Tom Ogren to describe the preference for planting male clones of trees and shrubs in urban environments. This practice, which has contributed to significantly higher pollen counts and increased seasonal allergies is likely the single biggest source of tree pollen in expanding suburban areas. That is land-use policy, not atmospheric carbon dioxide.

Air quality also plays a role. Particulate pollution, diesel exhaust, and ozone can irritate airways and exacerbate allergy symptoms, independent of pollen counts. Population growth and urban heat island effects can locally amplify pollen production and symptom severity. Warmer localized conditions in a city can trigger earlier plant growth. Again, these are regional environmental factors, not evidence of global climate-driven transformation.

Another important point is timescale. The article implies a trend based on recent seasons, but meaningful climate analysis requires at least 30 years of consistent, standardized pollen monitoring across the same sites. Pollen data are often sparse, localized, and methodologically inconsistent. Drawing sweeping climate conclusions from a handful of recent seasons is statistically weak and little more than mere opinion.

It is also worth noting that allergy medications and diagnostic awareness have improved significantly over the past two decades. Increased reporting of symptoms may reflect better recognition and treatment, not necessarily worsening environmental exposure.

None of this denies that climate has modestly warmed over the past century. It certainly has. But attributing fluctuations in pollen timing in a single region to global climate change requires rigorous long-term datasets showing a clear upward trend beyond natural variability. The WESA article does not present such data. It relies instead on expert opinion and generalized statements about warming.

Weather variability explains why one spring is earlier or more intense than another. Soil moisture explains why some years produce heavier pollen loads. Wind patterns explain distribution. Urban landscaping explains local exposure levels.

Year-to-year allergy changes are normal biological responses to local weather conditions. Converting those fluctuations into proof of climate change stretches correlation into causation. Climate Realism debunks articles just like this one every spring, and there are dozens of examples of such flawed reporting we’ve written about.

Sneezing in March is not a climate signal and WESA is doing a disservice to allergy sufferers in their coverage area by falsely leading them to think climate change is making them miserable.