Allergy seasons grow worse with climate change
RICHMOND, Va. (WTVR) – Even though March was abnormally cool, it was also unusually wet. That moisture ended the drought, and spurred plant growth for the beginning of Spring.
Many of you were already telling me on Facebook and Twitter that you were feeling allergy symptoms in February (before our March cool slump, but well into our wet spell), and some experts predict this year may end up being a prolonged allergy season. This could lead to “the worst” allergy season we’ve experienced in memory, if you look at the number of days where allergy sufferers experience symptoms. In case you’re wondering, it was likely the tree pollen that bothered you. It’s still waffling between Moderate and High, as of this posting.
As concentrations of carbon dioxide continue to increase in the lower atmosphere, the more “fuel” plants have to inhale and combine with sunshine and soil nutrients for their productive processes, including pollen production. Warmer Springs also trigger an earlier and prolonged growing season.
If you look at what people Googled since 2004, you can see the seasonal spikes when the allergy season peaks (you’ll generally notice a Spring March-April peak and a September peak). During abnormally warm springs (like last March, which had an early start to the allergy season), more Google searches were about pollen and allergies. This green plot below shows Google searches for “pollen.”
CLICK HERE for the interactive version of this Google plot, showing the searches for “allergies” and “Claritin.”
Obviously, not every year will be a horrible allergy year. Most of these peaks are reasonably close to each other in magnitude of searches over the past decade.
This abnormally cool March is one such reason why we won’t see every single year progressively becoming worse and worse for allergies. But over time (decades), as global concentrations of carbon dioxide increase and average temperatures also rise, scientists expect the end result will mean worse seasonal allergies then compared to what we’ve experienced before.
A 2011 study from the U.S. Department of Agriculture detailed since 1995, our ragweed pollen season has grown longer by as much as 13 to 27 days longer across much of the U.S. In other words, the ragweed season in the U.S. can last almost a month longer than in previous decades during the 20th century.
More allergy research needs to be done to link temperature, precipitation and climate change patterns, but looking at human Google searches alone, we can get a general idea of the correlation between what we experience and how our climate changes over time.