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Thanks to climate change, ticks and allergies are arriving earlier

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Is that familiar allergic tickle in your throat showing up earlier in the spring? Does it seem like ticks are spreading across New England earlier, too? If so, it’s not just you — it’s climate change.

Thanks to the quickly warming Gulf of Maine, the region is warming faster than the rest of the world. Since 1900, temperatures in metropolitan Boston have climbed by about 3 degrees Celsius (5.4 degrees Fahrenheit), while temperatures on the rest of the planet rose an average of 1.14 degrees Celsius.

That means we’re seeing shorter winters, earlier blooms, and more pollen. In a study published last week in the journal Nature Communications, scientists from the University of Michigan examined 15 types of pollen from different plants found in the United States and found, in computer simulations, that pollen counts are increasing.


Richard B. Primack, a biology professor at Boston University who focuses on climate change, said the new study’s findings should come as no surprise.

”Plants are responding [to warming temperatures] by flowering earlier,” he said. “So of course, pollen season is coming earlier than it did in the past.”

If greenhouse gas emissions grow at the current rate, the study’s authors found allergy season could begin up to 40 days earlier in the United States by the century’s end. Longer summers could also cause some plants — including ragweed, which is common in Massachusetts — to release pollen for 19 extra days. So pollen season will both start earlier and end later.

Another hallmark of climate change, increased precipitation and more severe storms, could also be exacerbating allergies. More rainfall, and especially heavy rainstorms, can make pollen irritation more severe during hay fever season, a 2021 study found.

Another yearly annoyance that’s exacerbated because of climate change: ticks. Milder winters, earlier springs, and wetter conditions are creating a perfect environment for the pests, which carry a host of dangerous diseases, including Lyme disease. They’re breeding, developing, and growing in population earlier in the year, and they’re also spreading northward into areas that used to be too cold for their liking, research shows.


As the climate is changing, a new kind of tick, known as the Lone Star tick, has also spread into New England, said Larry Dapsis, deer tick project coordinator and entomologist for the Cape Cod Cooperative Extension.

“The Lone Star tick has been spreading north steadily,” he said. “It’s a function of climate change: The earth is getting warmer, and we’re seeing plants and animals where we never used to see them before. This is a great example of that.”

Cases of tick-borne Lyme disease have been trending upward for years around the country, especially in the Northeast. Federal data isn’t available on Massachusetts because state officials have altered their reporting methods, which makes it hard to track trends, but EPA numbers show that Maine and Vermont have experienced the largest increases in reported case rates, with New Hampshire close behind.

“The incidence of Lyme disease has really increased dramatically over the last several decades in New England,” Primack said.

Several factors have led to that increase, the most important likely being an uptick in deer populations due to slowed rates of hunting, said Primack. But studies suggest climate change may be another key reason. And a landmark climate report issued last month by the United Nations said: “Climate change can be expected to continue to contribute to the geographical spread of the Lyme disease vector.”


Dapsis says he’s gotten more calls about ticks in recent years, though he thinks that could be because people have been spending more time outside throughout the COVID-19 pandemic. But as climate change persists, he expects to see it play a clearer role in the spread of ticks.

“I think those changes are slowly coming in,” he said.

Dharna Noor can be reached at dharna.noor@globe.com. Follow her on Twitter @dharnanoor.