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Fact check: Is pollen season getting worse?

Photographer captures perfect storm of pollen over Durham

Photographer Jeremy Gilchrist captured these stunning photos of clouds of yellow pollen colliding with a thunderstorm over Durham, NC Monday afternoon April 8, 2019.
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Photographer Jeremy Gilchrist captured these stunning photos of clouds of yellow pollen colliding with a thunderstorm over Durham, NC Monday afternoon April 8, 2019.

With the start of every spring, a blanket of pine pollen turns parts of North Carolina a yellowish-green. This year, it might have seemed even worse than usual. Photos of the “pollenpocalypse” were shared over and over on social media.

What gives? Is pollen season getting worse? The North Carolina Fact-Checking Project decided to take a closer look.

First, let’s explain pollen. The yellow you’re seeing is the microscopic byproduct of trees and other plants, released as part of their reproductive cycle, according to Johns Hopkins Medicine.

Is the pollen really worse this year than ever before, or does it always seem that way?

While Robert Bardon, associate dean of extension and engagement for the College of Natural Resources at N.C. State University, hasn’t seen any data yet, he says this year’s pollen season is probably longer than recent years because of a mild transition from spring to winter.

“Part of it is that the season started a little bit earlier this year,” Bardon said. “Some of our hardwood trees were blooming a little bit earlier.”

Bardon says this is due to a mild end to winter with relatively few freezes. Hardwood trees like maple, oak and hickory — which are prevalent in the Raleigh area — bloomed earlier.

According to Bardon, the pollen that makes up the yellow clouds and powder is actually pine pollen. It often does not cause allergies, though it does make more of a mess, as the Charlotte Observer reported in 2015.

“That’s not what causes allergies,” Bardon said. “It’s the hardwood pollens that people are seeing allergies with.”

A prescribed burn helicopter flying over the Georgia Wildlife Management Area caused clouds of pollen to waft up from the trees, a Facebook video from Georgia Department of Natural Resources shows.

Is climate change to blame for increased pollen counts?

Climate change has increased the growing season for many plants across the U.S., which affects the amount of pollen that plants produce. According to 2018 figures from Climate Central — a science and news organization that researches and reports the impacts of climate change — the growing season in the Raleigh Durham area has increased by 28.2 days since 1972.

One root cause of climate change — increased carbon dioxide emissions — is also causing plants to produce more pollen. Plants use carbon dioxide to produce food through photosynthesis, and because they have more resources they are producing more pollen.

pollen graphic.JPG
Courtesy of Climate Central

Is it worse in Raleigh than elsewhere?

While pollen counts are notoriously difficult to compare due to varying research methods across the U.S., Raleigh does appear to be a hotspot for pollen in the U.S. in some reports.

Raleigh was ranked fifth in the nation for pollen count, according to weather.com, on April 12 — a particularly bad day last week.

The Asthma & Allergy Foundation of America ranks Greensboro and Winston-Salem 35th and Raleigh 92nd in 2019 out of 100 worst allergy cities in its 2019 allergy capital report.

Is a high pollen count good for anyone or anything? Does it indicate a healthier ecosystem?

There are winners and losers. From a human perspective, the higher pollen counts lead to worse allergy symptoms and difficulty breathing for people with asthma. More Americans are suffering from allergies and asthma than ever before, according to Climate Central. Allergies now cost the U.S. $18 billion every year, according to the American College of Allergy, Asthma and Immunology.

The increased amount of pollen also affects pollinators like bees, according to Lewis Ziska, a research plant physiologist at the U.S. Department of Agriculture Agricultural Research Service. Because the trees are producing more pollen, they pack less protein into each grain, so the bees lose out some on their only source of protein. Higher pollen counts also stimulate the growth of weeds more than agricultural crops, which reduces crop yields, according to Ziska.

On the other hand, the increased pollen counts are good for making new trees, according to Bardon. Lumber production generates an economic contribution of more than $4 billion for North Carolina, according to N.C. State Extension, a public-private partnership organization that supports agricultural research at N.C. State.

When will this end? Can we reverse the trend?

The length of pine pollen season depends on several factors like temperature, growing season length, and the amount of precipitation, according to the Charlotte Observer. But the stuff that’s covering cars and windows is declining, since pine pollen is only released for two or three weeks every year.

According to Bardon, there are three major pollen seasons. In spring there is tree pollen season, followed by grass pollen season in summer. In fall there is ragweed pollen season. Depending on what they are allergic to, allergy sufferers may have to wait until winter to find relief.

The only way to reverse the current trend of increased pollen production is to reduce greenhouse gas emissions, according to Ziska. Even if emissions stopped today, though, it would take decades to see the effects, Ziska said.

“You’d need 20 to 30 years to see any differences in the actual environment,” Ziska said.

This story was produced by the North Carolina Fact-Checking Project, a partnership of McClatchy Carolinas, the Duke University Reporters’ Lab and PolitiFact. The NC Local News Lab Fund and the International Center for Journalists provide support for the project, which shares fact-checks with newsrooms statewide. To offer ideas for fact checks, email factcheck@newsobserver.com.

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