TEXAS (KXAN) — A new study shows warmer temperatures and higher atmospheric carbon dioxide levels are leading to longer, more intense allergy seasons — and Texans are bearing the brunt of it.

The culprit is a mixture of rising carbon dioxide levels as humans burn fossil fuels and the warmer temperatures that result, leading to fewer freezes and longer growing seasons.

NOAA has the ability to analyze ancient air bubbles trapped in ice cores, giving us a CO₂ record that spans the last 800,000 years. According to their analysis, carbon dioxide levels are at their highest levels in at least 800,000 years.

Since plants use carbon dioxide to live, this can mean allergy-producing flora are flourishing.

Dr. Sheila Amar, board-certified allergist with Allergy & Asthma Center of Georgetown, cites a 2021 study that found Texas is seeing a faster increase in a certain springtime pollen than anywhere else in the country.

“They specifically found that tree pollen in the spring had one of the largest increases,” Dr. Amar said. “On average, the spring tree pollen started about 20 days earlier — so about 20 days longer — and there was an average across the board of an increase of about 21% concentration of the actual pollen levels.”

Pollen levels are increasing as the climate warms, but if we limit future emissions from current rates, we can limit the worsening of our allergies as well.

Studies have shown since 2007, more CO₂ in the atmosphere is also leading to bigger, more aggressive poison ivy plants. That trend is expected to continue as well unless future emissions are reduced.