Allergist Vanitcha Pintavorn looks at Kim Gibbs' nose and ears and announces that her patient looks pretty clear.

"This is a good, good day," said Mrs. Gibbs, who suffers from severe weed and grass allergies. All of that, she knows, will change, perhaps starting today.

"It's coming," Mrs. Gibbs said.

Today is the unofficial beginning of ragweed allergy season, according to the American Academy of Allergy, Asthma & Immunology.

"Ragweed is very punctual," said Dennis Ownby, the chief of allergy and immunology at Medical College of Georgia. "It starts pollinating usually about Aug. 15, give or take about 24 hours."

And it is getting worse, with global warming as the likely culprit, the asthma and allergy group said. The group is devoting the September issue of its official scientific publication, the Journal of Allergy and Clinical Immunology , to the effects of climate change on allergies. The warming climate is leading to longer and heavier pollen seasons, and a bigger impact on patients, the authors of one of the review articles conclude.

"Both individuals with allergy and asthma are at risk of worsening disease, more symptomatic days, and reduced quality of life as a result of these environmental changes," they wrote.

Worsening air quality is also increasing allergies and asthma worldwide, they note. Drs. Pintavorn and Ownby see it in their practices.

"What worries me even more is the effects of air pollution are quite clear, and the combination of high air pollution and pollen is really bad for our allergy sufferers," Dr. Ownby said.

Ragweed seems to thrive and send out even more pollen in a high carbon-dioxide, poor-air-quality urban environment, Dr. Pintavorn said. As the Augusta area becomes more urbanized, with poorer air quality, it will have an impact, she said.

"Definitely, patients are going to suffer more," Dr. Pintavorn said.

Mrs. Gibbs is trying to approach it with a sense of humor. She has been taking allergy shots for four years and still has to use other allergy medications to keep things in check. If things start to go south, however, she knows who to call. Sitting on an exam table in Dr. Pintavorn's clinic, she points across the room at her doctor.

"Her number is in my speed dial," Mrs. Gibbs said.