When one tree loves another tree very much, it releases pollen to fertilize the ovules of that tree, plus whatever other trees happen to be around (you know how it goes). But when the pollen begins to blow, you’re probably not marveling at the miracle of tree reproduction—you’re dreading the allergies that accompany it.

The reason that pollen makes some people sniffle and sneeze is because their immune systems attack it like a parasite, says Leonard Bielory, professor and allergy specialist at Rutgers University Center of Environmental Prediction.

That’s because certain people’s immune systems recognize the protein sequence in pollen as similar to the protein sequence in parasites. When this happens, their bodies attempt to expel the “parasite” through sneezing and other symptoms. This attack on the pollen, Bielory says, “is the reaction we call allergy.”

The fact that some people’s bodies react this way is actually kind of weird, since pollen “is rather innocuous,” he says. Our immune system “really should not be reacting to it, because pollen is nothing more than the male reproductive component of plants.”

So Hot in Here

Reports of pollen allergies first appeared around the time of the industrial revolution. Whether that means that these allergies were the product of pollution, new diets, or changes in hygiene isn’t clear. What is clear, writes Charles W. Schmidt in this month’s issue of Environmental Health Perspectives, is the role of climate change in contemporary pollen allergies.

“When exposed to warmer temperatures and higher levels of CO2, plants grow more vigorously and produce more pollen than they otherwise would,” writes Schmidt.

Warming temperatures in some areas, like the northern United States, extend the periods during which plants release pollen. The combined effect of warming temperatures and more CO2 means that the amount of pollen in the air has been increasing and will continue to increase as climate change worsens. (According to a study presented by Bielory, pollen counts could double by 2040.)

This is bad news not just for people who have allergies, but also for people who don’t.

“In general, the longer you’re exposed to an allergen, the more likely you are going to be sensitized to that allergen,” Bielory says. People who have pollen allergies may experience intensified symptoms, and people who don’t normally have pollen allergies may start to.

Already, Schmidt writes, there “is evidence suggesting that hay fever prevalence is rising in many parts of the world.”

Does Honey Help?

With the increase in the number of pollen allergy-sufferers, it’s understandable that people have begun to seek natural ways to alleviate their symptoms. Some have even argued that consuming honey will build up your resistance because it contains pollen.

View Images A bee farmer collects pollen to be sold as health food in New Mexico. It won’t cure your allergies,though. Photograph by Martha Cooper, National Geographic

But as Rachel E. Gross points at out Slate, that theory’s just honey bunches of lies; mainly because the pollen that makes you sneeze doesn’t come from flowers.

In the spring, the pollen that gives humans allergies comes from trees. In the summer, people have allergic reactions to grass pollen; and at the end end of summer and beginning of fall, people begin to suffer from pollinating weeds—especially ragweed, which has spread from the United States to Europe and the Middle East.

Really, the “natural” ways to deal with pollen allergies are to stay clean, keep your windows closed, and go outside when pollen counts are lower, such as after it rains. If your symptoms are bad enough, take over-the-counter medication or see an allergist. And if you don’t mind the risk of malnutrition or life-threatening diseases, there’s always hookworms.