JAPAN/Please don’t blame Dr. Jay Portnoy, an allergy specialist in Kansas City, Missouri. He doesn’t go around planting ragweed. But he does treat people who suffer from asthma and hay fever, and he figures he will be busier now that the ragweed pollen that exacerbates these conditions is around longer each season than it used to be.

“These are really common diseases and they’re very expensive and they definitely affect quality of life and it’s just going to get worse for pollen sufferers,” Portnoy said of the report he helped write on climate change’s impact on the ragweed pollen season. “Of course for allergists like me, it’s job security.”

Really, though, it’s not his fault: “I’m not ‘Ragweed Appleseed,’ I don’t go around planting ragweed. I’m just the messenger. The reality is I’m going to have more patients.”

Ragweed-triggered allergies cost $21 billion a year in the United States, so scientists tracked ragweed pollen in North America. They found the pollen season is lengthening. It’s more dramatic the further north you go. In Saskatchewan, the pollen season is USA/nearly four weeks longer than it was in 1995.

Luckily, ragweed pollen season doesn’t begin until mid-summer. That’s this plant’s natural inclination. It’s a short-day plant, and does not bloom until the days start getting shorter, sometime around June 21.