Warmer temperatures in the past few decades have lengthened the ragweed pollen season in North America, according to a recent study.
- Pollen! (Dartmouth College Electron Microscope Facility)
One of the expected effects of the earth’s warming climate is an explosion of plantlife that will thrive in hot, CO2-rich air. Some folks, like these Fox News scribes/car mechanics, argue that that’s a good thing because of increased crop yields. But the downsides to more flora are readily apparent: more invasive species, more backyard weeding and – most awfully – a plague of pollen.
Warmer temperatures in the past few decades have already lengthened the ragweed pollen season in North America, according to a study published last month in the Proceedings of the National Academy of Sciences.
Researchers from more than a dozen allergy centers, universities and an agricultural laboratory determined that, because of milder winters and warmer seasonal temperatures, ragweed plants now spew pollen into the air 13 to 27 days longer than they did in 1995. Projecting forward, that means that allergy sufferers could be spewing snot into tissues for weeks longer in the future if temperatures continue to go up.
The study was based on two decades of climate and pollen records, the latter from the National Allergy Bureau in the U.S. and the Aerobiology Research Laboratories in Canada, and was confined to areas above the 44th parallel that are experiencing more days without frosts. The researchers found no change in ragweed levels at monitoring stations in Texas, Arkansas and Oklahoma. The study complements the findings of a 2008 examination of CO2 levels and ragweed. Researchers involved in that study found that pollen production has shot up from 61 to 90 percent in some varieties of the weed.
So what? Well, for one thing, asthma rates in kids under age 5 have rocketed by more than 160 percent from 1980 to 1994, according to the Centers for Disease Control and Prevention, and the number of people suffering from asthma is expected to grow by more than 100 million by 2025. While the researchers in this study didn’t make the direct link from ragweed to asthma, pollen is one of the potential drivers behind all these gaspy people. Allergic disorders cost the U.S. about $21 billion each year, the CDCP says.