The increased use of fossil fuels (coal, oil, gas) in the past 60 years has caused a marked rise in the levels of CO2 in the atmosphere, from about 310 parts per million (ppm) in 1950 to nearly 380 ppm in 2013. The rise in CO2 has, in turn, resulted in a sharp increase in pollen counts.
It makes perfect sense from a biological perspective. As you know, plants require C02 for their metabolic processes, just as we require oxygen for ours. In the pant metabolic process known as photosynthesis, plants combine CO2 and water, producing sugars and oxygen releasing oxygen into the atmosphere. The 25% rise in CO2 over the past 60 years represents a rich new supply of CO2 for plant photosynthesis. As a result, many plants are growing faster and more vigorously than in the past. They’re also producing more pollen; pollen counts have more than doubled in the past five years in some areas, according to an article in USA Today.
Unfortunately, what has been good for plants has not been so good for allergy sufferers. There has been a noticeable rise in the incidence of allergies such as hay fever, and also allergic asthma, in areas with high pollen counts. That’s not likely to change any time soon, since nothing much has been done to curb the steady rise in CO2.
This might be a good time to consider a career as an allergist. Someone’s going to need to diagnose, test, and treat all those new allergy sufferers (smile)!