

By Minda Berbeco



To those who suffer from seasonal allergies, these questions only bring more concerns. Rather than worry, though, perhaps we could start to plan ahead to reduce carbon emissions. Photo courtesy of Shutterstock


This change is most obvious with the troublesome ragweed plants, which are the curse of many allergy sufferers. A group of flowering plants found all over the U.S., the hardy ragweed loves a disturbed environment. It pops up along roadways and at the edges of agricultural fields, colonizing abandoned lots. Ragweed is common enough that you most certainly have seen it before, and it is highly likely that a ragweed plant’s pollen has made you or a loved one sneeze at least once. 

Ragweed pollen is one of the largest causes of allergic rhinitis—also known as hay fever—the sneezy, runny nose reaction many people are familiar with.

Unlike many other plants, ragweed doesn’t ring in the spring with large flowering blooms. Rather, it flowers in the late summer, releasing pollen just in time for a congested fall. Normally this plant is trouble enough, having a pollen season that can last between two and three months. Now, with a longer-frost free season (the amount of time between the spring thaw and fall freeze) due to a warming climate, the ragweed plant has a longer time period to get larger and hardier to produce more pollen. 

A longer growing season is only one part of the problem. Ragweed also responds positively to increases in carbon dioxide in the atmosphere. Carbon dioxide levels before the Industrial Revolution were about 280 parts per million. With the increase in emissions through the burning or fossil fuels and other human activities, those levels have recently reached 400 parts per million.


Those who are familiar with allergens, though, know that it’s not just how large the plant is, or even how much pollen it’s producing that can increase the risk of an allergic reaction. There’s also the potency of the pollen itself—the amount of allergen in the pollen. It turns out that ragweed plants grown in higher CO2 environments carry more allergens in the pollen.

Larger plants, creating more pollen, means more allergies. Sounds like a terrific future. But of course, it’s not the future, it’s occurring right now. How do your sinuses feel at the thought of that?





Visit EcoWatch’s CLIMATE CHANGE and HEALTH page for more related news on this topic.