CO2 ... achoo!
An agricultural researcher in Maryland found that increased levels
of carbon dioxide, the most significant greenhouse gas, may cause some
weeds to release more pollen. The Agricultural Research Service in
Maryland planted ragweed, a common allergen, in and around Baltimore.
They found the city locations, which had higher levels of carbon
dioxide, produced more robust and faster-growing ragweed. Doubling the
level of carbon dioxide meant 60 percent more pollen produced by other
common weeds. Other research has shown trees produce more cones, another
source of pollen, after exposure to high levels of carbon dioxide.
Unfortunately for allergy sufferers, a sensitivity to allergens is
closely related to asthma, which has been on the rise for decades.
"We're already seeing this impact on weeds and trees. We are
now beginning to suspect it's playing a role in the doubling and
tripling of asthma rates in the US since the 1980s," said Dr. Paul
Epstein, associate director of the Center for Global Health and the
Environment at Harvard University.
-- Albany Times Union, 5/26