Turning Archive 2006
>Climate Change: The View From the Patio
By Henry Fountain - New York Times
The poison ivy plant has been shown to produce a more toxic poison when exposed to higher levels of carbon dioxide.
(June 4, 2006) -- Scientists had some sobering news last week about the potential impact of climate change, and it didn't come from the foot of a shrinking glacier in Alaska or the shores of a tropical resort where the rising ocean is threatening the beachfront bar.
It came from a North Carolina forest, at an experimental plot where scientists can precisely control the concentration of carbon dioxide in the air. Duke researchers discovered that when exposed to higher levels of CO2, the greenhouse gas released in ever-increasing quantities from human activity, poison ivy goes haywire.
The researchers found that the weedlike plant grew much faster under CO2 conditions similar to those projected for the middle of the century. The plant also produced a more noxious form of its rash-causing chemical: a more poisonous poison ivy.
"We were surprised to find it," said William H. Schlesinger, a Duke professor who took part in the study.
While much of the discussion of climate change focuses on the big picture of rising sea levels and increasing global air and ocean temperatures, the Duke finding helps explain the smaller picture. Climate change may be a real nuisance in the backyard.
Poison ivy is only the latest entry on a growing list of pests, both plant and animal, that may be nurtured. Japanese beetles, a voracious eater of turf and trees, live longer under higher levels of carbon dioxide. The ranges of other invasive insects, like fire ants, are expected to increase as the planet warms. Disease-carrying ticks have already been shown to have moved northward in Sweden. Mosquitoes could fly farther, too.
Poplars and birch trees are flowering earlier in New England, and some global warming forecasts predict that the region's sugar maples will eventually disappear. Elevated carbon dioxide has been shown to cause ragweed and certain pine trees to produce more pollen. "It's not a pretty picture," said Paul R. Epstein, associate director of the Center for Health and the Global Environment at Harvard Medical School.