Poison Ivy Gets More Poisonous

Poison ivy is, according to this piece in The Wall Street Journal, growing faster and producing more potent oil than is has in earlier
decades. Why? Because, the Journal explains, it really likes the new carbon-dioxide rich atmosphere that humans have been providing. The paper reports on research conducted by Lewis Ziska, a plant physiologist for the U.S. Department of Agriculture in Beltsville, Md. Ziska exposed one group of poison ivy plants to about 300 parts per
million of carbon dioxide — about the same level found in the
atmosphere in the 1950s. Another group was exposed to 400 parts per
million of CO2 — about the same level in the atmosphere today. After about eight months, leaf size, stem length and
weight and oil content of the plants raised at current carbon-dioxide
levels were, on average, 50 percent to 75 percent higher than the plants under the
1950s conditions. Not only did the higher CO2 level
double the growth rate, but it made for hardier plants that recovered
more quickly from the ravages of grazing animals. Read more in the Wall Street Journal.