DURHAM, N.C., May 30 (UPI) -- North Carolina scientists have found a new downside to the greenhouse effect -- poison ivy grows faster and more toxic in an atmosphere rich in carbon dioxide.
The study was carried out in an enclosed woodland at Duke University, Earthtimes.org reported. They increased the level of carbon dioxide in the atmosphere in one part of the forest to that predicted by the year 2050 and compared growth there over a six-year period to that in other areas.
While trees and woody plants grew 31 percent faster in the CO2-rich area, the poison ivy grew 149 percent faster. It also produced a more allergenic form of urushiol, the chemical that causes its irritating and sometimes dangerous rash.
Scientists say that the health of U.S. forests is already at risk because vines are outgrowing and smothering trees. The Duke experiment shows that trend is likely to get worse, while an irritating vine that already poisons 350,000 people a year will be even more common, the report said.
