More carbon dioxide in the air makes weeds stronger.
That's the conclusion of a study published in the current issue of Weed Science, after researchers grew weeds in glasshouse experiments at ambient and elevated carbon dioxide levels.
They tested four species of invasive exotic plants in Australia that previously have been controlled with glyphosate.
All four were grown in the glasshouse, then sprayed with glyphosate. Three of the four showed significantly higher survival rates with elevated levels of carbon dioxide.
Full text of the article, "Exotic C4Grasses Have Increased Tolerance to Glyphosate under Elevated Carbon Dioxide," Weed Science,Vol. 59, No. 1, January-March 2011,is available at http://www.wssajournals.org/doi/full/10.1614/WS-D-10-00080.1