According to Canadian researchers, flooded wetlands emit greenhouse gases in large quantities. Worse, their studies have confirmed that the creation of reservoirs in wetlands unleash poisons into the human food supply. Several studies of reservoirs have suggested that they release large quantities of carbon dioxide and methane. But in the existing reservoirs, it has been impossible to quantify the problem because no one knew as to how much gas the land emitted before the reservoir was built. Carol Kelly of the University of Manitoba and her colleagues created an experimental