(Reuters) – The U.S. Environmental Protection Agency was ordered by a federal appeals court on Friday to take a fresh look at whether glyphosate, the active ingredient in the weed killer Roundup, posts an unreasonable risk to humans and the environment. In a 3-0 decision, the 9th U.S. Circuit Court of Appeals in Pasadena, California, agreed with several environmental, farmworker and food-safety advocacy groups that the EPA did not adequately consider whether glyphosate causes cancer and threatens endangered species. The litigation began in 2020 when two of the nonprofits, the Natural Resources…