The study's finding is disheartening, if not surprising, to researchers in the field. Scientists already knew that higher carbon dioxide concentrations can decrease protein, zinc and iron levels in important crops, and this study shows a similar effect for B vitamins, says Camilo Mora, a climate change scientist at the University of Hawaii Manoa who was not involved with the new work. "It's just another piece of evidence to show how bad climate change is," he says.