SCIENCE: U.N. climate change group releases strongest statement yet linking humans to rising temperatures Stephanie Paige Ogburn, E&E reporter Published: Friday, September 27, 2013 Scientists announced they are more certain than ever before that humans are the main cause of global warming. Please subscribe to ClimateWire to read the full story. Username: Password: Forgot your access codes? Recover them. Not a subscriber? Sign up for a trial. Ready to subscribe? Click here.