claim: Some experts think we’re on track to hit 550 ppm by the end of the century, which would cause average global temperatures to rise by 6 degrees Celsius
evidence: International Council of Academies of Engineering and Technological Sciences (CAETS) in 2007, issued a Statement on Environment and Sustainable Growth: As reported by the Intergovernmental Panel on Climate Change (IPCC), most of the observed global warming since the mid-20th century is very likely due to human-produced emission of greenhouse gases and this warming will continue unabated if present anthropogenic emissions continue or, worse, expand without control.