claim: Temperatures in the Southwest increased by nearly two degrees Fahrenheit ( one degree Celsius ) from 1901 to 2010, and some climate models forecast a total rise of six degrees or more by the end of this century.
evidence: For example, based on projections made by the Intergovernmental Panel on Climate Change and results from the United Kingdom Hadley Centre's climate model ( HadCM2 ), a model that accounts for both greenhouse gases and aerosols, by 2100 temperatures in Idaho could increase by 5 °F ( 2.8 °C ) ( with a range of 2-9 °F ) in winter and summer and 4 °F ( 2.2 °C ) ( with a range of 2-7 °F ) in spring and fall.