The models that have been constructed agree that when, as...

The models that have been constructed agree that when, as has been predicted, the level of carbon dioxide or its equivalent in other greenhouse gases doubles from pre-Industrial Revolution concentrations, the global average temperature will increase, and that the increase will be 1.5 to 4.5 degrees Celsius or 3 to 8 degrees Fahrenheit... In Dallas, for instance, a doubled level of carbon dioxide and other gases like methane, would increase the number of days a year with temperatures above 100 degrees from 19 to 78 each year.