[C]an I be completely honest? I didn’t realize, until I was halfway through trying to derive the Nordhaus Model, that the units weren’t Fahrenheit. Everyone, including myself, keeps saying “we expect there to be, on average, a 3 degree increase in temperature by 2080″, and I always implicitly mentally mapped that to Fahrenheit and not to Celsius. Be honest – did you? To scientists, and noted Francophiles like Jim Manzi, it is very natural to use the metric system. But to everyday Americans, that’s really an increase of “5.4 degrees (F)” in how we discuss weather.
He asks: "should journalists report, and bloggers discuss, this to American audiences in Fahrenheit? Celsius? Both?"