'There is no connection between heatwaves in DC & CO2. The 1930s saw 268 days over 95F, or an avg. of 27 days per year. By contrast, the decade from 2000 to 2009 saw only 43 days over 95 degrees, or an avg. of 4 days per year. The current decade has averaged 12 days per year over 95F. Very hot days were 3 to 7 times more common during 1930s, than they have been since start of year 2000'