It looks like the CH4 has an even greater cooling effect than the CO2 or am I not looking at this right? (realclimate.org)
Even greater cooling of 17 °C per decade has been observed high in the ionosphere, at 350 km altitude. (planet3.org)
Exterior Race - inspired exterior appointments that deliver enhanced performance for the Chrysler Crossfire SRT6 include a fixed rear spoiler that results in reduced lift and enhanced aerodynamic balance at high speeds, and an integrated front fascia «chin» spoiler that reduces lift while providing greater cooling air flow to the front bakes. (media.fcanorthamerica.com)