The detection of an 11-year global temperature signal by Douglass and Clader, and in other sutdies cited by David Douglass in his letter, is an important acheivement. However, these studies assume that the driver is the measured 11-year variation in total solar irradiance. They do not attempt to estimate the possible contributions of the equally well-measured 11-year variations in solar ultraviolet flux, and in solar modulation of galactic cosmic rays. Both of these variable solar influences are under study as possible drivers of 11-year global temperature variation [e.g. Haig, 1996; Svensmark and Friis-Christensen, 1997.