7 WGCM CFMIP/IPCC Climate Sensitivity Meeting, Exeter, April 2004 CWV Sensitivity to Ts dCWV/dTs = 3.5 kgm -2 K -1 for HadAM3 and Satellite Microwave Observations over tropical oceans Corresponds to ~9%K -1 in agreement with Wentz & Schabel (2000) who analysed observed trends What about upper tropospheric moisture?