An additional model test of positive feedback from high desert albedo

Charney's (1975) suggestion that high desert albedo initiates a biogeophysical positive feedback response by the atmosphere has been tested in the 2‐D zonal atmospheric model, ZAM2. The results agree with the earlier test in the NASA GISS 3‐D GCM model (Charney et al. 1975) in confirming a positive feedback through precipitation but indicate a negative feedback in terms of temperature. The latter suggests that tropical deserts may play a role in air conditioning or placing an upper‐bound on the temperature of our planet.