claim: "a [cloudcover] change in the Tropics could lead to a negative feedback in the global climate, with a feedback factor of about –1.1, which if correct, would more than cancel all the positive feedbacks in the more sensitive current climate models" (Lindzen et al.
evidence: In Australia, the annual number of hot days (above 35°C) and very hot days (above 40°C) has increased significantly in many areas of the country since 1950.