Lindzen hypothesized that the Earth may act like an infrared iris. A sea surface temperature increase in the tropics would result in reduced cirrus clouds and thus more infrared radiation leakage from Earth's atmosphere. Additionally, rising temperatures would cause more extensive drying due to increased areas of atmospheric subsidence. This hypothesis suggests a negative feedback which would counter the effects of warming by lowering the climate sensitivity. Satellite data from CERES has led researchers investigating Lindzen's theory to conclude that the Iris effect would instead warm the atmosphere. Lindzen disputed this, claiming that the negative feedback from high-level clouds was still larger than the weak positive feedback estimated by Lin et al.