Stabilization of Venus' climate by a chemical-albedo feedback

It has been suggested that the atmospheric concentration of SO₂ observed on Venus coincides with the equilibrium concentration over pyrite-magnetite assemblage (pyrite-magnetite buffer). If the atmospheric SO₂ abundance is controlled by the chemical reaction at the planetary surface, we expect coupling between the atmospheric SO₂ abundance and the surface temperature. Here, we propose that the pyrite-magnetite buffer combined with cloud albedo feedback controls the surface temperature on Venus. We show that this mechanism keeps the surface temperature in a rather narrow range around the presently observed value against large variations of solar luminosity and total atmospheric mass.