3D Climate Simulations of the Archean Find That Methane has a Strong Cooling Effect at High Concentrations

Methane is thought to have been an important greenhouse gas during the Archean, although its potential warming has found be limited at high concentrations due shortwave absorption. We use Met Office Unified Model, a general circulation model, further explore climatic effect of different Archean methane concentrations. Surface peaks pressure ratio pCH4:pCO2 approximately 0.1, reaching maximum up 7 K before significant cooling above this ratio. Equator-to-pole temperature differences also tend increase pCH4 ≤ 300 Pa, which driven by difference in radiative forcing equator and poles reduction latitudinal extend Hadley circulation. 3D models are fully capture methane, these impacts