Analysis of Water Vapour Feedback and its Impact on Surface Temperature

Department of Physics, University of Oxford, OX26HD Oxford, United Kingdom

^* Corresponding author: siyun.yang@some.ox.ac.uk

Abstract

The accumulation of greenhouse gases is the main reason for the global warming process. Water vapour, being one of the most abundant and powerful greenhouse gas, strongly influences the warming process in multiple ways. Despite being a greenhouse gas itself, the amount of water vapour in the atmosphere is directly related to the surface temperature of the earth. To understand the global warming process, a deeper look into water vapour and its unique positive feedback mechanism is meaningful. This paper will discuss the mechanism of water vapour feedback, the equilibrium established between the content of water vapour in the air and the surface temperature of the earth. In addition, this study will calculate the time scale and magnitude of the response of water vapour to varying (in real cases increasing) surface temperature, and qualitatively analyse how water vapour feedback would affect the global warming process by serving as an amplifier for the greenhouse effect. These results establish a mathematical model for water vapour feedback’s impact on surface temperature rise and could be used as a starting point for lab experiments and more complex analysis.