Question: How would you expect water vapour in earth's atmosphere to impact earth's climate?
Water vapour is one of the most important greenhouse gases on earth because it significantly amplifies any change in temperature.
Water vapour plays a significant role in the regulating delicate balance that maintains earth's temperature. Due to its sheer abundance in the atmosphere, water vapour is the largest overall contributor to the radiative forcing of greenhouse gases. The additional radiative forcing of anthropogenic greenhouse gas emissions has led to an increase in air temperature. As a result, evaporation rates increase and the amount of water vapour in our atmosphere rises. Since water vapour is a greenhouse gas, increasing amounts of water vapour in our atmosphere will lead to greater atmospheric warming, amplifying increasing temperatures.
Question: How are greenhouse gases like carbon dioxide and water vapour similar? What makes them different? Why do we focus on carbon dioxide as opposed to water, when water is the 'most important' greenhouse gas?