climate sensitivity

Climate sensitivity refers to how much the Earth's surface warms in response to increased radiative forcing, such as from greenhouse gases. A key feedback mechanism is the water vapor feedback: as the atmosphere warms, it holds more water vapor, which is a potent greenhouse gas, leading to further warming.1

Without additional feedbacks, a doubling of CO2 might cause about 1°C warming. However, positive feedbacks, like water vapor, increase this sensitivity. Climate models project warming to be greater over land than oceans, and faster in the Northern Hemisphere due to its lower ocean coverage. Significant warming is also observed in the Arctic, linked to melting sea ice reducing surface albedo. Future climate change depends on greenhouse gas emissions, with scenarios aiming to limit warming below 2°C.123