Answer:
The feedback loop involving water vapor and temperature is a positive feedback loop. As temperature increases, the amount of water vapor that can be held in the atmosphere also increases. This leads to an increase in the amount of water vapor in the atmosphere, which further amplifies the greenhouse effect and contributes to additional warming.
In other words, warmer temperatures lead to more water vapor in the atmosphere, which traps more heat, causing further warming, and so on. This positive feedback loop can amplify the initial warming effect caused by other factors such as greenhouse gas emissions or changes in solar radiation.
Conversely, if the temperature decreases, the amount of water vapor that can be held in the atmosphere decreases, which can lead to a decrease in the amount of water vapor present in the atmosphere, reducing the greenhouse effect and contributing to cooling. However, this negative feedback loop is weaker than the positive feedback loop described above, and it tends to be dominated by the positive feedback loop under most circumstances.