Saturation of Water Vapor Saturation of Water Vapor Water evaporates, forming a gas phase in air. The amount of water vapor that air can hold, though, is limited. The amount of water vapor that air can hold is a strong function of temperature.
Warm air can hold a lot more vapor than cold air can.
K are typical of the tropics, and this air can hold some 25 grams of water per cubic meter. The behavior of water vapor is crucial to predicting global warming, because water itself is a strong greenhouse gas. Increasing the temperature a little bit by increasing CO 2 will enable the atmosphere to hold more water vapor, which will tend to increase the greenhouse forcing the the temperature still further.