what is VPD vapor pressure deficit how does it will change when density increased under climate change

VPD (vapor pressure deficit) is the difference between the amount of moisture in the air and the amount of moisture it can hold when it is fully saturated. It is a measure of the drying power of the air and is often used to determine the level of stress on plants during periods of high temperature and low humidity.

As density increases under climate change, the VPD will also increase. This is because as the density of the air increases, its capacity to hold moisture also increases. This means that for a given amount of moisture in the air, the VPD will be higher when the air is denser. This can lead to increased stress on plants as the air becomes drier and temperatures rise, making it more difficult for them to obtain the moisture they need to survive.