Research brief: How to incorporate increased vapour pressure deficit into climate models

With projected increases in temperature in the future, the amount of water vapour that can be held at saturation – before it condenses into clouds, dew or water film – increases exponentially. As this deficit increases plants tend to close their stomata, which reduces water fluxes into the boundary layer. Do models currently capture the observed leaf-level response to increasing vapour pressure deficit? What about at very high levels of this deficit?