Plants and Drought in a Changing Climate

Abstract

Purpose of review Climate is changing in response to rising concentrations of atmospheric CO 2 and it is commonly asserted that this will cause droughts to become more frequent and severe. However, different metrics of drought give diverging estimates of future impacts. I present a summary of the significant yet underappreciated influence that plant stomatal and growth responses to CO 2 have on drought, and highlight new insights into the impacts of drought on plants in a warmer world. Recent findings Plants influence the water availability on land, and thus reduce the duration and intensity of droughts under higher CO 2 conditions. Plants are concurrently more vulnerable to mortality when droughts occur under hotter conditions. Summary The frequency and severity of drought in the future depends on the response of plants to a changing climate-ignoring plant responses leads to over-prediction of drought. Nonetheless, the impact of current frequencies of drought on plants could lead to higher mortality rates in the future as plants must withstand drought stress simultaneously with hotter temperatures.