Since Monteith published his seminal paper on evaporation and introduced the canopy resistance 50 years ago, evaporation research has shown great progress, such that his contribution describing evaporation as the delicate interplay between supply, demand and control, needs a tribute. We first identify the key contributions of John Monteith to this development and then identify a new set of challenges in the field of ecohydrology made possible by his breakthrough. These relate to adequate prediction of the occurrence, frequency and severity of drought, in relation to vegetation water use and resilience, and the interplay between the carbon and water cycles. Importantly, since Monteith published his paper, development of satellite remote sensing has made it possible to generalize site level processes and to investigate vegetation, carbon and water relations at global scale. This emerging field of research, tentatively called global ecohydrology, is set to address key questions related to the resilience and vulnerability of the world's ecosystems to their changing environment. Copyright © 2014 John Wiley & Sons, Ltd.