Purpose of review <p>We review three intriguing paradoxes related to potential evapotranspiration in a warming climate: global ‘evaporation, aridity, and drought paradoxes’.</p> Recent findings <p>The ‘evaporation paradox’ is the contradiction between the expected increase in atmospheric evaporative demand and the observed decrease in its proxy—pan evaporation. The ‘aridity (drought) paradox’ refers to the conflicting perspectives on whether terrestrial aridification (drought) intensifies or mitigates under global warming.</p> Summary <p>Before the mid-1990s, the enhancing effect of rising air temperature on pan evaporation is outweighed by the weakening effects of reduced shortwave radiation and wind speed, leading to a decrease in global mean pan evaporation and the emergence of the ‘evaporation paradox’. After that, rising air temperature and radiation drive an upward trend in pan evaporation, causing the paradox to disappear. We validate the deduction that neglecting stomatal responses in traditional potential evapotranspiration calculations is a key factor underlying the ‘aridity paradox’. For the ‘drought paradox’, this neglect explains the paradoxical trends in drought indices but fails for drought extent and frequency.</p>