The talk will provide a broad overview of moist convection in the earth's atmosphere, focusing on the control of convective intensity by large-scale processes, feedbacks on the dynamics of large-scale circulation systems, and the sensitivity of atmospheric water vapor to microphysical processes in convective clouds. We will explore the idea of convective criticality and look at recent obsverations of the tropical atmosphere as a means of understanding how ensembles of convetive clouds interact with the larger scale circulation.