Our work in climate statistics is motivated by the need to understand potential climate changes under rising CO2 levels and their impact on human societies. We apply statistics to understand the properties of both observations and large-scale climate models. We seek to characterize changing climate means, variability, and extremes, and also to emulate them: to develop reduced-form statistical models that capture important aspects of the changing climate system. We study the dynamics driving model behavior; our work focuses on impacts-relevant factors including temperature, precipitation, soil moisture, and their interactions.