This research area focuses on the processes, forcings, and feedbacks in the climate system that shape the magnitude, patterns, and timescales of climate change and variability in the geological past, the present and the future. It considers both natural and human-induced forcings at global, regional, and local scales. The research further examines the impacts and risks of climate change on marine and terrestrial ecosystems and their biodiversity. Research draws on field measurements, laboratory analyses, reconstructions of paleoclimate, monitoring with satellite data, and modeling. Key themes include atmosphere-ocean-land-ice interactions, circulation variability, ice sheet and glacier changes, the hydrological cycle, greenhouse gas dynamics, and climate-ecosystem interactions.