This introductory chapter summarizes the most prominent abiotic components of recent climate change to establish the environmental context from which the discussion in the rest of the book proceeds. From an ecological perspective, climate change is most meaningfully considered as the suite of abiotic changes occurring across Earth coincident with the onset of the Industrial Revolution and progressing over the past 150 years. These abiotic changes include rising temperatures, temperature variability, changes in precipitation and snow cover, and diminishing sea and land ice. All these changes can be linked to ecological dynamics, though it is probably fair to state that most research to date on the ecological consequences of climate change has focused on temperature changes.