Taking Earth's Temperature: Delving Into Climate's Past is a gripping one-hour documentary that showcases scientific discoveries about climate change. Its central message is that we can't know where we're going until we know where we've been. Like detectives, scientists explore clues in lake sediments, coral reefs, deep caves, tree rings, and glaciers. The filmmakers follow one field expedition to Alaska, travel to laboratories where research data are generated and then integrated into a global network, and interview scientists who work with predictive models to understand what past climate changes might mean for Earth's climate future.