Explore Earth's geological history and climate changes in this captivating Christmas Lecture by geologist Chris Jackson. Delve into the planet's oldest rocks and fossils, uncovering the story of radical climate shifts throughout time. Discover how the Earth's finely balanced tectonic system, particularly volcanoes, has regulated atmospheric carbon dioxide levels. Learn about the interconnectedness of the atmosphere, weather, and oceans, and examine the roles of greenhouse gases, carbon cycles, and volcanic activity in shaping our planet. Investigate paleobotany, mass extinctions, and even the surprising connection between jellyfish and Earth's systems. This engaging lecture, originally broadcast on BBC4, offers a comprehensive look at Earth as a dynamic, interconnected system, blending scientific insights with adventure and exploration.