The book addresses aspects of Carbon exchange between the main Earth’s reservoirs (atmosphere, oceans, lithosphere, and biosphere) and how this dynamic has been acting at different timescales up to millions of years as a planetary climate stabilizer. Although humans are steadily introducing carbon dioxide into the atmosphere, some fundamental understanding for why the planet will not go into a catastrophic runaway greenhouse scenario is provided. It is also discussed how our own emissions compare with some seminal perturbations in the C cycle in the geological past. The physical mechanism of the greenhouse effect and its consequences for rising temperatures, sea level rise, and polar ice melt, is also generally covered. The book ends with discussions on some of the technical and scientific solutions for mitigating and reducing emissions, as well as the challenges faced by a society that will have to live with an Earth system in a state far from its previous dynamic equilibrium.