The Story of Earth's Climate in 25 DiscoveriesOver 4. 5 billion years, Earth's climate has transformed tremendously. Before our more temperate recent past, the planet swung from one extreme to anotherfrom a greenhouse world of sweltering temperatures and high sea levels to a "snowball earth" in which glaciers reached the equator. During this history, we now know, living things and the climate have always influenced and even shaped each other. But the climate has never changed as rapidly or as