Animation of erupting volcanoes, lava flows and storms on the primordial Earth. During the Archean epoch of the Earth磗 past, more than 2.5 billion years ago, stretching as far back as some 3.8 billion years ago. Volcanic activity was much more pronounced, and the atmosphere lacked oxygen and was much richer in greenhouse gases. This kept the surface warm enough for some liquid water, despite the Sun only emitting some 70 of its current energy output. Despite these hellish conditions, life began on Earth during the Archean epoch.