Further evidence has been uncovered pointing toward a large asteroid or comet that impacted the Earth 12,800 years ago, toward the end of the last ice age, an event that may have triggered the extinction of numerous species of large mammals, and disrupting human populations around the globe. This new
The levels of carbon dioxide found in the atmosphere in modern times have been found to be nearly ten times higher than any other time since the extinction of the dinosaurs, 65 million years ago. The event that came the closest to today’s CO2 levels, the Paleocene-Eocene Thermal Maximum (PETM), occurred 55.5 million years ago, where a spike in greenhouse gasses caused global temperatures to increase by 5–8 °C over what we’re experiencing today. While the existence and cause of the PETM is well established, the source of the massive amount of CO2 that caused the temperature spike has been a complete mystery to scientists.