Cosmic collisions and global warming
The "Paleocene-Eocene Thermal Maximum" or PETM is considered the planet's largest warming event. The event happened approximately 55 million years ago, and saw a rise in temperatures of 5 to 8 degrees celsius in a relatively short amount of time. Scientists know that the PETM was tied to a massive surge of carbon, but it's always been a topic of debate as to how this large amount carbon was released into the atmosphere and ocean.
Now, Dr. Morgan Schaller has found what he thinks is direct evidence of a meteorite impact that struck earth around the time of the PETM. They can't say for sure that this strike might have triggered this period of global warming, but they say the timing is nothing short of remarkable.