Ancient heat wave?
About 55 million years ago, an intense heat wave hit the planet. Earth's surface temperature surged by 9 degrees Fahrenheit (5 degrees Celsius). Then, after a relatively short time, the heat subsided, only to be followed by at least two similar, but smaller heat waves.
Based on chemical clues preserved in rocks, scientists believe a surge of carbon dioxide warmed the planet. But where did all of this greenhouse gas come from?
A team of scientists is proposing that it came from the melting of permafrost, frozen soil packed with organic matter, after cycles in the Earth's orbit warmed up the areas near the poles. The melting released a massive amount of carbon into the atmosphere, keeping reflected sunlight from escaping and causing the heat wave....
comments powered by Disqus
- The Story Behind ‘Woman in Gold’: Nazi Art Thieves and One Painting’s Return
- Scott Walker, Allergic to Dogs, May Run Against Political History
- Russian History Receives a Makeover That Starts With Ivan the Terrible
- Parsing Ronald Reagan’s Words for Early Signs of Alzheimer’s
- Here's a look at history of 'religious freedom' laws
- Charlatan or Sage? Contested Legacy of the late Dr. Ben, a Father of African Studies
- Historians make it easy for visitors to DC to understand the history of the Mall
- History's Grandin Wins Bancroft Prize for "The Empire of Necessity"
- Nobel prize-winning scientist writes a history of science
- Ken Burns tackles history of cancer