The Mauna Loa Observatory in Hawai’i recently recorded the highest concentration of carbon dioxide, or CO2, levels in human history. In fact, the last time CO2 levels surpassed 400 parts per million was during the Pliocene, a geological epoch between two and five million years ago, when oceans surged 50 feet higher and small icecaps barely clung to the poles.
Click here for original story, Ancient plankton help researchers predict near-future climate
Source: Phys.org