Policy Documents

NIPCC IR1 - Chapter 3 - Paleoclimate and Recent Temperature

August 29, 2011

Chapter 3 reviews the latest research on paleoclimatology and recent temperatures, finding new evidence that the Medieval Warm Period of approximately 1,000 years ago, when there was about 28 percent less CO2 in the atmosphere than there is currently, was both global and warmer than today’s world. Research also reveals a significant period of elevated air temperatures that immediately preceded the Little Ice Age, during a time that has come to be known as the Little Medieval Warm Period. Other researchers have documented a decade-long cooling period following the record heat of 1998.