Horsepower (image) The Earth Institute at Columbia University Caption New research suggests that unusual weather aided the rise of the Mongol empire in the 1200s. Many modern Mongolians live as their ancestors did -- but climate change may finally drive them off their land. Credit Kevin Krajick/Earth Institute, Columbia University Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.