Climate Change Helped Genghis Khan Create the Mongol Empire, Researchers Find

A brief spell of mild weather and plentiful rains in the usually arid Mongolian steppe might have helped Genghis Khan and his descendents form the largest land empire in world history, a new study has found

According to researchers at Columbia University's Lamont-Doherty Earth Observatory, the nomadic horsemen of Mongolia enjoyed a brief run of mild temperature- a natural shift in climate- that made the land fertile and helped feed the small groups of travelling herds.

Genghis Khan rose to power in Khan in the early 1200s. A few decades later, he had created an efficient military system. He and later his descendents consolidated a vast region- from Russia, China, Korea, Southeast Asia, Persia, India and even Middle-East and parts of Europe, USA today reports.

The usually hot grasslands of Mongolia began receiving good rainfall during early 13th century, researchers found. The mild weather coupled with rain changed the course of history for Central Asia.

"The transition from extreme drought to extreme moisture right then strongly suggests that climate played a role in human events," Amy Hessl, a tree-ring scientist at West Virginia University. "It wasn't the only thing, but it must have created the ideal conditions for a charismatic leader to emerge out of the chaos, develop an army and concentrate power."

In the current study, researchers used rings from dead pine trees to reconstruct the climatic conditions in the central grasslands during Genghis Khan's time.

The tree rings during his time were wide, meaning that the region was wet and the temperature was mild, USA Today reports.

"Where it's arid, unusual moisture creates unusual plant productivity, and that translates into horsepower. Genghis was literally able to ride that wave," said Hessl in a news release.

The disappearance of Maya , collapse of the Roman empire and fall of Asia's Angkor civilization have all been linked to wild changes in climate. But most research focuses on drastic events such as floods or drought. According to the study authors, this is the first time that researchers have been able to link complex climate shifts with the rise of one of the world's largest empires.

Since the mid-20th century, average temperatures have risen in Mongol. According to the researchers, the drought-like conditions in the region might be linked with global warming.

The study is published in the journal, Proceedings of the National Academy of Sciences.