The Mongol invasion had the most significant impact. According to the study's accounting, re-growth of forests during the Mongol invasion absorbed 700 million tons of carbon from the atmosphere, equaling the amount of carbon global society now produces annually from gasoline.
the land was arid and dry so much of the mongols' were multiple clans of pastoral nomads. - they herded sheep and goats and were hunter-foragers, north of the gobi desert in east asia.