Uh, I'd rather not
You have to wonder if this is going to inspire a wave of green mass murder.
Study: Genghis Khan's Mass Killings Cut Carbon Footprint
Genghis Khan's bloodthirsty, bow-wielding horsemen conquered vast swaths of Europe, the Middle East and Asia, destroying countless civilizations that stood in their path. But a new study suggests that the Mongol tyrant's empire wasn't just the largest and most brutal the world has ever seen -- it was also, in its own perverse way, the greenest.
According to research published in The Holocene journal, the Mongol invasions of the 13th and 14th centuries shrank humanity's carbon footprint, scrubbing some 700 million tons of carbon dioxide from the atmosphere. That's roughly equivalent to the amount of carbon produced from the global use of gasoline every year.
Modern environmentalists, though, are unlikely to approve of the way Khan and his successors earned their eco-friendly credentials. During the 150-year Mongol Empire, the Khan's armies seized control of about 22 percent of the world's total land area and slaughtered up to 40 million people. The death of so many -- if a city refused to surrender to Mongol rule, all of its inhabitants would be executed -- meant that large areas of farmland could no longer be cultivated. Those fields eventually returned to forests, which absorbed large amounts of CO2 from the atmosphere.
"It's a common misconception that the human impact on climate began with the large-scale burning of coal and oil in the industrial era," the study's lead author, Julia Pongratz of the Carnegie Institution's Department of Global Ecology, said in a statement. "Actually, humans started to influence the environment thousands of years ago by changing the vegetation cover of the Earth's landscapes when we cleared forests for agriculture."
Pongratz's study assessed the carbon impact of several other historical events that also saw massive depopulation followed by a period of reforestation. They included the European Black Death at the end of the 14th century, the fall of China's Ming Dynasty in the late 17th century and the conquest of the Americas in the 16th and 17th centuries. But Pongratz and her team found that none of these mass die-offs had a significant effect on the world's climate.
"We found that during the short events such as the Black Death and the Ming Dynasty collapse, the forest regrowth wasn't enough to overcome the emissions from decaying material in the soil," she said. "But during the longer-lasting ones like the Mongol invasion ... there was enough time for the forests to regrow and absorb significant amounts of carbon."
History's verdict of Khan isn't likely to change because of Pongratz's research. "Genghis the Tree Hugger" doesn't have the same gravitas as "Genghis the Destroyer" -- but she hopes that her study could lead to smarter land-use choices.
"In the past, we have had a substantial impact on global climate and the carbon cycle, but it was all unintentional," she said. "Based on the knowledge we have gained from the past, we are now in a position to make land-use decisions that will diminish our impact on climate and the carbon cycle."
Study: Genghis Khan's Mass Killings Cut Carbon Footprint
Genghis Khan's bloodthirsty, bow-wielding horsemen conquered vast swaths of Europe, the Middle East and Asia, destroying countless civilizations that stood in their path. But a new study suggests that the Mongol tyrant's empire wasn't just the largest and most brutal the world has ever seen -- it was also, in its own perverse way, the greenest.
According to research published in The Holocene journal, the Mongol invasions of the 13th and 14th centuries shrank humanity's carbon footprint, scrubbing some 700 million tons of carbon dioxide from the atmosphere. That's roughly equivalent to the amount of carbon produced from the global use of gasoline every year.
Modern environmentalists, though, are unlikely to approve of the way Khan and his successors earned their eco-friendly credentials. During the 150-year Mongol Empire, the Khan's armies seized control of about 22 percent of the world's total land area and slaughtered up to 40 million people. The death of so many -- if a city refused to surrender to Mongol rule, all of its inhabitants would be executed -- meant that large areas of farmland could no longer be cultivated. Those fields eventually returned to forests, which absorbed large amounts of CO2 from the atmosphere.
"It's a common misconception that the human impact on climate began with the large-scale burning of coal and oil in the industrial era," the study's lead author, Julia Pongratz of the Carnegie Institution's Department of Global Ecology, said in a statement. "Actually, humans started to influence the environment thousands of years ago by changing the vegetation cover of the Earth's landscapes when we cleared forests for agriculture."
Pongratz's study assessed the carbon impact of several other historical events that also saw massive depopulation followed by a period of reforestation. They included the European Black Death at the end of the 14th century, the fall of China's Ming Dynasty in the late 17th century and the conquest of the Americas in the 16th and 17th centuries. But Pongratz and her team found that none of these mass die-offs had a significant effect on the world's climate.
"We found that during the short events such as the Black Death and the Ming Dynasty collapse, the forest regrowth wasn't enough to overcome the emissions from decaying material in the soil," she said. "But during the longer-lasting ones like the Mongol invasion ... there was enough time for the forests to regrow and absorb significant amounts of carbon."
History's verdict of Khan isn't likely to change because of Pongratz's research. "Genghis the Tree Hugger" doesn't have the same gravitas as "Genghis the Destroyer" -- but she hopes that her study could lead to smarter land-use choices.
"In the past, we have had a substantial impact on global climate and the carbon cycle, but it was all unintentional," she said. "Based on the knowledge we have gained from the past, we are now in a position to make land-use decisions that will diminish our impact on climate and the carbon cycle."