A surprising environmental impact has emerged from history: scientists estimate that the Mongol invasions under Genghis Khan may have removed around 700 million tonnes of carbon from the atmosphere.
This occurred not because of climate policies, but due to the large-scale depopulation caused by the conquests, which led to abandoned farmlands reverting to forests that absorbed massive amounts of CO₂.
Researchers highlight this as one of the few times in recorded history where human actions — albeit through devastating means — led to a net cooling effect on the planet.
The estimate draws from studies on land-use change and biomass recovery following the collapse of agricultural systems across Eurasia during the 13th and 14th centuries.
While the environmental consequence is undeniable, scientists stress that such effects came at an enormous human cost — reminding us that true sustainability must be rooted in preservation, not destruction.
