The ‘Great Dying’ of 1492 led to lower CO2 and a cooler planet

A group of UCL Geography researchers have pieced together evidence that human actions impacted atmospheric CO₂ and the global climate well before the beginning of the Industrial Revolution.

PhD researcher Alexander Koch, together with Professor Mark Maslin, Dr Chris Brierley, and Professor Simon Lewis, calculated that 55 million indigenous people died after Europeans spread epidemics, warfare and famines across the Americas in the 1500s

They find that the ‘Great Dying’ led to a collapse of human land use and caused a reforestation event large enough to lower global atmospheric CO₂.

This triggered carbon-cycle feedbacks that lowered CO₂ even further and caused an anomalously cold period during the ‘Little Ice Age’ affecting the 16th century and later.

See

• The Conversation
• The full study is published in Quaternary Science Reviews