Onset of extensive human fire use 50,000 y ago

Area of Science:

• Paleoclimatology
• Archaeology
• Earth Science

Background:

• Fire is crucial to the carbon cycle, but the timeline of human fire use is unclear.
• Understanding human impact on fire history is key to understanding the carbon cycle.
• Previous research has not precisely dated the onset of large-scale human fire use.

Purpose of the Study:

• To reconstruct East Asian fire history over the past 300,000 years.
• To determine the timing of increased human fire use and its drivers.
• To assess the human contribution to the carbon cycle via fire.

Main Methods:

• Analysis of a pyrogenic carbon record from the East China Sea.
• Integration of extensive archaeological data.
• Comparison of fire history with climate data and regional fire records.

Main Results:

• A pyrogenic carbon record reveals a significant increase in fire activity in East Asia starting approximately 50,000 years ago.
• This increase in fire activity is decoupled from monsoon climate patterns.
• Similar patterns of increased fire activity are observed in Europe, Southeast Asia, and the Papua New Guinea-Australia regions.

Conclusions:

• The intensified global expansion of modern humans and population growth drove increased fire utilization from 50,000 years ago onward.
• This suggests a substantial human imprint on the carbon cycle via fire use, predating the Last Glacial Maximum.
• Human activity, not just climate, has significantly shaped fire regimes and the carbon cycle for millennia.