The planetary substrate, 12,000 years
The Civilization Record
The long-run background quantities the four layers stand on: population, land, energy, climate, water, matter, each a series back to 10,000 BCE.
Water
The planet holds 1.386 billion km³ of water; 2.5% is fresh, and the accessible part is under 1%. Human withdrawal has gone from zero to 4,000 km³ a year, and agriculture takes 70% of it.
Total water volume
million km³
10.000 BCE: 1.3862025 CE: 1.386
Annual renewable freshwater flux
km³ / yr
10.000 BCE: 42.0002025 CE: 42.000
Human freshwater withdrawal
km³ / yr
10.000 BCE: 02025 CE: 4.100 (log)
Agriculture share of total withdrawal
%
10.000 BCE: 90,02025 CE: 70,0
Groundwater net depletion
km³ / yr
10.000 BCE: 15,02025 CE: 250
Worth knowing
Humans appropriate about half of accessible runoff.
Virtual water in trade: importing water-intensive goods effectively moves water from wet regions to dry ones.
The Aral Sea has lost most of its volume to irrigation withdrawal since 1960, a scale marker.
Agriculture takes 70% of global freshwater withdrawal; industry 19%, municipal 11%.