Story perspectives

Deep Soil Holds 850 Billion Tons, Trials Raise Carbon 50%

5/17/2026

Summary

Story summary

The University of Western Australia review found deep soil carbon holds over 850 billion tons, 50-60 percent of top-soil carbon.
Standard IPCC accounting stops at roughly 12 inches, so most surveys miss this deep carbon.
Warmer temperatures, heavy rain, deep tillage, or fresh deep-rooted plant inputs can disturb subsoil and cause microbes to decompose old carbon.
Trials of deep biochar, compost, and straw placement raised subsoil carbon by 29-51 percent within years.

1 of 1

Story summary

The University of Western Australia review found deep soil carbon holds over 850 billion tons, 50-60 percent of top-soil carbon.
Standard IPCC accounting stops at roughly 12 inches, so most surveys miss this deep carbon.
Warmer temperatures, heavy rain, deep tillage, or fresh deep-rooted plant inputs can disturb subsoil and cause microbes to decompose old carbon.
Trials of deep biochar, compost, and straw placement raised subsoil carbon by 29-51 percent within years.