2. Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.
By inference, degraded soils have the potential to store up to five (5) times more organic carbon in their surface layers than they currently hold.
But only under changed management.

3. What Carbon looks like in nature
We can tell, just by looking, that there is more carbon in one area than the next area. The amount of vegetation - both trees and grasses tells us about carbon levels

4. This cattle ranch in Sonora, Mexico, is typical of hundreds of millions of hectares of grazing land in arid and seasonally dry areas worldwide.

5. This is the neighboring ranch, La Inmaculada.

6. This is the neighboring ranch, La Inmaculada.
Same area
Same rainfall
Same soils
Same plant species
Same season (pictures taken on the same day)
La Inmaculada actually has more cattle than the drier ranch
The only difference is management

9. Same area
Same rainfall
Same soils
Same plant species
Same season (pictures taken on the same day)
The area above actually has more livestock
It also has far more wildlife, including buffalo, elephant, and lion
The only difference is management

10. When properly managed, grass plants store large amounts of carbon material below the soil surface
Improper management (common in most of the world) leads to poor carbon storage - LH pots
Proper management (RH pot) means plants hold very large amounts of carbon out of sight, below the soil surface

11. When properly managed soils become darker
Carbon is black.
When properly managed soils become darker
And because they contain carbon, which is black, the soil changes colour

12. The simple maths behind Soil Carbon
One hectare = 10,000 sq. metres
Soil 33.5 cm deep (1 foot approx)
Bulk density = 1.4 tonnes per cubic metre
Soil mass per hectare = about 4,700 tonnes
1% change in soil organic matter = 47 tonnes
Which gives about 27 tonnes Soil Carbon
This captured 100 tonnes of atmospheric CO2
Bulk density
Soils vary in weight per given volume. Healthy, biologically active soils weigh around 1 tonne per cubic metre, whilst heavy clays that contain little or no organic matter (such as clays that might be used for brickmaking) weigh up to 1.8 tonnes per cubic metre. In general, healthy soils are more porous, have more air holes and contain more light weight organic matter than biologically degraded soils.
For this example we have chosen to us a commonly occurring bulk density of 1.4 tonnes per cubic metre.
% Change in Soil Organic Matter
Once the mass of a soil is calculated by multiplying volume by Bulk Density, it is possible to calculate the change in mass per % change in Soil Organic Matter (SOM). At any Bulk Density the change remains the same, regardless of whether the soil improves from 1% SOM to 2% or from 10% SOM to 11%.
Soil Organic Matter contains approximately 58% elemental Carbon
Converting Carbon Dioxide (CO2) to Carbon
On the Periodic Table, carbon has a weight of 12 and oxygen 16. Carbon dioxide, which contains 2 x oxygen and 1 x carbon therefore weighs To achieve a 1 unit move in carbon from carbon dioxide the conversion ratio is 44/12 or For every tonne of carbon sequestered 3.67 tonnes of carbon dioxide must be removed from the atmosphere.
The full maths for this slide
10,000 sq. metres x cm = 3,355 cubic metres per hectare
3,355 cubic metre x 1.4 BD = 4,697 tonnes of soil per hectare to a depth of 33.5 cm
A 1% change in this mass = tonnes
Which contains x 58% = tonnes of Carbon
Captured Carbon tonnes x 3.67 = tonnes CO2

13. Soil carbon potential change and CO2 consumption per annum in Australia
Prof. Peter Grace - QUT (personal communication)

14. Prof. Keith Paustian - University of Colorado (personal communication)

15. What we see now…

16. Blinds us to what could be…