10 Questions and Answers about Soil Carbon and Carbon Markets

Different soil types

1// What is soil carbon?

Soil carbon refers to the inorganic and organic carbon  content of soil. Soil organic carbon plays a crucial role in soil health, fertility, and its capacity to sequester carbon dioxide (CO2) from the atmosphere, contributing to climate change mitigation.

10 questions and answers about soil carbon PDF2// What is soil health?

Soil health is the ability of the soil to sustain the productivity, diversity, and environmental services of terrestrial ecosystems. It can be characterized through the  measurement of biological, chemical, and physical soil

properties (i.e., soil organic carbon concentration, aggregate stability, and carbon mineralization potential).

3// What is soil organic matter vs soil organic carbon?

Soil organic matter (SOM) is the converted dead plant, microbial, and animal biomass in the soil, which enriches soil fertility, structure, and water-holding capacity.

Soil organic carbon (SOC) is specifically the portion of SOM that consists of carbon atoms. SOC is most directly associated with carbon sequestration and its potential impact on mitigating climate change.

4// What is soil inorganic carbon?

Soil inorganic carbon (SIC) consists of carbonates inherited from the parent material and newly formed carbonates during soil development. It is particularly important in arid and semi-arid regions.

5// What is a soil profile?

A soil profile is a vertical cross-section revealing distinct layers or horizons with characteristics like color, texture, and composition, offering insights into soil formation and properties.

6// What is soil carbon stock?

Soil carbon stock is the total amount of carbon stored in a defined soil area to a specified depth, including both organic and inorganic forms. It is a vital indicator of soil’s climate change mitigation potential.

7// What are the ecosystem services provided by soil?

Soil provides ecosystem services such as nutrient cycling, water purification, carbon sequestration, and habitat support for organisms, contributing to agricultural productivity, clean water, flood and climate regulation, and biodiversity.

8// What is the societal value of soil carbon?

The societal value of soil carbon lies in its ability to combat climate change by storing carbon, improving agricultural productivity, and sustaining ecosystems, resulting in global food security, environmental health, and climate resilience.

9// What are carbon credits?

Carbon credits are a trading system representing the reduction or removal of greenhouse gas emissions like carbon dioxide. This allows individuals or organizations to offset their emissions by investing in projects that mitigate climate change. Farmers can play a role by adopting agricultural practices that remove CO2 from the atmosphere and selling the credits generated by emission reduction.

10// How are carbon credits measured?

Carbon credits are measured in units of carbon dioxide equivalent (CO2e) by quantifying the climate change mitigation potential of the emissions reduced or removed by a specific project or activity.

This handout is funded by a grant from the Foundation for Food & Agriculture Research (FFAR)