Greenhouse gases in Australian agriculture: understanding the role of soils, forests and livestock methane

Tackling greenhouse gas (GHG) emissions is considered to be one of the most serious national and international challenges of our time. Australia has a sizable potential to mitigate GHG emissions and sequester carbon in agricultural production and land use systems.

• 20 September 2011 | Updated 14 October 2011

• Overview
• Sequestration in forests, tree plantings and regrowth
• Soil Carbon and the National Research Program
• Biochar
• Methane emissions from livestock
• More about carbon research projects

Overview

CSIRO is leading national research towards reducing emissions and increasing carbon storage in agriculture through measuring and predicting changes in carbon levels, identifying and developing carbon-friendly practices and technologies and providing the best science information to policy makers. 

Options for addressing greenhouse gas levels in agriculture include through:

• carbon sequestration in forests tree plantings and regrowth
• storage in soils and degraded rangelands
• production and use of biochar
• changed fire management in tropical savannas
• abatement of methane emissions from livestock
• the substitution of biofuels for fossil fuels

Sequestration in forests, tree plantings and regrowth

The science behind carbon accounting for forests is well tested and developed. A recent CSIRO report Carbon and rural land use: key findings, found that forestry-related options have the greatest potential for sequestering carbon, making up about 75 per cent of that which is realistically attainable. 

CSIRO calculates an average rate of carbon storage of 9 t CO₂-e (tonnes of carbon dioxide equivalents) per hectare per year achievable across land areas where carbon forestry is predicted to be economically viable at a carbon price of at least A$20/t of CO₂-e. CSIRO notes that market, social and regulatory factors cast a large amount of uncertainty over the total area to be planted.

For more information about Managing carbon in forests.

Soil Carbon and the National Research Program

Soil carbon (the amount of organic carbon stored in the soil) plays a vital role in soil and plant health and productivity. Increases in soil carbon can reduce the amount of carbon that remains in the atmosphere that contributes to global warming and climate change.

The influence of agricultural practices on the amount of carbon present in Australian soils is being examined through a national program of sampling, testing and analysis led by CSIRO. The Soil Carbon Research Program will provide data from which realistic sequestration options and targets for Australia can be formed.

Soil Carbon Sequestration Potential: A review for Australian agriculture - key findings, provides an analysis of the current evidence for changes in soil organic carbon stocks resulting from agriculture land use changes.

For more information about Soil carbon: the basics. 

Biochar

Biochar continues to attract interest because of its potential to store carbon in the soil for very long periods of time and to simultaneously improve soil structure and crop yields.

Two major research projects are underway through the Sustainable Agriculture Flagship to try to fill knowledge gaps and gain a better understanding of biochars (70 different biochars are being studied) and their potential in agriculture and carbon sequestration.

For more information, read the Biochar fact sheet.

Frequently Asked Questions about Soil Carbon and Biochar.

Methane emissions from livestock

Australia's cattle and sheep industries are significant producers of methane - 15.9 per cent of Australian GHG emissions came from agriculture and 67.4 per cent of that was methane produced by ruminants*. 

The Sustainable Agriculture Flagship is conducting research to understand the management and dietary factors that affect methane emissions from cattle in Northern Australia, where half of the nation's cattle herd grazes.

For more information, please visit Reducing livestock methane emissions. 

* National Greenhouse Gas Inventory, May 2010