Zero Emission Network

In this section

• Overview
• The Methane Problem
• Commodity Comparison
• Organic Agriculture
• Food Miles
• Soil Carbon
• Solutions

Overview

According to the Australian Green House Office, in 2005 the greenhouse gas (GHG) inventory states Agriculture contributed 16% of Australia's greenhouse gas emissions making Agriculture the second largest emitter in Australia under UNFCCC reporting standards.

Livestock alone accounts for 11% of Australia's emissions largely coming form the methane (CH4) released from enteric fermentation and manure management using the same reporting standards.

The impact of Agriculture and Livestock is larger than these figures suggest as significant amounts of the emissions from the Stationary Energy and Transport Sectors are used for the purposes of agriculture.

Unfortunately the issue of agricultural emissions is ignored by many climate change campaigners and commentators because they see them as too hard or difficult to deal with.

For a in depth look at this issue you can also read a letter to WWF by Geoffry Russell from Animal Liberation South Australia titled Australia’s Biggest Climate Forcing (353KB PDF)

The Methane Problem

The IPCC Guidelines for GHG Inventory Reporting calculate global warming potential (GWP) of methane as being 25 times the level of carbon dioxide when looking at the average effect over 100 years (as defined in the IPCC Fourth Assessment Report (AR4)).

Methane only exists in the atmosphere an average of 12 years before it breaks down into carbon dioxide and water vapour, hence the GWP figure of 25 seriously under estimates the actual impact of methane on global warming in the short term.

Australia's methane impact is further understated because the Australian Greenhouse Office uses a GWP for methane of 21 and not 25 for their greenhouse gas inventory calculations. This is due to the UNFCCC having agreed that the revised figures of GWP for different gases will not apply to greenhouse gas reporting until the second commitment period (2013-2017).

GWP figures for methane based on a 20 year period are available and have been calculated at 62 in the IPCC's TAR and are now calculated as 72 in AR4 (see IPCC WG1 AR4 Report Chapter 2 page 212).

We can re-calculate Australia's GHG emissions using a GWP based on 20 years for methane which is 72 according to the 4AR rather than a 100 year GWP of 21. Then we have a better idea of the actual effect of the different sectoral emissions on global warming in the shorter term (See figures and graphs below for changing totals and percentages of emissions).

Australia's total GHG emissions

Methane GWP 21 = 559.1 Mt CO2-e
Methane GWP 72 = 833.2 Mt CO2-e

Methane as a percentage of Australian GHG emissions

Methane GWP 21 = 20.2%
Methane GWP 72 = 46.5%

Agriculture as a percent of total Australian GHG emissions

Methane GWP 21 = 16%
Methane GWP 72 = 30%

Live stock as a percent of total Australian GHG emissions #

Methane GWP 21 = 11%
Methane GWP 72 = 25%

# Based on AGO's National Greenhouse Gas Inventory 2005 Table 3.

The change in emission percentages per sector are represented graphically below at 72 GWP and are compared against the original AGO graphs using a 21 GWP for methane. Calculations are based on the AGO's National Greenhouse Gas Inventory 2005 Table 1 and simply recalculate the total sectoral GHG emission in Carbon Dioxide Equivalents with the new GWP figure for methane of 72 instead of 21 and then calculate a new percentage against the new total.

Sectoral Emissions in Carbon Dioxide Equivalents CO2-e using a GWP of 72 for methane and the AGO 2005 GHG Inventory figures.

• Stationary Energy= 284.5 Mt CO2-e = 34%
• Agriculture= 251.1 Mt CO2-e =30%
• Fugitive Emissions= 92.4 Mt CO2-e = 11%
• Transport= 82.0 Mt CO2-e = 10%
• Waste= 57.8 Mt CO2-e = 7%
• Land Use,Land Use Change and Forestry= 38.2 Mt CO2-e = 5%
• Industrial Processors= 29.7 Mt CO2-e = 4%

Commodity Comparison

Below table sourced from Australia's National Greenhouse Gas Inventory 1990, 1995 and 1999, End Use Allocation of Emissions

(a) Excludes energy.
(b) Average for all products in group - not enough data to disaggregate.

Organic Agriculture

Nitrous Oxide Emissions from soil account for 3% (Methane 21 GWP) or 2% (Methane 62 GWP) of national emissions. Reduction in the use of artificial fertilisers would significantly reduce these emissions.

Organic agricultural systems such as Biodynamics do not use artificial fertilisers and hence would reduce emissions from this source.

Permaculture, developed by Bill Mollison and David Holmgren, is another agricultural system that is organic and system orientated. There are a large number of places that run permaculture courses including Holmgren Design Services, The Permaculture Institute, and Djanbung Gardens.

Organic agriculture also tends to build organic matter into the soil and hence potentially offers an additional income source for farmers. Once a price of carbon is established farmers can be paid for the carbon they store in their soils*.

*Farming practices that cause emissions of greenhouse gases such as methane and nitrous oxide and/or cause a reduction in soil carbon content should pay the costs associated with these farming practices if a carbon price system (ie tax or cap) is being used to reduce greenhouse gas emissions.

Biodynamic Orchard - JPriestley's Citrus Orchard

Food Miles

Much of the food we eat travels significant distances to market.

Reducing the distance food has traveled and buying fresh food that is grown locally and in season reduces emissions associated with transport and refrigeration.

Farmers markets are a growing movement which enable people to buy locally grown food directly from the farmers.

See the Australian Farmers Market Association for a list of Farmers Markets around Australia.

Read the Food Miles discussion on this BBC website.

There is even a food miles cafe in Melbourne called the 100 Mile Cafe.

Soil Carbon

Organic agriculture and other methods can increase soil carbon and have the potential to sequester large amounts of atmospheric carbon.

Farmers could create an additional income stream by being paid to sequester carbon however the greenhouse gases they release must also be accounted for in any tax or trading system.

A number of groups now promote the issues of soil carbon such as the Carbon Coalition Against Global Warming and Amazing Carbon

Solutions

• Reduce livestock emissions by eating less meat and dairy, or more simply by eating none at all.
• Reduce rice emissions by eating less traditionally wet grown rice. Dry land grown rice can reduce emissions.
• Reduce fertiliser use and increase soil organic content by moving towards organic agriculture and buying organic foods.
• Move food less distances and grow and sell food locally and in season.
• Include agricultural emissions in carbon taxing trading schemes.
• Investigate bio char options (for more information see Facts and Figures - Offsets).
• Investigate options for regional bio-energy production using genuine agricultural waste, this could be combined with bio char production.