Carbon Accounting at the Farm Level: Scenarios to Achieving Net-Zero Status

Abstract

The global transition toward net-zero agriculture requires robust, location-specific carbon accounting systems at the farm level. This study examines greenhouse gas (GHG) emissions on broadacre farms in Western Victoria, Australia, and a production and income analysis to evaluate the cost-effectiveness of various mitigation options at the farm level. Two calculators, the Greenhouse Accounting Framework (GAF) and the Meat & Livestock Australia (MLA), were used to collect data from eight mixed farms, and two scenarios were developed. The average emissions per sheep from MLA and GAF were 0.28 tCO₂-e and 0.27 tCO₂-e, respectively, and the profit per sheep of eight farms varied from AUD 146 to AUD 185, and per cattle from AUD 819 to AUD 1250. In general, enteric fermentation contributed 38%–84%, and manure management contributed 2%–5% of Scope 1 emissions. For Scope 3 emissions, from synthetic fertilizer use were the highest contributors to total emissions (up to 53%). In contrast, Scope 2 emissions from energy use contributed less to the total emissions (0%–1%). This study provides two farm management practices, including whole farm tree plantation and sheep stock reduction to achieve carbon neutrality at the farm level. However, this resulted in 20%–99% decrease in profitability, depending on the farm type and operation. Achieving net zero requires a higher carbon price of around AUD 250 to AUD 320 to offset this income loss. The study highlights a combined assessment of greenhouse gas emissions and the associated economic costs and benefits of different farm management practices in underpinning the shift of farmers toward carbon neutrality.