Farming carbon: an economic analysis of agroforestry for carbon sequestration and dryland salinity reduction in Western Australia

Abstract

The widespread removal of native trees from the agricultural zone and replacement with annual crops and pastures is a major cause of dryland salinity in Australia. It has been recognised that a large proportion of the landscape needs to be replanted to trees to prevent further salinisation. However, for much of the agricultural zone, agroforestry is not an option due to lack of species that can viably generate the products currently demanded by the market. The emerging carbon market may provide a new agroforestry option for landholders, through carbon sequestration. This analysis assesses the viability of growing trees for the purpose of selling carbon credits, from a landholder's perspective. Benefits of trees in preventing the onset of dryland salinity are accounted for. Two regions in Western Australia; a low rainfall (330 mm/year) region and a medium rainfall (550 mm/year) region, are analysed. At the expected carbon price of A$15/tCO 2 -e, growing trees for carbon is not a viable alternative for landholders in the low rainfall region, due to low sequestration rates. In the medium rainfall region, growing trees for carbon and timber is a viable alternative; however the opportunity costs of land mean the carbon price would still need to be higher than expected for growers to choose this alternative. Accounting for the salinity prevention benefits makes growing trees a more attractive investment for landholders in both regions. However in both regions, even after accounting for salinity benefits, the price of carbon would need to be A$25-A$46/tCO 2 -e higher than expected to make growing trees a worthwhile investment.

Beyond Copenhagen: mitigating climate change and achieving food security through soil carbon sequestration

“…Thus, payments to land managers for sequestering C in agricultural soils and forestry projects, not only as sink projects under the Clean Development Mechanism (CDM) of the Kyoto Treaty (Zomer et al 2008) but also for enhancing ecosystem services would be an important strategy to alleviate poverty and advance regional/global food security. Selling credits of soil carbon sequestered through restoration of salt-affected (Flugge and Abadi 2006;Lal 2010) and other degraded/desertified soils (Lal 2009) would promote the concept of "farming carbon", a step towards achieving the U.N. Millennium Development Goals of combating poverty and reducing hunger. The term "Farming Carbon" implies increasing the carbon pool (stock) in soils (and trees) with the purpose of trading carbon thus sequestered as a farm commodity similar to that of trading corn, soybeans, milk, meat, etc.…”

Agroforestry systems: helping smallholders adapt to climate risks while mitigating climate change

“…The unstable nature of the carbon market is an important consideration on the expansion of AFS for climate change mitigation. To date price of carbon at global market has decreased considerably in the last years from USD 16 to nearly USD 7 . A modeling of strict carbon farming in the Western Australia found that cost of carbon farming was at USD 45/tCO 2 ‐eq and USD 66/tCO 2 ‐eq for wheatbelts .…”

Marginal abatement costs of greenhouse gas emissions: broadacre farming in the Great Southern Region of Western Australia

“…Nevertheless, some research effort has been devoted to estimating average abatement costs in broadacre agriculture (Appendix S2). Flugge and Abadi (), Kragt et al . () and Thamo et al .…”