Carbon sequestration opportunities | Environment Victoria

Carbon sequestration opportunities

Given the scale of the climate crisis and the urgent need to both reduce emissions and draw down carbon from the atmosphere, there may be new economic benefits associated with opportunities to re-capture and store (or sequester) atmospheric carbon.

Biosequestration refers to the absorption and storage of carbon dioxide within vegetation and in soil. Australia’s commitment to a national emissions trading scheme (or Carbon Pollution Reduction Scheme) has the potential to create new markets for carbon credits created through biosequestration. CSIRO is conducting significant research into quantifying the potential benefits. (59)

Agricultural soils are among the planet's largest reservoirs of carbon. The UN Food and Agriculture Organisation estimates that soils are capable of sequestering more than 10 percent of anthropogenic carbon emissions and that retaining and increasing soil carbon through improved agricultural practices has a role to play in mitigating climate change. (60)

Over the last 50 years, the organic carbon content of Australian agricultural soils has declined between 50 and 80 percent. (61) Continued ploughing, stubble burning and removal of crop waste gradually strips carbon from the soil, leaving it without structure and unable to hold as much water. As soil carbon is a prime determinant of agricultural productivity, losses of this magnitude can have significant economic and environmental implications in addition to their impact on greenhouse gas emissions.

Proponents of soil carbon sequestration argue that with appropriate changes to land management, such as the adoption of pasture cropping , broad-acre cropping (62) and grazing enterprises have the capacity to achieve net sequestration of carbon of up to 25 tonnes of carbon dioxide per tonne of product sold. (63)

Improved farming practices that sequester soil carbon also have the added benefit of re-building agricultural soils by improving nutrient availability, water-holding capacity and soil structure, thereby enhancing productivity and grain quality, as well as increasing the resilience of the Australian landscape to climate change and other pressures.

However, soil carbon is highly variable across soil types, management practices, weather patterns and time. As a consequence of difficulties in measurement and accounting, it is unlikely that soil biosequestration will be included in any formal emissions trading scheme in the short-term. However, the Commonwealth Government is continuing to investigate its potential benefits to assess whether to include it in a formal trading scheme in future. (64)

The other form of carbon biosequestration is via vegetation, primarily trees. The Victorian biosequestration industry is small and emerging, with less than 5,000 ha of trees planted to date and less than 1,000 ha of that complying with a recognised carbon offset standard. Most of these plantings are occurring on private land.

While many biosequestration suppliers prefer monoculture plantings, Victorian suppliers sell offsets from biodiversity plantings at a premium price, which recognises their additional environmental benefits. Another way to achieve biodiversity benefits in addition to carbon sequestration benefits would be to adopt an incentive-based approach to encourage private sector investors to produce biodiversity outcomes. Government could provide an additional ‘top up’ payment to procure biodiversity benefits, allowing the landholder to sell carbon offsets created by reforestation on the carbon market. (65)

One local example of using native vegetation for biosequestration is the Glenelg Hopkins Carbon Pool, pioneered by Peter and Christine Forster. The regional trading pool envisages establishing a market whereby greenhouse gas-emitters could buy credits for about $30/tonne, with landholders receiving payments of about $20/tonne. The other $10/tonne would go into a regional pool to cover administration and insurance against bushfire or other disaster. (66)

At a national level, Landcare CarbonSMART (67) operates a carbon pool to provide a financial incentive for landholders to maintain eligible vegetation on their land and assist them to regenerate land parcels not being used for agriculture. This is achieved by calculating the amount of carbon absorbed by the vegetation and selling the carbon to individuals and businesses to help them offset their carbon emissions. Landholders receive annual payments and, when the price of carbon rises, so too will their payments. The value of carbon is predicted to grow strongly over the next decade.

However, while these schemes offer the potential for multiple benefits in terms of carbon sequestration and biodiversity, it is important to look at them in the broader catchment context and recognise and plan for potential negative impacts. In particular, the water needs of tree plantations and the impact on water availability and stream flows need to be carefully considered and managed.

Questions for discussion:

What kind of information or support do people need to help them adjust to reduced water availability and explore new opportunities?

Do all farmers need the same kind of support?

What types of people or approaches are likely to be most successful in promoting change?
 

References

(59) http://www.csiro.au/resources/carbon-and-rural-land-use-key-findings--ci_pageNo-3.html

(60) Food and Agriculture Organization, Land and Water Development Division at http://www.fao.org/ag/agL/agll/carbonsequestration/background.stm

(61) Jones, C. (2008) Submission to the Inquiry into Climate Change and the Australian Agricultural Sector, Senate Standing Committee on Rural and Regional Affairs and Transport, with particular reference to the Australian Soil Carbon Accreditation Scheme

(62) A technique in which annual grain or fodder crops are direct-drilled into perennial groundcover

(63) Jones, C. (2008) Submission to the Inquiry into Climate Change and the Australian Agricultural Sector, Senate Standing Committee on Rural and Regional Affairs and Transport, with particular reference to the Australian Soil Carbon Accreditation Scheme

(64) Victorian Government (2008) Opportunities in Carbon Sequestration, Department of Sustainability and Environment

(65) Victorian Government (2008) Opportunities in Carbon Sequestration, Department of Sustainability and Environment

(66) Forsters take on the carbon pool”, The Weekly Times, 13 May 2009

(67) http://www.carbonsmart.com.au/