A brief overview of the potential and challenges of soil carbon storage
Carbon sequestration, or the process of capturing and storing carbon dioxide from the atmosphere, is one of the key strategies to mitigate climate change and reduce greenhouse gas emissions. Soil is the largest terrestrial carbon reservoir, storing more carbon than the atmosphere and vegetation combined. However, soil carbon stocks have been declining due to land degradation, deforestation, and intensive agriculture. This not only contributes to global warming, but also reduces soil fertility, water retention, and crop productivity.
In Australia, agriculture is both a major source and a potential sink of carbon emissions. According to the Department of Agriculture, Water and the Environment, agriculture accounted for 13% of Australia’s total greenhouse gas emissions in 2019, mainly from livestock enteric fermentation, manure management, and soil cultivation. On the other hand, agriculture also has the potential to sequester up to 63 million tonnes of carbon dioxide equivalent per year by 2030, through improved land management practices, such as reduced tillage, cover cropping, crop rotation, and organic amendments. These practices can enhance soil organic matter, which is the main component of soil carbon, and improve soil health and function.
Carbon sequestration in agriculture can also provide multiple co-benefits for farmers and the environment. For instance, increasing soil carbon can improve soil structure, water infiltration, nutrient cycling, and biological activity, which can lead to higher crop yields and resilience to drought and erosion. Moreover, carbon sequestration can generate additional income for farmers through carbon credits, which are financial incentives for reducing or avoiding greenhouse gas emissions. Australia has a national carbon market, the Emissions Reduction Fund, which supports farmers to adopt carbon farming projects and sell their verified carbon credits to the government or other buyers.
Challenges and Opportunities for Carbon Sequestration in Australia
Despite the potential and benefits of carbon sequestration in agriculture, there are also some challenges and barriers that need to be addressed. One of the main challenges is the uncertainty and variability of soil carbon measurement and monitoring. Soil carbon is influenced by many factors, such as climate, soil type, land use history, and management practices, and can vary significantly across space and time. Therefore, accurate and reliable methods of estimating and verifying soil carbon changes are essential for ensuring the credibility and integrity of carbon farming projects and credits. However, current methods are often costly, time-consuming, and labor-intensive, which can deter farmers from participating in the carbon market.
Another challenge is the lack of awareness and knowledge among farmers and the public about the benefits and opportunities of carbon sequestration in agriculture. Many farmers may not be aware of the best practices and technologies that can enhance soil carbon and reduce emissions, or the financial incentives and support available for carbon farming. Moreover, there may be some misconceptions and myths about carbon sequestration, such as the belief that it will reduce soil productivity, increase fertilizer use, or compromise food security. Therefore, more education and extension services are needed to inform and empower farmers and the public about the science and practice of carbon sequestration in agriculture.
To overcome these challenges and harness the opportunities of carbon sequestration in agriculture, Australia needs a holistic and collaborative approach that involves multiple stakeholders, such as farmers, researchers, policymakers, industry, and civil society. Some of the key actions that can facilitate and accelerate carbon sequestration in agriculture include:
- Developing and adopting more efficient and affordable methods of soil carbon measurement and monitoring, such as remote sensing, machine learning, and blockchain.
- Providing more incentives and support for farmers to implement carbon farming practices, such as subsidies, grants, loans, insurance, and technical assistance.
- Strengthening the carbon market and policy framework, such as setting clear and consistent rules, standards, and guidelines for carbon farming projects and credits.
- Enhancing the research and innovation capacity, such as investing in more interdisciplinary and participatory research, and fostering the transfer and adoption of new technologies and practices.
- Increasing the awareness and engagement of farmers and the public, such as conducting more outreach and communication campaigns, and creating platforms and networks for knowledge sharing and collaboration.
Carbon sequestration in agriculture is a win-win solution for both climate change mitigation and adaptation, and for enhancing the sustainability and profitability of Australian agriculture. By addressing the challenges and seizing the opportunities of carbon sequestration, Australia can become a global leader and model in this field, and contribute to the global efforts to achieve net-zero emissions by 2050.
