Australia’s carbon sequestration potential Summary report Introduction – setting the scene See section 1 of Australia’s carbon sequestration potential: Technical report for further details. Why carbon sequestration is needed Permanently removing significant amounts of Greenhouse Gases (GHG) from the atmosphere, combined with ambitious emissions reductions, is the only realistic path for the world to reach the goals of the Paris Agreement (UNFCCC, 2015) and limit the worst impacts of climate change. It is estimated globally that beyond deep decarbonisation, up to 10 gigatonnes of carbon dioxide equivalent (CO2-e) annually will need to be permanently removed from the atmosphere by 2050, and up to 20 gigatonnes annually of CO2-e reductions by 2100 (NASEM, 2019). As part of this global effort Australia has committed to a net GHG emissions reduction target of 43% below 2005 levels by 2030 and net zero emissions by 2050 delivered through decarbonisation and permanent atmospheric carbon dioxide removal. Carbon sequestration is a key component of achieving this target. Aerial view of rural properties on the Murrumbidgee River, south of Murrumbateman, NSW This report This report summarises the findings of a review of current technology options for carbon sequestration. The review is compiled from existing knowledge, literature sources and consultation with subject matter experts. This report presents the overall conclusions of the assessment and summarises the technology assessments. More detail and the assumptions that underpin the estimates can be found in the full technical report. Key definitions Emissions types • Avoided emissions refer to deliberate activities that prevent carbon from being released into the atmosphere. This reduces the amount of greenhouse gas being added to current levels. • Negative emissions refer to deliberate activities that remove (and store) CO2 from the atmosphere. This directly reduces levels of atmospheric GHGs. Technical vs economic potential and realisable sequestration Both technical and economic potential sequestration levels need to be considered when assessing the various technologies: • Technical potential sequestration is the maximum level that is biophysically or technically possible. In general, technical potential is limited only by current climatic and other biophysical capacity or system storage capacity at the current level of technology efficacy. • Economic potential sequestration is the level attainable given current efforts to implement technical and management changes. Economic potential is considered within the context of technological, policy, regulation and social limitations that define the sequestration possibilities. • Realisable sequestration is potentially available once shared resource limitations, availability and other inter-dependencies are considered. Types of sequestration technology There are 3 approaches to sequestration considered in this report (following Minx et al. 2018): • Biological solutions take advantage of natural biological systems to take up and store atmospheric CO2 (also known as natural, nature-based or natural-climate solutions). Examples include permanent planting and soil carbon. • Engineered solutions rely on chemistry to capture and store atmospheric CO2. Examples include mineral carbonation and direct air capture. • Hybrid solutions combine aspects of biological and engineered solutions. Examples include bioenergy carbon capture and storage, which uses biomass to capture carbon and produce energy, and then captures the carbon released and sequesters it in geological stores. Potential sequestration TECHNICAL The maximum biophysically or technically possible sequestration. It does not consider economic feasibility, nor consider competition for resources such as energy, water or land. ECONOMIC Considers economic feasibility and concerted efforts to implement technical and management changes. Unresolved competition for resources. REALISABLE Considers and resolves competition for resources, with incentive structures in place and barriers removed. Figure 1. Types of sequestration Key findings – results and the way forward See section 2 of Australia’s carbon sequestration potential: Technical report for further details. Technology assessment findings This review assessed each technology against common criteria, where possible, to explore the technical potential of the technology to contribute to carbon sequestration in Australia. Estimates in this report have been prepared by reviewing the latest literature, consulting experts and synthesising into key findings; these are relevant at the time of the publication of this report. Cliffs along the coast of the Great Australian Bight Figure 1. Technology summary Technical and economic sequestration potential The level of technical, economic and realisable sequestration of different technologies is a critical measure to inform Australia’s planning. Biological solutions provide high economic sequestration potential The biological technologies are well developed and have good economic sequestration potential, particularly plantation and farm forestry (32 Mt/year), permanent plantings (16 Mt/year), and soil carbon (5–29 Mt/year by 2050). Uptake has been high in these methods because of their technology maturity and the policy support provided through the carbon farming initiative and the Emissions Reduction Fund. Biological options that could offer increased sequestration levels in the future include blue and teal carbon. Biological solutions in most cases have a shorter length of storage (less than 100 years) than geological options (hundreds to millions of years). In addition, climate change and variability may affect sequestration potential and length of storage for biological solutions. Nonetheless at present, they provide the majority of the low-cost, readily scalable sequestration solutions. Engineered (and Hybrid) solutions have high technical potential and long sequestration storage times, but are less mature Engineered methods have high technical potential sequestration capacity, including direct air capture bioenergy carbon capture and storage, and pyrolysis biochar. The technical potential for geological storage is large, though is more uncertain. High costs have to date, limited their uptake, and in many cases, they are less commercially mature than biological solutions. In addition, many of the engineered technologies include some form of geological storage. Gaps between actual and economic potential sequestration levels represent opportunities for Australia The gap between actual and economic potential sequestration levels is significant in many technologies Where the gap between these estimates is large, it points to an area of opportunity where economically feasible sequestration can be unlocked by reframing regulation, changing incentives, or leveraging co-benefits. (see Barriers and enablers). Technical potential similarly can be converted into economic potential sequestration with new research and development and innovation, to lower costs and overcome technical barriers. Adverse impacts and co-benefits Sequestration levels should not be considered in isolation; the potential adverse impacts of technologies as well as potential co-benefits should be considered to provide a complete picture of the options available. Many technologies are associated with environmental co-benefits Many technologies, particularly biological solutions are associated with environmental benefits e.g. increased soil productivity and agricultural returns. These co‑benefits available from sequestration activities can help to drive uptake. For example, increased biodiversity and reduced erosion associated with permanent plantings can encourage implementation, particularly on less productive land. On productive land, soil carbon approaches or permanent plantings used as shelterbelts can be incorporated into existing land uses. Further research to quantify and value co-benefits, and communications efforts to reach potential users, will be important to support increased uptake of technologies. Many of the technologies could create new sources of economic activity, particularly for regional Australia Most of the technologies have the potential for significant economic and social benefits associated with regional development and employment. For biological solutions, this often involves strengthening and supporting existing industries, such as agriculture or forestry, by increasing productivity and diversifying income streams. For the engineered solutions, regional hubs can be developed around technologies that can create new, and reinvent existing, industries. Competition is emerging for the resources required for sequestration One of the key constraints in developing economic potential sequestration is competition for finite resources, either with existing industries or between sequestration technologies. A balanced approach will be needed to maximise the environmental, social and economic value from the resource use, while still achieving carbon targets (see Review conclusions). Some of the most critical resources in competition will be: • land – biological solutions can compete with existing land uses such as agriculture • water – both biological and engineered solutions can consume additional water, and biological solutions such as permanent plantings, can alter catchment flows • feedstocks – several of the technologies have feedstocks (input materials) that are a shared resource (e.g. woody biomass can be used for permanent plantings, biochar or bioenergy). • energy – many of the engineered solutions have significant energy demand. Flowing water in the Hugh River Barriers and enablers Identifying the barriers to the uptake of technologies can enable the strategic design of methods to remove them and increase the uptake. Current enablers can be supported to encourage further uptake, and new enablers can be put into place to remove barriers. Managing barriers and enablers will be critical to Australia’s carbon sequestration strategy. Early-stage engagement with proponents, regulators and communities may expose risks that may lead to quicker resolution of barriers. Ongoing research will also be needed to continue exploring the issues, as scaling up some technologies may reveal new barriers and competition for resources. Research to reduce the cost per unit could improve uptake for some technologies There is a strong relationship between cost per tonne of sequestration and the commercial readiness level of the technology. Where costs are high, projects development is limited despite the sequestration potential. This is particularly the case for many engineered solutions (e.g. direct air carbon capture and storage (DACCS) has significant sequestration potential but high costs). Technologies with high sequestration levels and high costs would benefit from investment into research to bring down the unit cost associated with capture and storage. This could increase the national economic sequestration potential. The same applies to barriers imposed by the high costs of carbon measurement, reporting and verification. Innovative approaches to measurement and verification could reduce costs and improve the economics of scaling both biological and engineered technologies. Co-benefits could be leveraged and communicated to assist uptake and scaling Measuring value and rewarding delivery of co-benefits could improve the economics of scaling some of the sequestration technologies, and efficiently meet multiple societal needs. Allowing market mechanisms that encourage benefit stacking (where multiple income sources for the same activity are delivering a range of positive outcomes) will improve the overall value proposition of technology implementation. Providing supporting information to potential users on the environmental, social and economic benefits of technologies may also assist uptake. For most of the biological solutions, further assessment and quantification of the benefits, co-benefits and costs as well as better understanding of the land use trade-offs could support scaling. Aligning early-stage projects to other areas of co-benefit may help to create co-funding opportunities (e.g. biochar projects can be used to support afforestation and produce products that could be used in downstream industries). Many of the opportunities for sequestration are in regional areas. Understanding the regional benefits, including first nations values and benefits, will be critical to maximise social benefit, sustain social license to operate, as well as drive uptake and scaling. Further, regional opportunities will require suitable supply chains and logistics at a low cost to enable and support sequestration activities. A national foresighting capability to support an increase in negative emissions See section 3.1 of Australia’s carbon sequestration potential: Technical report for further details. In this report, the current state of a range of sequestration options has been produced. This has generated a series of technical and economic potential sequestration estimates for 2050. This report is based on current knowledge and estimates. Advances in technology and research development mean that these fields are rapidly evolving, which may impact both the technical and economic sequestration potential. A new national capability will be required to provide improved and updated estimates, to identify and assess and develop optimised portfolios of options, and to guide investment and the design of incentives that unlock emerging opportunities. These decisions must be informed by data on each technology's environmental, social and economic value. Decision making must also be informed by analyses of the implications, trade-offs and opportunities for different technologies and regions. Adverse impacts and co-benefits should be accounted for, as well as costs, and resource use and competition. Competition and dependencies exist between some technologies, with some needing a common shared finite resource such as water or biomass. A purposeful allocation of resources between competing demands will be needed to achieve best use. Finally, to ensure technologies are ready for deployment in the time frames needed, we must identify the key success factors for scaled implementation and incorporate these factors into an accelerated research and development process. The ability to carefully design for these factors will determine the rate at which technologies can be successfully scaled and the extent to which their scaling maximises opportunities for co-benefits. Building analytic capacity to resolve these matters should be a priority for Australia. Developing the national capability requires a modelling capability underpinned by innovations in emerging technologies. This will allow us to explore and quantify national and regional trade-offs and feedbacks of different portfolios of sequestration technologies and quantify the efficacy, benefits, co‑benefits, and risk over time. It also provides the capacity to explore the efficacy of new policy levers and incentives to deliver their intended outcomes. It also allows risks and potential risks to be identified as implications for the broader economy, such as on food systems and prices. Analyses should be ongoing because technologies are at different levels of technical maturity and are evolving with investment and scale. As the technologies and uptake trajectories change, a process of both monitoring, reporting and evaluation of outcomes, and an ability to recalibrate sequestration technology strategy in the light of changing circumstances and evidence will be required. Roadmap for a national foresighting capability See section 3 of Australia’s carbon sequestration potential: Technical report for further details. The roadmap to develop a national foresighting capability has 4 stages: STAGE 1 Research current technologies and their potential. This refers to the information delivered in this review, and further work to explore individual approaches in detail and address many of the gaps identified in this review. This stage should be repeated, ideally annually, to ensure new and emerging technologies and innovation breakthroughs are captured. STAGE 2 Build the modelling approach (see Review conclusions). The integrated assessment modelling approach will be built around state-of-the-art earth system and economic models coupled together in a net zero transition framework. STAGE 3 Develop the portfolio (see Review conclusions). The portfolio should be modelled and optimised based on technological, earth system, social, economic and policy considerations. STAGE 4 Implement across multiple pathways. Achieving Australia’s negative emission potential requires the development of pathways to implementation. Policy drivers and other levers can be designed to potentially advance technology development, reduce costs and incentivise the markets. Figure 2. Australia’s roadmap for a national foresighting capability Review conclusions Sequestration of GHGs through avoided and negative emissions technologies is needed in conjunction with decarbonisation for Australia to reach it’s net emission reduction targets. Evidence-based strategies will enable us to meet these goals, sustain social licence and underpin credible markets, while achieving important environmental, social and economic benefits. A portfolio of technologies will be needed to achieve Australia’s carbon targets The scale of carbon removal required for our national and global targets looks challenging when considering the biophysical limiting factors of any one technology. No single technology is sufficient to provide a pathway to Australia’s emissions reduction target. But Australia has good opportunities to sequester carbon by deploying a range of different technologies. The technologies are at different levels of maturity, as indicated by the varying technology and commercial readiness levels. Different technologies also have different operating mechanisms and rely on different resources. Understanding the theoretical limits to the emissions reduction associated with each approach allows us to strategically plan a combination of technologies to meet our removal needs. The portfolio of technologies will generate a range of co-benefits There are co-benefits associated with many of the reviewed technologies, which can be leveraged to assist uptake and scaling. Many co-benefits include environmental and socio‑economic benefits that flow back into local communities. Opportunity for Australia Australia is well positioned with abundant land-resources, significant geological storage capacity, vast marine estate and low-emission-energy resource potential (CSIRO Low Emission technology Roadmap) to translate the potential identified in this report into realisable sequestration. Australia also has a well-developed carbon market which is a necessary institutional structure to support the scaling of these technologies. Further, Australia has good underpinning knowledge infrastructure and a skilled, digitally-literate and digitally-enabled workforce to develop and implement a portfolio of carbon sequestration options. While the natural resource and land base provides an opportunity to sequester carbon, the short to medium term focus should be to bring down the costs and increase the scale of delivering sequestration. This will require a combination of research, skills, delivery process building, market instrument design, and community engagement to develop social licence and to realise the co-benefits created through the scaling opportunity. Competition for resources will require careful management The achievable level of carbon sequestration will be limited by the resources available (see Adverse impacts and co-benefits). Taking this into account is key prioritising technologies that will have the most significant impact. It will be important to manage use of resources to maximise the environmental, social and economic value while still achieving carbon sequestration targets. Technologies – at a glance See sections 4–15 of Australia’s carbon sequestration potential: Technical report for further details. This section summarises the technology assessments around 3 key questions: 1. What is the technology? – Description and current uptake – how the technology acts to sequester carbon, and its current use in Australia 2. What is the sequestration potential? – Sequestration levels – the actual, technical and economically feasible (economic sequestration potential) amounts of CO2-e sequestered by the technology – Length of storage – the likely duration of sequestered carbon as a balance of its turn-over rate and risks to stocks – Adverse social or environmental impacts – other negative impacts that the technology may have – Risks to the sequestration potential – factors that may reduce the economic sequestration level – Co-benefits – other benefits (apart from carbon sequestration) that the technology may provide 3. How easily can it be further developed and implemented? – Readiness – the technology readiness level and commercial readiness level (ARENA 2014), assessed on a scale of 1–9 – Cost – $ per tonne of carbon (CO2-e) sequestered – Current barriers – barriers to uptake and scaling; for example, financial, policy, regulatory, industry, supply chain or market blockers – Potential enablers – methods to improve uptake and scaling through regulation or improvements to technology or practices. Permanent plantings What is the technology? Permanent plantings are plantings of woody vegetation on non-forested land, typically on previously cleared agricultural land. The plantings are not for harvest and are typically of native vegetation, and carbon in permanent plantings is sequestered in the living biomass, forest debris and soil. Emission type Negative Capture technology Biological Storage technology Biological What is the sequestration potential? The economic potential sequestration offered by permanent plantings is relatively high. Permanent plantings of native vegetation also offer considerable environmental benefits, and are particularly suitable in areas of low productivity. Large plantings can affect water resources. Actual (2010–2020) 2.1 Mt/year Technical potential (2050) ~480 Mt/year Economic potential (2050) ~16 Mt/year Length of storage 25–100 years Adverse social or environmental impacts • Change to conventional land use • Large-scale plantings can affect catchment water flow and resources • Increased fuel load and fire risk Risks to the sequestration potential • Climate change (increased temperature, altered rainfall) • Drought, fire, pests and disease Co-benefits • Improved biodiversity and landscape connectivity • Improved soil health and soil carbon • Reduced erosion • Improved productivity, especially in areas where plantings are mixed with other land uses (e.g. shelterbelts; see Case study) • Diversification of farm income How easily can it be further developed and implemented? Permanent planting is well established, with several private companies, nongovernmental organisations and not-for‑profit organisations specialising in establishing and maintaining plantings. However, the current carbon price means that alternative land uses in productive areas are more profitable than carbon farming. Methods to reduce costs and increase return could encourage uptake. Readiness Technology readiness level: 9 Commercial readiness level: 4–5 Cost per tonne of carbon sequestered $20–$30 Emissions Reduction Fund methodology Yes Current barriers • Concerns with changes to conventional land use and potential impacts on communities • Costs/economics • Availability of suitable land • Limited availability of seeds or tubestock • Cost of seeds or tubestock Potential enablers • Better quantification of co-benefits • Inclusion of soil carbon in assessment methodologies • Innovative methods for cost reduction • Increased carbon price • Improved supply chain for seeds or tubestock Case study Shelterbelt tree plantings Integrating shelterbelt tree plantings within agricultural landscapes can deliver multiple benefits to both landholders and the environment. These include: • providing habitat for flora and fauna and increasing habitat connectivity across landscapes • providing windbreaks to protect crops and livestock, leading to reduced animal stress and increased productivity • reducing evaporation from the soil surface, meaning increased soil water availability to support pasture growth • reducing windspeed and slowing surface water flows to reduce soil erosion. If the planting uses commercial plantation species, this can provide additional economic benefits. An experimental investigation of the impacts of linear (shelterbelt) tree plantings across four sites in northern Tasmania was undertaken by CSIRO, the University of Tasmania, and Private Forests Tasmania. The aim of the study was to better understand the potential benefits of integrating commercial plantation trees (Pinus radiata) into existing farming systems. The study found that, compared with unsheltered or open paddocks, tree shelters (CSIRO 2018): • reduced average wind speeds by 20–50% • reduced evaporation by 15–20%. The study also found that in the shelter of the planting, the pasture produced 30% more biomass than unsheltered or open paddocks. Economic analysis of a square paddock of approximately 25 hectares showed that the returns from tree planting over 25 years was approximately $54,000, comprising tree harvest ($14,000), shelter benefits to productivity ($42,000), carbon sequestration ($3,000) and amenity/land value ($1,000). Net costs, including fencing, were approximately $6,000. The study showed that the integration of trees into farming systems can bring benefits that are worth several times the value of the trees, and that small areas of trees can make a disproportionate impact on overall returns and environmental impacts. Shelterbelt established adjacent to grazing paddock, protecting livestock from wind. Photo credit: Arthur Lyons. Plantation and farm forestry What is the technology? Plantation and farm forestry can increase carbon sequestration by establishing new plantations and by changing management practices in existing plantations. This sequesters carbon in living biomass, forest debris and harvested wood products. Emission type Negative Capture technology Biological Storage technology Biological What is the sequestration potential? The economic potential sequestration for plantation and farm forestry is ~32 Mt forestry and can offer benefits to regional communities. However, the economic potential sequestration varies with species and soil type, and can be threatened by drought, fire, pests and disease. Environmental benefits such as reduced erosion are also balanced by environmental risks such as increased water use. Actual (2010–2020) 11.5 Mt/year Technical potential (2050) 631 Mt/year Economic potential (2050) ~32 Mt/year Length of storage 25–100 years Adverse social or environmental impacts • Impacts on catchment water flow and resources • Increased fuel load and fire risk Risks to the sequestration potential • Climate change (increased temperature, altered rainfall) • Drought, fire, pests and disease Co-benefits • Economic and social benefits for regional communities • Improved biodiversity and landscape connectivity • Improved soil health and soil carbon • Reduced erosion How easily can it be further developed and implemented? Plantation and farm forestry technologies are well developed, but competition for land and high costs limit the expansion of these technologies for carbon sequestration. New processing methods and markets for wood products may improve feasibility for sequestration. Readiness Technology readiness level: 9 Commercial readiness level: 4–5 Cost per tonne of carbon sequestered $10–$30 Emissions Reduction Fund Methodology Yes Current barriers • Availability of suitable land • Competition for land • Capital for establishment and processing plants • Regulatory burden on the establishment of new forests • Operational and supply chain costs Potential enablers • Innovative market creation for wood-based products, such as bioenergy and biochar • Better quantification of co-benefits • Innovative methods for cost reduction • Increased carbon price Human induced regeneration of native forest What is the technology? Human induced regeneration of native forest involves changing the management of non‑forested land to promote the establishment of native forest cover (e.g. ending land clearing, reducing rates of domestic livestock grazing and controlling feral grazing animals). The carbon in native forest is sequestered in the living biomass, forest debris and soil. Emission type Negative Capture technology Biological Storage technology Biological What is the sequestration potential? Human induced regeneration offers relatively low levels of sequestration because regeneration occurs opportunistically and is highly dependent on local seedstock and conditions. Native forests offer the same benefits as permanent plantings but are likely to take longer to establish. Actual (2010–2010) 20 Mt/year Technical potential (2050) 60 Mt/year Economic potential (2050) 39 Mt/year Length of storage 25–100 years Adverse social or environmental impacts • Disruption to conventional land use • Potential increases in non-native species • Increased fuel load and fire risk Risks to the sequestration potential • Climate change (increased temperature, altered rainfall) • Drought, fire, pests and disease Co-benefits • Restoration of native cover • Improved biodiversity and landscape connectivity • Improved soil health and soil carbon • Reduced erosion • Improved productivity • Diversification of farm income How easily can it be further developed and implemented? Methods to encourage natural regeneration are straightforward (e.g. fencing), and the costs of sequestration per tonne of carbon are very low. Better methods of verifying carbon sequestration, including soil carbon, could improve carbon pricing for natural regeneration. Readiness Technology readiness level: 9 Commercial readiness level: 5–6 Cost per tonne of carbon sequestered $5 Emissions Reduction Fund Methodology Yes Current barriers • Concerns with changes to conventional land use and potential impacts on communities • Measurement and verification of sequestration Potential enablers • Further quantification of benefits and co-benefits • Inclusion of soil carbon in assessment methodologies • Further analysis of economic potential sequestration Avoided land clearing What is the technology? Avoided land clearing aims to avoid emissions by retaining areas of mature native vegetation that would otherwise have been cleared. Carbon in uncleared land is stored in the living biomass, vegetation debris and soil and additional carbon can be sequestered as the forest continues to grow. Emission type Avoided Capture technology Biological Storage technology Biological What is the sequestration potential? The carbon sequestration potential for avoided land clearing is low, and the major emission type for the technology is an avoided emission rather than negative emission type. However, similarly to permanent plantings and natural regeneration, avoided land clearing offers significant environmental benefits. Actual (2010–2020) 2.3 Mt/year Technical potential (2050) ~9 Mt/year Economic potential (2050) ~8 Mt/year Length of storage 25–100 years Adverse social or environmental impacts • Reduced production on land • Increased fuel load and fire risk Risks to the sequestration potential • Climate change (increased temperature, altered rainfall) • Drought, fire, pests and disease Co-benefits • Maintenance of native cover • Improved biodiversity and landscape connectivity • Improved soil health and soil carbon • Reduced erosion • Improved productivity • Diversification of farm income How easily can it be further developed and implemented? Avoided land clearing is straightforward and well established and costs are low. Avoided land clearing is best suited to less productive areas. The regulatory environment requires documented evidence to allow carbon pricing, and easing some of these restrictions may increase uptake. Readiness Technology readiness level: 9 Commercial readiness level: 2–3 Cost per tonne of carbon sequestered $5–$10 Emissions Reduction Fund Methodology Yes Current barriers • Concerns with changes to conventional land use and potential impacts on communities • Measurement and verification of sequestration • Low incentives in the policy and regulatory environment • Documentation requirements for carbon pricing Potential enablers • Further analysis of barriers to uptake • Relaxing land availability constraints • Inclusion of soil carbon in assessment methodologies • Further analysis of economic potential • Reduced regulatory complexity Savanna fire management What is the technology? Savanna fire management uses prescribed or planned fires for the purposes of reducing the extent of and likelihood of large, high-intensity, late dry-season fires. This land management practice in northern Australia reduces emissions from the late dry season fires, and increases carbon being sequestered in dead organic matter and in living plants. Only the sequestration component was considered for this review. Emission type Avoided or Negative Capture technology Biological Storage technology Biological What is the sequestration potential? The sequestration potential of savanna fire management is low, and the practice is restricted to two rainfall zones in northern Australia. However, the technology also reduces emissions and offers significant environmental and Indigenous community benefits. Actual (2016–2020) 5.6 Mt/year Technical potential (2050) 6 Mt/year Economic potential (2050) 6 Mt/year Length of storage 25–100 years Adverse social or environmental impacts • Limited land management options due to need to maintain sequestration • Lack of intensive fire as a management option Risks to the sequestration potential • Climate change (increased temperature, altered rainfall) • Drought and water stress Co-benefits • Employment opportunities for Indigenous communities • Increased ground cover and biodiversity • Reduced erosion • Reduced mortality of flora and fauna • Reduced invasive woody vegetation and grasses How easily can it be further developed and implemented? Savanna burning abatement estimation protocols are well established and based on extensive scientific study. Recent changes to the savanna burning methodology have not increased uptake. This indicates that the barrier may lie in the limitations that the technology places on future land management options. Readiness Technology readiness level: 9 Commercial readiness level: 3–5 Cost per tonne of carbon sequestered $5 Emissions Reduction Fund Methodology Yes (for sequestration) Current barriers • Area of land suitable for burning • Possible concern by landholders in maintaining sequestration for 100 years Potential enablers • Further analysis of barriers to uptake Soil carbon What is the technology? Land management can increase carbon sequestration in the soil by increasing the rate at which carbon is accumulated (such as improving plant cover and retaining stubble), decreasing the rate at which carbon is lost (such as reducing rates of decomposition and minimising erosion losses), or changing the material added to the soil so that it lasts longer. Emission type Avoided and Negative Capture technology Biological Storage technology Biological What is the sequestration potential? Soil is a very effective carbon sink, and land management changes leading to increased soil carbon are associated with a range of productivity and environmental benefits. However, soil carbon is not a permanent form of sequestration. Actual (2021–2022) 0 Mt/year Technical potential (2050) 115 Mt/year Economic potential (2050) 5–29 Mt/year Length of storage 25–100 years Adverse social or environmental impacts • Risk of increased nitrous oxide emission due to higher level of inorganic nitrogen in the soil • Reduced future land use options Risks to the sequestration potential • Climate change (increased temperature, altered rainfall) • Risk of reversal Co-benefits • Sustaining and improving productivity • Reducing the need for fertiliser inputs • Reducing drought impacts • Improving farm resilience to climate change How easily can it be further developed and implemented? There has been rapid uptake of soil carbon technologies in farming management as the industry recognises the related benefits to productivity. It will be important to develop mechanisms to ensure that soil carbon levels are maintained. Cheaper methods to measure carbon levels are also needed to enable verification and monitoring. Readiness Technology readiness level: 9 Commercial readiness level: 3-4 Cost per tonne of carbon sequestered $7–$13 Emissions Reduction Fund Methodology Yes Current barriers • High cost of monitoring, reporting and verification in many applications to date • Uncertainty of length of storage • Onus on future managers to maintain Potential enablers • Clear articulation of benefits to productivity • Direct subsidy to limit practices that deplete soil carbon • Cheaper methods to measure soil carbon • Market or value chain mechanisms that reward practices that build soil carbon Blue and teal carbon What is the technology? Blue carbon describes carbon sequestration in vegetated coastal ecosystems, specifically mangrove, saltmarsh and seagrass ecosystems. Teal carbon describes carbon sequestration in inland freshwater wetlands. Carbon is sequestered in these ecosystems in the living biomass and soil (sediment), and management practices are used to promote carbon accumulation or prevent emissions. Emission type Avoided or Negative Capture technology Biological Storage technology Biological What is the sequestration potential? Blue and teal carbon ecosystems store more carbon on average than most terrestrial ecosystems and typically sequester carbon at faster rates. While there are no reliable estimates of the potential or economic sequestration levels of blue and teal carbon technologies, several large-scale regional projects show that emissions reduction strategies, such as tidal introduction, can yield substantial net abatement. Actual (2021–2022) 1.1 Mt/year Technical potential (2050) 3–4 Mt/year Economic potential (2050) Unknown Mt/year Length of storage 25–100 years Adverse social or environmental impacts • Potential impacts on Indigenous values and ownership rights Risks to the sequestration potential • Climate change (sea level rise, increased temperature, changes in rainfall) • Severe tropical storms • Pests and disease Co-benefits • Improved biodiversity • Sustaining and improving fisheries • Protection of coastal regions from storm surges • Ecosystem services (e.g. pollutant removal) • Potential Indigenous community benefits How easily can it be further developed and implemented? The technologies for ecosystem restoration and tidal reintroduction are well established. However, the implementation costs are relatively high and the complexity of legal rights in the coastal zone can make permissions difficult. There is also a high cost of data collection to support modelled estimates. Readiness Technology readiness level: 9 Commercial readiness level: 3–4 Cost per tonne of carbon sequestered $18–$30 Emissions Reduction Fund Methodology Yes (for blue carbon) No (for teal carbon) Current barriers • Complex land tenure and permissions systems • Poor estimates of technical potential and economic potential sequestration Potential enablers • Identification of feasible areas • Innovative business models • Better estimates of lifecycle costs • Further analysis of economic potential sequestration • Inclusion of sediment sequestration Pyrolysis biochar What is the technology? Biochar is a charcoal-like material produced from the slow pyrolysis (heating in the absence of oxygen) of biomass (e.g. forestry and crop residues, and food, green or municipal organic waste). Biochar sequesters the carbon that was the original plants, and has various uses. Emission type Negative Capture technology Biological Storage technology Biological What is the sequestration potential? The technical potential of pyrolysis biochar is reasonable, and it offers long storage times and additional environmental and economic benefits (e.g. from increased soil health). Actual (2021–2022) 0.04 Mt/year Technical potential (2050) 30–60 Mt/year Economic potential (2050) Unknown Mt/year Length of storage >500 years Adverse social or environmental impacts • If land is specifically used to produce biomass, disruption to conventional land use • Potential human health impacts (fine dust) • Potential environmental impacts of any harmful components Risks to the sequestration potential • No risks identified Co-benefits • Biochar can be added to soil to increase soil carbon and productivity • Biochar can be used in various industries (e.g. in the manufacture of composite materials, where it increases mechanical properties and durability) How easily can it be further developed and implemented? Pyrolysis technologies are well developed and significant amounts of biomass are available from farm, garden and food waste. However, the industry in general is not yet developed and will require decreased costs and increased end markets to drive uptake. Readiness Technology readiness level: 9 Commercial readiness level: 2–4 Cost per tonne of carbon sequestered $80–$120 Emissions Reduction Fund Methodology Yes (for application of biochar to agricultural soil) Current barriers • Cost/economics • Competition for land use and biomass • Complex logistics and supply chains • Limited end markets Potential enablers • Innovative business model and development of end markets • Policy incentives to drive industry investment and development • Better estimates of lifecycle costs • Further analysis of possible measurement methods for carbon pricing Geological storage What is the technology? Geological storage is the final part of the carbon capture and storage process. CO2 is captured using various approaches either at emission sources or from the atmosphere. It is then transported by pipeline or ship, compressed and injected into permeable rock layers. In Australia, the 2 most applicable types of reservoirs are depleted oil or gas fields and saline aquifers, and there are currently several projects in different stages of development. Emission type Capture technology Storage technology Engineered What is the sequestration potential? The sequestration potential with geological storage is high and offers a very long-term option. Carbon capture and storage projects have reached the operational stage in several places around the world. Actual (2021–2022) 2.26 Mt/year Technical potential (2050) 227 Gt/year Economic potential (2050) 50 Mt/year Length of storage >million years Adverse social or environmental impacts • Potential CO2 leakage and groundwater contamination or level increase risk • Risk of transportation leakage Risks to the sequestration potential • No risks identified Co-benefits • Potential for regional community benefits associated with regional hubs • Potential carbon credit trading How easily can it be further developed and implemented? The technology for geological storage is well developed; however, uptake is low and a number of projects are experiences difficulties. Some people view the technology as prolonging the use of fossil fuels and delaying the uptake of renewable energy; communities are concerned about well integrity, groundwater contamination and leaking emissions. The technology is also relatively expensive; the main costs are associated with transportation and compression of CO2. Readiness Technology readiness level: 9 Commercial readiness level: 4–5 Cost per tonne of carbon sequestered $14–35 Emissions Reduction Fund Methodology Yes Current barriers • Requires large capital investment • Complexity of policy and regulatory environment • Lack of social license and Indigenous engagement • Timeframes for development Potential enablers • Reduction in regulation complexity • Development of innovative business models (e.g. long forward contracts to de-risk upfront investment) • Reduction of costs and timeframes for development Bioenergy with carbon capture and storage What is the technology? Bioenergy with carbon capture and storage is a 2-step negative emissions technology. In the first step, biomass is converted to energy (either heat and electricity through combustion; biofuels through gasification or fermentation; or hydrogen through gasification, pyrolysis or fermentation). In the second step, CO2 released in the conversion is captured, compressed and stored underground in rock layers. This review considers both steps separately; see Geological storage for the second step. Emission type Negative Capture technology Biological Storage technology Engineered What is the sequestration potential? The sequestration potential with bioenergy is relatively high, and together with geological storage offers a very long-term storage option. Current energy production from biomass accounts for 47% of Australia’s renewable energy production and 3% of total energy consumption. Actual (2021–2022) No estimate Technical potential (2050) 181 Mt/year Economic potential (2050) 25–38 Mt/year Length of storage >million years (with geological storage) Adverse social or environmental impacts • Disruption to conventional land use • Risk to food security • Reduced soil health due to the use of crop residues Risks to the sequestration potential • Biomass supply Co-benefits • Generation of electricity from biomass waste streams How easily can it be further developed and implemented? The individual components of the technology (converting biomass into energy; capturing, transporting and storing CO2), are all mature; however, the combination of the technologies has low uptake due to uncertain policy support and economic feasibility. Innovate business models and incentives will be needed to encourage uptake. Readiness Technology readiness level: 2–9 Commercial readiness level: 2 Cost per tonne of carbon sequestered $100 Emissions Reduction Fund Methodology Yes Current barriers • Cost/economics • Requires large capital investment • Competition for land use • Lack of incentives in the regulatory and policy environment Potential enablers • Innovative business models • Provision of subsidies and tax credits and other incentives • Better understanding of the technical and economic potential sequestration Direct air capture What is the technology? CO2 is present in air at about 400 parts per million. In direct air capture, CO2 is separated from air using solid adsorbents or liquid absorbents, and prepared for storage or use in further applications. Emission type Capture technology Engineered Storage technology What is the sequestration potential? The carbon capture potential is relatively high; however, the length of storage depends on its use (e.g. use as a fuel will re‑release the carbon). Actual (2021–2022) No estimate Technical potential (2050) 980 Mt/year globally Economic potential (2050) No estimate Length of storage Depends on storage type Adverse social or environmental impacts • Potential environmental impacts through use of absorbents and adsorbents • Localised impact on land and water use Risks to the sequestration potential • No risks identified Co-benefits • Use of captured CO2 as feedstock for other products (e.g. sustainable aviation fuel or urea for fertiliser) • Generation of new economic activity and employment opportunities How easily can it be further developed and implemented? Direct air capture technology is developed but the process is expensive. Energy costs are a particular barrier; the theoretical minimum energy requirement for separating CO2 from an air stream is around triple that of capturing CO2 from a power station flue. Readiness Technology readiness level: 4–7 Commercial readiness level: 1 Cost per tonne of carbon sequestered $300–$600 Emissions Reduction Fund Methodology No Current barriers • High cost of current technologies • High energy requirement • Potentially large water usage • Considerable land requirements • Lack of support in policy and regulatory environment • Public acceptance Potential enablers • Development of low-cost, low‑emission pathways for use • Development of a full analysis methodology to support direct air capture carbon trading • Development of scaling pathways including innovative business models Mineral carbonation and enhanced weathering What is the technology? Mineral carbonation and enhanced weathering capture CO2 from the atmosphere through chemical reactions. In mineral carbonation, CO2 reacts with minerals containing calcium (Ca) and magnesium (Mg) to form stable carbonate minerals. In enhanced weathering, silicate minerals react with CO2 in water to break down, but the CO2 stays dissolved in the water and is eventually washed into the ocean. Both processes occur naturally as part of the global carbon cycle, but engineered solutions can increase the rate of atmospheric CO2 removal to achieve negative emissions. Emission type Negative Capture technology Engineered Storage technology Engineered What is the sequestration potential? Mineral carbonation and enhanced weathering offer high sequestration potential, and long-term storage. The main challenge for mineral carbonation and enhanced weathering is that they are very slow processes. Actual (2021–2022) 0.1 Mt/year Technical potential (2050) 36 Mt/year Economic potential (2050) No estimate Length of storage >1000 years Adverse social or environmental impacts • Generation of possible harmful by-products • Potential increased seismicity and groundwater contamination Risks to the sequestration potential • No risks identified Co-benefits • Could make use of tailings as a value stream • Resulting carbonates can be incorporated in industrial products (e.g. concrete) How easily can it be further developed and implemented? At present, there is only demonstration-scale technology available for mineral carbonation, and the technology is expensive. Further research is required to assess the potential of the technology for carbon sequestration in Australia. Readiness Technology readiness level: 5–7 Commercial readiness level: 1 Cost per tonne of carbon sequestered $28–$300 Emissions Reduction Fund Methodology No Current barriers • Cost of grinding and transporting feedstock material • Low reaction rates requiring excess feedstock • Lack of suitable locations • Access to sufficient raw materials Potential enablers • Research to improve reaction rates and lower costs • Research to identify location and quantities of feedstock • Establish a pilot project Summary tables Tables 1–3 summarise the results of the technology assessments, for carbon sequestration levels and storage time, adverse impacts and co-benefits, and barriers and enablers. Table 1. Economic potential estimated for 2050 and actual carbon sequestration levels for 2021–22 with corresponding length of storage TECHNOLOGY TYPE ECONOMIC POTENTIAL SEQUESTRATION 2050 (MT PER YEAR) ACTUAL SEQUESTRATION 2021‑22 (MT PER YEAR) LENGTH OF STORAGE (YEARS) Permanent plantings 16 2.11 25–100 Plantation and farm forestry 32 11.51 25–100 Human induced regeneration of native forest 39 202 25–100 Avoided clearing 7.7 2.31 25–100 Savanna fire management 6 5.61 25–100 Soil carbon 5–29 0 25–100 Blue and teal carbon No estimate 1.11 25–100 Pyrolysis biochar No estimate <0.1 >500 Geological storage 50 2.26 – (Gorgon project 2020-21) >million Bioenergy carbon capture and storage 25–38 No estimate >million Direct air capture No estimate No estimate Depends on storage technology Mineral carbonation and enhanced weathering No estimate 0.1 >1000 Summary of technology potential. 1AGEIS 2010-2020. 2AGEIS 2016-2020 Footnote: AGEIS – https://ageis.climatechange.gov.au/ Table 2. Adverse impacts and co-benefits TECHNOLOGY ADVERSE SOCIAL OR ENVIRONMENTAL IMPACTS CO-BENEFITS Permanent plantings • Disruption to conventional land use • Large-scale plantings can affect catchment water flow and resources • Increased fuel load and fire risk • Restoration of native cover • Improved biodiversity and landscape connectivity • Improved soil health and soil carbon • Reduced erosion • Improved productivity, especially in areas where plantings are mixed with other land uses • Diversification of farm income Plantation and farm forestry • Impacts on catchment water flow and resources • Increased fuel load and fire risk • Economic and social benefits for regional communities • Improved biodiversity and landscape connectivity • Improved soil health and soil carbon • Reduced erosion • Diversification of farm income TECHNOLOGY ADVERSE SOCIAL OR ENVIRONMENTAL IMPACTS CO-BENEFITS Human induced regeneration of native forest • Disruption to conventional land use • Potential increases in non-native species • Increased fuel load and fire risk • Restoration of native cover • Improved biodiversity and landscape connectivity • Improved soil health and soil carbon • Reduced erosion • Improved productivity • Diversification of farm income Avoided land clearing • Reduced production on land • Increased fuel load and fire risk • Maintenance of native cover • Improved biodiversity and landscape connectivity • Improved soil health and soil carbon • Reduced erosion • Improved productivity • Diversification of farm income Savanna fire management • Limited land management options due to need to maintain sequestration • Lack of intensive fire as a management option • Employment opportunities for Indigenous communities • Increased ground cover and biodiversity • Reduced erosion • Reduced mortality of flora and fauna • Reduced invasive woody vegetation and grasses Soil carbon • Increased nitrous oxide emission due to higher level of inorganic nitrogen in the soil • Reduced future land use options • Sustaining and improving productivity • Reducing the need for fertiliser inputs • Reducing drought impacts • Improving farm resilience to climate change • Diversification of farm income Blue and teal carbon • Potential impacts on Indigenous values and ownership rights • Improved biodiversity • Sustaining and improving fisheries • Protection of coastal regions from storm surges • Ecosystem services (e.g. pollutant removal) • Potential Indigenous community benefits Pyrolysis biochar • Disruption to conventional land use • Potential human health impacts (fine dust) • Potential environmental impacts of any harmful components • Biochar can be added to soil to increase soil carbon and productivity • Biochar can be used in various industries (e.g. in the manufacture of composite materials, where it increases mechanical properties and durability) Geological storage • Potential CO2 leakage and groundwater contamination or level increase risk • Risk of transportation leakage • Potential for regional community benefits associated with regional hubs • Potential carbon credit trading Bioenergy with carbon capture and storage • Disruption to conventional land use • Risk to food security • Reduced soil health due to the use of crop residues • Generation of electricity from biomass waste streams Direct air capture • Potential environmental impacts through use of absorbents and adsorbents • Localised impact on land and water use • Use of captured CO2 as feedstock for other products (e.g. sustainable aviation fuel or urea for fertiliser) • Generation of new economic activity and employment opportunities Mineral carbonation and enhanced weathering • Generation of possible harmful by-products • Potential increased seismicity and groundwater contamination • Could make use of tailings as a value stream • Resulting carbonates can be incorporated in industrial products (e.g. concrete) Table 3. Barriers and enablers TECHNOLOGY BARRIERS ENABLERS COST ($/t) TRL CRL Permanent plantings • Concerns with changes to conventional land use and potential impacts on communities • Costs/economics • Availability of suitable land • Limited availability of seeds or tubestock • Cost of seeds or tubestock • Better quantification of co-benefits • Inclusion of soil carbon in assessment methodologies • Innovative methods for cost reduction • Increased carbon price • Improved supply chain for seeds or tubestock 20–30 9 4–5 Plantation and farm forestry • Availability of suitable land • Competition for land • Capital for establishment and processing plants • Regulatory burden on the establishment of new forests • Operational and supply chain costs • Innovative market creation for wood‑based products, such as bioenergy and biochar • Better quantification of co-benefits • Innovative methods for cost reduction • Increased carbon price 10–30 9 4–5 Human induced regeneration of native forest • Concerns with changes to conventional land use and potential impacts on communities • Measurement and verification of sequestration • Further quantification of benefits and co-benefits • Inclusion of soil carbon in assessment methodologies 5 9 5–6 Avoided land clearing • Concerns with changes to conventional land use and potential impacts on communities • Measurement and verification of sequestration • Low incentives in the policy and regulatory environment • Documentation requirements for carbon pricing • Further analysis of barriers to uptake • Relaxing land availability constraints • Inclusion of soil carbon in assessment methodologies • Reduced regulatory complexity 5–10 9 2–3 Savanna burning • Area of land suitable for burning • Possible concern by landholders in maintaining sequestration for 100 years • Further analysis of barriers to uptake 5 9 5 Soil carbon • High cost of monitoring, reporting and verification • Uncertainty of length of storage • Onus on future managers to maintain • Clear articulation of benefits to productivity • Direct subsidy to limit practices that deplete soil carbon • Cheaper methods to measure soil carbon • Market or value chain mechanisms that reward practices that build soil carbon 7–13 9 3–4 TECHNOLOGY BARRIERS ENABLERS COST ($/t) TRL CRL Blue and teal carbon • Complex land tenure and permissions systems • Poor estimates of technical and economic potential sequestration • Identification of feasible areas • Innovative business models • Better estimates of lifecycle costs • Inclusion of sediment sequestration 18–30 9 3–4 Pyrolysis biochar • Cost/economics • Competition for land use and biomass • Complex logistics and supply chains • Immature and/or competing end‑markets • Innovative business model and development of end markets • Policy incentives to drive industry investment and development • Better estimates of lifecycle costs 80–120 9 2–4 Geological storage • Requires large capital investment • Complexity of policy and regulatory environment • Lack of social license and Indigenous engagement • Timeframes for development • Reduction in regulation complexity • Development of innovative business models (e.g. long forward contracts to de-risk upfront investment) • Reduction of costs and timeframes for development 14–35 9 4–5 Bioenergy with carbon capture and storage • Cost/economics • Requires large capital investment • Competition for land use • Lack of incentives in the regulatory and policy environment • Innovative business models • Provision of subsidies and tax credits and other incentives • Better understanding of the technical and economic potential sequestration 100 2–3 2 Direct air capture • High cost of current technologies • High energy requirement • Potentially large water usage • Considerable land requirements • Lack of support in policy and regulatory environment • Public acceptance • Development of low-cost, low‑emission pathways for use • Development of a full analysis methodology to support direct air capture carbon trading • Development of scaling pathways including innovative business models 300–600 4–7 1 Mineral carbonation and advance weathering • Cost of grinding and transporting feedstock material • Low reaction rates requiring excess feedstock • Lack of suitable locations • Access to sufficient raw materials • Research to improve reaction rates and lower costs • Research to identify location and quantities of feedstock • Establish a pilot project 28–300 5–7 1 References ARENA (2014) Technology Readiness Levels for Renewable Energy Sectors. URL: https://arena.gov.au/ assets/2014/02/Technology-Readiness-Levels.pdf AEGIS – Australian National Greenhouse Accounts https://ageis.climatechange.gov.au/ UNFCCC 2015 – https://unfccc.int/files/meetings/paris_ nov_2015/application/pdf/paris_agreement_english_.pdf NASEM – 2019 National Academies of Sciences, Engineering, and Medicine. 2019. Negative Emissions Technologies and Reliable Sequestration: A Research Agenda. Washington, DC: The National Academies Press. https://doi.org/10.17226/25259 Minx et al: Minx, J. C et al 2018 Negative Emissions – Part 1: Research Landscape and Synthesis, Environ. Res. Lett. 13 063001 CSIRO Low Emission technology Roadmap, Campey, T., Bruce, S., Yankos, T., Hayward, J., Graham, P., Reedman, L., Brinsmead, T., Deverell, J. (2017) Low Emissions Technology Roadmap. CSIRO, Australia. CSIRO 2018, Mendham DS (2018). Modelling the costs and benefits of Agroforestry systems – Application of the Imagine bioeconomic model at four case study sites in Tasmania. Aerial photo of farmland on the Murrumbidgee River outside Murrumbateman, NSW Citation Fitch P, Battaglia M & A Lenton (2022). Australia’s carbon sequestration potential – Summary report. CSIRO and the Climate Change Authority, Canberra. Copyright © Commonwealth Scientific and Industrial Research Organisation 2022. To the extent permitted by law, all rights are reserved and no part of this publication covered by copyright may be reproduced or copied in any form or by any means except with the written permission of CSIRO. Acknowledgements This project was funded by the Climate Change Authority and the Clean Energy Regulator. Contributing authors: Paul Feron, Lei Gao, Yuan Mei, Allison Hortle, Lynne MacDonald, Mark Pearce, Sandra Occhipinti, Stephen Roxburgh, Andy Steven. The authors would like to thank and acknowledge the helpful advice provided by Ben Holt, Will Howard, Erik Olbrei and Ramone Bissett. Initial writing and editing by Biotext Pty Ltd. 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As Australia’s national science agency and innovation catalyst, CSIRO is solving the greatest challenges through innovative science and technology. CSIRO. Unlocking a better future for everyone. Contact 1300 363 400 +61 3 9545 2176 csiro.au/contact csiro.au Further information Peter Fitch peter.fitch@csiro.au Michael Battaglia michael.battaglia@csiro.au Andrew Lenton andrew.lenton@csiro.au