As we reach the end of a year where headlines have focused on fires, floods, and rising temperatures, it has never been clearer that Australia needs to accelerate progress towards net zero emissions.
There is now broad international consensus that to transition to net-zero emissions – and to limit global warming to less than 1.5 degrees Celsius – requires both the reduction of greenhouse gas emissions and removal of carbon dioxide from the atmosphere.
This includes avoiding the release of carbon dioxide into the atmosphere from existing carbon stores, known as avoided emissions; and removal of carbon dioxide from the atmosphere for sequestration, known as negative emissions and carbon dioxide removal.
A recent CSIRO report, commissioned by the Climate Change Authority, has now provided a comprehensive assessment of Australia’s carbon sequestration potential.
Why is carbon sequestration so important?
The most recent Assessment Report from the UN Intergovernmental Panel on Climate Change, published earlier in 2022, states: ‘the deployment of carbon dioxide removals to counterbalance hard-to-abate residual emissions is unavoidable’.
It concludes that in order to meet the goals of the Paris Agreement, up to 4.1 (gigatonnes of carbon dioxide equivalent (GtCO2-e) would have to be removed each year by 2030, and up to 6.4 GtCO2-e a year by 2050.
Those figures refer to global totals, but we know that every country – including Australia – has a role to play in reducing its net or total emissions.
Researchers from CSIRO led by the Towards Net Zero Emissions Mission and Permanent Carbon Locking Future Science Platform have recently completed a report that examines the storage capacities, removal rates, and Australia’s comparative advantages across different sequestration options.
“To reach net-zero emissions and achieve the 43% reduction by 2030 as set out by the current Australian Government will require deep net emissions reductions,” says Peter Fitch, a CSIRO researcher who was a lead author of the report. “That’s a significant challenge, especially for some hard-to-abate sectors that need extra time to make the transition.”
“This report is really a look at one set of tools in our climate policy toolkit,” continues Mr Fitch. “We examined the existing literature and gathered as much information as we could from a range of experts, trying to answer questions about how much carbon we store today, and how much we could potentially store by 2050.”
Dr Will Howard is Lead Scientist at the Climate Change Authority (CCA), the independent statutory body that was established to provide advice on climate change to the Australian Government, and he agrees that now is the right time to start exploring Australia’s options for sequestration.
“There’s a real urgency to this,” says Dr Howard. “It’s a big and urgent task to bring emissions down through decarbonisation and sequestration. We are clear that sequestration is not a substitute for emissions reduction: it’s in addition, not instead of. But it’s a critically important tool that can help us build ambitious, evidence-based reduction targets.”
Key findings from the report
A wide range of available technologies can help with carbon sequestration, each at a different stage of maturity, and deployable at different scales. Some options, such as forestry, soil carbon and avoided land clearing are natural or nature-based solutions, while others such as geological storage and direct air capture are engineered solutions.
CCA commissioned CSIRO to produce a technical report comparing ten different sequestration options that could be applied in Australia, identifying not just their potential contributions but also any existing barriers to uptake and any co-benefits that might be realised by their scaling.
“The report provides a national stocktake of where we are currently,” says Mr Fitch. “But then what we have done is explore other pathways. We asked what is technically possible – what could we achieve if our only limits were biophysical, unconstrained by economics, energy, water or land use?”
The approach of the research team was to consider each technology independently, without taking into account competition for resources such as energy, land or water use. That means that there is further work to be done in assessing the options and mapping the most effective way forward.
However, there are still some very encouraging findings that will inform ongoing work.
“Australia has many opportunities in both nature-based solutions and engineered solutions,” says Mr Fitch. “Some of our advantages include a large land mass, market and regulatory strengths, a skilled workforce, and a culture of innovation. Collaboration between organisations like CSIRO, CCA, universities and other research institutions means if we choose pathways where there’s a need to focus on developing technology, we’ll be in a good position to do that. There are plenty of options out there; the next step is to deepen our understanding of the opportunities and trade-offs and choose the options that provide the best overall value and benefit to the nation.”
What comes next?
Both CSIRO and the CCA are keenly aware that the recently completed report is merely the start of an intensified focus on carbon sequestration, rather than an end.
“The report is an important first step in developing a strong evidence base for emissions reduction targets, and establishing what potential contribution sequestration can make,” says Ben Holt, Assistant Manager of Science, Adaptation and Sequestration at the Climate Change Authority. “The next steps are to explore ways to unlock that potential, and to develop a shared consensus about the further role sequestration could play in Australia's transition.”
CSIRO is currently running a number of stakeholder workshops to understand what the scale and cost trajectories for some of the sequestration technologies might look like. When these are completed, CCA will publish an Insights Report, which draws together findings from the process so far and provides advice to the Australian Government on some potential ways forward.
“In order to build a national capability around carbon sequestration we need to take a broad view,” says Dr Howard. “We want to work out how we can upscale in a significant way and bring down the cost of technologies. That means we’re listening to technical and regulatory experts, as well as the people who are focused on the pure science.”
From Mr Fitch’s perspective, it’s also important that the ongoing work centres the diverse needs and values of Australian communities.
“A key thing on CSIRO’s radar is really understand the costs and benefits of each sequestration option,” he says. “Many of the opportunities are in regional Australia, and we know how important it is to facilitate a transition to net zero that is rapid but also fair and socially just.”