Time to remove carbon from the atmosphere

Who knew that the projections for climate heating include assumptions of large scale removal of carbon from the atmosphere. Australia urgently needs a roadmap to achieve this. We need to bring together leaders from local and international carbon removal start-ups and scientists with broader climate leaders from policy, industry, finance, and others to help develop and facilitate the implementation of a roadmap for the future of atmospheric carbon removal in Australia.

It’s now well understood that avoiding dangerous climate change requires reaching net zero emissions globally by mid-century, with deep decarbonisation of electricity, transport and buildings starting now. Not as well understood, however, is that the “net” in net zero budgets require the removal of vast amounts of historical carbon dioxide (CO₂) emissions from the atmosphere.

The Intergovernmental Panel on Climate Change (IPCC) have recognised atmospheric carbon removal as a major lever to achieve safe temperatures and typical Paris Agreement-aligned scenarios assume we will start removing around 4 billion tonnes in the early 2030s ramping up to around 10 billion tonnes every year, for well past 2100.

For context that is 7-20 per cent of current global emissions.

For comparison the IPCC estimated 2019 global emissions from building and transport accounted for 3.3 billion tonnes and 8.7 billion tonnes of CO₂ equivalent respectively (scope 1).

This has profound implications for all policy makers, boards, chief executives, sustainability managers and climate tech investors with net zero mandates.

Atmospheric carbon removal is needed for two main reasons

Firstly, it’s intuitive that the slower we are at eliminating emissions the more CO₂ we will need to remove from the atmosphere to balance the carbon budget.

We are finally seeing real progress on decarbonising energy with renewables, storage and electrification, and technology breakthroughs to help decarbonise heavy industry, transport and agriculture.

But we’ve already spent too much of the remaining carbon budget, and we need to remove historical emissions to balance the deficit while we scale these solutions. Even the relatively ambitious decarbonisation scenarios require billions of tonnes of historical emissions to be removed alongside rapid decarbonisation.

The second reason is to correct what climate modellers refer to as temperature “overshoot”. The latest IPCC report (AR6) talks about net zero CO₂ by 2050, but a temperature goal to achieve 1.5?C by 2100.This difference in dates is in large part because of temperature overshoot.

Even if we achieve net zero CO₂ emissions globally by 2050, modelled scenarios suggest we will breach 1.5?C or even 2?C. Most modelled pathways to meeting Paris commitments assume that once we achieve net zero, we need to continue to ramp up the removal of historical emissions to deliver net negative emissions and bring temperature back down to safe levels (See Figure 1 Below).

Deep decarbonisation of all activities that produce greenhouse gas emission remains the biggest priority for climate policy and action.

How does CDR work?

The good news is that there are a range of promising methods to reliably remove and durably store atmospheric CO₂ at scale.

In fact, many ways to remove atmospheric CO₂ accelerate or mimic the natural carbon cycles and store carbon in ecosystems, geology and oceans.

The less good news is that most of these solutions are at technology and commercial readiness levels analogous to solar PV in the 1980s or 1990s. We need to get them to where solar is now by 2030.

Removal, and storage in ecological carbon sinks including forests and grasslands, are an important part of this solution. The challenge is the level of carbon debt is becoming so high and available and suitable land for these solutions is finite.

Moreover, there is still much work to do to protect existing ecological carbon sinks from damage by human activity, as well as damage from the impacts of climate change such as fires and floods.

Atmospheric carbon removal

There has been a major endeavour among scientists to develop novel solutions for atmospheric carbon removal.

This includes accelerating the rate at which magnesium rich volcanic rocks naturally react with and trap CO₂ from the atmosphere. Companies are exploring circular economy solutions to carbonate the millions of tonnes of suitable mine tailings for thousands of metal mines around the world.

Another novel solution which has gained major traction is direct air capture and carbon storage (DACCS).

DACCS uses sorbents or solvents to trap dilute amounts of CO₂ from the air like a molecular level filter. The CO₂ is then released (usually using heat or electricity) in a concentrated form that can then be geologically stored.

Where to from here?

Australia has significant potential to harness existing resources and capabilities to deploy new atmospheric carbon removal solutions including land management, renewable energy, geology, mining and infrastructure. The EU, US and UK are taking are taking decisive action to ensure they have the CDR capacity they’ll need, and Australia needs to do the same.

We can’t afford to follow traditional slow timelines for the diffusion of innovation.

We need to apply what we’ve learned from the past 30 years of hard work in renewable energy to avoid the same pit falls.

We need to take a cross-disciplinary, and foresight led approach to RD&D (research, development, and demonstration), focused on deployment-led innovation, not just publications.

We also know that getting this right requires much more than just getting the technology right. Achieving scale at speed means we need appropriate frameworks to deliver durable removals in addition to – not instead of – emissions reductions, as well as ecological protections, effective governance, just transition plans, centering on First Nation people’s needs and knowledge, scalable investment incentives, supply chain integration and collaboration mechanisms.

This isn’t something any individual company, research organisation or government can do alone.

We need to bring together leaders from Australian and international carbon removal start-ups and scientists with broader climate leaders from policy, industry, finance, and NGOs to help develop and facilitate the implementation of a roadmap for the future of atmospheric carbon removal in Australia.

This is why we, along with climate scientists from the Australian National University, University of Technology Sydney and University of Tasmania, have established the Climate Recovery Institute.

The Climate Recovery Institute will discuss these issues at Australia’s first atmospheric carbon removal summit on 27 September. Speakers will include carbon removal and storage experts from the US Department of Energy, the Australian Climate Change Authority, CSIRO, WWF, BHP, ANU, UTS, Sydney University, UTAS, CarbonNet and leading Australian and international atmospheric carbon removal start-ups including, Arca, MCi Carbon and Heirloom Carbon.

---