Thursday, April 17, 2014

Should Removing Greenhouse Gases from the atmosphere be more than a Plan B?

In this VEC blog, Guy Lomax notes that the IPCC has become the latest major institution to propose removing billions of tonnes of CO2 from the atmosphere to meet climate targets. But, he asks, is the Greenhouse Gas Removal debate focusing on the wrong questions?


The oceans and chalk cliffs: two sinks of CO2 from the atmosphere (well, the latter admittedly over geological timescales). In this VEC blog, Guy Lomax asks if humans are asking the right questions when it comes to creating new or enhancing existing GHG sinks. Photo credit: / Foter / Creative Commons Attribution 2.0 Generic (CC BY 2.0)


The IPCC’s latest report on climate change mitigation has become the most high-profile mainstream policy document to discuss the idea of removing greenhouse gases from the air on a massive scale. And like any big development in the climate change debate, it’s proving controversial among policymakers, the public and scientists alike. The draft showed many countries calling for the report to tone down the content on ways of taking carbon out of the air and whilst some organisations have stated their support for sensible and measured exploration of removing greenhouse gases from the atmosphere, others have already labelled it a “dangerous distraction”. But are its critics right about the risks of Greenhouse Gas Removal (GGR)? Should the world’s governments embrace these proposals or keep them locked down until we know more about them?

For the first time in the organisation’s history, the draft report takes seriously the possibility of removing billions of tonnes of CO2 from the atmosphere using Bioenergy with Carbon Capture and Storage (BECCS). This technology involves burning wood, specially-grown grasses or other plant material for energy, then capturing the CO2 produced and pumping it deep underground instead of releasing it to the atmosphere. Since these plants grow by capturing carbon from the air, the whole process ends up transferring CO2 from the atmosphere to geological stores such as abandoned oil fields, where in theory it remains for thousands to millions of years. According to research cited in the report, this technology could one day allow the world to suck up to 10 billion tonnes of CO2 per year from the air, representing about a quarter of the world’s current emissions, and could give us another chance at meeting our climate targets if we don’t cut our emissions quickly enough.

“we can’t yet say whether any will be feasible and safe at massive levels of deployment”


So what’s all the fuss about? Well, it comes down to two concerns that can equally apply to any gigatonne-level GGR proposal from Direct Air Capture and Enhanced Weathering, to Biochar and Ecosystem Restoration:

First, these approaches’ GHG removal potential are largely unproven in the ‘real world’, and overly cavalier implementation carries real risks of unwanted impacts on ecosystems and societies that could be catastrophic at the kinds of levels proposed in the report. For example, according to one BECCS expert, the 10 billion tonnes per year cited would require an area of farmland approximately the size of India to grow enough energy crops. This implies huge risks of environmental degradation, damage to existing ecosystems and rising food prices, for example.

Second, there are concerns around a moral hazard issue that if these GGR ideas are painted in too rosy a light, governments and industry could use it as an excuse to slacken efforts to cut emissions now. Why push too hard to clean up the energy system now when we’ll have a technology that can undo the damage down the line?

These concerns are absolutely right!

There’s a massive gap between the state of any of these approaches today and understanding their impacts at the scales proposed in the report. Even if they may one day be inexorably needed to restore balance in the carbon cycle, we can’t yet confidently say whether any will be feasible and safe at such massive levels of deployment. The focus on removing billions of tonnes of CO2 from the air in the far future takes us far beyond what we can reliably predict right now. So of course we’d be mad to pin all our hopes on BECCS or any other GGR system to pull us back from climate disaster, or use these speculative calculations as an excuse to keep emitting today.

So should GGR be stripped from the report until the academics have done enough research to prove GGR’s safety and efficacy? I don’t believe that’s good enough either, for two reasons.

Number one, the report’s studies do show us that GGR, if we can do it right and do it at scale, could be vital to keeping the door open to more ambitious long-term CO2 concentration targets that are otherwise almost certainly beyond our reach. And if we want to know if that kind of GGR is possible, we have a lot of work to do researching, testing, innovating and putting in place the wider infrastructure and policy groundwork. And a lot of this will need the involvement of businesses and the support of policymakers as well as raw academic research.

Number two is more fundamental, and gets to the core of where I believe the GGR debate is going wrong: people tend to focus on GGR as what James Meadowcroft calls climate recovery, a “Plan B” that we can deploy at a planet-sized scale after 2050 to pull CO2 levels back down to less dangerous levels. But as we’ve just seen, these questions are exactly the ones we can’t answer with any confidence from our vantage point in 2014 – so the debate continues.

Instead, we need to recognise that these approaches are not themselves a new and revolutionary thing. They amount to enhancing the planet’s CO2 sinks, one half of the IPCC’s existing definition of mitigation. As of 2009, natural GGR from growth of plants and dissolution of CO2 in the oceans were removing more than half of the carbon emitted to the atmosphere by humanity. Removing CO2 from the air can and should be an essential counterpart to cutting our excess emissions today, and it’s a pathway we’re currently missing out on.

“what kinds of policies can balance the urgency of developing GGR with the uncertainty of its long term future?”


The details confirm this high-level picture. It’s true that we can’t yet put firm numbers on the costs of GGR, but from early research it looks like several of them may cost well below $100 per tonne of CO2 removed, a cost that overlaps with mainstream clean energy technologies such as Solar PV, Fossil Carbon Capture and Storage and Bioenergy. Focusing on emissions cuts is making us miss some easy opportunities in sink enhancement. And even the more expensive options like Direct Air Capture might still be economical given the right circumstances.

Another problem is lock-in: the current generation of fossil-powered cars, factories and power stations are going to keep running for decades before we can replace them with clean alternatives. Finding some good GGR opportunities now means we can negate some of these stubborn emissions, cutting our net CO2 more quickly than we otherwise could and buying ourselves a little extra time to get emissions down.

So what kinds of policies can governments turn to in order to balance the urgency of developing GGR with the uncertainty of its long term future? I believe there are four principles they need to follow to get the balance right:

  • Open up more funding to support research, development and demonstration of GGR approaches to help answer the varying persisting questions over factors from the science and costs, to the risks and measuring stored carbon.
  • Identify those opportunities where GGR can be deployed early, safely and at low cost, and support them through whatever existing policy mechanisms and laws are most readily applicable, seizing some of the early potential and giving a boost to the safest, most readily useful approaches.
  • Commit to long-term integration of GGR in emissions accounting and wider climate and energy policy mechanisms as an equal to emissions reduction as far as possible, and begin work on how this might be achieved. This would be a complex and radical shift in policy focus that would need a lot of careful design to get right, but setting it as an ultimate goal at this stage might stimulate research, investment and innovation in GGR that is important if it is to play a significant role in future.
  • Finally, if we think that the vision of massive GGR rollout described in the IPCC report may ever be needed, we need to recognise that there’s a lot of groundwork to be done. There needs to be enough flexibility in the system that we would have the option of aggressively deploying GGR if needed without committing to it at this stage. The first three points will all go some way towards developing the science, policy, infrastructure and skills necessary, but are there other steps that could help avoid locking out the opportunity of large-scale GGR as society and the energy system evolve? For the case of BECCS, for example, how do we make sure that the Bioenergy industry and CCS technology develop together, so they are still compatible decades down the line?

Once governments start thinking about GGR as something relevant to our efforts today, not just to the hazy world of 50 years from now, it suddenly becomes a lot easier to design safe and effective policies. There are still uncertainties surrounding all GGR systems, be it the technology of industrial processes, the monitoring, reporting and verifying of ecological methods, and the economics, risks and politics to enable sustainable scale. However, with this lens we don’t need to predict quite so far into the future. The challenges are still there, but they become no larger than for many mainstream emissions reduction technologies such as biofuels or nuclear power: we can start having fact-based discussions about what we do and don’t know, what each technology needs and how we can keep the risks under control.

Then, only as we start putting some early, carefully managed GGR projects into action, will we eventually get a better idea of how much the will be able to help us in the long run.

By Guy Lomax