Imperative to get the carbon removal dialogue up to speed with the science – Guest Post – Noah Deich, UC Berkeley


On November 4th, Michael Ashcroft, of the Carbon Trust, and I gave a presentation on the topic of technologies for removing carbon from the atmosphere and their implications for industry and government, at the USEA, in Washington, D.C. 

Negative emissions, or Carbon Dioxide Removal (“CDR”) activities have recently gained increased press attention in the mass media as well as in NGO reports and scientific journals. This increased exposure for CDR approaches, which encompass both biological (e.g. afforestation, ecosystem restoration, land management, biochar, and bio-CCS) and chemical (e.g. direct air capture, enhanced mineral weathering) techniques – is a good thing for the climate change debate: we will likely need to have scalable, sustainable, cost-effective CDR systems as well as ways to reduce our emissions to avoid catastrophic climate change. The CDR field, however, largely remains in its infancy today, which is why Michael and I took the opportunity of the USEA workshop to share an overview of the current research on CDR approaches as well as our assessment of the need for increased investment into the field to spur the growth of the field.

Our full presentation can be found on the USEA website, and we’ve shared a couple of our key takeaways from the workshop, below:

Takeaway #1: CDR techniques are slowly getting reclassified away from solar radiation management (SRM) and the geoengineering umbrella, and are now viewed by leading climate experts more as complementary options to more traditional GHG mitigation techniques.

Take the following excerpt from the IPCC’s Fifth Assessment Report (WG3 – Chapter 6):

“The large majority of scenarios produced in the literature that reach roughly 450 ppm CO2eq by 2100 are characterized by concentration overshoot facilitated by the deployment of carbon dioxide removal (CDR) technologies.”

CDR options, in other words, are seen as a special class of GHG abatement tools, capable of cleaning up “over budget” carbon emissions:

(click to enlarge) Above:


The concept of CDR as a special class of GHG abatement strategies isn’t new. Take the GHG abatement curve that the consultancy McKinsey has been working on for the past decade:

(click to enlarge)


The better known techniques for drawing carbon out of the atmosphere are highlighted in orange in the above figure – and are scattered among other GHG abatement techniques like energy efficiency and renewable energy. Many of these techniques have also been part of international climate negotiations as far back as the Kyoto Protocol.

Bottom line here is that carbon removal is really just a class of GHG abatement techniques. We are likely to see increased conversation and development of these approaches as we get closer and closer to overflowing our “carbon budget,” and certainly as more and more groups advocate the ultimate need to decrease the levels of CO2 in the atmosphere.

CDR=A Better Drain

(click to enlarge)

Takeaway #2: All stakeholders need to start prioritizing and fostering carbon removal strategies with greater urgency.

A big problem today is the fact that we don’t have a clear idea of the viability, scalability, and sustainability of different CDR approaches:

Various CDR techniques

(click to enlarge)

Various CDR techniques are technically feasible but cost-prohibitive today, others are economically viable today but not scientifically proven in terms of permanence of removal, full lifecycle carbon balance etc., making it very difficult to project the future portfolio of CDR approaches that could be deployed.

These hurdles are certainly possible to overcome, as each of the emerging CDR fields are only at the beginning of their development cycles today:

The CDR field today

(click to enlarge) Source: Dan Kammen, UC Berkeley

Cap requirement + Time

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Even small investments in CDR R&D today would likely generate large future economic, social and environmental returns. The issue, however, is that existing market forces are not leading to even these small investments in CDR R&D. For one, carbon markets are still too weak to support CDR R&D (graph adapted from the World Bank report):

WB report

(click to enlarge)


And global CO2 consumption is less than 1% of global CO2 emissions today – also not providing a large enough signal.

The good news is that there are lots of opportunities for actors across the public, private, and civil sectors to take action on developing CDR systems. Corporate leaders, for example, have myriad opportunities for investment in CDR in their supply chain. Take the CDP 500 data from 2012:

Scope 1 emissions

(click to enlarge)

A preliminary analysis indicated that hundreds of companies have the potential for CDR in their supply chain, from afforestation, to ecosystem restoration, to carbon negative cement, and even carbon negative fuels, and their potential impact is tremendous.

Furthermore, NGOs and standards bodies can help incentivize CDR through updating protocols and standards in a way that appropriately rewards carbon removal alongside carbon abatement.

NGO standards


And policymakers have potentially the greatest opportunity to add tremendous value for society by investing in basic science, applied R&D, and long-term markets to support and advance CDR systems, from potentially creating an ‘ARPA-C’, to further incentivizing and mandating the monitoring, reporting and verification of different bio-carbon ecosystem restoration approaches, from ‘carbon farming to ‘forestry.’

Conclusion: getting the carbon removal dialogue up to speed with the science

CDR is gaining greater and greater scientific recognition and exposure in the dialogue on mitigating climate change. While CDR systems have great potential in the fight against climate, the CDR field needs public, private, and civil sector leadership today to catalyze development of scalable, sustainable, and cost-effective solutions.


noah-deich-headshot-300x300Noah Deich is a consultant for the Virgin Earth Challenge and an MBA candidate at the University of California, Berkeley. Prior to Berkeley, he spent five years working on clean energy and corporate sustainability consulting projects. At Berkeley, his studies focus on entrepreneurship and the energy industry, and has worked on independent study projects with two venture capital firms focused on clean energy and sustainability-focused investing. He is currently conducting an analysis of the economics of CDR solutions and business models employed by CDR companies.



The Washington Geoengineering Consortium does not necessarily endorse the ideas contained in this or any other guest post. Our aim is to provide a space for the expression of a range of perspectives on geoengineering.


  • nicholbrummer

    For those interested in Enhanced Weathering of Olivine.

    Below I’m linking a rather detailed description from Olaf Schuiling. It’s 28 pages, but you skim over the essentials quickly by reading sections 1-3 (intro), 12 (cost estimate), then 7-10 (details of the rock chemistry). Then read the remainder if you’re still interested 🙂 He also lists various ways in which Olivine could be used profitably at small scale in agriculture and elsewhere. He also gives a calculation of how much would be needed if you’d want to neutralise the total current CO2 emissions of humanity: big numbers, but, surprisingly, not much more than some existing mining industry operations.

    His cost estimate of €10 per ton CO2 sequestered chemically as carbonate, ‘for ever’, would be extremely competitive. This would compete with the ‘normal’ CCS that is widely considered for coal/gas/bio power plants. If that is true .. why do CCS at all? No need to sequester the CO2 where it is emitted if that isn’t necessary. And if I look at the above list of carbon prices, there may already be a business case to start doing some experiments in sea, at some scale. (sorry, this is just a pdf in my dropbox, the link won’t be alive forever)