Galina et al. (2019). Evolution of Carbon Capture and Storage by Mineral Carbonation: Data Analysis and Relevance of the Theme.

Authors: Author links open overlay panelNatália Ribeiro Galina, Gretta L.A.F. Arce, & Ivonete Ávila.

Full citation: Galina, N. R., Arce, G. L., & Ávila, I. (2019). Evolution of carbon capture and storage by mineral carbonation: Data analysis and relevance of the theme. Minerals Engineering142, 105879.

Abstract: Given the increased concentration of atmospheric carbon dioxide in the atmosphere due to the use of fossil fuels, the development of technologies to reduce emissions and negative effects of CO2 concentration is of crucial importance. Among all CCSU methods, mineral carbonation is a promising technology in which CO2 is transformed into a thermodynamically and environmentally stable carbonate. Thus, a recent analysis of the evolution of carbon capture research by mineral carbonation has been performed by the Laboratory of Combustion and Carbon Capture (LC3) at São Paulo State University (UNESP/BRAZIL). An article entitled “Evolution of carbon capture and storage by mineral carbonation: Data analysis and relevance of the theme” presents data on the evolution of mineral carbonation research over the last 15 years by analyzing the number of publications and citations concerning mineral carbonation research. This paper aimed to identify the main advances and technological challenges of CO2 capture by mineral carbonation, in which a critical analysis of 117 articles published between 2002 and 2018 has been performed. The results demonstrate the evolution of scientific interest and continued relevance of the theme in recent years by academic and industrial sectors. The analysis results reveal that the development of carbon capture technologies is vital to reduce CO2 emissions, once mineral carbonation technology is a promising route to reduce CO2 footprint of industrial processes in a near future. It was observed that the number of publications and citations have increased proportionally in the latest 7 years. The article also presented an analysis of the number of publications and lines of research according to sector. From the analysis of publications in different countries, it was possible to observe the most promising raw materials and carbonation routes in each region under analysis. In order to identify the most relevant research on mineral carbonation, the articles analyzed have been classified according to the number of citations and the 10 most cited articles were analyzed. Finally, the article presents the main technical and economic challenges to be overcome in order to enable the implementation of mineral carbonation processes on an industrial scale, as those that increase the efficiency of converting CO2 into carbonates and reduce its overall process budget.

Read Galina et al.’s complete paper in Minerals Engineering.

Lin, M. et al. (2019). Clearing Up the ‘Dark Side’ of Artificial Leaves.

Authors: Meng Lin, Lihao Han, Meenesh R. Singh, Chengxiang Xiang.

Full citation: Lin, M., Han, L., Singh, M. R., & Xiang, C. (2019). An Experimental-and Simulation-Based Evaluation on the CO2 Utilization Efficiency in Aqueous-based Electrochemical CO2 Reduction Reactors with Ion-Selective Membranes. ACS Applied Energy Materials.

Abstract: While artificial leaves hold promise as a way to take carbon dioxide — a potent greenhouse gas — out of the atmosphere, there is a “dark side to artificial leaves that has gone overlooked for more than a decade,” according to Meenesh Singh, assistant professor of chemical engineering in the University of Illinois at Chicago College of Engineering.

Artificial leaves work by converting carbon dioxide to fuel and water to oxygen using energy from the sun. The two processes take place separately and simultaneously on either side of a photovoltaic cell: the oxygen is produced on the “positive” side of the cell and fuel is produced on the “negative” side.

Singh, who is the corresponding author of a new paper in ACS Applied Energy Materials, says that current artificial leaves are wildly inefficient. They wind up converting only 15% of the carbon dioxide they take in into fuel and release 85% of it, along with oxygen gas, back to the atmosphere.

“The artificial leaves we have today aren’t really ready to fulfill their promise as carbon capture solutions because they don’t capture all that much carbon dioxide, and in fact, release the majority of the carbon dioxide gas they take in from the oxygen-evolving ‘positive’ side,” Singh said.

The reason artificial leaves release so much carbon dioxide back to the atmosphere has to do with where the carbon dioxide goes in the photoelectrochemical cell.

Graphic depicting the mechanics of an artificial leaf.
Artificial leaf with membrane that reduces the release of carbon dioxide back into the atmosphere. Credit: Aditya Prajapati and Meng Lin

When carbon dioxide enters the cell, it travels through the cell’s electrolyte. In the electrolyte, the dissolved carbon dioxide turns into bicarbonate anions, which travel across the membrane to the “positive” side of the cell, where oxygen is produced. This side of the cell tends to be very acidic due to splitting of water into oxygen gas and protons. When the bicarbonate anions interact with the acidic electrolyte at the anodic side of the cell, carbon dioxide is produced and released with oxygen gas.

Singh noted that a similar phenomenon of carbon dioxide release occurring in the artificial leaf can be seen in the kitchen when baking soda (bicarbonate solution) is mixed with vinegar (acidic solution) to release a fizz of carbon dioxide bubbles.

To solve this problem, Singh, in collaboration with Caltech researchers Meng Lin, Lihao Han and Chengxiang Xiang, devised a system that uses a bipolar membrane that prevents the bicarbonate anions from reaching the “positive” side of the leaf while neutralizing the proton produced.

The membrane placed in between the two sides of the photoelectrochemical cell keeps the carbon dioxide away from the acidic side of the leaf, preventing its escape back into the atmosphere. Artificial leaves using this specialized membrane turned 60% to 70% of the carbon dioxide they took in into fuel.

“Our finding represents another step in making artificial leaves a reality by increasing utilization of carbon dioxide,” Singh said.

Earlier this year, Singh and colleagues published a paper in ACS Sustainable Chemistry & Engineering, where they proposed a solution to another problem with artificial leaves: current models use pressurized carbon dioxide from tanks, not the atmosphere.

He proposed another specialized membrane that would allow the leaves to capture carbon dioxide directly from the atmosphere. Singh explains that this idea, together with the findings reported in this current publication on using more of the carbon dioxide captures, should help make artificial leaf technology fully implementable.

Read Meng et al.’s complete paper in ACS Applied Energy Materials

Sagues et al. (2019). Enhanced Carbon Dioxide Removal from Coupled Direct Air Capture-Bioenergy Systems

Authors: William J. Sagues1, Sunkyu Park2, Hasan Jameel1, Daniel L. Sanchez2*

Full citation: Sagues, W. J., Park, S., Jameel, H., & Sanchez, D. L. (2019). Enhanced carbon dioxide removal from coupled direct air capture–bioenergy systems. Sustainable Energy & Fuels3(11), 3135-3146.

Abstract: Negative emission technologies (NETs) play a prominent role in climate change mitigation strategies consistent with limiting global warming to well below 2°C. Direct air capture (DAC) and bioenergy with carbon capture and sequestration (BECCS) are the two leading engineered methods of CO2 removal currently under development. Major limitations to scaling DAC and BECCS technologies include high demands for energy and natural resources, respectively. To date, there has been almost no research on the synergies between DAC and BECCS technologies. 

BECCS refers to the utilization of renewable biomass resources for energy and the subsequent capture and sequestration of CO2 via injection into geologic formations.1–3 The advantages of using BECCS for engineered CO2 removal include relatively low cost and the existence of established technologies for both biomass conversion and CO2 capture and sequestration.3 The major drawbacks of BECCS technologies are their substantial land requirements, sustainability impacts at scale, limited resource potential, and social barriers to acceptance.4–6 Nonetheless, the US National Academy of Sciences recently classified BECCS as one of four CO2 removal technologies ready for immediate deployment.3 DAC refers to the direct removal of CO2 from the atmosphere and subsequent sequestration. Two leading DAC technology platforms employ liquid solvents and solid sorbents.7,8 Several companies are currently commercializing technologies that use these platforms, including Carbon Engineering, which uses a liquid alkaline solvent for thermal energy-driven calcium looping,9 and Global Thermostat and Climeworks, which use solid-supported amine sorbents for thermal energy-driven adsorption/desorption.10,11 The advantages of using DAC for engineered CO2 removal include flexibility in site location, low land footprint, and potentially limitless scale. However, DAC technologies suffer from high costs, substantial energy requirements, and commercial immaturity.7 The US National Academy of Sciences recently reported the levelized costs of CO2 removal via DAC to be uneconomical in current policy environments.3,12 

Many emerging DAC innovators claim that fossilized hydrocarbons, renewable electricity, or nuclear energy will provide the thermal energy necessary for operation.3 Biomass, however, is frequently neglected in such analyses: for instance, recent energy system modelling of DAC integration into low-carbon heat and power systems did not consider biomass as an energy source.13 Biomass combustion technologies hold several advantages over other low-carbon technologies for providing thermal energy for DAC, including high heating efficiencies, high technology readiness, and the ability to contribute to CO2 removal (Figure 1).14,15

Graphical representation of the information presented in the abstract.
Figure 1. Commercially established, low-carbon methods for obtaining thermal energy and their applicability towards carbon dioxide removal via direct air capture (left).14 Rangers of thermal and electrical energy demands for direct air capture recently reported by the US National Academy of Sciences (right) (values do not include energy required for CO2 compression).

The use of biomass as an energy source for DAC has been largely overlooked in prior literature. Here, we conduct a techno-economic and geospatial analysis to understand the economic and carbon removal potential of coupled BECCS and DAC technologies. The aforementioned limitations to BECCS and DAC technologies are curtailed when coupled into one system. We estimate biomass integrated DAC systems can increase net CO2 removal by 109 – 119% at lower costs than standalone reference systems. If hybrid BECCS-DAC systems were deployed across the US using biomass resources co-located with geologic storage, 1.5 Gt of CO2 could be sequestered annually without long-distance biomass or CO2 transport in 2030. Innovation in the design and implementation of coupled BECCS-DAC systems would have a profound impact on CO2 removal, if realized. However, social acceptance, environmental protection, and appropriate political incentives are necessary for large-scale deployment of CO2 removal systems fueled by biomass.6,9 Fortunately, the US Department of Energy has conducted thorough assessments of sustainable biomass availability to help minimize environmental and social harm as CO2 removal systems continue to advance.24 Historically, the lack of US policies placing a value on CO2 has been a barrier to the deployment of BECCS and DAC technologies, however, the US Congress recently enhanced the Section 45Q carbon oxide sequestration tax credit to help overcome this barrier.34

This analysis takes a significant step forward in the development of NETs by demonstrating the technical and economic viability of coupled BECCS-DAC systems capable of removing significant quantities of CO2 with lower cost and environmental impact. Moving forward, BECCS-DAC systems can drive efficient, cost-effective, and locationally-optimized usage of biomass resources for engineered CO2 removal. As the level of attention towards CO2 removal technology development continues to grow, BECCS-DAC systems deserve serious consideration.

Read Sagues et al.’s complete paper in Sustainabile Energy & Fuels.


1:  M. Allen, M. Babiker, Y. Chen, H. de Coninck, S. Connors, R. van Diemen and O.  P. Dube, Intergov. Panel Clim. Chang.

2: G. P. Peters and O. Geden, Nat. Clim. Chang., 2017, 7, 619–621.

3: National Academy of Sciences, Natl. Acad. Press, 2018, 131–171.

4: E. Baik, D. L. Sanchez, P. A. Turner, K. J. Mach, C. B. Field and S. M. Benson, Proc. Natl. Acad. Sci., , DOI:10.1073/pnas.1720338115.

5: H. J. Buck, Clim. Change, 2016, 139, 155–167.

6: K. S. Lackner, Science (80-. ).

7: D. Sandalow, J. Friedmann and C. McCormick, Direct Air Capture of Carbon Dioxide: ICEF Roadmap 2018,

8: E. S. Sanz-Pérez, C. R. Murdock, S. A. Didas and C. W. Jones, Chem. Rev., 2016, 116, 11840–11876.

9: D. W. Keith, G. Holmes, D. St. Angelo and K. Heidel, Joule, 2018, 2, 1–22.

10: 2014, No. 14715962.8 (European Patent).

11: 2015, No. 2015/0283501 (US Patent).

12 :C. Bataille, C. Guivarch, S. Hallegatte, J. Rogelj and H. Waisman, Nat. Clim. Chang., 2018, 8, 648–650.

13: F. Creutzig, C. Breyer, J. Hilaire, J. Minx, G. P. Peters and R. Socolow, Energy Environ. Sci., , DOI:10.1039/c8ee03682a.

14: McKinsey & Company, Decarbonization of industrial sectors: the next frontier, Functions/Sustainability and Resource Productivity/Our Insights/How industry can move toward a low carbon future/Decarbonization-of-industrial-sectors-The-next-frontier.ashx.

15: EU Biomass Availability and Sustainability Information System, Report on conversion efficiency of biomass,

Author affiliations: 

1Department of Forest Biomaterials, North Carolina State University, 2820 Faucette Dr., Raleigh, NC 27606, USA. 

2Department of Environmental Science, Policy, and Management, University of California-Berkeley, 130 Mulford Hall #3114, Berkeley, CA 94720.

Correspondence and requests for materials should be addressed to Daniel Sanchez:

Jacobson, Mark (2019). Why Carbon Capture and Direct Air Capture Cause More Damage than Good to Climate and Health

Author:  Mark Z. Jacobson Dept. of Civil & Environmental Engineering, Stanford University, Stanford, CA, USA.  Email:

Abstract:  Spending money on carbon capture and storage or use (CCS/U) and synthetic direct air capture and storage and use (SDACCS/U) increases carbon dioxide equivalent (CO2e) emissions, air pollution, and costs relative to spending the same money on clean, renewable electricity replacing fossil or biofuel combustion. In a recently published paper in Energy and Environmental Sciences on this issue (doi:10.1039/c9ee02709b), I analyzed data from an existing coal-CCU plant and an SDACCU plant. A net of only 10.8% of the CCU plant’s CO2e emissions and 10.5% of the CO2 removed from the air by the SDACCU plant are captured over 20 years, and only 20-31%, are captured over 100 years. The low net capture rates are due to uncaptured combustion emissions from natural gas used to power the equipment, uncaptured upstream emissions, and, in the case of CCU, uncaptured coal combustion emissions. Moreover, the CCU and SDACCU plants both increase air pollution and total social costs relative to no capture. Using wind to power the equipment reduces CO2e relative to using natural gas but still allows air pollution emissions to continue and increases the total social cost relative to no carbon capture. Conversely, using wind to displace coal without capturing carbon reduces CO2e, air pollution, and total social cost substantially. Further, using wind to displace coal reduces more CO2e than using the same wind to power the capture equipment. As such, spending money on wind powering carbon capture always increases CO2e compared with spending on the same wind replacing fossil fuels or biofuels. In sum, CCU and SDACCU increase or hold constant air pollution health damage and reduce little carbon before even considering sequestration or use leakages of carbon back to the air. Spending on capture rather than wind replacing either fossil fuels or bioenergy always increases CO2e, air pollution, and total social cost substantially. No improvement in CCU or SDACCU equipment can change this conclusion while fossil power plant emissions exist, since carbon capture always incurs an equipment cost never incurred by wind, and carbon capture never reduces, instead mostly increases, air pollution and fuel mining, which wind eliminates. Once fossil power plant emissions end, CCU (for industry) and SDACCU social costs need to be evaluated against the social costs of natural reforestation and reducing nonenergy halogen, nitrous oxide, methane, and biomass burning emissions. 

Read Jacobson’s complete paper in Energy & Environmental Science. 


Busch et al. (2019). Reforestation is a Cost-Effective Climate Solution

Authors: Jonah Busch, Jens Engelmann, Susan C. Cook-Patton, Bronson W. Griscom, Timm Kroeger, Hugh Possingham, & Priya Shyamsundar

Full citation: Busch, J., Engelmann, J., Cook-Patton, S. C., Griscom, B. W., Kroeger, T., Possingham, H., & Shyamsundar, P. (2019). Potential for low-cost carbon dioxide removal through tropical reforestation. Nature Climate Change9(6), 463.

Abstract: Reforestation offers one of the best ways to remove carbon dioxide from the atmosphere, turning it into solid carbon through photosynthesis and storing it in tree trunks, branches, roots, and soil. Reforestation can be a cost-effective climate solution, too, according to a recent study in Nature Climate Change of the cost of reforestation across 90 tropical countries that I conducted with colleagues at The Nature Conservancy and the University of Wisconsin.  

According to our analysis, a hypothetical tropics-wide carbon price of $20 per ton of carbon dioxide—around the current price in European and Californian carbon markets—would incentivize land users to increase reforestation by enough to remove an additional 5.7 billion tons of carbon dioxide (5.6%) from 2020-2050, equivalent to thirty years of current greenhouse gas emissions from Kuwait (Figure 1). 

A higher price of $50-100 per ton of carbon dioxide—consistent with what’s needed to achieve the Paris Climate Agreement—would increase removals by between 15.1 and 33.3 billion tons of carbon dioxide (14.8-32.5%) between 2020-2050—equivalent to thirty years of current emissions from the United Kingdom or Japan

We came to our conclusions by simulating the effects of payments for increased carbon removals on future land-cover changes, accounting for geographical differences across sites, and assuming that land users would be as responsive to changes in carbon prices as they were to historical variation in agricultural prices. 

The cost of reforestation compares favorably to other “negative emissions technologies” (NETs). We compared our cost estimates for tropical reforestation to Sabine Fuss and colleagues’ cost estimates for NETs that may become operational by 2050. On a cost-per-ton basis, tropical reforestation is more cost-effective in 2050 than bio-energy with carbon capture and storage (BECCS) and direct air carbon capture and storage (DACCS). It’s as cost-effective in 2050 as biochar, and less cost-effective than enhanced weathering or soil carbon sequestration. 

On average, avoiding deforestation is 7-10 times more cost-effective than reforestation, but reforestation is more cost-effective than avoiding deforestation in some places. Reforestation offers more abatement than avoided deforestation at $20 per ton in 21 out of 90 tropical countries studied.  

Tropical reforestation and avoided deforestation combined offer up to one-third of a comprehensive, cost-effective, near-term solution to climate change. The combined potential of increasing removals from reforestation and reducing emissions from deforestation at $20-50-100 per ton is 161-123-192 billion tons from 2020-2050. Averaged out on a per-decade basis, those levels of mitigation represent, respectively, 10-21-33% of the 197 billion tons of mitigation needed from 2020-2030 to hold global warming below 2 °C. This supports the finding of a landmark 2017 study by Bronson Griscom and colleagues, which found that twenty natural climate solutions worldwide offer more than one-third of the cost-effective near-term solution to climate change.

Based on these findings, tropical countries should accelerate reforestation, and developed countries should step up international finance for reforestation, especially through provisions of the Paris Climate Agreement related to reducing emissions from deforestation and forest degradation, “plus” re-growing forests (REDD+).

Graphical representation of the information presented in the abstract.Figure 1. Marginal abatement cost curves for increased removals from tropical reforestation and reduced emissions from avoided deforestation.

Read Busch et al.’s full paper in Nature Climate Change. 

Carton, Wim (2019). “Fixing” Climate Change by Mortgaging the Future: Negative Emissions, Spatiotemporal Fixes, and the Political Economy of Delay

Full citation: Carton, W. (2019). “Fixing” Climate Change by Mortgaging the Future: Negative Emissions, Spatiotemporal Fixes, and the Political Economy of Delay. Antipode51(3), 750-769.

Abstract: Modeling studies suggest that successful climate change mitigation now depends on the roll-out of “negative emissions”, that is, the large-scale removal of carbon dioxide from the atmosphere through a range of proposed technologies. This idea has been extensively criticized by other scientists for being unfeasible and unjust. Among others, a reliance on negative emissions over more short-term emission reduction strategies transfers the costs of mitigation, and the risks of potential failure, to future generations. In this article, I add to this literature by exploring the political economic effects that a focus on negative emissions has, or might have in the future. Building on a rich theoretical tradition within geography, and drawing on a literature review and a contemporary example, I highlight the risk that negative emissions become an active delaying strategy for the fossil fuel industry. I use a recent scenario exercise (‘Sky’) by the oil and gas company Shell to demonstrate how the mere promise of negative emissions can be used by companies to persuade investors and policy makers that substantial, continued use of fossil fuels is compatible with the goals of the Paris Agreement. The paper seeks to explain this dynamic by unpacking some of the assumptions that underlie the models used by scientists to create mitigation scenarios. I draw particular attention to the models’ methodological basis in cost-optimizing economics as one of the reasons why negative emissions scenarios appear to align so easily with the economic interests of companies such as Shell. The paper also makes a theoretical contribution to the field of environmental geography by conceptualizing these dynamics more generally. In the conclusion, I call for more critical attention to the ideological assumptions that underlie mainstream scenario exercises, and the way that these further certain social and economic interests over others.

Read Carton’s complete paper in Antipode.

The Hidden Politics of Carbon Removal and Solar Geoengineering

The Institute’s co-director, Simon Nicholson, teamed up with solar geoengineering governance expert Sikina Jinnah from UC Santa Cruz to study the fate of a resolution on carbon removal and solar geoengineering that was introduced at the UN Environment Assembly in March 2019. Nature Geoscience published their analysis last week. UC Santa Cruz’s Jennifer McNulty explains their paper’s significance:

At this point, the greatest danger of climate engineering may be how little is known about where countries stand on these potentially planet-altering technologies. Who is moving forward? Who is funding research? And who is being left out of the conversation?

The “hidden politics” of climate engineering were partially revealed earlier this year at the fourth United Nations Environment Assembly (UNEA-4), when Switzerland proposed a resolution on geoengineering governance. The ensuing debate offered a glimpse of the first discussion in a public forum of this “third rail” of climate change, according to Sikina Jinnah, an associate professor of environmental studies at the University of California, Santa Cruz, and an expert on climate engineering governance.

In a commentary that appears in the current issue of Nature Geoscience, Jinnah and coauthor Simon Nicholson of American University describe the politics and players who appear to be shaping the discussion. Their analysis, “The Hidden Politics of Climate Engineering,” concludes with a call for transparency to help resolve questions of governance and “ensure that the world has the tools to manage these potent technologies and practices if and when decisions are ever taken to use them.”

“Twenty years ago, climate engineering seemed far-fetched—if not crazy—but these ideas are being taken more seriously today in the wake of widespread governmental failure to adequately reduce greenhouse gas emissions,” said Jinnah. “The U.S is the biggest culprit in terms of shirking responsibility, but everyone is falling short.”

The Swiss proposal generated debate that revealed troubling schisms between the United States and the European Union. It also underscored the challenge of trying to establish governance for the two dominant geoengineering strategies—solar radiation management (SRM) and carbon dioxide removal (CDR)—at the same time, because the technologies present very different potential risks.

Still a purely theoretical strategy, SRM would involve altering planetary brightness to reflect a very small amount of sunlight away from the Earth to create a cooling effect. One well-known proposal is to inject tiny reflective particles into the upper atmosphere. “The idea is to mimic the effect of a volcanic eruption,” said Jinnah. “Many people are scared of its planet-altering potential, and rightfully so.” When a team at Harvard University announced its intention to do a small-scale outdoor experiment, the public backlash was swift; amid calls for a more inclusive process, the project timeline was pushed back to include input from a newly established advisory board.

By contrast, CDR has to this point been relatively less controversial. Carbon removal strategies include existing options like enhancing forest carbon sinks, and more technologically far-off options such as “direct air capture” strategies that would suck carbon from the atmosphere. CDR is baked into many climate-modeling scenarios, largely in the form of bio-energy with carbon capture and storage (BECCS). BECCS involves the burning of biomass for energy, followed by the capture and underground storage of emissions.

“Climate engineering experts are not talking about this as a substitute for greenhouse gas emission reductions,” emphasized Jinnah. “The potential of climate engineering is to lessen the impacts of climate change that we’re going to experience regardless of what we do now.”

Debate reveals areas of concern

To piece together their account of what happened at the UNEA-4 meeting, Jinnah and Nicholson interviewed attendees, reviewed documents, and scoured online comments. Their analysis highlights several areas of concern, including:

  • Disagreement among countries about the current state and strength of SRM governance
  • The domination of research by North American and European scientists
  • The need to “decouple” governance of SRM and CDR
  • A significant split between the United States and the European Union over the “precautionary approach”

The key functions of governance include building transparency, fostering public participation, and shedding light on funding. Jinnah noted that governance can also provide what she called a “braking” mechanism to avoid what some call a “slippery slope” toward deployment.

Significantly, the Swiss proposal, which Jinnah and Nicholson describe as “modest,” suggested a preliminary governance framework that drew strong opposition from the United States and Saudi Arabia. “The United States  wants to keep its options open, and it certainly doesn’t want the United Nations telling it what it can and cannot do,” observed Jinnah.

The lack of transparency around climate engineering makes it difficult to get a comprehensive picture of who’s doing what, and where, said Jinnah, but academic scientists in North America and Europe are leading the effort to explore SRM technology; CDR is already attracting private investment. Little is known about the extent of China’s activity in climate engineering.

“Very little is happening in the developing world, which is problematic because they will experience the most dramatic impacts of climate change and have the least institutional capacity to cope with it,” said Jinnah. “Some countries are facing an existential crisis and could potentially—potentially—want to see climate engineering. Or they could oppose it, because they want the focus to be on emissions reduction. But we don’t know, because governments haven’t articulated their positions.”

Jinnah bemoaned the lack of collaboration with developing countries and expressed a desire to see them build their capacity to engage with the policy and politics of climate engineering.

The debate also underscored some of the differences between SRM and CDR in terms of potential viability and deployment, prompting Jinnah to observe that “decoupling” them might break the logjam and foster greater progress on parallel tracks.

The United States favored a far less “precautionary” stance than the European Union, which has historically opted to protect the environment in the absence of scientific certainty, as it did on the issue of genetically modified foods. As one of the few countries with an active SRM research program, the United States appeared eager to preserve the status quo and “leave its decision space unchallenged,” Jinnah and Nicholson wrote.

An important step forward

Despite the breadth and depth of disagreement that surfaced at the meeting, Jinnah sees the debate as a necessary first step. “As a researcher, I think this debate was an incredibly important step forward, because you can’t study the politics of this issue without data, which in this case is countries articulating their positions on this controversial issue,” she said.

“Research is needed so we can better understand our options,” she emphasized, then added: “I’d rather not live in a world that thinks about solar radiation management, but unfortunately that’s not our reality.”

You can find Sikina Jinnah and Simon Nicholson’s paper, “The Hidden Politics of Geoengineering,” on the Nature Geoscience web site:

Smith et al. (2019) How to measure, report and verify soil carbon change to realise the potential of soil carbon sequestration for atmospheric greenhouse gas removal

Authors: Pete Smith1, Jean-Francois Soussana2, Denis Angers3, Louis Schipper4, Claire Chenu5, Daniel P. Rasse6, Niels H. Batjes7, Fenny van Egmond7, Stephen McNeill8, Matthias Kuhnert1, Cristina Arias-Navarro2, Jorgen E. Olesen9, Ngonidzashe Chirinda10, Dario Fornara11, Eva Wollenberg12, Jorge Álvaro-Fuentes13, Alberto Sanz-Cobena14, Katja Klumpp15

Full citation: Smith, P., Soussana, J. F., Angers, D., Schipper, L., Chenu, C., Rasse, D. P., … & Arias‐Navarro, C. (2019). How to measure, report and verify soil carbon change to realize the potential of soil carbon sequestration for atmospheric greenhouse gas removal. Global change biology.

Abstract:  One proposed option for removal of carbon dioxide from the atmosphere is by increasing the amount of carbon retained in the soil organic matter, an option known as soil organic carbon sequestration. Given that soils already contain a lot of carbon, and changes in soil organic carbon are slow, it is difficult to measure increases in soil carbon against the large background soil carbon stock. Because of this difficulty in measuring changes in soil organic carbon, a key barrier to implementing programmes to increase soil organic carbon is the need for credible and reliable measurement/monitoring, reporting and verification platforms. We review methods for measuring soil organic carbon change directly in soils, we examine novel developments for quantifying soil organic carbon change, and describe how surveys, long-term experiments and chronosequences (sites of different ages with changes at various stages of carbon gain) can be used for testing models and as benchmark sites in global frameworks to estimate soil organic carbon change. We review measurement/monitoring, reporting and verification platforms for soil organic carbon change already in use and describe a new vision for a global framework for measurement/monitoring, reporting and verification platform of soil organic carbon change. The proposed platform builds on existing repeat soil surveys, long-term experiments, remote sensing, modelling and novel measurement methods and could be applied at national, regional or global scales.

A graphical representation of the information presented in the accessible abstract.

Read Smith et al.’s full paper in Global Change Biology.

Author affiliations: 

1 Institute of Biological & Environmental Sciences, University of Aberdeen, 23 St Machar Drive, Aberdeen, AB24 3UU, UK

2 INRA, 147 rue de l’Université 75338 Paris Cedex 07, France

3 Agriculture and Agri-Food Canada, 2560 Hochelaga Blvd Quebec, Quebec G1V 2J3, Canada

4 Environmental Research Institute, University of Waikato, Hamilton, Private Bag 3105, Hamilton 3240, New Zealand

5 INRA, AgroParisTech. Bât. EGER F- 78850 Thiverval-Grignon, France

6 Norwegian Institute of Bioeconomy Research (NIBIO), Høgskoleveien 7, 1433 Ås, Norway 

7 ISRIC – World Soil Information, Droevendaalsesteeg 3. 6708PB Wageningen, The Netherlands

8 Manaaki Whenua – Landcare Research, PO Box 69040, Lincoln, New Zealand

9 Department of Agroecology, Aarhus University, Blichers Allé 20, Tjele, Denmark  

10 International Center for Tropical Agriculture (CIAT), A.A. 6713, Cali, Colombia

11 Agri-Food and Biosciences Institute, Belfast, Northern Ireland, Newforge Lane, BT9 5PX, Belfast, UK

12 CGIAR CCAFS Programme, University of Vermont (UVM), Burlington, VT 05405, USA

13 Soil and Water Department, Spanish National Research Council (CSIC) PO Box 13034, 50080 Zaragoza, Spain

14 Research Center for the Management of Environmental and Agricultural Risks (CEIGRAM), Universidad Politécnica de Madrid, Madrid 28040, Spain

15 INRA, VetAgro-Sup, UCA, Ecosystème Prairial, Clermont Ferrand, France