Carbon dioxide capture and storage: a status report

Abstract

Fossil fuel combustion is the largest source of anthropogenic greenhouse gas (GHG) emissions. As a result of combustion, essentially all of the fuel carbon is emitted to the atmosphere as carbon dioxide (CO₂), along with small amounts of methane and, in some cases, nitrous oxide. It has been axiomatic that reducing anthropogenic GHG emissions requires reducing fossil-fuel use. However, that relationship may no longer be as highly coupled in the future. There is an emerging understanding that CO₂ capture and storage (CCS) technology offers a way of using fossil fuels while reducing CO₂ emissions by 85% or more. While CCS is not the ‘silver bullet’ that in and of itself will solve the climate change problem, it is a powerful addition to the portfolio of technologies that will be needed to address climate change. The goal of this Commentary is to describe CCS technology in simple terms: how it might be used, how it might fit into longer term mitigation strategies, and finally, the policy issues that its emergence creates. All of these topics are discussed in much greater detail in the recently published Intergovernmental Panel on Climate Change (IPCC) Special Report on Carbon Dioxide Capture and Storage (SRCCS) (IPCC, 2005).     

Health, Safety and Environmental Risks of Underground Co2 Storage – Overview of Mechanisms and Current Knowledge

CO₂ capture and storage (CCS) in geological reservoirs may be part of a strategy to reduce global anthropogenic CO₂ emissions. Insight in the risks associated with underground CO₂ storage is needed to ensure that it can be applied as safe and effective greenhouse mitigation option. This paper aims to give an overview of the current (gaps in) knowledge of risks associated with underground CO₂ storage and research areas that need to be addressed to increase our understanding in those risks. Risks caused by a failure in surface installations are understood and can be minimised by risk abatement technologies and safety measures. The risks caused by underground CO₂ storage (CO₂ and CH₄ leakage, seismicity, ground movement and brine displacement) are less well understood. Main R&D objective is to determine the processes controlling leakage through/along wells, faults and fractures to assess leakage rates and to assess the effects on (marine) ecosystems. Although R&D activities currently being undertaken are working on these issues, it is expected that further demonstration projects and experimental work is needed to provide data for more thorough risk assessment.     

China's role in attaining the global 2°C target

In the recent climate change negotiations it was declared that the increase in global temperature should be kept below 2°C by 2100, relative to pre-industrial levels. China's CO₂ emissions from energy and cement processes already account for nearly 24% of global emissions, a trend that is expected to keep increasing. Thus the role of China in global GHG mitigation is crucial. A scenario analysis of China's CO₂ emissions is presented here and the feasibility of China reaching a low-carbon scenario is discussed. The results suggest that recent and continued technological progress will make it possible for China to limit its CO₂ emissions and for these emissions to peak before 2025 and therefore that the global 2°C target can be achieved.

Policy relevance

In signing the Copenhagen Accord, China agreed to the global 2°C target. Results from this article could be used to justify low-carbon development policies and negotiations. While many still doubt the feasibility of a low-carbon pathway to support the global 2°C target, the results suggest that such a pathway can be realistically achieved. This conclusion should increase confidence and guide the policy framework further to make possible China's low-carbon development. Related policies and measures, such as renewable energy development, energy efficiency, economic structure optimization, technology innovation, low-carbon investment, and carbon capture and storage (CCS) development, should be further enhanced. Furthermore, China can play a larger role in the international negotiations process. In the global context, the 2°C target could be reaffirmed and a global regime on an emissions mitigation protocol could be framed with countries’ emissions target up to 2050.     

Governance of bioenergy with carbon capture and storage (BECCS): accounting,rewarding, and the Paris agreement

Studies show that the ‘well below 2°C’ target from the Paris Agreement will be hard to meet without large negative emissions from mid-century onwards, which means removing CO₂ from the atmosphere and storing the carbon dioxide in biomass, soil, suitable geological formations, deep ocean sediments, or chemically bound to certain minerals. Biomass energy combined with Carbon Capture and Storage (BECCS) is the negative emission technology (NET) given most attention in a number of integrated assessment model studies and in the latest IPCC reports. However, less attention has been given to governance aspects of NETs. This study aims to identify pragmatic ways forward for BECCS, through synthesizing the literature relevant to accounting and rewarding BECCS, and its relation to the Paris Agreement. BECCS is divided into its two elements: biomass and CCS. Calculating net negative emissions requires accounting for sustainability and resource use related to biomass energy production, processing and use, and interactions with the global carbon cycle. Accounting for the CCS element of BECCS foremost relates to the carbon dioxide capture rate and safe underground storage. Rewarding BECCS as a NET depends on the efficiency of biomass production, transport and processing for energy use, global carbon cycle feedbacks, and safe storage of carbon dioxide, which together determine net carbon dioxide removal from the atmosphere. Sustainable biomass production is essential, especially with regard to trade-offs with competing land use. Negative emissions have an added value compared to avoided emissions, which should be reflected in the price of negative emission ‘credits’, but must be discounted due to global carbon cycle feedbacks. BECCS development will depend on linkages to carbon trading mechanisms and biomass trading.

Key policy insights

• A standardized framework for sustainable biomass should be adopted.

• Countries should agree on a standardized framework for accounting and rewarding BECCS and other negative emission technologies.

• Early government support is indispensable to enable BECCS development, scale-up and business engagement.

• BECCS projects should be designed to maximize learning across various applications and across other NETs.

• BECCS development should be aligned with modalities of the Paris Agreement and market mechanisms.

     

A low-carbon society: global visions,pathways, and challenges

The feasibility of two low-carbon society (LCS) scenarios, one with and one without nuclear power and carbon capture and storage (CCS), is evaluated using the AIM/Enduse[Global] model. Both scenarios suggest that achieving a 50% emissions reduction target (relative to 1990 levels) by 2050 is technically feasible if locally suited technologies are introduced and the relevant policies, including necessary financial transfers, are appropriately implemented. In the scenario that includes nuclear and CCS options, it will be vital to consider the risks and acceptance of these technologies. In the scenario without these technologies, the challenge will be how to reduce energy service demand. In both scenarios, the estimated investment costs will be higher in non-Annex I countries than in Annex I countries. Finally, the enhancement of capacity building to support the deployment of locally suited technologies will be central to achieving an LCS.

Policy relevance

Policies to reduce GHG emissions up to 2050 are critical if the long-term target of stabilizing the climate is to be achieved. From a policy perspective, the cost and social acceptability of the policy used to reduce emissions are two of the key factors in determining the optimal pathways to achieve this. However, the nuclear accident at Fukushima highlighted the risk of depending on large-scale technologies for the provision of energy and has led to a backlash against the use of nuclear technology. It is found that if nuclear and CCS are used it will be technically feasible to halve GHG emissions by 2050, although very costly. However, although the cost of halving emissions will be about the same if neither nuclear nor CCS is used, a 50% reduction in emissions reduction will not be achievable unless the demand for energy service is substantially reduced.     

Development of a risk-hedging CO2-emission policy, part II: Risks associated with measures to limit emissions, synthesis, and conclusions

This paper is Part II of a two-part series in which the risks associated with unrestrained greenhouse-gas emissions, and with measures to limit emissions, are reviewed. A sustained limitation of global CO₂ emissions requires global population stabilization, a reduction in per capita emissions in the developed world, and a limitation of the increase in per capita emissions in the developing world. Reducing or limiting per capita emissions requires a major effort to improve the efficiency with which energy is transformed and used; urban development which minimizes the need for the private automobile and facilitates district heating, cooling, and cogeneration systems; and accelerated development of renewable energy. The following risks associated with these efforts to limit CO₂ emissions are reviewed here: (i) resources might be diverted from other urgent needs; (ii) economic growth might be reduced; (iii) reduction measures might cost more than expected; (iv) early action might cost more than later action; (v) reduction measures might have undesired side effects; (vi) reduction measures might require heavy-handed government intervention; and (vii) reduction measures might not work. With gradual implementation of a diversified portfolio of measures, these risks can be greatly reduced. Net risk is further reduced by the fact that a number of non-climatic benefits would result from measures to limit CO₂ emissions. Based on the review of risks associated with measures to limit emissions here, and the review of the risks associated with unrestrained emissions presented in Part I, it is concluded that a reasonable near-term (20–30 year) risk hedging strategy is one which seeks to stabilize global fossil CO₂ emissions at the present (early 1990's) level. This in turn implies an emission reduction of 26% for industrialized countries as a whole and 40–50% for Canada and the USA if developing country emissions are to increase by no more than 60%, which in itself would require major assistance from the industrialized countries. The effectiveness of global CO₂-emission stabilization in slowing down the buildup of atmospheric CO₂ is enhanced by the fact that the airborne fraction (ratio of annual atmospheric CO₂ increase to total annual anthropogenic emissions) decreases if emissions are stabilized, whereas it increases if emissions continue to grow exponentially. The framework and conclusions presented here are critically compared with so-called optimization frameworks.     

Initial public reactions to carbon capture and storage (CCS): differentiating general and local views

Carbon capture and storage (CCS) is considered a potential climate change mitigation option, but public opposition may hamper its implementation. A quasi-experimental approach is used to examine whether ‘not in my back yard’ (NIMBY) sentiments can be anticipated at the initial stage when CO₂ storage locations have been selected and communicated to the public. Furthermore, the psychological structure of initial reactions to CO₂ storage plans is studied to ascertain the differences between people living in the direct vicinity of a proposed CO₂ storage location (i.e. onsite residents) and people who do not (i.e. offsite residents). The results indicate that initial reactions to local CCS plans are not necessarily dominated by NIMBY sentiments. For onsite residents as well as offsite residents, trust in government affects their judgements of the risks and benefits associated with CCS, which in turn affects their inclination to protest against CCS plans. Onsite residents’ inclination to protest is affected by their perceptions of local safety risks, but this is less of a concern for offsite residents. The inclination to protest against CCS is unrelated to concern about climate change.     

Carbon capture and storage policy in the United States: A new coalition endeavors to change existing policy

Carbon capture and storage (CCS) is considered by some to be a promising technology to reduce greenhouse gas emissions, and advocates are seeking policies to facilitate its deployment. Unlike many countries, which approach the development of policies for geologic storage (GS) of carbon dioxide (CO₂) with nearly a blank slate, the U.S. already has a mature policy regime devoted to the injection of CO₂ into deep geologic formations. However, the existing governance of CO₂ injection is designed to manage enhanced oil recovery (EOR), and policy changes would be needed to manage the risks and benefits of CO₂ injection for the purpose of avoiding GHG emissions. We review GS policy developments at both the U.S. federal and state levels, including original research on state GS policy development. By applying advocacy coalition framework theory, we identify two competing coalitions defined by their beliefs about the primary purpose of CO₂ injection: energy supply or greenhouse gas (GHG) emission reductions. The established energy coalition is the beneficiary of the current policy regime. Their vision of GS policy is protective: to minimize harm to fossil energy industries if climate policy were to be enacted. In contrast, the newly formed climate coalition seeks to change existing GS policy to support their proactive vision: to maximize GHG reductions using CCS when climate policy is enacted. We explore where and at what scale legislation emerges and examine which institutions gain prominence as drivers of policy change. Through a detailed textual analysis of the content of state GS legislation, we find that the energy coalition has had greater success than the climate coalition in shaping state laws to align with its policy preferences. It has enshrined its view of the purpose of CO₂ injection in state legislation, delegated authority for GS to state agencies aligned with the existing policy regime, and protected the EOR status quo, while creating new opportunities for EOR operators to profit from the storage of CO₂ The climate coalition's objective of proactively putting GS policy in place has been furthered, and important progress has been made on commonly held concerns, such as the resolution of property rights issues, but the net result is policy change that does not significantly revise the existing policy regime.     

Designing policy for deployment of CCS in industry

Attaining deep greenhouse gas (GHG) emission reductions in industry in order to support a stringent climate change control target will be difficult without recourse to CO₂ capture and storage (CCS). Using the insights from a long-term bottom-up energy systems model, and undertaking a sectoral assessment, we investigated the importance of CCS in the industrial sector. Under climate policy aimed at limiting atmospheric concentration of GHGs to 650 ppm CO₂e, costs could increase fivefold when CCS is excluded from the portfolio of mitigation option measures in the industry sector as compared to when CCS is excluded in the power sector. This effect is driven largely by the lack of alternatives for deep emission reductions in industry. Our main policy conclusion is that a broader recognition of CCS in industrial applications in both current policy discussions and research, development, and demonstration funding programmes is justified. In recognition of the heterogeneity of the many types of industrial production processes, the size and location of industrial CO₂ sources, the specific need for CCS-retrofitting, and the exposure of most industrial sectors to international trade, policies aimed at supporting CCS must distinguish between the different challenges faced by the power and industrial sectors.     

Energy-intensive manufacturing sectors in China: policy priorities for achieving climate mitigation and energy conservation targets

In this study, a long-range energy alternative planning (LEAP) model was built to evaluate the relative priority of three kinds of policies expected to be implemented for the energy-intensive manufacturing sectors (EIMS) in China to achieve CO₂ mitigation and energy conservation targets. These policies encourage (1) the use of more electricity instead of coal; (2) the continuous improvement of energy efficiency; and (3) a shift to other less energy-demanding sectors. The results indicate that the policy of shifting economic activity from the EIMS to other sectors is most helpful for China to achieve its targets of mitigating CO₂ emissions and conserving energy. Encouraging the EIMS to use more electricity can help China to achieve a higher proportion of non-fossil-fuel based energy in its overall primary energy consumption. No single policy will allow China to achieve all the targets, emphasizing the need for an integrated policy design that combines all types of policies.

Key policy insights

• The policy of encouraging a shift to less energy intensive industries should receive the highest priority in aiming to peak China's energy-related CO₂ emissions as early as possible, and lower overall CO₂ emissions, coal consumption and primary energy consumption in the long run.

• Encouraging a shift to electricity should go hand-in-hand with greater energy efficiency, otherwise such a policy cannot help China significantly reduce energy-related CO₂ emissions.

• Encouraging the EIMS to use more electricity should receive the highest priority in helping China achieve a higher proportion of non-fossil-fuel based energy in its overall primary energy consumption.

     

Carbon leakage in aviation policy

ABSTRACT

The inherently global, connected nature of aviation means that carbon leakage from aviation policy does not necessarily behave similarly to leakage from other sectors. We model carbon leakage from a range of aviation policy test cases applied to a specific country (the United Kingdom), motivated by a desire to reduce aviation CO₂ faster than achievable by currently-planned global mitigation efforts in pursuit of a year-2050 net zero CO₂ target. We find that there are two main components to leakage: one related to passenger behaviour, which tends to result in emissions reductions outside the policy area (negative leakage), and one related to airline behaviour, which tends to result in emissions increases outside the policy area (positive leakage). The overall leakage impact of a policy, and whether it is positive or negative, depends on the balance of these two components and the geographic scope used, and varies for different policy types. In our simulations, carbon pricing-type policies were associated with leakage of between +50 and ?150% depending on what is assumed about scope and the values of uncertain parameters. Mandatory biofuel use was associated with positive leakage of around 0–40%, and changes in airport landing costs to promote more fuel-efficient aircraft were associated with positive leakage of 50–150%.

Key policy insights

• Carbon leakage in aviation policy arises from airline responses (typically positive leakage) and passenger responses (typically negative leakage).

• Depending on the geographical scope, policy type and values for uncertain parameters, leakage may be between around ?150 to +150%.

• Of the policies investigated in this study, leakage was typically most negative for carbon pricing and most positive for environmental landing charges.

• Absolute values of leakage are smallest where policies are considered on the basis of all arriving and departing flights.

     

Quality of geological CO2 storage to avoid jeopardizing climate targets

We explore allowable leakage for carbon capture and geological storage to be consistent with maximum global warming targets of 2.5 and 3 °C by 2100. Given plausible fossil fuel use and carbon capture and storage scenarios, and based on modeling of time-dependent leakage of CO₂, we employ a climate model to calculate the long-term temperature response of CO₂ emissions. We assume that half of the stored CO₂ is permanently trapped by fast mechanisms. If 40?% of global CO₂ emissions are stored in the second half of this century, the temperature effect of escaped CO₂ is too small to compromise a 2.5 °C target. If 80?% of CO₂ is captured, escaped CO₂ must peak 300?years or later for consistency with this climate target. Due to much more CO₂ stored for the 3 than the 2.5 °C target, quality of storage becomes more important. Thus for the 3 °C target escaped CO₂ must peak 400?years or later in the 40?% scenario, and 3000?years or later in the 80?% scenario. Consequently CO₂ escaped from geological storage can compromise the less stringent 3 °C target in the long-run if most of global CO₂ emissions have been stored. If less CO₂ is stored only a very high escape scenario can compromise the more stringent 2.5 °C target. For the two remaining combinations of storage scenarios and climate targets, leakage must be high to compromise these climate targets.     

Envisioning carbon capture and storage: expanded possibilities due to air capture,leakage insurance,and C-14 monitoring

In order to meet the challenge of climate change while allowing for continued economic development, the world will have to adopt a net zero carbon energy infrastructure. Due to the world’s large stock of low-cost fossil fuels, there is strong motivation to explore the opportunities for capturing the CO₂ that is produced in the combustion of fossil fuels and keeping it out of the atmosphere. Three distinct sets of technologies are needed to allow for climate neutral use of fossil fuels: (1) capture of CO₂ at concentrated sources like electric power plants, future hydrogen production plants and steel and cement plants; (2) capture of CO₂ from the air; and (3) the safe and permanent storage of CO₂ away from the atmosphere. A strong regime of carbon accounting is also necessary to gain the public’s trust in the safety and permanence of CO₂ storage. This paper begins with an extensive overview of carbon capture and storage technologies, and then presents a vision for the potential implementation of carbon capture and storage, drawing upon new ideas such as air capture technology, leakage insurance, and monitoring using a radioactive isotope such as C-14. These innovations, which may provide a partial solution for managing the risks associated with long-term carbon storage, are not well developed in the existing literature and deserve greater study.     

Sinks and the Kyoto Protocol

Abstract

Deliberate land management actions that enhance the uptake of CO₂ or reduce its emissions have the potential to remove a significant amount of CO₂ from the atmosphere over the next three decades. The quantities involved are large enough to satisfy a substantial portion of the Kyoto Protocol commitments for many countries, but are not large enough to stabilise atmospheric concentrations without also implementing major reductions in fossil fuel emissions. ‘Sinks’ can be deployed relatively rapidly at moderate cost and thus could play a useful bridging role while new energy technologies are developed.

There is no difference in climatological effect between CO₂ taken up by the land and CO₂ reductions due to other causes. There are potential regulatory differences, related to the security with which the CO₂ is held and to the accuracy with which it can be measured and verified. A variety of policy approaches are available to address these differences.     

Coal to gas: the influence of methane leakage

Carbon dioxide (CO₂) emissions from fossil fuel combustion may be reduced by using natural gas rather than coal to produce energy. Gas produces approximately half the amount of CO₂ per unit of primary energy compared with coal. Here we consider a scenario where a fraction of coal usage is replaced by natural gas (i.e., methane, CH₄) over a given time period, and where a percentage of the gas production is assumed to leak into the atmosphere. The additional CH₄ from leakage adds to the radiative forcing of the climate system, offsetting the reduction in CO₂ forcing that accompanies the transition from coal to gas. We also consider the effects of: methane leakage from coal mining; changes in radiative forcing due to changes in the emissions of sulfur dioxide and carbonaceous aerosols; and differences in the efficiency of electricity production between coal- and gas-fired power generation. On balance, these factors more than offset the reduction in warming due to reduced CO₂ emissions. When gas replaces coal there is additional warming out to 2,050 with an assumed leakage rate of 0%, and out to 2,140 if the leakage rate is as high as 10%. The overall effects on global-mean temperature over the 21st century, however, are small.     

All adrift: aviation,shipping, and climate change policy

All sectors face decarbonization for a 2 °C temperature increase to be avoided. Nevertheless, meaningful policy measures that address rising CO₂ from international aviation and shipping remain woefully inadequate. Treated with a similar approach within the United Nations Framework Convention on Climate Change (UNFCCC), they are often debated as if facing comparable challenges, and even influence each others’ mitigation policies. Yet their strengths and weaknesses have important distinctions. This article sheds light on these differences so that they can be built upon to improve the quality of debate and ensuing policy development. The article quantifies ‘2 °C’ pathways for these sectors, highlighting the need for mitigation measures to be urgently accelerated. It reviews recent developments, drawing attention to one example where a change in aviation mitigation policy had a direct impact on measures to cut CO₂ from shipping. Finally, the article contrasts opportunities and barriers towards mitigation. The article concludes that there is a portfolio of opportunities for short- to medium-term decarbonization for shipping, but its complexity is its greatest barrier to change. In contrast, the more simply structured aviation sector is pinning too much hope on emissions trading to deliver CO₂ cuts in line with 2 °C. Instead, the solution remains controversial and unpopular – avoiding 2 °C requires demand management.

Policy relevance

The governance arrangements around the CO₂ produced by international aviation and shipping are different from other sectors because their emissions are released in international airspace and waters. Instead, through the Kyoto Protocol, the International Civil Aviation Authority (ICAO) and the International Maritime Organization (IMO) were charged with developing policies towards mitigating their emissions. Slow progress to date, coupled with strong connections with rapidly growing economies, has led to the CO₂ from international transport growing at a higher rate than the average rate from all other sectors. This article considers this rapid growth, and the potential for future CO₂ growth in the context of avoiding a 2 °C temperature rise above pre-industrial levels. It explores similarities and differences between these two sectors, highlighting that a reliance on global market-based measures to deliver required CO₂ cuts will likely leave both at odds with the overarching climate goal.     

The promise of carbon capture and storage: evaluating the capture-readiness of new EU fossil fuel power plants

To what degree are recently built and planned power plants in the EU ‘capture-ready’ for carbon capture and storage (CCS)? Survey results show that most recently built fossil fuel power plants have not been designed as capture-ready. For 20 planned coal-fired plants, 13 were said to be capture-ready (65%). For 31 planned gas-fired power plants, only 2 were indicated to be capture-ready (6%). Recently built or planned power plants are expected to cover a large share of fossil fuel capacity by 2030 and thereby have a large impact on the possibility to implement CCS after 2020. It is estimated that around 15–30% of fossil fuel capacity by 2030 can be capture-ready or have CO₂ capture implemented from the start. If CCS is implemented at these plants, 14–28% of baseline CO₂ emissions from fossil fuel power generation in 2030 could be mitigated, equivalent to 220–410 MtCO₂. A key reason indicated by utilities for building a capture-ready plant is (expected) national or EU policies. In addition, financial incentives and expected high CO₂ prices are important. The implementation of a long-term regulatory framework for CCS with clear definitions of ‘capture- readiness’ and policy requirements will be important challenges.     

Post-Kyoto energy strategy of the Russian Federation,outlooks and prerequisites of the Kyoto mechanisms implementation in the country

Abstract

Energy sector emissions from Russia have declined by about 33% from 1990 levels. We estimate that some 60–70% of the reduction is due to economic decline, and about 8–12% of it is due to reforms in the energy sector; the remainder being due to the wider use of natural gas and structural changes in the economy. Vigorous institutional and technological measures to promote energy efficiency could lead to savings of over 100 million t.c.e. per year by 2010, and keep CO₂ emissions fairly close to current levels over the decade. In our view, international emissions trading should not lead to global emissions growth, but should facilitate the best energy saving and efficiency. Consequently, we propose that the available assigned amount should be divided into two components. That part arising from ‘type 1’ reductions, produced by special projects and measures relating to GHG reduction taken since 1990, should be freely traded; whereas the remaining ‘type 2’ surplus, without a clear link to real emission reduction activity, should only be traded if the revenues are recycled into special projects resulting in emissions reduction equal to or more than the amount of emissions sold.     

The drivers of Chinese CO2 emissions from 1980 to 2030

China's energy consumption doubled within the first 25 years of economic reforms initiated at the end of the 1970s, and doubled again in the past 5 years. It has resulted of a threefold CO₂ emissions increase since early of 1980s. China's heavy reliance on coal will make it the largest emitter of CO₂ in the world. By combining structural decomposition and input–output analysis we seek to assess the driving forces of China's CO₂ emissions from 1980 to 2030. In our reference scenario, production-related CO₂ emissions will increase another three times by 2030. Household consumption, capital investment and growth in exports will largely drive the increase in CO₂ emissions. Efficiency gains will be partially offset the projected increases in consumption, but our scenarios show that this will not be sufficient if China's consumption patterns converge to current US levels. Relying on efficiency improvements alone will not stabilize China's future emissions. Our scenarios show that even extremely optimistic assumptions of widespread installation of carbon dioxide capture and storage will only slow the increase in CO₂ emissions.