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1.
The capture and storage of CO2 from combustion of fossil fuels is gaining attraction as a means to deal with climate change. CO2 emissions from biomass conversion processes can also be captured. If that is done, biomass energy with CO2 capture and storage (BECS) would become a technology that removes CO2 from the atmosphere and at the same time deliver CO2-neutral energy carriers (heat, electricity or hydrogen) to society. Here we present estimates of the costs and conversion efficiency of electricity, hydrogen and heat generation from fossil fuels and biomass with CO2 capture and storage. We then insert these technology characteristics into a global energy and transportation model (GET 5.0), and calculate costs of stabilizing atmospheric CO2 concentration at 350 and 450 ppm. We find that carbon capture and storage technologies applied to fossil fuels have the potential to reduce the cost of meeting the 350 ppm stabilisation targets by 50% compared to a case where these technologies are not available and by 80% when BECS is allowed. For the 450 ppm scenario, the reduction in costs is 40 and 42%, respectively. Thus, the difference in costs between cases where BECS technologies are allowed and where they are not is marginal for the 450 ppm stabilization target. It is for very low stabilization targets that negative emissions become warranted, and this makes BECS more valuable than in cases with higher stabilization targets. Systematic and stochastic sensitivity analysis is performed. Finally, BECS opens up the possibility to remove CO2 from the atmosphere. But this option should not be seen as an argument in favour of doing nothing about the climate problem now and then switching on this technology if climate change turns out to be a significant problem. It is not likely that BECS can be initiated sufficiently rapidly at a sufficient scale to follow this path to avoiding abrupt and serious climate changes if that would happen.  相似文献   

2.
Many papers have shown that bioenergy and land-use are potentially important elements in a strategy to limit anthropogenic climate change. But, significant expansion of bioenergy production can have a large terrestrial footprint. In this paper, we test the implications for land use, the global energy system, emissions and mitigation costs of meeting a specific climate target, using a single fossil fuel and industrial sector policy instrument, but with five alternative bioenergy and land-use policy architectures. These scenarios are illustrative in nature, and designed to explore trade-offs. We find that the policies we examined have differing effects on the different segments of the economy. Comprehensive land policies can reduce land-use change emissions, increasing allowable emissions in the energy system, but have implications for the cost of food. Bioenergy penalties and constraints, on the other hand, have little effect on food prices, but result in less bioenergy and thus can increase mitigation costs and energy prices.  相似文献   

3.
Energy is crucial for supporting basic human needs, development and well-being. The future evolution of the scale and character of the energy system will be fundamentally shaped by socioeconomic conditions and drivers, available energy resources, technologies of energy supply and transformation, and end-use energy demand. However, because energy-related activities are significant sources of greenhouse gas (GHG) emissions and other environmental and social externalities, energy system development will also be influenced by social acceptance and strategic policy choices. All of these uncertainties have important implications for many aspects of economic and environmental sustainability, and climate change in particular. In the Shared-Socioeconomic Pathway (SSP) framework these uncertainties are structured into five narratives, arranged according to the challenges to climate change mitigation and adaptation. In this study we explore future energy sector developments across the five SSPs using Integrated Assessment Models (IAMs), and we also provide summary output and analysis for selected scenarios of global emissions mitigation policies. The mitigation challenge strongly corresponds with global baseline energy sector growth over the 21st century, which varies between 40% and 230% depending on final energy consumer behavior, technological improvements, resource availability and policies. The future baseline CO2-emission range is even larger, as the most energy-intensive SSP also incorporates a comparatively high share of carbon-intensive fossil fuels, and vice versa. Inter-regional disparities in the SSPs are consistent with the underlying socioeconomic assumptions; these differences are particularly strong in the SSPs with large adaptation challenges, which have little inter-regional convergence in long-term income and final energy demand levels. The scenarios presented do not include feedbacks of climate change on energy sector development. The energy sector SSPs with and without emissions mitigation policies are introduced and analyzed here in order to contribute to future research in climate sciences, mitigation analysis, and studies on impacts, adaptation and vulnerability.  相似文献   

4.
Proponents of climate change mitigation face difficult choices about which types of policy instrument(s) to pursue. The literature on the comparative evaluation of climate policy instruments has focused overwhelmingly on economic analyses of instruments aimed at restricting demand for greenhouse gas emissions (especially carbon taxes and cap-and-trade schemes) and, to some extent, on instruments that support the supply of or demand for substitutes for emissions-intensive goods, such as renewable energy. Evaluation of instruments aimed at restricting the upstream supply of commodities or products whose downstream consumption causes greenhouse gas emissions—such as fossil fuels—has largely been neglected in this literature. Moreover, analyses that compare policy instruments using both economic and political (e.g. political “feasibility” and “feedback”) criteria are rare. This article aims to help bridge both of these gaps. Specifically, the article demonstrates that restrictive supply-side policy instruments (targeting fossil fuels) have numerous characteristic economic and political advantages over otherwise similar restrictive demand-side instruments (targeting greenhouse gases). Economic advantages include low administrative and transaction costs, higher abatement certainty (due to the relative ease of monitoring, reporting and verification), comprehensive within-sector coverage, some advantageous price/efficiency effects, the mitigation of infrastructure “lock-in” risks, and mitigation of the “green paradox”. Political advantages include the superior potential to mobilise public support for supply-side policies, the conduciveness of supply-side policies to international policy cooperation, and the potential to bring different segments of the fossil fuel industry into a coalition supportive of such policies. In light of these attributes, restrictive supply-side policies squarely belong in the climate policy “toolkit”.  相似文献   

5.
This paper analyzes the role of transport electrification in the broader context of energy system transformation and climate stabilization. As part of the EMF27 model inter-comparison exercise, we employ the MESSAGE integrated assessment modeling framework to conduct a systematic variation of availability, cost, and performance of particular energy supply technologies, thereby deriving implications for feasibility of climate stabilization goals and the associated costs of mitigation. In addition, we explore a wide range of assumptions regarding the potential degree of electrification of the transportation sector. These analyses allow us to (i) test the extent to which the feasible attainment of stringent climate policy targets depends on transport electrification, and (ii) assess the far-reaching impacts that transport electrification could have throughout the rest of the energy system. A detailed analysis of the transition to electricity within the transport sector is not conducted. Our results indicate that while a low-carbon transport system built upon conventional liquid-based fuel delivery infrastructures is destined to become increasingly reliant on biofuels and synthetic liquids, electrification opens up a door through which nuclear energy and non-biomass renewables can flow. The latter has important implications for mitigation costs.  相似文献   

6.
It has been suggested that calculations of historical responsibility for global warming should be used to distribute mitigation requirements in future climate agreements. For a medium-term mitigation scenario, we calculate regional mitigation costs resulting from global allocation schemes based on the Brazilian Proposal that solely incorporate historical responsibility as a burden sharing criterion. We find that they are likely to violate ability-to-pay principles. In spite of less stringent abatement requirements, developing country regions experience cost burdens (as a percentage of GDP) in the same range as those of developed countries. We also assess the policy options available for calculating historical responsibility. The periodic updating of responsibility calculations over time, concerns over the robustness and availability of emissions data, and the question of whether past emissions were knowingly harmful, may lead to policy choices that increase the relative historical responsibility attributed to developing countries. This, in turn, would increase their mitigation cost burden.  相似文献   

7.
Can near-term public support of renewable energy technologies contain the increase of mitigation costs due to delays of implementing emission caps at the global level? To answer this question we design a set of first and second best scenarios to analyze the impact of early deployment of renewable energy technologies on welfare and emission timing to achieve atmospheric carbon stabilization by 2100. We use the global multiregional energy?Ceconomy?Cclimate hybrid model REMIND-R as a tool for this analysis. An important design feature of the policy scenarios is the timing of climate policy. Immediate climate policy contains the mitigation costs at less than 1% even if the CO2 concentration target is 410?ppm by 2100. Delayed climate policy increases the costs significantly because the absence of a strong carbon price signal continues the carbon intensive growth path. The additional costs can be decreased by early technology policies supporting renewable energy technologies because emissions grow less, alternative energy technologies are increased in capacity and their costs are reduced through learning by doing. The effects of early technology policy are different in scenarios with immediate carbon pricing. In the case of delayed climate policy, the emission path can be brought closer to the first-best solution, whereas in the case of immediate climate policy additional technology policy would lead to deviations from the optimal emission path. Hence, technology policy in the delayed climate policy case reduces costs, but in the case of immediate climate policy they increase. However, the near-term emission reductions are smaller in the case of delayed climate policies. At the regional level the effects on mitigation costs are heterogeneously distributed. For the USA and Europe early technology policy has a positive welfare effect for immediate and delayed climate policies. In contrast, India looses in both cases. China loses in the case of immediate climate policy, but profits in the delayed case. Early support of renewable energy technologies devalues the stock of emission allowances, and this effect is considerable for delayed climate policies. In combination with the initial allocation rule of contraction and convergence a relatively well-endowed country like India loses and potential importers like the EU gain from early renewable deployment.  相似文献   

8.
This paper synthesizes the results from the model intercomparison exercise among regionalized global energy-economy models conducted in the context of the RECIPE project. The economic adjustment effects of long-term climate policy are investigated based on the cross-comparison of the intertemporal optimization models ReMIND-R and WITCH as well as the recursive dynamic computable general equilibrium model IMACLIM-R. A number of robust findings emerge. If the international community takes immediate action to mitigate climate change, the costs of stabilizing atmospheric CO2 concentrations at 450?ppm (roughly 530?C550?ppm-e) discounted at 3% are estimated to be 1.4% or lower of global consumption over the twenty-first century. Second best settings with either a delay in climate policy or restrictions to the deployment of low-carbon technologies can result in substantial increases of mitigation costs. A delay of global climate policy until 2030 would render the 450?ppm target unachievable. Renewables and CCS are found to be the most critical mitigation technologies, and all models project a rapid switch of investments away from freely emitting energy conversion technologies towards renewables, CCS and nuclear. Concerning end use sectors, the models consistently show an almost full scale decarbonization of the electricity sector by the middle of the twenty-first century, while the decarbonization of non-electric energy demand, in particular in the transport sector remains incomplete in all mitigation scenarios. The results suggest that assumptions about low-carbon alternatives for non-electric energy demand are of key importance for the costs and achievability of very low stabilization scenarios.  相似文献   

9.
Using the mathematical formalism of the Brazilian Proposal to the IPCC, we analyse eight power technologies with regard to their past and potential future contributions to global warming. Taking into account detailed bottom-up technology characteristics we define the mitigation potential of each technology in terms of avoided temperature increase by comparing a “coal-only” reference scenario and an alternative low-carbon scenario. Future mitigation potentials are mainly determined by the magnitude of installed capacity and the temporal deployment profile. A general conclusion is that early technology deployment matters, at least within a period of 50–100?years. Our results conclusively show that avoided temperature increase is a better proxy for comparing technologies with regard to their impact on climate change, and that numerous short-term comparisons based on annual or even cumulative emissions may be misleading. Thus, our results support and extend the policy relevance of the Brazilian Proposal in the sense that not only comparisons between countries, but also comparisons between technologies could be undertaken on the basis of avoided temperature increase rather than on the basis of annual emissions as is practiced today.  相似文献   

10.
Developing countries like India are under international pressure to sign a legally binding emissions treaty to avert catastrophic climatic change. Developing countries, however, have argued that any international agreement must be based on historic and per capita carbon emissions, with developed countries responsible for reducing their emissions first and funding mitigation and adaptation in other countries. Recently, however, several scholars have argued that Indian government climate change discourses are shifting, primarily by recognizing the “co-benefits” of an alignment between its development and climate change objectives, and by displaying increasing “flexibility” on mitigation targets. This study investigates the factors driving shifting Indian discourses of climate change by conducting and analyzing 25 interviews of Indian climate policy elites, including scientists, energy policy experts, leading government officials, journalists, business leaders, and advocates, in addition to analysis of articles published in Economic and Political Weekly (a prominent Indian policy journal), and reports published by the government and other agencies. Our analysis suggests that India’s concerns about increasing energy access and security, along with newer concerns about vulnerability to climate change and the international leadership aspirations of the Indian government, along with emergence of new actors and institutions, has led to plurality of discourses, with potential implications for India’s climate change policies.  相似文献   

11.
The prospect of learning about various uncertainties relevant to analyses of the climate change issue is important because it can affect estimates of the costs of both damages and mitigation, and it can influence the optimal timing of emissions reductions. Baseline scenarios representing future emissions in the absence of mitigation are one of the major sources of uncertainty. Here we investigate how fast we might realistically expect to learn about the outlook for long-term population growth, as one determinant of future baseline emissions. That is, we estimate how long it might take to substantially revise current estimates of the likelihood of various population size outcomes over the twenty-first century. We draw on recent work showing that, because population growth is path dependent, we can learn about the long term outlook by waiting to observe how population changes in the short term. We then explore the implications of uncertainty and of this learning potential for mitigation costs and for optimal emissions. Using a simple model, we show that uncertainty in population growth translates into an uncertainty in the optimal tax rate of about $200/tC by 2050 for a range of stabilization levels. When learning is taken into account, it allows for mitigation strategies to change in response to new information, leading to a slight reduction in the expected value of mitigation costs, and a substantial reduction in the likelihood of high cost outcomes. We also find that while learning can lead to large revisions over the next few decades in anticipated population growth, this potential does not imply large changes in near-term optimal emissions reductions. Results suggest that further work on the potential for learning about other determinants of emissions could have larger effects on expected mitigation costs.  相似文献   

12.
This paper provides a novel assessment of the role of direct air capture of CO2 from ambient air (DAC) on the feasibility of achieving stringent climate stabilization. We use the WITCH energy-economy-climate model to investigate the long term prospects of DAC, implementing a technological specification based on recent estimates by the American Physical Society (APS 2011). Assuming global cooperation on a stringent climate policy we find that: (1) DAC is deployed only late in century, after other low carbon options, though at a very significant scale; (2) DAC has an impact on the marginal and total abatement costs (reducing them) and on the timing of mitigation (postponing it); (3) DAC also allows for a prolonged use of oil, with a positive welfare impact for energy exporting countries. Finally, we assess the role of DAC in a less than ideal climate policy by exploring its potential for engaging energy exporting countries in climate mitigation activities by means of a “clean oil” market in which oil exporters can sell oil decarbonized via DAC.  相似文献   

13.
The ability to directly remove carbon dioxide from the atmosphere allows the decoupling of emissions and emissions control in space and time. We ask the question whether this unique feature of carbon dioxide removal technologies fundamentally alters the dynamics of climate mitigation pathways. The analysis is performed in the coupled energy-economy-climate model ReMIND using the bioenergy with CCS route as an application of CDR technology. BECCS is arguably the least cost CDR option if biomass availability is not a strongly limiting factor. We compare mitigation pathways with and without BECCS to explore the impact of CDR technologies on the mitigation portfolio. Effects are most pronounced for stringent climate policies where BECCS is a key technology for the effectiveness of carbon pricing policies. The decoupling of emissions and emissions control allows prolonging the use of fossil fuels in sectors that are difficult to decarbonize, particularly in the transport sector. It also balances the distribution of mitigation costs across future generations. CDR is not a silver bullet technology. The largest part of emissions reductions continues to be provided by direct mitigation measures at the emissions source. The value of CDR lies in its flexibility to alleviate the most costly constraints on mitigating emissions.  相似文献   

14.
100-year Global Warming Potentials (GWPs) are used almost universally to compare emissions of greenhouse gases in national inventories and reduction targets. GWPs have been criticised on several grounds, but little work has been done to determine global mitigation costs under alternative physics-based metrics . We used the integrated assessment model MESSAGE to compare emission pathways and abatement costs for fixed and time-dependent variants of the Global Temperature Change Potential (GTP) with those based on GWPs, for a policy goal of limiting the radiative forcing to a specified level in the year 2100. We find that fixed 100-year GTPs would increase global abatement costs (discounted and aggregated over the 21st century) under this policy goal by 5–20 % relative to 100-year GWPs, whereas time-varying GTPs would reduce costs by about 5 %. These cost differences are smaller than differences arising from alternative assumptions regarding agricultural mitigation potential and much smaller than those arising from alternative radiative forcing targets. Using the land-use model GLOBIOM, we show that alternative metrics affect food production differently in different world regions depending on regional characteristics of future land-use change to meet growing food demand. We conclude that under scenarios of complete participation, the choice of metric has a limited impact on global abatement costs but could be important for the political economy of regional and sectoral participation in collective mitigation efforts, in particular changing costs and gains over time for agriculture and energy-intensive sectors.  相似文献   

15.
This study investigates the use of bioenergy for achieving stringent climate stabilization targets and it analyzes the economic drivers behind the choice of bioenergy technologies. We apply the integrated assessment framework REMIND-MAgPIE to show that bioenergy, particularly if combined with carbon capture and storage (CCS) is a crucial mitigation option with high deployment levels and high technology value. If CCS is available, bioenergy is exclusively used with CCS. We find that the ability of bioenergy to provide negative emissions gives rise to a strong nexus between biomass prices and carbon prices. Ambitious climate policy could result in bioenergy prices of 70 $/GJ (or even 430 $/GJ if bioenergy potential is limited to 100 EJ/year), which indicates a strong demand for bioenergy. For low stabilization scenarios with BECCS availability, we find that the carbon value of biomass tends to exceed its pure energy value. Therefore, the driving factor behind investments into bioenergy conversion capacities for electricity and hydrogen production are the revenues generated from negative emissions, rather than from energy production. However, in REMIND modern bioenergy is predominantly used to produce low-carbon fuels, since the transport sector has significantly fewer low-carbon alternatives to biofuels than the power sector. Since negative emissions increase the amount of permissible emissions from fossil fuels, given a climate target, bioenergy acts as a complement to fossils rather than a substitute. This makes the short-term and long-term deployment of fossil fuels dependent on the long-term availability of BECCS.  相似文献   

16.
This article presents the synthesis of results from the Stanford Energy Modeling Forum Study 27, an inter-comparison of 18 energy-economy and integrated assessment models. The study investigated the importance of individual mitigation options such as energy intensity improvements, carbon capture and storage (CCS), nuclear power, solar and wind power and bioenergy for climate mitigation. Limiting the atmospheric greenhouse gas concentration to 450 or 550 ppm CO2 equivalent by 2100 would require a decarbonization of the global energy system in the 21st century. Robust characteristics of the energy transformation are increased energy intensity improvements and the electrification of energy end use coupled with a fast decarbonization of the electricity sector. Non-electric energy end use is hardest to decarbonize, particularly in the transport sector. Technology is a key element of climate mitigation. Versatile technologies such as CCS and bioenergy are found to be most important, due in part to their combined ability to produce negative emissions. The importance of individual low-carbon electricity technologies is more limited due to the many alternatives in the sector. The scale of the energy transformation is larger for the 450 ppm than for the 550 ppm CO2e target. As a result, the achievability and the costs of the 450 ppm target are more sensitive to variations in technology availability.  相似文献   

17.
Legislation to decarbonise energy systems within overall greenhouse gas reduction targets represents an immense and unprecedented energy policy challenge. However there is a dichotomy between this level of policy ambition and prior modelling studies that find such targets economically, technologically and socially feasible under idealised ?Dfirst-best policies. This paper makes a significant contribution to current analytical efforts to account for realistic ?Dsecond-best climate mitigation policy implementation. This is achieved via a technical classification of secondbest common mode issues at a detailed national level: both internal (behavioural change, infrastructure implementation) and external (new technologies, resource availability). Under a combinatory second-best scenario, meeting targets greater than a 70% reduction in CO2 by 2050 entail costs above a subjective barrier of 1% of GDP, while extreme mitigation scenarios (>90% CO2 reduction) are infeasible. These high costs are equally due to disappointing progress in behavioural and technological mitigation efforts. Expensive second-best mitigation scenarios can still rely on extreme assumptions including the full deployment of the UK??s offshore wind resource or the complete diffusion of energy efficiency measures in end-use sectors. By demonstrating the fragilities of a low carbon energy system pathway, policy makers can explore protective and proactive strategies to ensure targets can actually be met. Additionally, systematic analysis of failure in stringent long term decarbonisation scenarios teaches energy analysts about the trade-offs in model efficacy vs. confidence.  相似文献   

18.
This study explores the importance of bioenergy to potential future energy transformation and climate change management. Using a large inter-model comparison of 15 models, we comprehensively characterize and analyze future dependence on, and the value of, bioenergy in achieving potential long-run climate objectives. Model scenarios project, by 2050, bioenergy growth of 1 to 10 % per annum reaching 1 to 35 % of global primary energy, and by 2100, bioenergy becoming 10 to 50 % of global primary energy. Non-OECD regions are projected to be the dominant suppliers of biomass, as well as consumers, with up to 35 % of regional electricity from biopower by 2050, and up to 70 % of regional liquid fuels from biofuels by 2050. Bioenergy is found to be valuable to many models with significant implications for mitigation and macroeconomic costs of climate policies. The availability of bioenergy, in particular biomass with carbon dioxide capture and storage (BECCS), notably affects the cost-effective global emissions trajectory for climate management by accommodating prolonged near-term use of fossil fuels, but with potential implications for climate outcomes. Finally, we find that models cost-effectively trade-off land carbon and nitrous oxide emissions for the long-run climate change management benefits of bioenergy. The results suggest opportunities, but also imply challenges. Overall, further evaluation of the viability of large-scale global bioenergy is merited.  相似文献   

19.
This paper presents an approach to estimating world-regional carbon mitigation cost functions for the years 2020, 2050, and 2100. The approach explicitly includes uncertainty surrounding such carbon reduction costs. It is based on the analysis of global energy-economy-environment scenarios described for the 21st century. We use one baseline scenario and variants thereof to estimate cumulative costs of carbon mitigation as a function of cumulative carbon emission reductions. For our baseline for estimating carbon mitigation cost curves, we use the so-called IIASA F scenario. The F scenario is a high-growth, high-emissions scenario designed specifically to be used as a reference against which to evaluate alternatives. Carbon emissions and energy systems costs in the F scenario are then compared with (reduced) emissions and (higher) costs (including macroeconomic adjustment costs) of alternative scenarios taken from the IIASA scenario database. As a kind of sensitivity analysis of our approach, we also present the results of a scenario involving assumptions on particularly rapid technological progress.  相似文献   

20.
Today’s climate policies will shape the future trajectory of emissions. Consumption is the main driver behind recent increases in global greenhouse gas emissions, outpacing savings through improved technologies, and therefore its representation in the evidence base will impact on the success of policy interventions. The IPCC’s Special Report on Global Warming of 1.5 °C (SR1.5) summarises global evidence on pathways for meeting below-2 °C targets, underpinned by a suite of scenarios from integrated assessment models (IAMs). We explore how final energy demand is framed within these, with the aim to making demand-related assumptions more transparent, and evaluating their significance, feasibility, and use or underutilisation as a mitigation lever. We investigate how the integrated assessment models compensate for higher and lower levels of final energy demand across scenarios, and how this varies when mitigating for 2 °C and 1.5 °C temperature targets through an analysis of (1) final energy demand projections, (2) energy-economy relationships and (3) differences between energy system decarbonisation and carbon dioxide removal in the highest and lowest energy demand pathways. We look across the full suite of mitigation pathways and assess the consequences of achieving different global carbon budgets. We find that energy demand in 2100 in the highest energy demand scenarios is approximately three to four times higher than the lowest demand pathways, but we do not find strong evidence that 1.5 °C-consistent pathways cluster on the lower end of demand levels, particularly when they allow for overshoot. The majority of demand reductions happen pre-2040, which assumes absolute decoupling from economic growth in the near-term; thereafter final energy demand levels generally grow to 2100. Lower energy demand pathways moderately result in lower renewable energy supply and lower energy system investment, but do not necessarily reduce reliance on carbon dioxide removal. In this sense, there is more scope for IAMs to implement energy demand reduction as a longer-term mitigation lever and to reduce reliance on negative emissions technologies. We demonstrate the need for integrated assessments to play closer attention to how final energy demand interacts with, relates to, and can potentially offset supply-side characteristics, alongside a more diverse evidence base.  相似文献   

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