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1.
While most long-term mitigation scenario studies build on a broad portfolio of mitigation technologies, there is quite some uncertainty about the availability and reduction potential of these technologies. This study explores the impacts of technology limitations on greenhouse gas emission reductions using the integrated model IMAGE. It shows that the required short-term emission reductions to achieve long-term radiative forcing targets strongly depend on assumptions on the availability and potential of mitigation technologies. Limited availability of mitigation technologies which are relatively important in the long run implies that lower short-term emission levels are required. For instance, limited bio-energy availability reduces the optimal 2020 emission level by more than 4 GtCO2eq in order to compensate the reduced availability of negative emissions from bioenergy and carbon capture and storage (BECCS) in the long run. On the other hand, reduced mitigation potential of options that are used in 2020 can also lead to a higher optimal level for 2020 emissions. The results also show the critical role of BECCS for achieving low radiative forcing targets in IMAGE. Without these technologies achieving these targets become much more expensive or even infeasible.  相似文献   

2.
In order to address the pressing challenge of climate change, countries are now submitting long-term climate strategies to the United Nations Framework Convention on Climate Change (UNFCCC) process. These strategies include within them potential future use of ‘negative emissions technologies’ (NETs). NETs are interventions that remove carbon from the atmosphere, ranging from large-scale terrestrial carbon sequestration in forests, wetlands and soils, to use of carbon capture and storage technologies. We assess here how NETs are discussed in 29 long-term climate strategies, in order to ascertain the risk that including the promise of future NETs may delay the taking of short-term mitigation actions. Our analysis shows that almost all countries plan to rely on NETs, particularly enhanced use of natural carbon sinks, even as a wide array of challenges and trade-offs in doing so are highlighted. Many strategies call for improved accounting systems and market incentives in realizing future NETs. While no strategy explicitly suggests that NETs can be a substitute for short-term mitigation, most estimate substantial potential for future use of NETs even in the face of acknowledged uncertainties. This, we suggest, may have the consequence of resulting in what we describe here as ‘a spiral of delay’ characterized by the promise of future NET options juxtaposed with the simultaneous uncertainty around these future options. Our analysis highlights that this inter-connected delaying dynamic may be intrinsic to what we term ‘governing-by-aspiration’ within global climate politics, wherein the voicing of lofty future ambition risks replacing current action and accountability.  相似文献   

3.
This empirical study assesses the relationship between the characteristics of developing countries and the amount of official climate mitigation finance inflow. A two-part model and robustness checks were used to analyse 1998–2010 Rio Marker data on 180 developing countries. The results show that developing countries with higher CO2 intensity, larger carbon sinks, lower per capita gross domestic product (GDP) and good governance tend to be selected as recipients of climate mitigation finance, and receive more of it. CO2 emission is not used as a determinant of mitigation finance until the actual financial disbursement. Poverty aid tends to be allocated to countries with low CO2 emissions, possibly to avoid diverting aid from poorer developing countries. However, such a diversion is unavoidable if the share of mitigation finance in climate finance and in overall official development assistance (ODA) continues to escalate. This study calls for an equitable allocation of total ODA mitigation and adaptation finance in addition to the 0.7% ODA/gross national income target, and for transparent criteria and the verification of reporting on the allocation of mitigation finance.  相似文献   

4.
《Climate Policy》2001,1(2):189-210
Two different mitigation scenarios for stabilising carbon dioxide concentration at 450 ppmv by 2100 have been developed, based on the recently developed B1 baseline scenario (part of the IPCC Special Report on Emission Scenarios). In both mitigation scenarios, a global uniform carbon tax has been applied as a proxy of pressure on the system to induce a variety of mitigation measures — assuming the presence of some international mechanism for globally cost-efficient implementation of such measures. The two scenarios differ in the timing of mitigation action: early action versus delayed response. Analysis of the scenarios has led to the following findings. First, stabilisation at a carbon dioxide concentration of 450 ppmv from the B1 baseline scenario is technically feasible. In the first quarter/second quarter of this century most of the reduction will come from energy-efficiency and fuel switching options; later on the introduction of carbon-free supply options will account for the bulk of the required reductions. Second, postponing measures foregoes the benefits of learning-by-doing, and, as a result, an early action strategy will at low discount rates lead to reduced mitigation costs compared to delayed response. The most difficult period for the mitigation scenarios is the 2010–2040 period (exact timing depends on early action or delayed response), when ‘bending the curve’ towards a lower carbon emission system will have to be initiated. Finally, while overall costs seems to be limited, there are large differences in costs and benefits for individual regions and sectors for instance in terms of redirection of investments, changing fuel trade patterns and changing energy expenditures.  相似文献   

5.
Limiting climate change to 2 °C with a high probability requires reducing cumulative emissions to about 1600 GtCO2 over the 2000–2100 period. This requires unprecedented rates of decarbonization even in the short-run. The availability of the option of net negative emissions, such as bio-energy with carbon capture and storage (BECCS) or reforestation/afforestation, allows to delay some of these emission reductions. In the paper, we assess the demand and potential for negative emissions in particular from BECCS. Both stylized calculations and model runs show that without the possibility of negative emissions, pathways meeting the 2 °C target with high probability need almost immediate emission reductions or simply become infeasible. The potential for negative emissions is uncertain. We show that negative emissions from BECCS are probably limited to around 0 to 10 GtCO2/year in 2050 and 0 to 20 GtCO2/year in 2100. Estimates on the potential of afforestation options are in the order of 0–4 GtCO2/year. Given the importance and the uncertainty concerning BECCS, we stress the importance of near-term assessments of its availability as today’s decisions has important consequences for climate change mitigation in the long run.  相似文献   

6.
Carbon Sequestration and the Restoration of Land Health   总被引：1，自引：0，他引：1  
Carbon sequestration, the conversion of greenhouse gas CO2 toorganic matter, offers a powerful tool with which to combat climate change. The enlargement of carbon sinks stored in soil and biota is an essential tool in buying time while mankind seeks means to reduce emissions of greenhouse gases and to reduce the elevated levels of atmospheric CO2. Carbon sequestration within the context of the Kyoto Protocol of the United Nations Framework Convention on Climate Change (UNFCCC) also has great potential as an incentive for combating land degradation and desertification and restoring fertility to degraded land.Decisions regarding carbon sinks during finalization of the operational details of the Kyoto Protocol in 2001 fit well the needs of countries facing land degradation and desertification. However, incentives for such mitigation through the Clean Development Mechanism of the protocol are limited to forestry issues. Iceland provides a good example of the multiple role of carbon sequestration in meeting national commitments to UNFCCC, conserving and restoring biological diversity, combating soil erosion, revegetation of eroded land and reforestation. Linking carbon sequestration with such goals has resulted in increased funds for soil conservation and restoration of degraded land in Iceland.  相似文献   

7.
Carbon sequestration in agroforestry systems   总被引：2，自引：0，他引：2  
《Climate Policy》2013,13(4):367-377
Abstract

Management of trees in agroecosystems such as agroforestry, ethnoforests, and trees outside forests can mitigate green house gas (GHG) emissions under the Kyoto Protocol. Agroforestry systems are a better climate change mitigation option than oceanic, and other terrestrial options because of the secondary environmental benefits such as helping to attain food security and secure land tenure in developing countries, increasing farm income, restoring and maintaining above-ground and below-ground biodiversity, corridors between protected forests, as CH4 sinks, maintaining watershed hydrology, and soil conservation. Agroforestry also mitigates the demand for wood and reduces pressure on natural forests. Promoting woodcarving industry facilitates long-term locking-up of carbon in carved wood and new sequestration through intensified tree growing. By making use of local knowledge, equity, livelihood security, trade and industry, can be supported. There is need to support development of suitable policies, assisted by robust country-wide scientific studies aimed at better understanding the potential of agroforestry and ethnoforestry for climate change mitigation and human well-being.  相似文献   

8.
In this paper, we present a method to quantify the effectiveness of carbon mitigation options taking into account the `permanence' of the emissions reduction. While the issue of permanence is most commonly associated with a `leaky' carbon sequestration reservoir, we argue that this is an issue that applies to just about all carbon mitigation options. The appropriate formulation of this problem is to ask `what is the value of temporary storage?' Valuing temporary storage can be represented as a familiar economic problem, with explicitly stated assumptions about carbon prices and the discount rate. To illustrate the methodology, we calculate the sequestration effectiveness for injecting CO2 at various depths in the ocean. Analysis is performed for three limiting carbon price assumptions: constant carbon prices (assumes constant marginal damages), carbon prices rise at the discount rate (assumes efficient allocation of a cumulative emissions cap without a backstop technology), and carbon prices first rise at the discount rate but become constant after a given time (assumes introduction of a backstop technology). Our results show that the value of relatively deep ocean carbon sequestration can be nearly equivalent to permanent sequestration if marginal damages (i.e., carbon prices) remain constant or if there is a backstop technology that caps the abatement cost in the not too distant future. On the other hand, if climate damages are such as to require a fixed cumulative emissions limit and there is no backstop, then a storage option with even very slow leakage has limited value relative to a permanent storage option.  相似文献   

9.
A variety of proposed activities to mitigate greenhouse gas emissions will impact on scarce water resources, which are coming under increasing pressure in many countries due to population growth and shifting weather patterns. However, the integrated analysis of water and carbon impacts has been given limited attention in greenhouse mitigation planning. In this Australian case study, we analyse a suite of 74 mitigation measures ranked as highest priority by one influential analysis, and we find that they have highly variable consequences for water quantity. We find: (1) The largest impacts result from land-based sequestration, which has the potential to intercept large quantities of water and reduce catchment yields, estimated to exceed 100 Mm3/MtCO2-e of carbon mitigated (100,000 l per tonne CO2-e). (2) Moderate impacts result from some renewable power options, including solar thermal power with a water cost estimated at nearly 4 Mm3/MtCO2-e. However, the water impacts of solar thermal power facilities could be reduced by designing them to use existing power-related water supplies or to use air or salt-water cooling. (3) Wind power, biogas, solar photovoltaics, energy efficiency and operational improvements to existing power sources can reduce water demand through offsetting the water used to cool thermal power generation, with minor savings estimated at 2 Mm3/MtCO2-e and amounting to nearly 100 Mm3 of water saved in Australia per annum in 2020. This integrated analysis significantly changes the attractiveness of some mitigation options, compared to the case where water impacts are not considered.  相似文献   

10.
Terrestrial carbon sinks and sources were introduced into climate change mitigation related policy relatively late in the design of the architecture of those policies. Much literature addresses how terrestrial sources and sinks differ from emissions from fossil fuel combustion and, hence, is a possible justification for differential treatment of them in policy design. Late introduction in climate policy discussions and perceived differences appear to have resulted in very different policy approaches for sinks versus fossil emission sources. The attempt to differentiate has generated complexity in policy design and likely inefficiency in the operation of these policies. We review these issues and find that the characteristics claimed to apply to sinks apply as well to fossil sources, and differences that do exist are often more a matter of degree than of kind. Because cap-and-trade has gained momentum as the instrument of choice to control fossil emissions, we use as a starting point, how such a cap-and-trade system could be altered to include terrestrial carbon sinks and sources.  相似文献   

11.
Carbon capture and storage (CCS) could achieve drastic cuts in the CO2 emissions associated with fossil fuels in the near to medium term and has been promoted as a significant climate change mitigation option. As the profile of this family of technologies grows rapidly, there remain many uncertainties relating to its viability, effectiveness and desirability. In this paper we begin to map out some of the key issues associated with CCS, using a multi-criteria approach to explore how an (admittedly small) selection of stakeholders perceive alternative storage options and energy scenarios. We present five long-term scenarios describing alternative ways in which the UK energy system could develop and which deploy different levels of carbon storage. The key storage options considered are oil and gas fields (both disused and with enhanced oil recovery), traps in saline aquifers, saline aquifers outside traps and on-shore sites. The relative performance of the scenarios and the storage reservoirs included within them have been assessed against a set of socio-economic, technical and environmental criteria by a small selection of stakeholders to the carbon storage debate. Whilst we cannot make strong conclusions regarding precise stakeholder opinions at this stage due to the small size of the sample, the broad delineation of the arguments for and against CCS are evident. Multi-criteria assessment (MCA) appears to hold much potential as a useful tool for characterising and better understanding differences in stakeholder assessments of CCS and its implications, and for identifying options around which greater consensus on the desirability (or otherwise) of CCS as a mitigation strategy might emerge.  相似文献   

12.
Terrestrial carbon pools in southeast and south-central United States   总被引：1，自引：0，他引：1  
Analyses of regional carbon sources and sinks are essential to assess the economical feasibility of various carbon sequestration technologies for mitigating atmospheric CO2 accumulation and for preventing global warming. Such an inventory is a prerequisite for regional trading of CO2 emissions. As a U.S. Department of Energy Southeast Regional Carbon Sequestration Partner, we have estimated the state-level terrestrial carbon pools in the southeast and south-central US. This region includes: Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Texas, and Virginia. We have also projected the potential for terrestrial carbon sequestration in the region. Texas is the largest contributor (34%) to greenhouse gas emission in the region. The total terrestrial carbon storage (forest biomass and soils) in the southeast and south-central US is estimated to be 130 Tg C/year. An annual forest carbon sink (estimated as 76 Tg C/year) could compensate for 13% of the regional total annual greenhouse gas emission (505 Tg C, 1990 estimate). Through proper policies and the best land management practices, 54 Tg C/year could be sequestered in soils. Thus, terrestrial sinks can capture 23% of the regional total greenhouse emission and hence are one of the most cost-effective options for mitigating greenhouse emission in the region.  相似文献   

13.
This paper evaluated the impacts of climate change mitigation technology options on CO2 emission reductions and the effects of model representations regarding renewable intermittency on the assessment of reduction by using a world energy systems model. First, different diffusion scenarios for carbon dioxide capture and storage (CCS), nuclear power, and wind power and solar PV are selected from EMF27 scenarios to analyze their impacts on CO2 emission reductions. These technologies are important for reducing CO2 intensity of electricity, and the impacts of their diffusion levels on mitigation costs are significant, according to the analyses. Availability of CCS in particular, among the three kinds of technologies, has a large impact on the marginal CO2 abatement cost. In order to analyze effects of model representations regarding renewables intermittency, four different representations are assumed within the model. A simplistic model representation that does not take into consideration the intermittency of wind power and solar PV evaluates larger contributions of the energy sources than those evaluated by a model representation that takes intermittency into consideration. Appropriate consideration of renewables intermittency within global energy systems models will be important for realistic evaluations of climate change mitigation scenarios.  相似文献   

14.
Invoking health benefits to promote climate-friendly household behavior has three unique advantages: (i) health co-benefits accrue directly to the acting individual, they are "private goods" rather than public ones; (ii) the evidence base for, and magnitude of health co-benefits is well-established; and (iii) the idea of a healthy life-style is well-engrained in public discourse, much more so than that of a climate-friendly life-style. In previous research, assessing the influence of information on health effects on people’s motivation to adopt mitigation actions, health co-benefits for the individual were typically confounded with collective health co-benefits, for example from pollution reduction. The present research aims to overcome this limitation by providing information on individual health co-benefits that are unconditional on the actions of others (direct health co-benefits). We report effects of this kind of health information on stated willingness to adopt mitigation actions as well as on simulation-based carbon emission reductions in a pre-registered experimental setting among 308 households in 4 mid-size case-study cities in 4 European high-income countries: France, Germany, Norway and Sweden. For each mitigation action from the sectors food, housing, and mobility, half of the sample received the amount of CO2equivalents (CO2-eq) saved and the financial costs or savings the respective action generated. The other half additionally received information on direct health co-benefits, where applicable. For households receiving information on direct health co-benefits, we find a higher mean willingness to adopt food and housing actions, and a greater proportion very willing to adopt one or more mitigation actions (OR 1.86, 95% CI 1.1, 3.12); and a greater simulated reduction in overall carbon footprint: difference in percent reduction -2.70%, (95% CI -5.34, -0.04) overall and -4.45%, (95% CI -8.26, -0.64) for food. Our study is the first to show that providing information on strictly unconditional, individual health co-benefits can motivate households in high-income countries to adopt mitigation actions.  相似文献   

15.
The U.K. has extensive databases on soils, land cover and historic land use change which have made it possible to construct a comprehensive inventory of the principal terrestrial sources and sinks of carbon for approximately the year 1990, using methods that are consistent with, and at least as accurate as, the revised 1996 guidelines recommended by IPCC where available – and including categories which are not currently considered under the UN Framework Convention on Climate Change. This country inventory highlights issues concerning methodology, uncertainty, double counting, the importance of soils and the relative magnitude of sources and sinks which are reported to the UNFCCC relative to other sources and sinks. The carbon sinks (negative values in MtC a-1) for categories reported to the UNFCCC, based on the IPCC categories, were estimated to be: forest trees and litter (–2.1), U.K. forest products (–0.5, ignoring imports and exports), non-forest biomass (–0.3), forest soils (–0.1) and soils on set-aside land (–0.4). The carbon sources (positive values) reported under the UNFCCC were estimated to be: losses of soil organic carbon resulting from cultivation of semi-natural land (6.2) and from urbanization (1.6), drainage of peatlands (0.3) and fenlands (0.5), and peat extraction (0.2). A range of other sources and sinks not covered by the IPCC guidelines were also quantified, namely, the accumulation of carbon in undrained peatlands (–0.7, ignoring methane emission), sediment accretion in coastal marshes (–0.1), the possible U.K. share of the CO2 and N fertilization carbon sink (–2.0) and riverine organic and particulate carbon export to the sea (1.4, which may be assumed to be a source if most of this carbon is released as CO2 in the sea). All sinks totalled –6.2 and sources 10.2, giving a net flux to the atmosphere in 1990 of 4.0 MtC a-1. Uncertainties associated with categories, mostly based on best guesses, ranged from ±15% for forest biomass and litter to ±60% for CO2 and N fertilization.  相似文献   

16.
Activities to reduce net greenhouse gas emissions by biological soil or forest carbon sequestration predominantly utilize currently known, readily implementable technologies. Many other greenhouse gas emission reduction options require future technological development or must wait for turnover of capital stock. Carbon sequestration options in soils and forests, while ready to go now, generally have a finite life, allowing use until other strategies are developed. This paper reports on an investigation of the competitiveness of biological carbon sequestration from a dynamic and multiple strategy viewpoint. Key factors affecting the competitiveness of terrestrial mitigation options are land availability and cost effectiveness relative to other options including CO2 capture and storage, energy efficiency improvements, fuel switching, and non-CO2 greenhouse gas emission reductions. The analysis results show that, at lower CO2 prices and in the near term, soil carbon and other agricultural/forestry options can be important bridges to the future, initially providing a substantial portion of attainable reductions in net greenhouse gas emissions, but with a limited role in later years. At higher CO2 prices, afforestation and biofuels are more dominant among terrestrial options to offset greenhouse gas emissions. But in the longer run, allowing for capital stock turnover, options to reduce greenhouse gas emissions from the energy system and biofuels provide an increasing share of potential reductions in total US greenhouse gas emissions.  相似文献   

17.
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18.
Climate is simulated for reference and mitigation emissions scenarios from Integrated Assessment Models using the Bern2.5CC carbon cycle–climate model. Mitigation options encompass all major radiative forcing agents. Temperature change is attributed to forcings using an impulse–response substitute of Bern2.5CC. The contribution of CO2 to global warming increases over the century in all scenarios. Non-CO2 mitigation measures add to the abatement of global warming. The share of mitigation carried by CO2, however, increases when radiative forcing targets are lowered, and increases after 2000 in all mitigation scenarios. Thus, non-CO2 mitigation is limited and net CO2 emissions must eventually subside. Mitigation rapidly reduces the sulfate aerosol loading and associated cooling, partly masking Greenhouse Gas mitigation over the coming decades. A profound effect of mitigation on CO2 concentration, radiative forcing, temperatures and the rate of climate change emerges in the second half of the century.  相似文献   

19.
Designing effective mitigation policies for greenhouse gas (GHG) emissions from agriculture requires understanding the mechanisms by which management practices affect emissions in different agroclimatic conditions. Agricultural GHG emissions and carbon sequestration potentials have been extensively studied in the Mediterranean biome, which is a biodiversity hot spot that is highly vulnerable to environmental changes. However, the absolute magnitude of GHG emissions and the extent to which research efforts match these emissions in each production system, are unknown. Here, we estimated GHG emissions and potential carbon sinks associated with crop and livestock production systems in the Mediterranean biome, covering 31 countries and assessing approximately 10,000 emission items. The results were then combined with a bibliometric assessment of 797 research publications to compare emissions estimates obtained with research efforts for each of the studied items. Although the magnitude of GHG emissions from crop production and the associated carbon sequestration potential (261 Tg CO2eq yr−1) were nearly half of those from livestock production (367 Tg CO2eq yr−1), mitigation research efforts were largely focused on the former. As a result, the relative research intensity, which relates the number of publications to the magnitude of emissions, is nearly one order of magnitude higher for crop production than for livestock production (2.6 and 0.4 papers Tg CO2eq−1, respectively). Moreover, this mismatch is even higher when crop and livestock types are studied separately, which indicates major research gaps associated with grassland and many strategic crop types, such as fruit tree orchards, fiber crops, roots and tubers. Most life cycle assessment studies do not consider carbon sequestration, although this single process has the highest magnitude in terms of annual CO2eq. In addition, these studies employ Tier 1 IPCC factors, which are not suited for use in Mediterranean environments. Our analytical results show that a strategic plan is required to extend on-site field GHG measurements to the Mediterranean biome. Such a plan needs to be cocreated among stakeholders and should be based on refocusing research efforts to GHG balance components that have been afforded less attention. In addition, the outcomes of Mediterranean field studies should be integrated into life cycle assessment-based carbon footprint analyses in order to avoid misleading conclusions.  相似文献   

20.
The Intergovernmental Panel on Climate Change (IPCC) released the report of Working Group III of the Sixth Assessment Report "climate change 2022: mitigating climate change". The report accessed and summarized the latest research progress on climate change mitigation since the release of the Fifth Assessment Report, which will provide an important reference for the international community to further understand climate change mitigation actions, system transformation, and the pursuit of sustainable development. The report pointed out that human activities had cumulatively emitted about 2.4 trillion tons of CO2 from 1850 to 2019, of which 58% was emitted before 1990. In order to control the level of global temperature rise in the future, deep and immediate mitigation actions are required. In both low and minimum emission scenarios, fossil energy needs to be greatly reduced; renewable energy will be the mainstay of future energy supply; achieving carbon neutrality requires relying on negative emission technologies and increasing carbon sinks. Technological progress is one of the key conditions for helping the world combat climate change. Accelerated and equitable climate action is critical to sustainable development. The report's conclusions once again show that China's carbon neutrality target is in line with the mitigation path of the Paris Agreement's temperature rise target of less than 2 °C and striving to achieve 1.5°C. In the future, China should strengthen special research programs on the national concerns and key contents covered in the report. While strengthening scientific interpretation and effective use of the report's conclusions, it is also necessary to actively participate in the IPCC scientific assessment process, actively contribute Chinese wisdom, and contribute to the international dissemination of Chinese climate governance concepts. © 2022 Chinese Journal of Digestive Endoscopy All rights reserved.  相似文献   

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