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2.
Carbon dioxide (CO 2) sequestration has been proposed as a key component in technological portfolios for managing anthropogenic climate change, since it may provide a faster and cheaper route to significant reductions in atmospheric CO 2 concentrations than abating CO 2 production. However, CO 2 sequestration is not a perfect substitute for CO 2 abatement because CO 2 may leak back into the atmosphere (thus imposing future climate change impacts) and because CO 2 sequestration requires energy (thus producing more CO 2 and depleting fossil fuel resources earlier). Here we use analytical and numerical models to assess the economic efficiency of CO 2 sequestration and analyze the optimal timing and extent of CO 2 sequestration. The economic efficiency factor of CO 2 sequestration can be expressed as the ratio of the marginal net benefits of sequestering CO 2 and avoiding CO 2 emissions. We derive an analytical solution for this efficiency factor for a simplified case in which we account for CO 2 leakage, discounting, the additional fossil fuel requirement of CO 2 sequestration, and the growth rate of carbon taxes. In this analytical model, the economic efficiency of CO 2 sequestration decreases as the CO 2 tax growth rate, leakage rates and energy requirements for CO 2 sequestration increase. Increasing discount rates increases the economic efficiency factor. In this simple model, short-term sequestration methods, such as afforestation, can even have negative economic efficiencies. We use a more realistic integrated-assessment model to additionally account for potentially important effects such as learning-by-doing and socio-economic inertia on optimal strategies. We measure the economic efficiency of CO 2 sequestration by the ratio of the marginal costs of CO 2 sequestration and CO 2 abatement along optimal trajectories. We show that the positive impacts of investments in CO 2 sequestration through the reduction of future marginal CO 2 sequestration costs and the alleviation of future inertia constraints can initially exceed the marginal sequestration costs. As a result, the economic efficiencies of CO 2 sequestration can exceed 100% and an optimal strategy will subsidize CO 2 sequestration that is initially more expensive than CO 2 abatement. The potential economic value of a feasible and acceptable CO 2 sequestration technology is equivalent – in the adopted utilitarian model – to a one-time investment of several percent of present gross world product. It is optimal in the chosen economic framework to sequester substantial CO 2 quantities into reservoirs with small or zero leakage, given published estimates of marginal costs and climate change impacts. The optimal CO 2 trajectories in the case of sequestration from air can approach the pre-industrial level, constituting geoengineering. Our analysis is silent on important questions (e.g., the effects of model and parametric uncertainty, the potential learning about these uncertainties, or ethical dimension of such geoengineering strategies), which need to be addressed before our findings can be translated into policy-relevant recommendations. 相似文献
3.
Carbon dioxide (CO 2) 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 CO 2 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, CH 4) over a given time period, and where a percentage of the gas production is assumed to leak into the atmosphere. The additional
CH 4 from leakage adds to the radiative forcing of the climate system, offsetting the reduction in CO 2 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 CO 2 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. 相似文献
4.
ABSTRACTThe 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 CO 2 faster than achievable by currently-planned global mitigation efforts in pursuit of a year-2050 net zero CO 2 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. 相似文献
5.
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 CO 2 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 CO 2 at concentrated sources like electric power plants, future hydrogen production plants and steel and cement plants; (2) capture
of CO 2 from the air; and (3) the safe and permanent storage of CO 2 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 CO 2 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. 相似文献
6.
Carbon leakage is central to the discussion on how to mitigate climate change. The current carbon leakage literature focuses largely on industrial production, and less attention has been given to carbon leakage from the electricity sector (the largest source of carbon emissions in China). Moreover, very few studies have examined in detail electricity regulation in the Chinese national emissions trading system (which leads, for example, to double counting) or addressed its implications for potential linkage between the EU and Chinese emissions trading systems (ETSs). This article seeks to fill this gap by analysing the problem of ‘carbon leakage’ from the electricity sector under the China ETS. Specifically, a Law & Economics approach is applied to scrutinize legal documents on electricity/carbon regulation and examine the economic incentive structures of stakeholders in the inter-/intra-regional electricity markets. Two forms of ‘electricity carbon leakage’ are identified and further supported by legal evidence and practical cases. Moreover, the article assesses the environmental and economic implications for the EU of potential linkage between the world’s two largest ETSs. In response, policy suggestions are proposed to address electricity carbon leakage, differentiating leakage according to its sources. Key policy insights Electricity carbon leakage in China remains a serious issue that has yet to receive sufficient attention. Such leakage arises from the current electricity/carbon regulatory framework in China and jeopardizes mitigation efforts. With the US retreat on climate efforts, evidence suggests that EU officials are looking to China and expect an expanded carbon market to reinforce EU global climate leadership. Given that the Chinese ETS will be twice the size of the EU ETS, a small amount of carbon leakage in China could have significant repercussions. Electricity carbon leakage should thus be considered in any future EU–China linking negotiations. 相似文献
7.
Measured and projected increases in carbon dioxide content of the atmosphere point towards a significant global warming. The
regional effects of such a warming will be of primary importance in determining the social and economic consequences. Four
methods of arriving at tentative regional scenarios are discussed and illustrated by application to Australia and New Zealand.
Methods used include numerical modelling, extreme warm and cold year ensembles, dynamical/empirical reasoning and palaeoclimatic
reconstructions from the Hypsithermal. A surprising degree of consistency is revealed between the various approaches to a
scenario for a CO 2-warmed Earth and the climatic conditions which prevailed during the Hypsithermal. The best overall analogy to a CO 2-warmed Earth seems to be this epoch, especially as recent evidence suggests it to be one of higher CO 2 concentrations. High priority should be given to further investigations using numerical models which include an interactive
dynamic ocean and hydrologic cycle including variable cloudiness, as well as more detailed reconstruction of climatic conditions
during the Hypsithermal in areas sensitive to any circulation changes. 相似文献
8.
利用雷电监测设备预警雷电,以便于及时采取规避措施减免人员伤亡和经济损失,从而降低评估场所的雷击风险值。本文从这一角度出发,分析了雷电监测预警系统的应用,着重研究了采取预警措施后影响到的参数 LX及其取值方法,结合预警系统的命中率、漏报率,推导建立了风险评估计算公式。给出了安装预警设备后的风险评估流程图,归纳总结了重要场所安装预警设备后影响到的主要风险类型。并以某石化工厂为例,进行了实例应用分析和风险对比。为采取雷电监测预警措施的场所进行合理的雷击风险评估提供可借鉴的方法。 相似文献
9.
PAGE09 is an updated version of the PAGE2002 integrated assessment model (Hope 2011a). The default PAGE09 model gives a mean estimate of the social cost of CO 2 (SCCO 2) of $106 per tonne of CO 2, compared to $81 from the PAGE2002 model used in the Stern review (Stern 2007). The increase is the net result of several improvements that have been incorporated into the PAGE09 model in response to the critical debate around the Stern review: the adoption of the A1B socio-economic scenario, rather than A2 whose population assumptions are now thought to be implausible; the use of ranges for the two components of the discount rate, rather than the single values used in the Stern review; a distribution for the climate sensitivity that is consistent with the latest estimates from IPCC 2007a; less adaptation than in PAGE2002, particularly in the economic sector, which was criticised for possibly being over-optimistic; and a more theoretically-justified basis of valuation that gives results appropriate to a representative agent from the focus region, the EU. The effect of each of these adjustments is quantified and explained. 相似文献
10.
CO 2 capture and storage (CCS) in geological reservoirs may be part of a strategy to reduce global anthropogenic CO 2 emissions. Insight in the risks associated with underground CO 2 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 CO 2 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 CO 2 storage (CO 2 and CH 4 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. 相似文献
11.
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 CO 2 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
12.
Abstract The social cost of carbon (SCC) is the value of the climate change impacts from 1 tonne of carbon emitted today as CO 2, aggregated over time and discounted back to the present day. We used PAGE2002, the same probabilistic integrated assessment model as used by the Stern Review (Stern et al., 2006), to calculate the SCC and to examine how it varies with discount rate; and find that it is not sensitive to the path of emissions on which the tonne of carbon is superimposed. The mean value of the SCC is $43 per tonne under both a business-as-usual scenario, and under a scenario aimed at stabilizing CO 2 concentrations at 550 ppm. This counter-intuitive result is caused by the interplay between the logarithmic relationship between forcing and concentration, the nonlinear relationship of damage to temperature, and discounting. However, the SCC is sensitive to a number of scientific and economic inputs to the model. Two recent distributions for the sensitivity of climate to a doubling of atmospheric CO 2 (Murphy et al., 2004; Stainforth et al., 2005) increase the mean value of the SCC from $43 to $68 and $90 per tonne. Using a pure rate of time preference of 0.1% per year, as in the Stern Review, gives a mean SCC of $365 per tonne. 相似文献
13.
选取1949—2015年间对宁波市影响较大、灾情记录完整的58个台风样本,基于灾损数据,采用灰色关联分析法建立台风灾情关联度,选取台风灾害致灾因子、台风灾情综合关联度,利用BP神经网络建立台风灾情预估模型。结果表明,利用台风灾情关联度评估台风灾情大小合理可用,台风灾害致灾因子与灾情评价指标及台风灾情综合关联度间均存在一定的相关性,利用BP神经网络预估模型对台风灾情预估效果较好,其中训练样本、测试样本的模拟值与实际值相关系数分别达到0. 94、0. 865,均通过了0. 01信度的显著性检验,训练集、测试集灾情级别预报一致率为85. 3%、77. 8%,相关研究成果可为政府决策部门的抗台减灾工作提供科学依据。 相似文献
14.
Solar Radiation Management (SRM) has two characteristics that make it useful for managing climate risk: it is quick and it is cheap. SRM cannot, however, perfectly offset CO 2-driven climate change, and its use introduces novel climate and environmental risks. We introduce SRM in a simple economic model of climate change that is designed to explore the interaction between uncertainty in the climate’s response to CO 2 and the risks of SRM in the face of carbon-cycle inertia. The fact that SRM can be implemented quickly, reducing the effects of inertia, makes it a valuable tool to manage climate risks even if it is relatively ineffective at compensating for CO 2-driven climate change or if its costs are large compared to traditional abatement strategies. Uncertainty about SRM is high, and decision makers must decide whether or not to commit to research that might reduce this uncertainty. We find that even modest reductions in uncertainty about the side-effects of SRM can reduce the overall costs of climate change in the order of 10%. 相似文献
15.
This article explores the causes for differences in the average CO 2 emissions intensity of the new passenger car (NPC) fleet in member states (MS) across Europe. Although EU policies mitigating CO 2 emissions from NPCs have been in place since 1999, MS strongly diverge in the absolute amount and relative change in emissions over the last decade. The authors employ a qualitative approach to analyse the factors, in particular national vehicle taxes, contributing to this divergence and the relative contribution of national and European policies in reducing national CO 2 emissions from NPCs. The analysis shows that there has been a significant reduction in CO 2 emissions intensity of NPCs since 2007 across most MS, compared with the six years previous to that date. This would indicate that EU-wide policies, such as the CO 2 vehicles regulation, along with the economic recession in 2008, have influenced national NPC CO 2 emissions. Generally, countries with CO 2-differentiated vehicle taxes are observed as more likely to have achieved greater reductions in CO 2 emissions. However, over the same period there have been many confounding factors, such as economic instability in the EU, that also influence NPC emissions. Using more detailed case study analyses of six countries, the authors find that there is scope for well-designed national vehicle tax policies to drive NPC emissions down further than the EU average. In countries with the highest success rate, such as the Netherlands, the design of the vehicle tax, as part of a well-aligned policy package, has been very important in delivering the biggest reductions in CO 2 emissions from NPCs. POLICY RELEVANCE The transport sector continues to be an intractable source of CO2 emissions. Governments around the world are seeking effective policies to deal with the increase in passenger car CO2 emissions appropriate to their own circumstances. This article examines the experience of EU MS with CO2-differentiated vehicle taxes in reducing CO2 emissions in the context of other national and international contributing factors. It should therefore both be useful to policy makers and contribute to climate policy research in general. 相似文献
16.
The theoretical potential for carbon forests to off-set greenhouse gas emissions may be high but the achievable rate is influenced by a range of economic and social factors. Economic returns (net present value, NPV) were calculated spatially across the cleared land area in Australia for ‘environmental carbon plantings’. A total of 105 scenarios were run by varying discount rate, carbon price, rate of carbon sequestration and costs for plantation establishment licenses for water interception. The area for which NPV was positive ranged from zero ha for tightly constrained scenarios to almost the whole of the cleared land (104 M ha) for lower discount rate and highest carbon price. For the most plausible assumptions for cost of establishment and commercial discount rate, no areas were identified as profitable until a carbon price of AUD$40 t CO 2 ?1 was reached. The many practical constraints to plantation establishment mean that it will likely take decades to have significant impact on emission reductions. Every 1 M ha of carbon forests established would offset about 1.4 % of Australia’s year 2000 emissions (or 7.4 Mt CO 2 year ?1) when an average rate of sequestration per ha was reached. All studies that predict large areas of potentially profitable land for carbon forestry need to be tempered by the realities that constrain land use change. In Australia and globally, carbon plantings can be a useful activity to help mitigate emissions and restore landscapes but it should be viewed as a long-term project in which co-benefits such as biodiversity enhancement can be realised. 相似文献
17.
In view of the uncertainty of the origin of the secular increase of N 2O, we studied heterogeneous processes that contribute to formation of N 2O in an environment that comes as close as possible to exhaust conditions containing NO and SO 2, among other constituents. The N 2O formation was followed using electron capture gas chromatography (ECD-GC). The other reactants and intermediates (SO 2, NO, NO 2 and HONO) were monitored using gas phase UV-VIS absorption spectroscopy. Experiments were conducted at 298 and 368 K as well as at dry and high humidity (approaching 100% rh) conditions. There is a significant heterogeneous rate of N
2
O formation at conditions that mimic an exhaust plume from combustion processes.The simultaneous presence of NO, SO 2, O 2 in the gas phase and condensed phase water, either in the bulk liquid or adsorbed state has been confirmed to be necessary for the production of significant levels of N 2O. The stoichiometry of the overall reaction is: 2 NO+SO 2+H 2O N 2O+H 2SO 4. The maximum rate of N 2O formation occurred at the beginning of the reaction and scales with the surface area of the condensed phase and is independent of its volume. A significant rate of N 2O formation at 368 K at 100% rh was also observed in the absence of a bulk substrate. The diffusion of both gas and liquid phase reactants is not rate limiting as the reaction kenetics is dominated by the rate ofN 2O formation under the experimental conditions used in this work. The simultaneous presence of high humidity (90–100% rh at 368 K) and bulk condensed phase results in the maximum rate and final yield of N 2O approaching 60% and 100% conversion after one hour in the presence of amorphous carbon and fly-ash, respectively.Work performed in partial fulfillment of the requirements of Dr ès Sciences at EPFL. 相似文献
18.
Methane emission from West Siberian forest-steppe and subtaiga reed fens (that is, fens dominated by Phragmites australis) observed in summer 2013, is considered using the static chamber method. The obtained medians of CH 4 fluxes varied from -0.08 to 2.7 mg CH 4/m 2 per hour. Eenvironmental factors affecting methane emission are analyzed. It was found that CH 4 emissions from the reed fens correlate only with the concentration of salt ions in the wetland water and with the plant community structure. The latter probably also depends on water salinity. It was revealed that in fens the ratio between fluxes of CH 4 and CO 2 does not depend on the water table level that contradicts the general pattern simulated by mathematical models of CH 4 emission. It was found that Phragmites australis fens and similar ecosystems should be considered as a separate wetland class from the point of view of methane emission study. 相似文献
19.
This paper examines three issues in quantifying project-level emissions reductions (ERs): baseline and additionality determination, leakage assessment, and measurement of net emissions. It finds no systematic differences between land use change and forestry (LUCF) and energy projects in addressing these issues. Rather, the ease of quantification depends on the following: - •The level and distribution of direct financial benefits that result from the project, since this is a key determinant of additionality.
- •The degree to which the project is integrated with a broader physical and economic system, since this determines the amount of leakage.
- •The internal homogeneity and geographic dispersion of the project components—a key determinant of measurement costs.
These dimensions cut across the energy versus LUCF distinction. 相似文献
20.
A change in economic structure influences the total energy consumption as well as CO 2 emissions of a country, given the inherent difference in levels of energy intensity and energy fuel mix of different economic sectors. Its significance has been recognized in recent literature on China’s emission mitigation which could arguably raise China’s mitigation potential and thus the possibility of keeping the 2-degree trajectory on track. This article utilizes the past trend of economic structural change of five East Asian developed economies to project the energy consumption and CO 2 emissions of China in the coming decades. A special delineation of the economic sector is made, putting private consumption together with the three typical economic production sectors, to resolve the mismatch between the statistical data of energy consumption and economic production, in that residential energy consumption is typically merged into the tertiary sector, although it does not directly correspond to gross domestic product (GDP) output. Results suggest that the level of CO 2 emissions would be lower if China followed a development pathway emphasizing the development of the tertiary sector and continuously shrinking her secondary sector, making it possible for China to contribute more to global carbon mitigation. The impact from the rise of private consumption would be relatively insignificant compared to deindustrialization. In addition to continuous improvement in technology, economic structural change, which reduces carbon emission intensity, would be essential for China to be able to achieve the carbon emission level pledged in the Paris Agreement. Key policy insights For China, significant economic structural reform, particularly deindustrialization, is necessary to achieve the goal of ‘peak emission by 2030’. Any additional contribution from China to the global effort to maintain a 2-degree trajectory would be limited – from a ‘fair-contribution’ perspective based on share of population or GDP – because the implied mitigation targets would be almost impossible to achieve. If developing countries follow the pathway of developed economies, particularly in developing energy-intensive industries, energy consumption and CO2 emissions would significantly increase, reducing the possibility of keeping global temperature rise within the 2-degree Celsius benchmark. 相似文献
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