Equitable cost-benefit analysis of climate change policies

The literature of welfare-maximising greenhouse gas emission reduction strategies pays remarkably little attention to equity. This paper introduces three ways to consider efficiency and equity simultaneously. The first method, inspired by Kant and Rawls, maximises net present welfare, without international cooperation, as if all regions share the fate of the region affected worst by climate change. Optimal emission abatement varies greatly depending on the spatial and temporal resolution, that is, the grid at which ‘maximum impact’ is defined. The second method is inspired by Varian's no-envy. Emissions are reduced so as to equalise total costs and benefits of climate change over all countries of the world and over all time periods. Emission reductions are substantial. This method approximately preserves the inequities that would occur in a world without climate change. The third method uses non-linear aggregations of welfare (the utilitarian default is linear) in a cooperative setting. This method cannot distinguish between sources of inequity. The higher the aversion to inequity, the higher optimal greenhouse gas emission reduction.     

Capital Malleability, Emission Leakage and the Cost of Partial Climate Policies: General Equilibrium Analysis of the European Union Emission Trading System

Computable general equilibrium (CGE) models are the premier analytical platform for assessing the economic impacts of climate change mitigation. But these models tend to treat physical capital as “malleable”, capable of reallocation among sectors over the time-period for which equilibrium is solved. Because the extent to which capital adjustment costs might dampen reallocation is not well understood, there is concern that CGE assessments understate the true costs of greenhouse gas (GHG) reduction policies. This paper uses a multi-region, multi-sector CGE model to investigate cap-and-trade schemes, such as the European Union Emission Trading System which cover a subset of the economy, elucidating the effects of capital malleability on GHG abatement, the potential for emission leakage from abating to non-abating sectors, and the impacts on welfare. To simplify the complex interactions being simulated within the CGE model, that analysis is complemented with an analytical model. A partial climate policy results in negative internal carbon leakage, with emissions declining not only in capped sectors but also in non-regulated ones. This result is stronger when capital is intersectorally mobile. Interestingly, in partial climate policy settings capital malleability can amplify or attenuate welfare losses depending on the attributes of the economy.     

Games of Climate Change with International Trade

We analyse games of greenhouse gas emission reduction in which the emissions and the emission reduction costs of one country depend on other countries' emission abatement. In an analytically tractable model, we show that international trade effects on costs and emissions can either increase or decrease incentives to reduce emissions and to cooperate on emission abatement; in some specifications, optimal emission reduction is unaffected by trade. We therefore specify the model further, calibrating it to larger models that estimate the costs of emission reduction, trade effects, and impacts of climate change. If trade effects are driven by total emission reduction costs of other countries cooperation is slightly more difficult than in the case without trade effects. If trade effects are determined by relative emission reduction efforts in other countries, cooperation becomes easier. Carbon leakage does not affect our qualitative insights, although it does change the numbers.     

On the fair division of greenhouse gas abatement cost

This paper introduces a solution for the fair division of emission reduction costs in the climate change regime. Our primary focus is on the fair division of efficiency gains that arise from exchanging the initial allocation of emission entitlements, rather than the initial allocation itself. We propose to complement the competitive Walrasian solution with welfare bounds, the ethical justification of which rests on commonality of ownership. Simulations with an intertemporal computable general equilibrium model illustrate the relevance of such welfare bounds. For a wide range of initial allocations of emission entitlements – including an equal per capita allocation – we find that developing countries should be fully compensated for their emission abatement efforts, but should not receive any further transfers.     

Climate change and the transition to a low carbon economy – Carbon targets and the carbon budget

Carbon intensive fuels generate a significant negative externality which is quite relevant for climate change mitigation policy. We propose a dynamic growth model where output is produced using two types of energy sources: fossil fuel and renewable energy. Fossil fuel discovery, extraction, and associated costs are incorporated in our model together with the dynamics of greenhouse gas emissions and consequent damages. Consistent with the empirical facts, our numerical solutions suggest that fossil fuels, especially coal, should not be exploited to depletion. Furthermore, renewable energy should be gradually phased in to meet targets consistent with the Paris 2015 agreement. We show that adopting those policies should slow down the growth rate of cumulative emissions; but the outcome is contingent upon the carbon emission targets set for advanced countries, as distinct from those assigned to developing countries.     

Local air pollution and global climate change: A combined cost-benefit analysis

This article presents the findings of a combined cost-benefit analysis of local air pollution and global climate change, two subjects that are usually studied separately. Yet these distinct environmental problems are closely related, since they are both driven by the nature of present energy production and consumption patterns. Our study demonstrates the mutual relevance of, and interaction between, policies designed to address these two environmental challenges individually. Given the many dimensions air pollution control and climate change management have in common, it is surprising that they have only little been analyzed in combination so far. We attempt to cover at least part of the existing gap in the literature by assessing how costs and benefits of technologies and strategies that jointly tackle these two environmental problems can best be balanced. By using specific technological options that cut down local air pollution, e.g. related to particulate emissions, one may concurrently reduce CO₂ emissions and thus contribute to diminishing global climate change. Inversely, some of the long-term climate change strategies simultaneously improve the quality of air in the short run. We have extended the well-established MERGE model by including emissions of particulate matter, and show that integrated environmental policies generate net global welfare benefits. We also demonstrate that the discounted benefits of local air pollution reduction significantly outweigh those of global climate change mitigation, at least by a factor of 2, but in most cases of our sensitivity analysis much more. Still, we do not argue to only restrict energy policy today to what should be our first priority, local air pollution control, and wait with the reduction of greenhouse gas emissions. Instead, we propose to design policies that simultaneously address these issues, as their combination creates an additional climate change bonus. As such, climate change mitigation proves an ancillary benefit of air pollution reduction, rather than the other way around.     

The importance of the design of market-based instruments for CO2 mitigation: An AGE analysis for Spain

In the past few decades, economists have defended the use of market-based instruments (MBI) in environmental and climate policy. There have been many papers which have compared the costs of attaining environmental objectives with MBIs and with command and control instruments. However very few have compared different MBIs in examining these costs. This paper seeks to analyse various MBIs for CO₂ mitigation from the viewpoint of cost-effectiveness, using an AGE (applied general equilibrium) model for the case of Spain. A distinction is drawn between (1) quantity instruments, which represent different extents of a market for emission permits; and (2) price instruments, which represent different types of tax. Each instrument can affect different segments of the emission sources and therefore can have very different effects on the economy as a whole. We show how MBI can help to minimise mitigation costs, but also how taxes and tradable emission permits that are limited or constrained by many exemptions and distortions can raise costs considerably.     

Climate Policy,Learning, and Technology Adoption in Small Countries

A significant reduction in global greenhouse gas emissions requires international cooperation in emission abatement as well as individual countries’ investment in the adoption of abatement technology. The existing literature on climate policy pays insufficient attention to small countries, which account for a substantial proportion of global emission. In this study, we investigate how climate policy and learning about climate damage affect investment in abatement technology in small countries. We consider three alternative climate policy instruments: emission standards, harmonized taxes and auctioned permits. We say that learning is feasible if an international environmental agreement (IEA) is formed after the resolution of uncertainty about climate damage. We find that, either with learning and quadratic abatement costs or without learning, harmonized taxes outperform emission standards and auctioned permits in terms of investment efficiency. Without learning, a large cost of nonparticipation (that a country incurs) in the IEA can be beneficial to the country. Whether learning improves investment efficiency depends on the size of this nonparticipation cost.     

Policy instruments for evolution of bounded rationality: Application to climate-energy problems

We demonstrate how an evolutionary agent-based model can be used to evaluate climate policies that take the heterogeneity of strategies of individual agents into account. An essential feature of the model is that the fitness of an economic strategy is determined by the relative welfare of the associated agent as compared to its immediate neighbors in a social network. This enables the study of policies that affect relative positions of individuals. We formulate two innovative climate policies, namely a prize, altering directly relative welfare, and advertisement, which influences the social network of interactions. The policies are illustrated using a simple model of global warming where a resource with a negative environmental impact—fossil energy—can be replaced by an environmentally neutral yet less cost-effective alternative, namely renewable energy. It is shown that the general approach enlarges the scope of economic policy analysis.     

CLIMATE CHANGE AND OVERLAPPING GENERATIONS

This paper examines the interplay between discounting and the distribution of welfare between generations in formulating climate change response strategies. The analysis shows that one can understand Nordhaus's (1994) standard representative agent model for climate policy analysis as a reduced form of an overlapping generations model that embodies more realistic demographic assumptions. In this setting, alternative Pareto efficient allocations may be supported as competitive equilibria given appropriate sets of income transfers between generations. Numerical simulations establish that increased intergenerational transfers entail reduced monetary discount rates and increased rates of greenhouse gas emissions abatement. Short-run policy choices are highly sensitive to normative judgments concerning the relative weight attached to the welfare of future generations.     

Trade Liberalization and Environmental Regulation on International Transportation

Incorporating pollution emissions from international transportation into a model of strategic trade and environmental policies, we investigate the effect of trade liberalization and environmental regulation on national welfare and the environment. Our model includes imperfectly competitive markets for international transportation and final products. We find that trade liberalization may reduce each country's welfare unless some level of environmental regulation on international transportation is in place. When international trade is liberalized initially, a mutual increase in the common emission tax rates may improve each country's welfare. However, when international trade is highly protected initially, imposing an emission tax may reduce welfare.     

Climate policy in Western Europe and avoided costs of air pollution control

Abatement of CO₂ emissions will be accompanied by reduced air pollutant emissions such as particulate matter (PM), SO₂, and NO_x. This, in turn, will reduce the need for end of pipe (EOP) pollution control technologies to meet future air quality targets. This dynamic could put more stringent air quality goals within reach, and increase the political feasibility of climate policy. This paper presents a CGE model that has been modified to include the emissions and EOP abatement of PM, SO₂, and NO_x from stationary sources in the EU-17. Emissions of pollutants are modeled as fixed-factor complementary inputs to their associated source. Abatement in each sector is modeled as a substitution between the pollutants and discrete abatement technologies, each of which is sector-specific and characterized by a marginal abatement cost and technical capacity constraint. Scenarios are run to 2020, to assess the costs and co-benefits of simultaneous air quality and climate policies. We find that under the Kyoto Protocol in 2010, the welfare cost of pollution control is reduced by 16% compared to the baseline, effectively offsetting the cost of CO₂ abatement by 15%. The co-benefit results depend heavily on policy choices, and their magnitude relative to total costs is likely to decline as greenhouse targets become more ambitious. In our scenarios, pollution control cost savings range from 1.3 to 20% in 2020, yielding a climate cost offset range of 0.2 to 3.9%. The CO₂ credit imports allowed by the EU via the Clean Development Mechanism (CDM) offer a total savings of $9.7bn in 2020, but only need to be compensated by an additional $0.3–0.4bn in domestic pollution control from stationary sources.     

气候变化对德国农业的影响与相关对策

本文分析和研究了气候变化对德国农业和林业的正反两方面的影响,肯定了德国农业和林业对气候保护、减少温室气体排放的积极作用。阐述了德国为减少温室气体排放采取的相应措施,如改进传统农业,扩大现代农业,大力生产可再生长原料,促进可再生能源的利用。这些做法对我国发展现代农业,促进农业和林业领域节能减排具有积极的参考作用。     

Greening Asia's Economic Development

Asia is facing serious environmental challenges including urban air pollution and the effects of global climate change. As a major source of greenhouse gases, what happens in Asia will play a crucial role in determining the extent to which the world warms over coming decades. This paper reviews key environmental challenges faced by the region and the growing opportunities for a transition to a cleaner economy powered by zero‐emission energy sources. Economic mechanisms – including emissions pricing, reverse auctions, and renewable portfolio standards with green certificate schemes – have the potential to underpin a much greener development model for the Asian Century.     

Climate policy vs. agricultural productivity shocks in a dynamic computable general equilibrium (CGE) modeling framework: The case of a developing economy

The main objective of this paper is to compare the cost of climate policy consistent with the 2 °C global warming target (Paris Agreement target) with the cost of climate change induced agricultural productivity shocks, using a recursive dynamic CGE model for India. The social cost of carbon, in terms of loss in agriculture sector, is estimated to be about 2 percent of GDP, at zero rate of discount, under conservative forecasts of fall in agricultural productivity. In comparison, the cost of climate policy consistent with the Paris Agreement target of 2 °C is about 1 percent of GDP. Thus, there is a strong case for the adoption of ambitious climate policy in India, provided other countries also adhere to the same. Besides, revenues generated from the carbon tax and emission allowance could be a means to support the development and adoption of new energy and agricultural technologies, to increase social sector expenditure and to reduce abatement costs.     

In or out: efficient inclusion of installations in an emissions trading scheme?

Regulators around the world are currently considering national emissions trading schemes (ETS) as cost-effective instruments to reduce greenhouse gas emissions. In the process, they are confronted with numerous design issues. The coverage of installations in an ETS is one such issue. While “blanket coverage” that includes all industrial emitters of greenhouse gases in an economy has some intuitive appeal, and seems equitable, it does not take into full account all the costs related to the extent of coverage. This paper shows that an alternative approach of “partial coverage” based on benefit–cost analysis can achieve the same emission reduction outcome at lower social cost. The approach is based on maximizing the benefits from inclusion of installations in an ETS at the same time as taking all relevant transaction costs into account. A broad definition of transaction costs is used, which covers the regulatory costs to the government as well as regulatory costs imposed on covered installations. We find that particularly for relatively modest emissions reduction targets the cost savings of a “partial coverage” compared to “blanket coverage” are significant.     

国际气候谈判中欧美分歧探析

国际合作是人类应对全球气候变化的必然选择。由于利益诉求的差异,各国(国家集团)在国际气候谈判中产生了激烈的矛盾碰撞,导致谈判进程举步维艰。欧美在国际气候谈判中的矛盾是制约谈判进程的关键障碍之一。欧美为维护国家(集团)竞争力和争夺气候谈判领导权,在对待气候变化问题的态度、温室气体减排和构建后京都时代国际气候机制等重大问题上存在着深刻的分歧。     

Time Preference, Stock Externalities and Strategic Reactions

This paper examines the relationship between the rateof time preference and strategic reactions in dealing with climate change caused by anthropogenic greenhouse gas (GHG) emissions. Treating climate change as stock externalities, the RICE model (Nordhaus and Yang [1996]) is employed in this paper for simulation studies. The simulation results show that when regions' rate of time preference in evaluating climatechange is sufficiently low, the paths of efficient GHGemission reduction measurement and the inefficient Nash equilibrium outcome are close. The paper also provides general interpretations of such phenomena. Finally, the implications of a low rate of time preference on GHG emission reduction policies are discussed.     

Greenhouse Gas Abatement Cost Curves of the Residential Heating Market: A Microeconomic Approach

In this paper, we develop a microeconomic approach to deduce greenhouse gas abatement cost curves of the residential heating sector. Our research is based on a system dynamics microsimulation of private households’ investment decisions for heating systems to the year 2030. By accounting for household-specific characteristics, we investigate the welfare costs of different abatement policies in terms of the compensating variation and the excess burden. We investigate two policies: (i) a carbon tax and (ii) subsidies on heating system investments. We deduce abatement cost curves for both policies by simulating welfare costs and greenhouse gas emissions to the year 2030. We find that (i) welfare-based abatement costs are generally higher than pure technical equipment costs; (ii) given utility maximizing households a carbon tax is the most welfare-efficient policy and; (iii) if households are not utility maximizing, a subsidy on investments may have lower marginal greenhouse gas abatement costs than a carbon tax.     

欧盟关于气候变化政策的新进展

本文分析了欧盟理事会2008年3月批准了欧盟气候与能源的一揽子行动计划的背景,提出：欧盟高度重视气候变化,除了因为气候变化已经日益影响人类的生活外,主要是基于自身能源、经济增长和就业的考虑。分析了欧盟实现减排的方式,更新的排放交易机制将是主要手段,还有发展可再生能源、提高能效、利用清洁发展机制,以及应用碳捕捉与储存技术等,指出：欧盟气候变化关键目标是“两个20％”,即：到2020年,温室气体排放至少减少20％,能源消费中可再生能源的份额占20％。