生物碳汇类型的特性研究

温室气体增加被认为是全球变暖的主要原因,CO2是大气中最重要的温室气体,在对温室效应和全球气候变暖的贡献中,占70％。为应对全球变暖,各国采取多种措施致力于温室气体的减排增汇。减少二氧化碳温室效应,除人工减排增汇外,自然界生态系统的生物碳汇功能起着主导作用。生物碳汇主要类型有森林等陆生植物碳汇、水生高等植物和低等植物碳汇、水生高等动物碳汇等等,各种类型生物碳汇功效不尽相同,各具特性。     

Global warming and economic externalities

Despite worldwide policy efforts such as the Kyoto Protocol, the emission of greenhouse gases (GHG) remains a negative externality. Economic equilibrium paths in the presence of such an uncorrected externality are inefficient; as a consequence, there is no real economic opportunity cost to correcting this externality by mitigating global warming. Mitigation investment using resources diverted from conventional investments can raise the economic well-being of both current and future generations. The economic literature on GHG emissions misleadingly focuses attention on the intergenerational equity aspects of mitigation by using a hybrid constrained optimal path as the “business-as-usual” benchmark. We calibrate a simple Keynes-Ramsey growth model to illustrate the significant potential Pareto improvement from mitigation investment and to explain the equilibrium concept appropriate to modeling an uncorrected negative externality.     

Impacts of Novel Protein Foods on Sustainable Food Production and Consumption: Lifestyle Change and Environmental Policy

We analyse the impacts of a change in consumers’ preference for Novel Protein Foods (NPFs), i.e. a lifestyle change with respect to meat consumption, and the impacts of environmental policies e.g. tradable emission permits for greenhouse gases (GHGs) or an EU ammonia (NH₃) emission bound per hectare. For our analysis we use a global applied general equilibrium (AGE) model that includes consumers’ lifestyle change, different production systems, emissions from agricultural sectors, and an emission permits system. Our study leads to the following conclusions. Firstly, more consumption of NPFs assists in reducing global agricultural emissions of methane (CH₄), nitrous oxides (N₂O) and NH₃. However, because of international trade, emission reduction does not necessarily occur in the regions where more NPFs are consumed. Secondly, through lifestyle change of the ‘rich’, the emission reduction is not substantial because more ‘intermediate’ consumers will increase their meat consumption. Finally, for the same environmental target the production structure changes towards less intensive technologies and more grazing under environmental policy than under lifestyle change.

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Development without energy? Assessing future scenarios of energy consumption in developing countries

We analyze the relationship between economic development and energy consumption in the context of greenhouse gas mitigation. The main contribution of this work is to compare estimates of energy thresholds in the form of minimum energy requirements to reach high levels of development with output projections of per capita final energy supply from a group of integrated assessment models (IAMs). Scenarios project that reductions of carbon emissions in developing countries will be achieved not only by means of decreasing the carbon intensity, but also by making a significant break with the historically observed relationship between energy use and economic growth. We discuss the feasibility of achieving, on time scales acceptable for developing countries, both decarbonization and the needed structural changes or efficiency improvements, concluding that the decreases in energy consumption implied in numerous mitigation scenarios are unlikely to be achieved without endangering sustainable development objectives. To underscore the importance of basic energy needs also in the future, the role of infrastructure is highlighted, using steel and cement as examples.     

A strategic analysis of global warming: Theory and some numbers

We model the global warming process as a dynamic commons game in which the players are countries, their actions at each date produce emissions of greenhouse gases, and the state variable is the current stock of greenhouse gases. The theoretical analysis is complemented by a calibration exercise. The first set of results establishes theoretically, and then with illustrative numbers, the over-emissions due to a “tragedy of the commons.” The power of simple sanctions to lower emissions and increase welfare is then examined as is the effect of cost asymmetry. Finally, a complete theoretical charactrization is provided for the best equilibrium, and it is shown that it has a very simple structure; it involves a constant emission rate through time.     

Policy Framework for Transition to a Low-Carbon World Economy

Climate change mitigation policy is the most difficult to come before our polity in living memory. There can be no solution without international agreement involving all substantial economies, and yet each country has an incentive to free ride on others. The international agreement must have five parts: agreement on the objective in terms of concentrations of greenhouse gases in the atmosphere, agreement on allocation of an emissions entitlements budget among countries, agreement on rules for international trade in entitlements, agreement on developed countries taking the lead on development of low-emissions technologies, and agreement on assistance from developed countries for climate change mitigation in developing countries. Two sources of market failure must be corrected to achieve emissions reduction targets efficiently: the external costs of emitting greenhouse gases and the external benefits of private investment in innovation in relation to low-emissions technologies.     

International trade and the negotiability of global climate change agreements

This paper examines the incentives for individual countries to engage in global negotiations to reduce carbon emissions in order to prevent global warming. To reduce carbon emissions a country reduces consumption of its own good. The direct effect of reducing its own consumption is that consumption declines and with it utility. However, reducing carbon emissions also lowers global temperatures and that increases utility. The trade-off between these two effects determines the incentive for countries to reduce carbon emissions. We find that larger countries are more likely to participate because a given percentage reduction in output will result in a larger reduction in global temperatures. Longer time horizons also lead to greater willingness to participate. The presence of international trade makes carbon reduction agreements more likely because reducing the output of your own (export) good has a positive terms of trade effect which reduces the cost of output reduction.     

Stochastic Divergence or Convergence of Per Capita Carbon Dioxide Emissions: Re-examining the Evidence

This paper revisits the time-series literature on the convergence of per capita carbon dioxide (CO₂) emissions and examines the robustness of previous results. Using a sample of OECD countries for the period 1950–2002 we employ a battery of stationarity and unit root tests including those that allow for cross-sectional dependencies within the panel. We also correct for inaccuracies in previous studies that could result in a trend-stationary series being labelled as converging even if it were actually diverging from the international average. The body of evidence provided by our analysis suggests that per capita CO₂ emissions have not converged among OECD countries during the period under consideration. This finding is of importance to both climate change policy makers and to those who construct climate change models.      

Uncertainty,Learning and International Environmental Policy Coordination

In this paper we construct a simple model of global warming which captures a number of key features of the global warming problem: (i) environmental damages are related to the stock of greenhouse gases in the atmosphere; (ii) the global commons nature of the problem means that these are strategic interactions between the emissions policies of the governments of individual nation states; (iii) there is uncertainty about the extent of the future damages that will be incurred by each country from any given level of concentration of greenhouse gases but there is the possibility that at a future date better information about the true extent of environmental damages may become available; an important aspect of the problem is the extent to which damages in different countries may be correlated. In the first part of the paper we consider a simple model with two symmetric countries and show that the value of perfect information is an increasing function of the correlation between damages in the two countries in both the cooperative and non-cooperative equilibria. However, while the value of perfect information is always non-negative in the cooperative equilibrium, in the non-cooperative equilibrium there is a critical value of the correlation coefficient below which the value of perfect information will be negative. In the second part of the paper we construct an empirical model of global warming distinguishing between OECD and non-OECD countries and show that in the non-cooperative equilibrium the value of perfect information for OECD countries is negative when the correlation coefficient between environmental damages for OECD and non-OECD countries is negative. The implications of these results for international agreements are discussed.     

国际碳交易的经济学理论分析

二氧化碳等温室气体的过度排放造成的全球气温上升已经威胁到人类的生存和发展。对国际碳交易的内涵及经济学理论进行了分析,对深入理解、研究国际碳交易理论基础和实践经验具有非常现实的作用和意义。     

The process and a simple logic of ‘meso’. Emergence and the co-evolution of institutions and group size

‘Summing-up’ aggregation of micro decisions contrasts with structural emergence in complex systems and evolutionary processes. This paper deals with institutional emergence in the ‘evolution of cooperation’ framework and focuses on its size dimension. It is argued that some ‘meso’ (rather than ‘macro’) level is the proper level of cultural emergence and reproduction. Also Schumpeterian economists have discussed institutions as ‘meso’ phenomena recently, and Schelling, Axelrod, Arthur, Lindgren, and others have dealt with ‘critical masses’ of coordinated agents and emergent segregations. However, emergent group size has rarely been explicitly explored so far. In an evolutionary and game-theoretic frame, ‘meso’ is explained in terms of a sustainably cooperating group smaller than the whole population. Mechanisms such as some monitoring, memory, reputation, and active partner selection loosen the total connectivity of the static and deterministic ‘single-shot’ logic and thus allow for emergent ‘meso’ platforms, while expectations ‘to meet again’ remain sufficiently high. Applications of ‘meso-nomia’ include the deep structure of ‘general trust’ and macro-performance in ‘smaller’ and ‘well networked’ countries which helps to explain persistent ‘varieties of capitalism’.     

The political economy of global carbon emissions reductions

The discussion about what reductions in greenhouse gas emissions are required and how the emissions rights might be distributed globally has fostered the belief that there is a fundamental conflict between the rich nations of the “North” and the poor but populous nations of the “South.” The argument is that grandfathering the rights will only reinforce existing global inequalities, while per capita distribution of the rights would lead to such huge transfers of wealth to the South as to be unacceptable to the North. However, a very simple general equilibrium model highlighting key elements of the global economy shows that this perception is incorrect under a plausible interpretation of the goal of the United Nations Framework Convention on Climate Change to “avoid dangerous anthropogenic interference with the climate system.” Instead of using an economic damage function to determine the optimal level of emissions reductions, the model's utility functions are calibrated to reflect scientific understanding of what would be required to stabilize the atmosphere at safe concentrations of greenhouse gases. Among policy options that would accomplish this, the United States has a preference for grandfathering the allocation of emissions rights over a per capita allocation, but this preference is not strong and could be offset by other geopolitical considerations.     

Alternative evolutionary theories: A historical survey

Our overview has the objective of making our study relevant to bioeconomists. The need for the ‘alternatives’ to the Synthetic Theory of Evolution in social-economic studies was substantiated, for example, by Colombatto (Journal of Bioeconomics, 5, 1–25, 2003), who maintains that the natural-selection theory is ‘ill suited’ to describing evolutionary processes in economics. He proposed an alternative ‘non-Darwinian’ approach by equating the ‘non-Darwinian’ approach with a definite version of neo-Lamarckism. Yet, as we will show, there is a palette of alternative approaches within and beyond the neo-Lamarckism. We hope to give bioeconomists more choice in their theoretical modeling and constructing of analogies between biology and economics. It will also be shown that in the light of suggested definitions the concept of ‘universal Darwinism’ recently discussed in bioeconomics makes little sense as a generalizing category. In addition, in the concluding part of the paper we demonstrate that the majority of alternative approaches are far from being pigeonholed as archaic and once and for all wiped off the theoretical landscape. On the contrary, in recent years one can observe some revival of interest in the theoretical ‘heresies’.      

辽中县低碳农业现状分析和发展思路的探讨

全球气候变暖的趋势下,世界各国都在寻找与之相关解决方式,调整经济发展战略。农业生产与全球气候变化息息相关,农业是温室气体的第二大重要来源,如何减少农业温室气体排放量已成为当务之急。县域经济中农业占有相当大的比重,如何在县域农业中发展低碳农业,也已成为新农村建设研究的新课题。通过调查研究、现场走访的方式,总结了辽中县种植业、畜牧业、农副产品加工及农业旅游等的现状,发现县内在低碳农业方面的工作存在明显不足,根据这些实际情况提出了发展低碳农业的对策及具体措施,如发展新能源和设施农业等,旨在改善辽中县农村生态环境,为新农村建设提供科学决策,促进现代农业由高碳经济向低碳经济转型。     

我国未来人口发展与碳排放变动的模拟分析

构建人口-消费-碳排放系统动力学模型,对本世纪上半叶我国人口发展、经济增长、居民消费及碳排放进行动态仿真,定量考察未来我国人口发展与居民消费对碳排放的影响。在基准情景下,我国人口总数将于2032年达到峰值14.6亿人;一次能源消费总量将于2044年左右达到峰值63.6亿吨标准煤,碳排放总量将于2038年左右达到峰值约31.3亿吨碳;2050年我国人均碳排放量约为2.2吨碳,低于日本、欧洲1980年代以来的最低水平;居民消费碳排放的人均需求约为1.3吨碳,相当于美国居民1990年代后期排放水平的五分之一。从满足人口发展与居民基本生活需求的角度争取合理的碳排放空间,是我国争取国际气候谈判话语权的有力支撑点。     

Driving forces of global carbon emissions: From time- and spatial-dynamic perspectives

Up to date, collective efforts in greenhouse gas mitigation made by the international community have been rather ineffective. A major reason of the unsuccessfulness may be attributed to imprecise comprehension on the sources of greenhouse gas pollution and their changing dynamics. Utilizing the LMDI decomposition method, this paper investigates the time- and spatial-dynamics of drivers governing global carbon emissions. We decompose and quantify the effects of different drivers, that is, population, affluence, energy intensity and carbon intensity, across time on global carbon emissions. Next based on country-level decomposition, we also calculate and track the spatial gravity centers of the effects of the drivers. Our results show that energy intensity effect is the leading contributor for carbon emission mitigation, whereas economic development, carbon emission intensity and population serve as factors accelerating carbon emissions. We also find significant heterogeneities in the spatial dynamics of the contribution of different drivers, implying that differentiated climate change policies should be made at different countries to effectively curb global carbon emissions.     

Climate policy targets in emerging and industrialized economies: the influence of technological differences, environmental preferences and propensity to save

Although emerging economies claim that industrialized countries need to reduce their carbon emissions first, stabilization of the future global climate system requires immediate action by all countries. In a stylized two-country intertemporal general equilibrium model, we derive welfare maximizing emission caps in emerging and industrialized countries, taking account of country differences in technology, environmental preferences and propensity to save. Simultaneous target setting is compared to a sequential one in which the industrialized country commits itself to binding targets first. In the latter case, when the industrialized economy has stronger environmental preferences and a lower relative pollution production share, the industrialized economy can increase its joint economic and environmental welfare by setting a laxer target. On the other hand, when the emerging economy has considerably higher environmental preferences, our results suggest that the industrialized economy will choose a more restrictive target in a sequential setting than in a simultaneous one, contrary to first thought that a first mover is always pursuing a ‘symbolic’ policy with a lax target.     

The opportunity cost of land use and the global potential for greenhouse gas mitigation in agriculture and forestry

This paper analyses the role of global land management alternatives in determining potential greenhouse gas mitigation by land-based activities in agriculture and forestry. Land-based activities are responsible for over a third of global greenhouse gas emissions, yet the economics of land-use decisions have not been explicitly modeled in global mitigation studies. In this paper, we develop a new, general equilibrium framework which effectively captures the opportunity costs of land-use decisions in agriculture and forestry, thereby allowing us to analyse competition for heterogeneous land types across and within sectors, as well as input substitution between land and other factors of production. When land-using sectors are confronted with a tax on greenhouse gas emissions, we find significant changes in the global pattern of comparative advantage across sectors, regions, and land types. Globally, we find that forest carbon sequestration is the dominant strategy for GHG emissions mitigation, while agricultural-related mitigation comes predominantly from reduced methane emissions in the ruminant livestock sector, followed by fertilizer and methane emissions from paddy rice. Regionally, agricultural mitigation is a larger share of total land-use emissions abatement in the USA and China, compared to the rest of the world, and, within agriculture, disproportionately from reductions in fertilizer-related emissions. The results also show how analyses that only consider regional mitigation, may bias mitigation potential by ignoring global market interactions. For example, USA-specific analyses likely over-estimate the potential for abatement in agriculture. Finally, we note that this general equilibrium framework provides the research community with a practical methodology for explicit modeling of global land competition and land-based mitigation in comprehensive assessments of greenhouse gas mitigation options.     

The Study of Ethnicity and Nationalism Needs Better Categories: Clearing up the Confusions that Result from Blurring Analytic and Lay Concepts

Synopsis It has been difficult to make progress in the study of ethnicity and nationalism because of the multiple confusions of analytic and lay terms, and the sheer lack of terminological standardization (often even within the same article). This makes a conceptual cleaning-up unavoidable, and it is especially salutary to attempt it now that more economists are becoming interested in the effects of identity on behavior, so that they may begin with the best conceptual tools possible. My approach to these questions has been informed by anthropological and evolutionary-psychological questions. I will focus primarily on the terms ‘ethnic group’, ‘nation’, and ‘nationalism’, and I will make the following points: (1) so-called ‘ethnic groups’ are collections of people with a common cultural identity, plus an ideology of membership by descent and normative endogamy; (2) the ‘group’ in ‘ethnic group’ is a misleading misnomer—these are not ‘groups’ but categories, so I propose to call them ‘ethnies’; (3) ‘nationalism’ mostly refers to the recent ideology that ethnies—cultural communities with a self-conscious ideology of self-sufficient reproduction—be made politically sovereign; (4) it is very confusing to use ‘nationalism’ also to stand for ‘loyalty to a multi-ethnic state’ because this is the exact opposite; (5) a ‘nation’ truly exists only in a politician’s imagination, so analysts should not pretend that establishing whether something ‘really’ is or is not ‘a nation’ matters; (6) a big analytic cost is paid every time an ‘ethnie’ is called a ‘nation’ because this mobilizes the intuition that nationalism is indispensable to ethnic organization (not true), which thereby confuses the very historical process—namely, the recent historical emergence of nationalism—that must be explained; (7) another analytical cost is paid when scholars pretend that ethnicity is a form of kinship—it is not.