Modified ecological footprint accounting and analysis based on embodied exergy—a case study of the Chinese society 1981–2001

EC O L O G IC A L E C O N O M IC S 6 1 ( 2 0 07 ) 35 5 –3 76

a v a i l a b l e a t w w w. s c i e n c e d i r e c t . c o m

w w w. e l s e v i e r. c o m / l o c a t e / e c o l e c o n

ANALYSIS

Modified ecological footprint accounting and analysis based on embodied exergy—a case study of the Chinese society 1981–2001 B. Chen, G.Q. Chen⁎ National Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, Peking University, Beijing 100871, China

AR TIC LE I N FO

ABS TR ACT

Article history:

The resource consumption of the Chinese society from 1981 to 2001 is investigated by

Received 23 June 2005

ecological footprint (EF) as an aggregate indicator. Based on the theory of ecological

Received in revised form

thermodynamics, a modified calculation of ecological footprint termed as embodied exergy

3 March 2006

ecological footprint (EEEF) in contrast to the conventional one is performed and related

Accepted 4 March 2006

overall trends of the Chinese society 1981–2001 are analyzed. The annual policy for the

Available online 2 May 2006

individual sector is described in detail corresponding to the EF and EEEF components. Comparison of the conventional EF and the EEEF based on different views of ecological

Keywords:

production is outlined. The EF intensity and EEEF intensity are also presented to depict the

Ecological footprint

resource consumption level corresponding to unit economic output. Finally, EEEF is

Embodied exergy

suggested to serve as a modified indicator of EF towards illustrating the productions of

Resource consumption

the resource, environment, population and thereby reflecting the ecological overshoot of the general ecological system. © 2006 Elsevier B.V. All rights reserved.

1.

Introduction

There is ecological limit which cannot be exceeded concerning sustainability, posing unparalleled challenges on each level of the ecological system. Therefore, natural capital accounts focused on biophysical limits are increasingly prominent. Meanwhile, there is a felt need for the scarce productive land to support the social–economic–ecological complex system.

1.1.

Ecological footprint

Vitousek et al. (1986) attempted to determine the human economy's draw on terrestrial net primary productivity and estimate the magnitude of human appropriation of the products of photosynthesis. The total estimation made by

Vitousek is regarded as a conceptual predecessor of the EF, which assesses the relationship between the human and the resource (Wackernagel and Monfreda, 2004). Wackernagel and Rees (1996, 1997) proposed the ecological footprint (EF hereafter) as an indicator of the carrying capacity of regions, nations and the globe, and sometimes extended it as an indicator of sustainability. As is defined by Wackernagel and Rees (1996, 1997), the EF is the aggregate area of land and water in various ecological categories that is claimed by participants in that economy to produce all the resources they consume, and to absorb all their wastes they generate on a continuous basis, using prevailing technology, and later, the concept is modified a little as a measure of how much biocapacity a population, organization or process requires to produce its resources and absorb its waste using prevailing technology (Wackernagel and

⁎ Corresponding author. Tel.: +86 1062767167; fax: +86 1062750416. E-mail address: [email protected] (G.Q. Chen). 0921-8009/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.ecolecon.2006.03.009

356

EC O LO GIC A L E CO N O M ICS 6 1 ( 2 00 7 ) 3 5 5 –3 76

Monfreda, 2004). Wackernagel and Silverstein (2000) believed that the EF was consistent with the basic thermodynamic principles, thereby avoiding arbitrary weighting. In addition, as Wackernagel and Monfreda (2004) emphasized, ecological overshoot is the core concept of the sustainability, i.e., the natural capital is harvested faster than it regenerates, which leads to depleting the resource stock. Unlike the optimists of technology who think technical progress will reduce the ecological deficit or promote the carrying capacity, the technological advances seem to mask the increasing resource scarcity more than solve it (Wackernagel and Silverstein, 2000). Although the EF has been widely regarded as an effective and easy tool to measure the consumption of the resource and carrying capacity, an extensive academic debate on the interpretation of the EF emerged. Fora for the EF were therefore provided in Ecological Economics and some commentaries and thoughtful discussions were presented (Bergh and Verbruggen, 1999; Wackernagel et al., 1999; Costanza, 2000; Ayres, 2000; Deutsch et al., 2000; Herendeen, 2000; van Kooten and Bulte, 2000; Moffatt, 2000; Opschoor, 2000; Rapport, 2000; Rees, 2000; Simmons et al., 2000; Templet, 2000; Rees, 2000; Wackernagel and Silverstein, 2000; van Vuuren and Smeets, 2000). Whether it can be regarded as a single dimension to measure ecological carrying capacity, sustainability or a basis for equity is still in debate. The EF, at the very least, reflects the human appropriation of ecological system bioproductive areas followed the traditional geography and ecology. As a tool for communicating human dependence on life-support ecosystems (Deutsch et al., 2000), the EF approach can serve as a simple and vivid indicator of ecological evaluation on natural capital and normalize different type of bioproductive area into common units of global hectares. There are some potential improvements in the current EF method. First, as Bergh and Verbruggen (1999) pointed out, the physical consumption-land conversion factors function as implicit weights in the conversion as well as the aggregation, which impede the application of EF as an objective indicator in ecological evaluation without any arbitrary components. Second, ecological evaluation indicator should reflect both the quantity and quality of the resource, not just a hypothetical land area derived from the quantity of biomass produced from different types of bioproductive areas, and thus cannot distinguish the physical ecological degradation, lost and cost in natural capital, whereas the resource quality is the intrinsic value of the ecological products and the core of the sustainable or unsustainable development mode of the ecological system, e.g., land system. Third, to avoid the debate on the land required to absorb carbon (Ayres, 2000), alternative method should be presented to determine the ecological footprint caused by energy, especially fossil fuels. Although the energy produced from nuclear electricity and renewable resources, such as wind power, water power, photovoltaic and tide power, etc. are roughly investigated by Wackernagel and Monfreda (2004), the related estimation is based on some local case studies, which is still uncertain for the other regions or nations. Finally, as Wackernagel and Monfreda (2004) indicated, embodied energy should be considered, especially the free energy source dominated by the energy embodied in most renewable resources infrastructure.

In fact, although Erb (2004) assessed the EF based on actual area demand which is expressed in physical hectares based on the country-specific yields contrary to the conventional EF approach, the global average hectare is more necessary and valuable in view of the system ecology, for the regions and nations are not isolated in a integrated global ecological system, in which they interacted with and sustained each other through the “share of globally available biocapacity”. Moreover, how to determine the system and environment is the crucial point to assess the validity of EF as an indicator of ecological evaluation. With respect to the time and length scales, depending on the researcher's objectives and knowledge, the sense of the EF can be interpreted in different ways as a unified indicator. With the fundamental time scale of the ecospherical evolution and space scale of the global earth, the EF can serve as an indicator of sustainability, for each global hectare as ecological component is formed and sustained by the others. Meanwhile, on the smaller time and space scales, e.g., nation or region level, the EF can be regarded as an indicator for ecological competitive power, for the limited commodities appropriated by the human and the “actual land area” human demanded are out of consideration for the anthropogenic, temporary and local economic views, not the earth-centered ecocentrism (Chen, 2005, 2006). As Wackernagel et al. (2004a) indicated, the EF can be measured by either consumption or production. Associated with the EF based on consumption, the concept “ecological deficit” is proposed, whereas the concept “ecological overshoot” is presented based on production. Considering a country with much less net import compared to the domestic production, which can be termed as “production-based” country, the concept “ecological overshoot” is more appropriate to reflect the ecological resource depletion of the country. On the other hand, regarding a country with much more net import compared to the domestic production, which is termed as “servicebased” country, the concept “ecological deficit” seems to describe the seized resource fraction of the country from the “global ecological hectare share”, which should be understood as ecological competitive power. As Vitousek et al. (1997) emphasized, the use of land to yield goods and services represents the most substantial human alteration of the structure and function of the Earth ecosystem, which is necessary to be measured aggregately. The conventional EF method roots in the “land production” perspective, of which the ecological input of the system, e.g., globe, nation and region, includes all resources transformed by the bioproductive areas. Considering a larger productionsupporting scope, the concept of the ecological input can be extended and the EF method thereafter be generalized in the “environment production” perspective. Except for the free natural resources, the emission associated with environmental impact that is necessary to be assimilated by the parallel environment to support the production procedure, termed as sink capacity by Nelson (1995), can be defined as the virtual environmental input for the concerned system, which acted as an additional arm to Odum's three-arm production diagram (Odum, 1996), combining the natural resource input as the sum of the total ecological input. Based on the classification of different subjects, the ecological system can be classified as human-dominated

EC O L O G IC A L E C O N O M IC S 6 1 ( 2 0 07 ) 35 5 –3 76

system and the related environment, of which the production of the human-dominated system can be further divided into economic production and population production. The “ecological overshoot” refers to the ecological production status, indicating difference between economic production and environment production of certain population production. The different productivities of the human-dominated system and the related environment make the general ecological system, embracing both the human-dominated system and the related environment, develop in an unbalanced way. The ecological system has a ecological carrying capacity, or in a more accurate term as buffering capacity, considering the ecological system is resilient and the quantity of carrying capacity varies with the human innovation and biological evolution (Arrow et al., 1995). It should be noted that the carrying capacity refers to the capacity concentrating on the biophysical dimension and excluding the social and political dimensions in this paper (Daily and Ehrlich, 1996). Since the economic production is constantly expanding with the progress of technology, the boundary of the environment is always waning, with more and more environmental resources previously invested in the environment production being explored and utilized by the economic production system, as well as the increasing population. Due to the buffering capacity of the total ecological system, the growth of the economic production can be continued for a period of time, being masked by the apparently growing available resources. However, the primary input of the ecological system, i.e., the incipient exergy flow from the sun to the material earth, of which only 1% magnitude can be appropriated as the global cosmic exergy consumption, has definite limit estimated by Chen (2005). When the scales of the economic production, environment production and population production exceed much more than the ecological input and the stored exergy such as that in mineral fuels, the ecological system will eventually collapse, which is the long-term result of the overshoot status. Therefore, the unbalance development of three productions of the general ecological system, which often masks the real resource depletion, environment degradation and population growth, should be distinguished from the overshoot status of the general ecological system, which results in the final collapse. The environment supporting the production in this paper contains resources of large-scale earth processes with slow turnover times. Thus, the ecological carrying capacity approximately is assumed to be constant in the short-term time series of the EF calculation, indicating the ecological carrying capacity per capita varies only with the population. Time series research on EF has been done in order to “track” the amount of natural resource a population used in related to the carrying capacity of the ecological system of a region, nation or the globe (e.g., Haberl et al., 2001; Wackernagel et al., 2004a,b; Erb, 2004). Meanwhile, considering the environmental window of the ecological system, the amount of the previously used-up (directly or indirectly), available energy in the transformation process (Odum, 1988, 1996) referred as “energy memory” to make the product requires to be analyzed in a system ecology view in order to “track” both the quality and quantity of the resource used and embody the degraded available energy through the ecological system in organized

357

hierarchy. Thereafter, the ecological value is determined by the embodied energy in the ecologically average sense associated with the concerned time and spatial scales. Corresponding to the potential improvements of the EF method mentioned above, this paper proposes an embodied exergy theory of ecological value to complement the conventional EF approach. Stem from the energy theory of value as complement of the neoclassical theory of value (Odum, 1971, 1983; Odum and Brown, 1975; Costanza, 1980, 2000; Costanza and Herendeen, 1984; Costanza et al., 1997; Cleveland et al., 1984; Cleveland, 1999; Cleveland and Stern, 1999), the basic concepts and theory of emergy, exergy and embodied exergy are presented in the following subsections. The modified EF method, serving as a vivid and powerful quantitative indicator, will probe into the relationships among three points of a triangle, standing for population production, economic production and environment production, respectively.

1.2.

Embodied energy, exergy and embodied exergy

Cleveland analyzed the biophysical model of scarcity and traced the development of the biophysical economics from physiocracy to ecological economics and industrial ecology (Cleveland, 1999; Cleveland and Stern, 1999). As is shown in Cleveland's analysis, the Physiocrats hold the principle that economic production was subject to ‘Natural Law’, consisting of moral law and physical laws, and decided by the single physical factor focused on the productivity of agricultural land, neglecting the other energy resources and inorganic materials that do not come from agricultural land. Particularly, in Quesnay's view, land is the unique source of wealth. The core point of the physiocrats is that the source of wealth comes from ‘land production’ that is dominated by biophysical principles and the wealth can be reduced to land. Adam Smith also considered agriculture as a source of energetic matter feeding the human and animal population. However, the emphasis of the economic production was shifted to the labor and the factors contributing to labor productivity. Meanwhile, the idea of "work" as a universal measure of value and the notion of work as equivalent to effort or pain prevailed (Christensen, 2004). In addition, Podolinsky was the first explicitly to measure the ratio of the output and input in land production of agriculture from thermodynamic perspective. The biophysical analysis of the production process reconciled the labor theory of value with the thermodynamics and led to the conclusion that it is the physical and ecological limits governed the production, not the relationship of production proposed by Marx (Cleveland, 1999; MartinezAlier and Schlüpmann, 1990). In the late 1970s, Odum realized that wealth roots in the available energy related to environment, in which myriad systems and processes and that the value of services and commodities should be based on the energy required to produce them. To aggregate the value of ecological products, services and information into a common unit, a systematic ecological evaluation approach based on a concept of emergy was first proposed by Odum and Brown (1975) and Odum (1983, 1988, 1996). Emergy was regarded as “energy memory” to evaluate the direct and indirect work previously done to make a product or service, which was described as the

358

EC O LO GIC A L E CO N O M ICS 6 1 ( 2 00 7 ) 3 5 5 –3 76

available energy, that is, exergy (Odum, 1988). Also, the maximum power principle stem from Darwin's theory of natural selection and Lotka's hypothesis of natural selection as an energy-maximum process was suggested by Odum. The economic value, argued by Odum, is reduced to solar energy, considering the fact that money and energy flow in the opposite direction in the economy. Moreover, the renewable energy resources of solar radiation, precipitation, wind, wave and so on are internalized in the economic production. Systems with various scales have been evaluated by emergy analysis (Campbell, 1997; Higgins, 2003; Odum et al., 1987a,b; Pillet and Odum, 1984; Ulgiati et al., 1994, 1995; Ulgiati and Brown, 1998,1999). Costanza (1980) analyzed the direct and indirect energy required to produce goods and services in the U.S. economy. The total energy required for the production of economic or environmental goods and services, termed as embodied energy, is presented to link the ecological and economic systems as an attempt to internalize the factors, especially natural resources, which are external to the existing economic system, indicating that market-determined dollar values and embodied energy values are proportional for all but the primary energy sectors with appropriate system boundaries. Two basic assumptions are made to construct the embodied energy theory of value that measures the cost of production from a biophysical perspective (Cleveland, 1999). In addition, solar exergy as one principal net input of the earth, is regarded as the unique and ultimate limiting factor of the production and cannot be created or recycle, but dissipated, within the system boundary, whereas it is not the case for the other factors of production, land, labor, capital and technology that are interdependent (Huettner and Costanza, 1982). Furthermore, Cleveland et al. (1984) asserted that production was the economic process that upgraded the organization level of goods and services, depending on the availability of free energy, and, therefore, the biophysical constraints imposed on economic production should be accounted so as to modify the former standard economic models. Almost at the same time, Szargut developed a method for calculating the chemical exergy, dealt with exergy analysis of typical thermal processes, and the economic and ecological implication of exergy, thus gave rise to the analysis of cumulative exergy consumption and cumulative exergy losses, which in turn introduced the concepts of thermal– ecological cost and thermal–ecological economy based on the requirement of minimization of the depletion of non-renewable natural resources (Szargut, 1980, 1989, 2004; Szargut and Morris, 1985; Szargut et al., 1971, 2002). Wall (1977, 1986) introduced the concept of exergy, which is a unified measure of matter, energy and information, into resource accounting. Sciubba addressed five production factors including capital, labor, energy, material and environmental remediation costs for sustainability issues and proposed extended exergy accounting (EEA) to provide a unified assessment to converse the non-energetic expenditures, e.g., capital and labor, and the environmental remediation cost concerned as externalities in thermo-economics, into resource consumption indices (Sciubba, 1998, 2001a,b, 2003, 2004, 2005). Thereafter, Farber et al. (2002) elucidated that available energy (or termed as exergy) is the basic commodity and

ultimately the only scarce factor of production which cannot be substituted, satisfying the production-based theory and thereby determining the exchange value. The energy-based concepts of value have to follow the thermodynamic principles. Furthermore, not only the energy content, but also the organization degree, order corresponding to the environment should be considered. Therefore, scarcity, irreplaceability and availability construct the infrastructure of the indicators or concepts to assess the ecological system services. Exergy for a given system is defined as the maximal amount of work that can be extracted from the system in the process of reaching equilibrium with its local environment, chosen to have a direct bearing on the behavior of the system with respect to the time and length scales, depending on the observer's objectives and knowledge (Jørgensen, 1992a,b, 1994, 1999, 2000, 2001; Jørgensen et al., 1995, 1999, 2000; Chen, 2005, 2006; Szargut, 1980; Wall, 1977, 1986) that is, tot Ex ¼ T0 ðStot eq −S Þ

ð1Þ Stot eq

and Stot where T0 is the temperature of the environment, are the entropies in thermodynamic equilibrium and at the given deviation from equilibrium, respectively, of the total system as a combination of the given system and the local environment. The exergy content of different energy and material resources is represented in detail by Wall (1977, 1986). The chemical exergy of substances and materials is given below: Ex ¼

X i

ni ðli −li0 Þ þ RT0

X i

ni ln

ci ci0

ð2Þ

where T0 is the temperature of the environment, ni is the ith mole number, μi is the chemical potential of substance i in its present state, μi0 is the chemical potential of substance i in its environmental state, ci is the chemical concentration of substance i in its present state and ci0 is the chemical concentration of substance i in its environmental state. It can be seen from the definition of exergy that the magnitude of the exergy of a system is dependent on the states of both the system and the environment. Regarding the resource level, exergy represents the physical maximum work which can be extracted from the system when it interacts with the environment. Thus, the definition, calculation and assessment of the resource depend on the determination of the boundary between the system and the environment. Different boundaries lead to different concepts of resource. The system and the environment are determined at the same time. Exergy stands facing both the system and the environment, revealing the differences between the system and the environment, which indicate the essence of the resource. Resource enters into the society and becomes commodity. Exergy accounting provides a convenient way to unify and measure different types of materials and energy and evaluate the quality of the resources and degradation in the conversion. Research on exergy conversion in the society has been done for Sweden, Italy, Japanese, Norway, Canada, Brazil, Turkey, China and the U.S. (e.g., Wall, 1990, 1997; Wall et al., 1994; Rosen, 1992; Ayres et al., 1998, 2003; Ertesvåg and Mielnik, 2000; Ertesvåg, 2001, 2005; Sciubba, 1995, 2003, 2005; Milia and Sciubba, 2006; Chen and Chen, 2006). Exergy associated with a system may also play distinctive roles as buffering capacity

EC O L O G IC A L E C O N O M IC S 6 1 ( 2 0 07 ) 35 5 –3 76

and environmental impact, considering the subjective for observer, system and environment, respectively. For the observer stand facing both the system and the local environment, exergy can server as a unified measure of the real resource availability. For the system itself, exergy is regarded as the global buffering capacity (Mejer and Jørgensen, 1979; Jørgensen, 1981; Dincer, 2002; Dincer et al., 2004) and, in the meantime, exergy may also record the environment impact made by the system on the local environment (Wall, 1998; Wall and Gong, 2001a,b; Sciubba, 1999, 2001a,b). Finally, the concept, embodied exergy as a kind of embodied energy, is thereafter proposed as the appropriate indicator of evaluating the total resource consumption and economic output. The scarcity of exergy in the earth, based on a systematic study on the global exergy consumption of the earth and a budget of the exergy consumption with respect to main terrestrial processes is represented (Chen, 2005, 2006). Conceptual framework for ecological evaluation is also proposed based on the embodied exergy, defined as positive and equal to the cosmic exergy directly or indirectly used in making a product or service, or as negative and with a magnitude of the cosmic exergy directly or indirectly in need for the natural reduction or technical treatment of an emission. Cosmic exergy is the fundamental natural resource for driving and sustaining the ecosphere and the human society. The scarcity of cosmic exergy availability on the earth is of great implications on the sustainable development. Therefore, embodied exergy can be regarded as a general unified measure in ecological evaluation. The resource scarcity, cosmic exergy scarcity and relative discussion are presented and the detailed mechanism governing transformation between cosmic exergy and terrestrial exergy is also explored in Chen's work (Chen, 2005, 2006). Based on the overall exergy budget of the earth system and the scarcity of the exergy availability as the fundamental natural resource of the earth system with essential implication to the problem of global sustainability, this paper outlines a conceptual framework with corresponding numeraire for the EF analysis on the fundamental, global scarcity of the cosmic exergy availability revealed by the cosmic exergy consumption of the earth. Therefore, EFs of a region, nation or the globe, are found determined by the cosmic exergy consumed in the ecological chain, as a whole from the very beginning level of solar and cosmic background microwave (CBM) radiations to the final level in the ecosphere or human society, of the formation of the product, referred to as embodied exergy, as a revision of Odum's solar emergy in terms of replacing the embodied energy assessment by an embodied cosmic exergy assessment, and a generalization of Szargut's cumulative exergy in terms of extending the assessment baseline from natural resources in traditional sense, such as fossil fuels, to the cosmic exergy as the basic ecological resource in its fundamental sense.

2.

Methodology

Researches on the EF in the society have been done in Austria, Philippines, South Korea, Benin, Bhutan, Costa Rica, the

359

Netherlands, etc., where method of EF application and assessment of sustainability are presented and discussed (e.g., Wackernagel and Rees, 1996, 1997; Wackernagel and Richardson, 1998; Wackernagel et al., 1999, 2004a,b; Monfreda et al., 2004; van Vuuren and Smeets, 2000; Haberl et al., 2001; Kratena, 2004; Stöglehner, 2003; Senbel et al., 2003; McDonald and Patterson, 2004; van Vuuren and Bouwman, 2005; Fricker, 1998). Chen et al. (2004) estimated the per capita EF between 1981 and 2000 in China based on the conventional EF method proposed by Wackernagel and Rees (1996). Moreover, Faucheux and O'Connor (1998) briefly suggested that measures of trade balances in exergy or embodied energy terms could easily be constructed concerning the National eMergy Surplus (NES). This paper follows two distinct strategies to study the EF of the Chinese society from 1981 to 2001. First, we follow the conventional EF approach based on global hectares with some latest improvements suggested by Wackernagel and Monfreda (2004) and Wackernagel et al. (2004a). Second, we modify Wackernagel's approach and investigate the EF based on embodied exergy. For the national-scale system, which is defined as the political border, the embodied exergy footprint contains the imported, gathered, constrained and extracted commodities as exergy carriers and the output. (Wackernagel and Rees, 1996). The whole country, except Hong Kong, Macao and Taiwan, is choosing as the boundary of the conversion process analysis. For avoidance of repetitive and cross calculations, the entrance boundary points are set at the same level of the resource inflow and outflow.

2.1.

Conventional national EF accounting

The conventional national EF accounting grounds on six basic assumptions (Wackernagel and Monfreda, 2004). The total area available to supply six potentially renewable demands, including cropland, pasture, forests, built-up land, fisheries and energy within a specified country, region or territory, are presented to determine the biocapacity. When the EF is greater than the biocapacity, ecological deficit emerges. Moreover, ecological overshoot may occur when overexploitation of resources or accumulation of waste exceeds the capacity and triggers the sudden collapse of the total ecological system (Wackernagel and Monfreda, 2004). The calculation of conventional EF in this paper is totally based on the detailed process of national EF accounting underlying most recently published EF calculations (Monfreda et al., 2004). The equivalence factor represents the world average potential ‘usable’ productivity contained in a given bioproductive area relative to the world average potential ‘usable’ bioproductive areas, which is aggregated on the anthropogenic mode of the utilization of biomass, thereby excluding some of the biomass beyond the human utilization scope. For this study, the time series of equivalence factors from 1981 to 2001 are cited from the work presented by Wackernagel et al. (2004a). Yield factors are determined by the variable ratio between the given bioproductive area and the global average bioproductive area of the same land use in long periods of time

360

EC O LO GIC A L E CO N O M ICS 6 1 ( 2 00 7 ) 3 5 5 –3 76

(Haberl et al., 2001). The variable local yields method, that is, both global and local yields refer to the year of consumption, is opted to calculate. Footprints of renewable resources, e.g., cropland, pasture, forest and fisheries, are revised according to the classification of primary products and secondary products. Only the primary products are included in the EF accounts, whereas the imported or exported secondary products are added to the total traded EF. Footprint of built-up area is set equal to the same amount of cropland it replaces with the yield factor of cropland. The productivity of land inundated by hydropower reservoir, which is formed by the dam, is uncertain. Due to the high variety, the area of the hydropower is calculated with the equivalence factor of 1.0 and yield factor of 1.0 (Monfreda et al., 2004). At an average output of 8200GJ/ha/year, the built-up footprint of a wind power plant on average-quality pasture is 1.8 gha/MW. Considering the energy embodied in construction of wind farm, as pointed by Wackernagel and Monfreda (2004), the carbon sequestration footprint is 16.9gha/MW. Photovoltaic (PV) accounts for part of the solar power. Pacca and Horvath (2002) estimated the carbon emission footprint embodied in a PV system amounted to be 211gha/MW. The nuclear power is regarded as the fossil fuel in the conventional EF accounts. In China, the EFs of the wind power and photovoltaic are relatively small compared to the other resources and can be neglected in this analysis.

2.2.

Embodied exergy EF accounting

This paper presents a conceptual framework with corresponding numerics for ecological evaluation based on the fundamental, global scarcity of the exergy availability revealed by the study of Chen (2005, 2006). Ecological values of all products are determined by the cosmic exergy consumed in the ecological chain, as a whole from the very beginning level of solar and CBM radiations to the final level in the ecosphere or human society, of the formation of the product, termed as embodied exergy. Similar to Odum's illustration of energy transformation and transformities with each stage in the chain, the exergy decreases by a constant ratio. The decreasing exergy corresponds to increasing transformities. Thus, the transformity may represent the position of exergy flows and storages in the exergy hierarchy. Due to the universal exergy consumption, hierarchial exergy structure is universal, which may result in fundamental consequence of the second law of thermodynamics. Since the existence of the geobiosphere, the atmosphere, ocean and earth cycles are necessarily coupled with each other, each flow within this system being a by-product of the others as co-products. For coupled large-scale earth processes, Odum (1996) obtained data on flows of matter or energy. With reference environment choose by Odum, energy is the same as exergy. Then, the embodied exergy transformities are given as the quotients of the embodied exergy base divided by the fluxes. Embodied exergy accounting starts with an evaluation of the earth exergy process. As exergy due to earth heat and gravitational effect associated with sun and moon is

negligible compared with the cosmic exergy inflow due to the thermal difference between the sun and the cosmic background, the global embodied exergy sustaining the global earth is equal to the global cosmic exergy consumption, that is, approximately 1.38 × 1021 Jc/year (Chen, 2005). The total surface area of the earth is 5.1 × 1014 m2. Therefore, the global embodied exergy density (hereafter GEED) is the ratio of the global cosmic exergy consumption to the surface area of the earth, i.e., 2.71 × 106 Jc/m2 year. Renewable resources, including surface wind, physical energy of rain on land, chemical energy of rain on land, physical stream energy, waves absorbed on shores, earth sedimentary cycle and chemical stream energy, are calculated as the ecological capacity. It should be noted that the global exergy flows are additive, whereas the global energy flows cannot be summed up, for the flows in the geobiosphere are coupled with each other, which is the apparent trouble of double count in emergy accounting. The embodied exergy transformities of the renewable resources in this paper are given as the quotients of the emergy base EMB divided by the global exergy flux as listed in Table 1 in Chen (2005). Since the atmosphere, the ocean and the earth cycles are coupled with each other in the geobiosphere, each flow in this global ecological system being a by-product of the others as co-products, it is reasonable to assign an equal emergy as the global emergy power divided by the number of the coupled pathways to each pathway with all the related transformities being based on the same baseline, which is different from the solar transformities obtained by dividing the annual global emergy flow by the fraction of the intercoupled energy flow. The EF of the ith product based on embodied exergy is calculated as follows: EFemx;i ¼ ðProductiond;i þ Importi −Exporti Þ  Transformityemx;i =GEED

ð3Þ

where EFemx,i is the ecological footprint based on embodied exergy of the ith product, Productiond,i is the yields of the ith domestic product calculated by exergy contents, and Importi and Exporti are the exergy contents of the imported and exported ith products, respectively. Transformityemx,i is the dimensionless quotient of the ith product's embodied exergy divided by its exergy, standing for the quantity of the embodied cosmic exergy required to make one joule of the ith product. GEED is the global embodied exergy density. As a first approximation, the embodied exergy transformity of the products in this paper is calculated according to the solar transformity proposed by Odum (1988, 1996), dividing the different global cosmic exergy consumption base value (Chen, 2005, 2006). All the thermal exergy of the materials are omitted. Exergy of electricity equal to its energy values. The exergy content of fossil fuels is set equal to the lower heating values multiplying the exergy factor (Kotas, 1985; Morris and Szargut, 1986; Schaeffer and Wirtshafter, 1992). The calculation of the woods exergy produced from the forest has reference to the exergy analysis for Japan (Wall et al., 1994). The exergy contents of the dry solid woods from broad-

361

Population

EC O L O G IC A L E C O N O M IC S 6 1 ( 2 0 07 ) 35 5 –3 76

1.40E+09 1.20E+09 1.00E+09 8.00E+08 6.00E+08 4.00E+08 2.00E+08 0.00E+00 1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

Year Fig. 1 – Population from 1981 to 2001 in China.

GDP (Yuan)

leaved forests and needle-leaved forests are 18.5MJ/kg and 18.9MJ/kg, respectively. Assuming the humidity of the wood is 25%, thus the average exergy of the broad-leaved and needleleaved wood is 13.9MJ/kg (the area of the broad-leaved timber forest are equal to the area of the needle-leaved timber forest in China according to the results of the National Forest Resource Census). The exergy of the woods is thereby estimated to be 8 GJ/m3. The exergy contents of the agricultural products are derived from the free energy of the nutrients of the products, of which protein, fat and carbohydrate are the main components (Ertesvåg and Mielnik, 2000; USDA, 2003; Wall, 1986, 1990; Wall et al., 1994). The exergy of the pasture resources is calculated according to the different types of rangeland and hay yields. The nutrition of the different hay includes rough protein, rough fat, rough fiber, rough ash, nitrogen free extract, calcium and phosphorous. The rangeland provides large amount of fodder resources for the livestock. As the dietary requirement changes, more food, such as pork, beef, mutton and milk, is needed from livestock husbandry. Increasing yield of livestock, accompanied by the over grazing and desertification, results in serious rangeland resources depletion. Considering the pasture resources are digested and converted by the herbivorous livestock and the livestock is regarded as the input interface to the society, the exergy of the pasture resources are thereby estimated. Most of the data available for the present EF analysis of China are from standard yearbooks compiled by the central government and subordinate ministries (e.g., CAY, 1982– 2003; CCIY, 1982–2002; CESY, 1986, 1991, 1991/1996, 1997/ 1999, 2000/2002; CEY, 1990–2003; CFY, 1949/1986, 1987–2003; CIESY, 1988–1990, 1992 1995, 1998, 2001–2003; RSYC, 1985– 2003; SYC, 1980–2002). Unlike the other countries, the statistical data of this year in China are often available 1–3 years later. State Statistical Bureau published the annual statistical yearbook and energy statistics yearbook,

including the main energy carrier flows broken down to the end-use sectors. The other yearbooks are compiled by the subordinated ministries with more detailed data and sometimes different statistical coverage.

3.

Chinese society from 1981 to 2001

The population in China had been steadily increasing during 1981–2001 (Fig. 1). Announced in 1979, the one-child family policy was enforced as the basic principle of China in order to control the fast growth of population. Nevertheless, the onechild policy seems to be a target which is difficult to be achieved, with the population increasing steadily from 1.01 × 109 in 1981 to 1.28 × 109 in 2001. Large increasing population in China leads to a low share of the essential natural resources, despite varied natural resources. Also, the energy efficiency of China is relative low compared with the other countries. Shortage of natural resources and extensive way of utilization impede the economic development. The economic development always has priority than the so-called compatible development of economic, environment and resources and the overwhelming motive to promote GDP makes the resource base overloaded and depleted in China. As shown in Figs. 2 and 3, the rapid development of the GDP or GDP per capita which has been considered as the hallmark of the Chinese economy experiences three major periods. During the first period (from 1981 to 1986), industrialization and reform of agriculture contributed most to the GDP growth. The rapidly growing industries and services drove the GDP during the second period (from 1987 to 1991). During the last period (from 1992 to 2001), GDP increased linearly at the average growth rate of 10%. Since the early 1990s, the Chinese economy has achieved a soft-landing after the central government takes some

1E+13 8E+12 6E+12 4E+12 2E+12 0 1981

1983

1985

1987

1989

1991 Year

1993

1995

Fig. 2 – GDP from 1981 to 2001 of China.

1997

1999

2001

362 GDP per capita (Yuan)

EC O LO GIC A L E CO N O M ICS 6 1 ( 2 00 7 ) 3 5 5 –3 76

8000.00 6000.00 4000.00 2000.00 0.00 1981

1983

1985

1987

1989

1991 Year

1993

1995

1997

1999

2001

Fig. 3 – GDP per capita from 1981 to 2001 of China.

measures to adjust the economic polices and restrain the over expanded infrastructures (Teather and Yee, 1999).

3.1.

Results

3.1.1.

Conventional EF method

3.1.1.1. EF. The EF per capita of China has increased during the period 1981–1996, reached the maximum (1.55gha) in 1996 and then declined after 1997 (Fig. 4). The fossil fuels, including coal, oil and natural gas, and the cropland contributed most to the EF among the six components of the EF per capita of China. The EFs of the coal, oil and natural gas increased from 0.34gha, 0.07gha and 0.007gha in 1981, reached the peak 0.68gha, 0.10gha and 0.009gha, and then fell to 0.57gha, 0.13gha and 0.01gha in 2001, respectively (Fig. 5). The long-run decline of the EF of the cropland has been slow, being 0.4gha on the average during the past 21years. The EFs of pasture kept constantly at 0.05gha, whereas the built-up land 0.02gha between 1981 and 2001. The EF of the forest stagnated around 0.11gha throughout the study period. The EF of the sea has increased, from 0.05gha in 1981 to 0.13 gha in 2001. The total EF is the result of the EF per capita multiplying the population. The total EF has risen from 1.13 × 109 gha in 1981 to 1.95 × 109 gha in 1996, and then declined little to 1.84 × 109 gha in 2001 (Fig. 6).

Ecological footprint per captia (gha)

3.1.1.2. Biocapacity. The biocapacity per capita changed little during the period 1981–2001, with the average being 0.67gha (Fig. 7). It was the counteraction of the growth of the population and the declining crop yields make the biocapacity

per capita remained stagnant, compared to the trends of the EF per capita. The total biocapacity tended to increase from 6.55 × 108 gha in 1981 to 7.37 × 108 gha in 1984, followed by a fluctuation around 7.53 × 108 gha between 1985 and 1995, and then recovered to the peak 8.62 × 108 gha in 1996, falling to 7.86 × 108 gha in 2001 (Fig. 8). The varying scope of the biocapacity amounted to 2.07 × 108 gha.

3.1.1.3. Ecological overshoot. The ecological overshoot per capita and the total ecological overshoot of China have varied in the similar way during the period 1981–2001 (Figs. 9 and 10). The ecological overshoot per capita (Fig. 9) and the total ecological overshoot (Fig. 10) expanded from 0.51gha and 5.06 × 108 gha in 1981 to 0.65gha and 8.36 × 108 gha in 2001, respectively. The ecological overshoot per capita and the total ecological overshoot reached the peak in 1997, amounting to 0.87gha and 1.08 × 109 gha, respectively. 3.1.1.4. Ratio of GDP to EF per capita. EF intensity, defined as the ratio of the EF and the real status of the economic output, which is often represented in GDP, is used to depict the resource consumption intensity corresponding to unit economic output. The ratio of GDP to EF per capita can be regarded as an attempt to show the close relationship between the “land demand” and economic output, as discussed by Farber et al. (2002) concerning the relationship between available energy and economic output. However, different from what is stated in Chen et al. (2004) that the ratio of GDP to EF per capita can be considered as a direct measure of the efficiency of resource use, it is much better to understand this indicator as

2.00

1.50

1.00

0.50

0.00 1981

1983

1985

Fossil fuels

1987 Cropland

1989

1991

Fisheries

1993 Forest

1995

1997

Pasture

Fig. 4 – Time series of per-capita EF in China 1981–2001.

1999 Built-up area

2001

363

EC O L O G IC A L E C O N O M IC S 6 1 ( 2 0 07 ) 35 5 –3 76

0.90 Ecological footprint of fossil fucls components (gha)

0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 1981

1983

1985

1987 Coal

1989

1991

Crude oil

1993

1995

1997

1999

2001

Natural gas

Fig. 5 – Time series of per-capita EF of fossil fuels in China 1981–2001.

a numeraire between the land area and the currency. The hypothesis implied by Chen et al. (2004) is that the “bioproductive land consumption” growth rate should keep in pace with the GDP growth rate, which is no always the case, especially in China as follows. First, the bioproductive land consumption growth rate varies in different sectors. Secondly, the developing imbalance among different sectors due to the unbalanced central planning investments affects the total bioproductive land consumption growth rate of the national economy. Finally, the “bioproductive land” does not aggregate all the available resources, especially the so-called renewable resources in China. The ratio of GDP to EF per capita in China increased steadily over the period 1981–2001, from 429 RMB/ gha in 1981 to 5139 RMB/gha in 2001 (Fig. 11).

3.1.2.

sea water contribute approximately contents to the total EEEF. The EEEfs per capita of the coal, oil and natural gas increased from 3.17 ha, 1.25ha and 0.13ha in 1981, reached the peak 5.82ha, 1.59 ha and 0.17 ha, and then fell to 3.85ha, 1.60ha and 0.25ha in 2001, respectively (Fig. 13). The long-run fluctuation of the EEEF per capita of the cropland has been slow, being 2.51ha on the average during the past 21years. The EEEF of built-up area has risen from 0.1ha in 1981 to 0.34ha in 2001. The EEEF of pasture moves around 0.24ha during the study period. The EEEF of forest stagnated throughout the study period within the scope of 0.12 ha to 0.26ha. The EEEF of the sea has increased from 0.28ha in 1981 to 1.67ha in 2001. The total EEEEF is the result of the EF per capita multiplying the population. The total EEEF has risen from 1981 to 1996 and then declined little from 1996 to 2001 (see Fig. 14).

Embodied exergy EF method

3.1.2.1. Embodied exergy EF.

The embodied exergy EF (hereafter EEEF) per capita of China has constantly increased during the period 1981–1996, reached the maximum (12.66 ha) in 1996, declined before 2000 and then resurged a little (12.30ha) in 2001 (Fig. 12). The fossil fuels, including coal, oil and natural gas, contributed most to the EEEEF among the six components of the EEEF per capita of China, whereas cropland, pasture and

3.1.2.2. Embodied biocapacity. The embodied biocapacity per capita changed from 11.45ha in 1981 to 8.98ha in 2001, with the average being 10.02ha. The varying scope of the embodied biocapacity per capita amounted to 2.47ha. 3.1.2.3. Embodied ecological overshoot. The embodied ecological overshoot increased continuously during the period 1981–2001 (Figs. 15 and 16). The ecological overshoot per

Total eoclogical footprint (gha)

2.50E+09 2.00E+09 1.50E+09 1.00E+09 5.00E+08 0.00E+00 1981

1983

Fossil fuels

1985

1987

Cropland

1989

1991

Fisheries

1993 Forest

1995

1997

Pasture

1999

2001

Built-up area

Fig. 6 – Time series of total EF components in China 1981–2001.

364

EC O LO GIC A L E CO N O M ICS 6 1 ( 2 00 7 ) 3 5 5 –3 76

Biocapacity per capita (gha)

2.00 1.80 1.60 1.40 1.20 1.00 0.80 0.60 0.40 0.20 0.00 1981

1983

1985

1987

Cropland

1989

Fisheries

1991

1993

Forest

1995

Pasture

1997

1999

2001

Built-up area

Fig. 7 – Time series of per-capita biocapacity components in China 1981–2001.

capita (Fig. 15) and the total ecological overshoot (Fig. 16) expanded from − 4.04ha and 7.31 × 109 ha in 1981, amounting to zero in 1990, reached the peak 2.97ha in 1996 and 1.48 × 1010 ha in 1997, respectively, and thereafter followed a reduction, amounting to 1.80ha and 1.33 × 1010 ha in 2001, respectively.

3.1.2.4. Ratio of GDP to EEEF per capita. Based on the concept of embodied exergy, EEEF Intensity, defined as the ratio of the EEEF and the real status of the economic output, which is often represented in GDP, is used to depict the resource consumption intensity corresponding to unit economic output. The ratio of GDP to EEEF per capita can be regarded as an attempt to show the close relationship between the land demand stemmed from embodied exergy and economic output. The ratio of GDP to EEEF per capita in China increased steadily over the period 1981–2001 from 66 RMB/ha in 1981 to 708 RMB/ha in 2001 (Fig. 17).

4.

Sectoral analysis

Total Biocapacity (gha)

As Wackernagel et al. (2004a) stated, the EF documents present ecological demand and supply and describes the

2.00E+09 1.80E+09 1.60E+09 1.40E+09 1.20E+09 1.00E+09 8.00E+08 6.00E+08 4.00E+08 2.00E+08 0.00E+00 1981

1983

1985

Cropland

1987

1989

Fisheries

quality of impacts and resource management brought about yield changes. For the varying components of the EF, sectoral analysis of time series will depict clearer cause–effect relationship concerning with more specific management practices in each sector. In China, the transitional stages of the constitution during the period 1981–2001 profoundly affected the corresponding EF time series. From 1949, the founding of the P.R. China, to 1978, the planned economy had been the dominate factor, which affected (often impeded) the development of the society. Since 1978, China has adopted the reform and open door policy. This period can be divided into two phases. First, the planned commodity economy was from 1978 to 1993. During this time, reform of the urban management system was mainly based on the principles of a planned market economy. China formulated a policy based on the principle of unified planning and unified management before 1993. Government intervention was gradually reduced during the period after 1993, when the planned commodity economy was transformed into the free market economy. The central and provincial governments had also gradually granted more autonomy to the municipalities, such as decisions for investments and establishment of different sectors. Along with the political reform performed in the transition from planned commodity economy to free market economy, different

1991 Forest

1993

1995

Pasture

1997

1999

Built-up area

Fig. 8 – Time series of total biocapacity components in China 1981–2001.

2001

365

Ecological overshoot per captia (gha)

EC O L O G IC A L E C O N O M IC S 6 1 ( 2 0 07 ) 35 5 –3 76

2.00

1.50

1.00

0.50

0.00 1981

1983

1985

Fossil fuels

1987

1989

Cropland

1991

Fisheries

1993 Forest

1995

1997

Pasture

1999

2001

Built-up area

Fig. 9 – Time series of per-capita ecological overshoot in China 1981–2001.

sectors have been adjusted and reformed greatly and directly, changing the supply and demand relationship of the resource and its relative conversions.

4.1.

spontaneously emerged in the early 1980s and over time were forced to be performed in the countryside by the state. The early production responsibility is not related to the yields. Under the unified production and management plan of the brigade, the production team is broken into several special groups, contracting the jobs that are needed to be finished with certain quantity and quality in a specified period for each group. The excess production will be rewarded while the shortage will be penalized. Then, the responsibility systems related to the yields mushroomed in different forms. One type of this responsibility system is to distribute some commercial crops, which need expertise and tending to the households or groups who are experienced. The contractors can deduct a percentage from the sum of the yields, by either work points or cashes as bonus. Another type, know as “household production contracting”, allocates a certain plot which cannot be sold out, rented or transferred to the individual household. Fixed yields, work points and investments are stipulated for each plot and the yields within the contracted quota should be turned over to the production team. In addition, all the production goods belong to the production team. Machineries and livings stocks are used according to the combined households in turn. Thus, the EF (EEEF) increased from 0.42 gha (2.31ha) in 1981 to 0.45gha (2.65ha) in 1983. From 1983, the household production contracting responsibility system was regarded as the basic agricultural

Cropland

Total ecological overshoot (gha)

Relative political infrastructure and organization of the agricultural production in the rural areas will be discussed below, for frequent and rapid transformation of the rural policies directly have corresponding impacts on the crop yields and in turn the EF or EEEF. Collectivization was thus put into practice and served as the main organization form of the Chinese agriculture from 1957 to 1979, which is divided into three levels, that is, production team, brigade and commune. The major decisions about the crop farming and investments on the agricultural production were made and circumscribed not by the peasant or the production team, but by the brigade and commune that are at the higher levels. Although collectivization provided basic public housing, education and heath care, the advantage arising from it is obvious, for the peasants and collectives cannot do crop what they want and get what they really need through the market which is strictly prohibited and thereby their activities and duties were frustrated which led to the lower labor productivity. As the communes based on the collectivization were proved to be unworkable, production responsibility systems

2.00E+09 1.80E+09 1.60E+09 1.40E+09 1.20E+09 1.00E+09 8.00E+08 6.00E+08 4.00E+08 2.00E+08 0.00E+00 1981

1983

Fossil fuels

1985

1987

Cropland

1989

1991

Fisheries

1993 Forest

1995

1997

Pasture

1999

2001

Built-up area

Fig. 10 – Time series of total ecological overshoot in China 1981–2001.

366

EC O LO GIC A L E CO N O M ICS 6 1 ( 2 00 7 ) 3 5 5 –3 76

Ratio of GDP to unit footprint (Yuan/gha)

6000 5000 4000 3000 2000 1000 0 1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

Fig. 11 – Time series of ratio of GDP to EF in China 1981–2001.

production system and the state grain procurement was partly abolished, decreasing from 113 types of procurement grains to 38, while the contracts between the state and the peasants are offered, which allow the rest of the procured grains to be circulated in the market. As a result, a large harvest is gained in 1984, with the EF (EEEF) being 0.45gha (2.81ha). Also, the state monopoly purchase and marketing policy which had been put into practice for 30years was replaced by contract purchase in 1985, keeping the EF (EEEF) at 0.43gha (2.58ha). In the following years (1986–1989), the EF (EEEF) began to be stagnant around 0.40gha (2.50ha). The remaining state grain quotas, especially the grain and cotton, were completed by the peasants who let the land idle and purchased through the market with the cash which is obtained by profitable sideline production. At the same time, the emergence of the rural industries, which are supported by the local government, attracted most of the leisure and surplus laborers released from the farmland. In addition, the scissors difference between the prices of the cheap agricultural products and the expensive agricultural goods, such as fertilizers and pesticides, increased and therefore frustrated the enthusiasm of the peasants. The household contract responsibility system with remuneration linked to the yields, two-layer management system featuring the integration of centralization and decentralization, that is, persisting with the state ownership and transferring the management right to the household,

were kept in place and further reinforced. However, along with the growth of the population and laborers, the contracted plots became more dispersed, impeding the extended agricultural reproduction. Meanwhile, the rural economy transformed from traditional self-sufficiency mode into the specialized and cooperated form. The central conference on rural policy in 1993 prescribed that the due land contract could be extended for 30years and the management right could be transferred freely during the contract period, which laid solid foundation for the large-scale crop farming and management. The marketing of the grain was also decontrolled by the government in 1993, with the EF (EEEF) rebounding to 0.40 gha (2.58ha). To release the pressure of the demand for scarce cultivated land, the management right of the “four barrens” is auctioned with more than 50years operating time. The auctioned barrens, summing up to 4.67 × 106 ha by 1995, stimulated enthusiasm of the farmers to reclaim and exploit large amount of non-cultivated land resources in China, thereby arousing the increase of the EF or EEEF. From 1996 to 2000, the new contracts and management certifications for nearly 98% farmers were signed. The heavy burden of the farmers were reduced, the total sum of the profit deduction and reserving fees being restricted within 5% of the net income of the farmers. From 1997 onwards, the agriculture structure has been accelerated to be industrialized with

EEEF per captia (ha)

14.00 12.00 10.00 8.00 6.00 4.00 2.00 0.00 1981

1983

1985

Fossil fuels

1987 Cropland

1989

1991

Fisheries

1993 Forest

1995

1997

Pasture

1999

2001

Built-up area

Fig. 12 – Time series of per-capita EEEF components in China 1981–2001.

367

EC O L O G IC A L E C O N O M IC S 6 1 ( 2 0 07 ) 35 5 –3 76

9.00

EEEF of fossil fucls components (ha)

8.00 7.00 6.00 5.00 4.00 3.00 2.00 1.00 0.00 1981

1983

1985

1987 1989 1991 Coal Crude oil

1993 1995 Natural gas

1997

1999

2001

Fig. 13 – Time series of EEEF of fossil fuels components in China 1981–2001.

development of some leading agricultural enterprises. The main form of the agricultural enterprises promotes the farmers by establishing stable purchase contract and communication channels, appeared in 2000, accompanied by order agriculture, characteristic agriculture and export agriculture. The structure of the agriculture is also decided indirectly by the government. The peasants are obligated to remit to the government an agricultural tax assessed in official state-fixed prices attached to the quota produces (Shambaugh, 2000). The tax is revised by the government to guarantee the supply of the basic foods to the urban areas with subsidized prices, such as grain and vegetables, which make up the primary exergy contents of the agricultural products. As a result, the income of the peasants is extremely low, which in turn leads to the dilemma that the peasants cannot afford the cost of the fossil fuels and electricity from the urban areas when local resources are prohibited to obtain and subsequently the improvement in the efficiency of the utilization of the resource seems impossible in the poor rural areas without the subsidy of the local government. The decontrolled measures took by the government with the grain coupon being abolished in 1993 transferred the circulation channel and system of the grain. Although some of the places restored the supply of some grains with lower

prices to guarantee the basic living conditions of the poverty by the end of 1993 due to the large price bulge of the grain, the marketing and circulation of the grain changed thoroughly from planning to market. From 1991 to 1995, the provincial governors are required to assume the responsibility of the grain supply, taking advantage of the market to regular the shortage and surplus grain among different provinces and guaranteeing the self-sufficiency of grain. The grain reserve of the central and local government had been established in order to regular the supply of the grain market. For example, the central government undersell up to 1.5 × 107 t grain to depress the inflation of the grain prices owing to the poor harvest in 1994, with the EF (EEEF) being 0.41gha (2.57ha). The structure of the cropping agriculture which reflects the priorities and measures taken by the government has been adjusted since 1980. The rice, wheat and soybeans, which are called “fine grains”, together with the corn and tubers, which are called “coarse grains”, constitute the grain. The rapid growth in grain (4% on the average during 1980– 1984 used to shift China into a net exported country in a short period and later on was soon reversed with a slow-down appeared during 1984–1988. Concerning the increasing imported grains (nearly 1.4 × 107 t/year) and the abolishment of the state procurement in 1985 mentioned above, the state which had built up surplus stocks of grain was forced to clear

1.80E+10

Total EEEF (ha)

1.60E+10 1.40E+10 1.20E+10 1.00E+10 8.00E+09 6.00E+09 4.00E+09 2.00E+09 0.00E+00 1981

1983 Fossil fuels

1985

1987

Cropland

1989

1991

Fisheries

1993 Forest

1995

1997

Pasture

1999

2001

Built-up area

Fig. 14 – Time series of total EEEF components in China 1981–2001.

368

EC O LO GIC A L E CO N O M ICS 6 1 ( 2 00 7 ) 3 5 5 –3 76

Embodied ecological overshoot per captia (ha)

14.00 12.00 10.00 8.00 6.00 4.00 2.00 0.00 1981

1983

1985

Fossil fuels

1987

Cropland

1989

1991

Fisheries

1993 Forest

1995

1997

Pasture

1999

2001

Built-up area

Fig. 15 – Time series of per-capita embodied ecological overshoot in China 1981–2001.

the grain stocks and in consequence the farmers who had more autonomy on production adjusted their production structure in relation to the institutional changes, leading to the stagnant status of the grain production. Also, when the contract of the grain was gradually abated theretofore and the prices again promoted, the incentive of the farmers is well protected with corresponding resurgence in the grain production of 1994 despite the serious natural disaster. To urge the grain production, the state also directly linked the procured grain production with fertilizers at the lower state-fixed prices. However, at times low price, heavy tax burden frustrated the incentive of the farmers to undertake the grain production. The coarse grain's proportion decreased slowly inasmuch as the diet of the people shift to the fine grains when the living standard is improved and of which the corn increased because of the necessity of feeding the livestock (Ash, 1998). There is growing concerns about the food agricultural production ability of China. Soil and water loss is one of the most serious problems by which the agriculture confronts, for large amount of nutrients in nearly 5 billion eroded soil each year carried to the sea from the local areas, weakening the foundation of the agriculture. Also of concern is that the wide regional inequalities of the grain production in China are serious, for the different provinces and counties are often directed by the government to promote a special crop production according to the local cropping conditions and economic status.

4.2.

Fossil energy

4.2.1.

Coal

There are abundant coal resources in China, amounted to be 9.99 × 1011 t (ensured reserves) on the average from 1981 to 2001. The distribution of the coal production is unbalanced with fourteen 10-million-ton coal complexes located in the north of the Yangtze River, of which seven located in the north China, concentrated in Shanxi and Hebei associated with 1.2 × 108 t coal yields (Jin et al., 1997). The intensified exploration cannot meet the increasing demand for the coal as necessary resources to support the economic development in the southeast China, which subsequently resulted in the longdistance dispatching and transportation of the coal from north to the east and south. The coal production can be divided into three major parts according to the administrative institutions: state-controlled unified central planning, local state-controlled and rural coal mines. In 1990, the unified central planning, local statecontrolled and rural production amounted to 44.5%, 19.0% and 36.0% of the total production, respectively. Based on the exploitation and design standard, the stock reservation coefficient of the coal mine should be 1.4 and the recovery ratio 75%. The real recovery ratio is 50%, which indicates the service life of the central unified planning coal mines are 36years or so (Jin et al., 1997). The coal industries developed sharply from 1949 to 1979, with 1498 new coal mines being exploited and production

Total embodied ecological overshoot(ha)

1.60E+10 1.40E+10 1.20E+10 1.00E+10 8.00E+09 6.00E+09 4.00E+09 2.00E+09 0.00E+00 1981

1983

Fossil fuels

1985

1987

Cropland

1989

1991

Fisheries

1993 Forest

1995

1997

Pasture

1999

2001

Built-up area

Fig. 16 – Time series of total embodied ecological overshoot in China 1981–2001.

369

EC O L O G IC A L E C O N O M IC S 6 1 ( 2 0 07 ) 35 5 –3 76

Ratio of GDP to unit EEEF (Yuan/ha)

700.0 600.0 500.0 400.0 300.0 200.0 100.0 0.0 1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

Fig. 17 – Time series of per-capita GDP to EEEF in China 1981–2001. amounted to 6.36 × 108 t, of which state-controlled unified central planning was 3.58 × 108 t and the local state-controlled 2.78 × 108 t (compared to the 3.0 × 107 t yielded in 1950). Although the technologies of the coal cutting, tunneling, transportation, lift, ventilation and drainage were gradually promoted, the hand operation mode was in general use associated with low capita production (less than 1t daily per capita). The structure of the coal production was also simple, being directly utilized along a chain of “a fire, a stream of fumes and a pile of ashes”, compared with the multiple utilization of the coal, such as the char coal and gases produced through the washery and post-treatment process in the other countries. In addition, the rapid growth in coal industry, highly administered and planned with state-controlled sector, was obtained at the cost of increasing initial investment which was apportioned among the consumers, resulting in the stagnant and relative low living standard of the people in China. In 1981, the coal production associated with 0.34gha/cap EF or 3.09ha/cap EEEF is adjusted because of the mismatch which included irregular cutting and tunneling and chaotic management of the whole coal industry. The production in 1982 started to increase slightly, with 87 coal mines adjusted and the production capacity of the new established mines expanded to 1.2 × 108 t (0.36 gha/cap or 3.26ha/cap). The coal production met the target 7 × 108 t (0.39gha/cap or 3.40ha/cap) in 1983 which was scheduled to be met in 1985. The increase was the first time obtained with the balance of the preparation and mining work. Also, the policy was specified to develop the rural coal mines (increased to 40,000 associated with 16% production increment), for the unemployment problem is serious and imperative to be solved by providing more jobs in coal industries regarding the return of thousands of the educated youth and the surplus laborers released from the countryside and rural areas. In 1984, the coal production continued the upward trend, summing up to 7.9 × 108 t (0.40gha/cap or 3.66 ha/cap), of which the production of the rural coal mines amounted to 2.1 × 108 t (27.5% upsurge compared with 1983). Considering the abundant coal resources which distributed in more than 1100 cities and towns and was suitable for the farmers to exploit, the government encouraged the peasants to contract and operate

the medium and small-sized coal mines so as to meet the rising demand for the coal under poor transportation facilities. With the coal being permitted to be transacted in the market, the coal being transported freely throughout the whole country and the marginal and scrappy coal fields being distributed to the peasants, the number of the rural coal mines skyrocketed to 50,000 and the corresponding yields amounted for 62% of the total coal production increment. The central government put the “General Contract Programme” into practice in 1985. The quantities of the coal production was divided into definite targets and directly related to the economic benefits of each level of the coal production department. Thus, the coal production increased drastically to 8.7 × 108 t (0.43gha/cap or 3.93 ha/cap). The coal production mounted to 1.08 × 109 t (0.52gha/cap or 4.64ha/cap) in 1990, accompanied by the improved mechanization and efficiency (1.217t daily per capita). Despite of the growth, the state-fixed price of the coal was still extremely low and the state of the operation of the state-owned coal mines was terrible. From 1991 to 1993, the economy of the Chinese society experienced the most serious inflation. Macroeconomic polices were implemented to cool down the overheated investments in a wide range of the industry economy, therein the coal investment and production gradually contracted because the demand for the coal which is less than the supply suppressed the coal production. Thereafter, the coal production revived and the deficit was 1.97 billion yuan, which is less than the “scheduled” deficit 2.00 billion yuan in 1994 and the deficit 3.26 billion yuan in 1993. In addition, the rural coal mines were initially reformed and consolidated, 13,000 smallsized coal mines without certification being closed. The deficit of the key state-owned coal mines decreased to 1.03 billion yuan, for the whole coal industry began to be transferred from the conventional policy based on the state-fixed yields to the marketing balance between the supply and demand in 1995. The coal production in 1996 mounted to the maximum 1.37 × 109 t (0.68gha/cap or 6.03ha/cap), of which the central controlled unified planning production was 5.4 × 108 t, the local state-controlled 5 2.2 × 108 t and the rural ones 6.1 × 108 t. The deficit of the key state-owned coal mines reduced to 0.6 billion yuan, with the production, diversified management and logistics departments being separated and independently accounted.

370

EC O LO GIC A L E CO N O M ICS 6 1 ( 2 00 7 ) 3 5 5 –3 76

In 1997, rectification and readjustment were performed in order to balance the wide gap between the supply and demand, corresponding coal production being 1.33 × 109 t (0.65gha/cap or 5.74ha/cap). Drastic measures were implemented in 1998, with the result that 94 key state-controlled coal mines associated with 237.9 billion asset and 4.35 million employees were handed over to the local government and no production plans and break-even indices which was prescribed by the State Coal Industry Bureau was needed to be finished thereafter. The decision to close various small-sized coal mines and decrease 2.5 × 108 t coal production was also made by the State Council. “14.40” Project was also scheduled to make 14 deficit coal enterprises bankrupted and 40 resource-depleted and lowquality coal mines closed in 1999 so as to adjust the basic structure of the coal industry. The coal production in 1998 fell to 1.23 × 109 t (0.60gha/cap or 5.29 ha/cap). The coal production further reduced to 1.04 × 109 t (0.58gha/ cap or 5.12ha/cap), with 31,200 closed small-sized coal mines, wherein 15,600 illegal coal mines and 2.68 × 108 t contracted production of the rural coal mines in 1999. Alongside with the unemployment of the coal industry amounted to 0.4 million, the deficit and debt of the coal industry were further decreased with much better technical and economic target. The coal production reached 9.99 × 108 t (0.57gha/cap or 5.01ha/cap) in 2000. Until the end of 2000, 4.6 × 104 small-sized coal mines were closed with only 2.5 × 104 left. The coal business order was further rectified by the government. Moreover, to alleviate the pressure of the civil coal market, the government supported the coal export by providing the refund of the export tax rates and decreasing the freight base and commodity inspection expense, with the result that the coal export amounted to 5.5 × 107 t. In 2001, the coal production rebounded, for the production structure was adjusted, the supply and demand tended to balance and the coal stocks continued to be disposed. Also, as regards the allocation of the state-controlled coal mines restored to more than 80% of the total coal production (only 57% in 1997), the government reinstated to regulate and control the whole coal market. Notwithstanding the effect of the policies administrated by the central and local government are often obvious and powerful, China's policy on coal industry has not followed a coherent programme. Take the development of the smallsized rural coal mines for instance, coal resources were badly wasted when the policy made in 1984 to develop the rural coal mines triggered the high-speed growth in coal production. Every coin has its two sides. On one hand, the small-sized rural coal mines satisfied the imperative need of the coal demand, supplemented the scarce capital of the government and met the local need of coal when the rural transportation facilities were poor. On the other hand, most rural coal mines possessed the production capacity less than 5.0 × 104 t annually associated with extremely simple and crude exploitation equipments. Generally, the exploitation of the rural coal mines focused on the shallow surface coal seam. After years of exploitation, the shallow coal resources were nearly depleted. Meanwhile, accompanied with large amount of discharge of mine waste water, methane drainage and waste rock, the non-exploited coal

seams left by the state-owned coal mines were spoiled by the rural coal industries in a predatory way, which led to serious destruction of the coal resources. Considering the profound ecological destruction and resource depletion, the central government changed the former policy in order to reverse the direction of the rural coal mines development. Higher cost had to be paid by the local rural coal industry. Albeit the central government regained powerful control of the integrated coal production, the losses of the local government and the peasants seemed to be covered. Thus, many rural coal mines rejected the prohibition and continued to operate under the acquiescence of the local government.

4.2.2.

Oil

The crude oil production amounted to 5.49 × 108 t (0.35gha/cap or 5.43ha/cap) during the sixth 5-year plan period (1981–1985), which in turn constrained the development of the civil transportation and heavy industries though the foreign exchange receipt about 26 billion dollars were gained. During the seventh 5-year plan period (1986–1990), the production of the former major oil industries located in the eastern China stabilized. The exploitation transferred to the western areas, where the Talimu Basin oil field was being explored. Meanwhile, the production of Daqing, Liaohe, Shengli, Dagang and Zhongyuan fields continued to increase with adjustment to stabilize the declining ratio and water content. The explored reserves accumulated 0.89 billion tons, the total production keeping rising gradually during the eighth 5year period (1991–1995) with four new million tonnages oil fields, that is, Tazhong, Shixi, Qiuling and Ansai being discovered. In addition, the import crude oil exceeded the export the first time in 1993, which indicated the dramatically increasing demand for crude oil. It can be concluded that the increasing crude oil production mainly depended on the production of the new discovered oil fields over the past 20years.

4.2.3.

Natural gas

It was until 1980 that the first natural gas reservoir was put into operation in Daqing. In the following years (1980–1995), the natural gas production developed slowly compared with the crude oil production. The investments in the natural gas industries are only tenth of the amount invested in petroleum industries and the heavy resource tax (2 15yuan/m3), added value tax (13%) and income tax (33%) further impede the exploitation of natural gas. Also, the materials input to the natural gas industries are regulated by the market, whereas the production is decided and fixed by the parent administrative department, at costs which the natural gas industries are always in deficit without the capability to operate at a profit to explore. Despite the disadvantages mentioned above, new gas fields discovered in the eighth 5-year period, encompassing Shaanxi-Gansu-Ningxia with 2.28 × 10 1 1 cum reserves, Eastern Sichuan with 2.0 × 1011 cum reserves and Xinjiang with 1.87 × 1011 cum reserves, provided sufficient resources to increase the production. The exploitation scale of the gas blanket expanded in Sichuan, Qinghai, Tuha and

EC O L O G IC A L E C O N O M IC S 6 1 ( 2 0 07 ) 35 5 –3 76

Xinjiang in 1996 in order to compensate the decreasing natural gas production accompanied by the declining crude oil production of the eastern oil fields. Seven gas fields were discovered and two were put into operation associated with production capacity 6.27 × 1011 cum and associated gas 2.28 × 10 cum. The supervisor mode transferred in 1997, from the focus on the simple safe and stable production to the multi-channel marketing, which in turn stimulated the further production increment. The natural gas production skyrocketed with 0.007gha/cap or 0.13ha/cap in 1981 and 0.013gha/cap or 0.23 ha/cap in 2001, for the large scale explored gas fields, distributed in Zhungeer, Talimu, Shanxi-Gansu-Ningxia and Sichuan were discovered with generation of new technologies, e.g., high resolution imaging well logging method. Investments in abroad natural gas resources and the obtained natural gas quotas also added to the civil increasing production.

4.3.

Forest

The forest resources are scarce in China, especially in the Yellow River Basin wherein percentage coverage of forest is extremely low, leading to serious soil and water loss associated with dramatically declining fertility of the cultivated land. Thereby, forestry is directly related to the agriculture as the basic guarantee. However, due to the increasing demand for woods in paper making industries and large amount of woods treated as fuels in rural areas, excessive cutting and false reproducing area accompanied by low conservation are quite common. Protection forest is developed to amend the microclimate, regulate the hydrologic cycle and features, conserve the soil and water resource, break the wind and maintain the healthy ecological system. Special forest is planted for the purpose of military, experiment, landscape and natural protection. Firewood forest, providing rapid growth wood as biomass fuels for the rural areas, are explained afore in the biomass part. The EF or EEEF of the forest sector fluctuated around 0.11gha/cap or 0.16ha/cap during 1981 and 2001. The forestation area reached the acme in 1987 (0.12gha/cap or 0.26ha/cap) and then gradually decreased until 2001 (0.08 gha/cap or 0.19ha/cap), reflecting the trend of the use of the forest from the simple cutting to the integrated utilization. The economic forest kept stable increasing during the past two decades, mirroring the rational economic utilization based on market demand. The firewood forest area increased in the 1980s, caused by the policy stipulated by the Forestry Ministry, and decreased in the 1990s, for the energy utilization mode of the rural areas became multiple when fossil fuels are introduced and the simple direct burning of the firewood are not preferred as before by the people. Meanwhile, the protection forest area had been rapidly on the rise since the 1990s, to a large extent indicating the awareness of recovery of the deteriorating soil and water resources and reserve of the scarce forest resources.

4.4.

Fishery

From 1966 to 1976, sideline production including fishery was prohibited in China, whereas the egalitarianism was strictly carried out and state unified procurement of aquatic products

371

made the fishery develop slowly. At the same time, the fishermen dislike fish breeding and prefer direct fishing. In the offshore areas, the catching capacity far overtook the reproducibility of the fish concerning the growing fishing boats and nets, with the result that belt fish and yellow-fin tuna could not format fishing season in the Yellow Sea and drastically decreased in the East China Sea. Moreover, the preservation, processing and transportation system left far behind the development of production. The EF or EEEF of the fishery sector has increased from 0.05gha/cap or 0.28ha/cap in 1981 to 0.13gha/cap or 1.67ha/cap in 2001. The bump years have been from 1976 to 1984, when the fishery production restored according to the policy of the national economy, namely, “Adjustment, Reform, Rectification and Improvement”. The whole fishery started to be adjusted, contracting the fishing production, developing the breeding and undertaking transoceanic fishery. The aquatic production has been increasing since 1985. As the breeding is established as the major part of the fishery, the freshwater and seawater breeding are developed and the inland water, shallow sea beach and waste low land exploited, enriching the “vegetable basket” of the urban residents and creating more than 10 million jobs. To protect the fishing season and offshore fishery resources, the Fishery Bureau of Zhejiang pioneered to set closed fishing seasons from July to October in 1979, which brought about far-reaching changes. The State Fishery Bureau prescribed that the individual fishing be prohibited while the state-owned fishing was permitted from July to October in eastern costal areas, which in turn was protested and denied by the individual fishermen in 1980. Thereafter, new ordinance was announced that the fishing be prohibited both for state-owned and individual fishery from August to October in the eastern China Sea and Yellow Sea between the north 27N and 34N areas. However, before 1995, the ordinance was totally disobeyed and offended without effective supervision, for the economic losses during the closed fishing season were difficult to endure whether for the state-owned aquaculture industries or individual ones. The State Fishery Bureau resumed setting closed fishing seasons in the eastern China Sea and Yellow Sea between the north 27N and 34N in July and August (summer season) and extending 30 sea miles from the forbidden zones for fishing in September and October in 1995. During this period, fishing with trawl and canvas expanding nets were both forbidden. Meanwhile, the State Fishery Bureau took measures to organize the idle fishermen to repair boats, nets and machines, undertake free technical training, and sometimes assist the surrounding peasants in harvesting and cropping. The closed fishing season system was further adjusted and improved in 2000, with 117,457 fishing boats laid up in the ports of eastern China Sea, Yellow Sea and South Sea. The canvas expansion nets fishing, which destroyed the growth and reproduction of the fish, especially the juvenile fish, was strictly supervised and gradually diminished. Illegal acts, such as electrifying, poisoning and exploding fishes, coupled with special utilization of fishing gears, such as electric catching devices, were also severely punished. Meanwhile, the ecological fish breeding mode has been propagated and generalized since 1990, wherein fishery is

372

EC O LO GIC A L E CO N O M ICS 6 1 ( 2 00 7 ) 3 5 5 –3 76

combined with agriculture and animal husbandry. Ecological fish breeding area amounted to 5.22 × 104 ha, coupled with 8.67 × 105 pigs and 3.34 × 106 fowls in Hunan, while in Sichuan, the ecological fish breeding areas based on the proportion that 1000 kg rice corresponding to 100 kg fish surpassed 3.33 × 104 ha in 1990. The paddy field fish breeding area of China rose to 1.53 × 106 ha in 2000. For example, in Guizhou, the poorest area in China, 994ha paddy areas distributed in 153 villages of 26 counties were coupled with the ecological fishery, with the result that the aquatic production accounted to 1.79 × 103 t and income from aquatic products 405 yuan per capita annually, as well as more than 3 × 105 peasants cast off the poverty and set out on a road to prosperity. Furthermore, after 2000 onwards, introduction, cultivation, trial cultivation and breeding system which is generalized and promoted helps to set up new fishery bases integrating tourism, sightseeing, recreation, famous species cultivation and popularization in one and improve the quality and economic benefit of the fishery.

4.5.

Pasture

During the third National Pasture Resource Census periods (1979–1995), the rangeland area adds up to 4 × 108 ha, amounted for 41.7% of the country, with 1 × 108 ha located in cultivated areas and 3 × 108 ha in pasture areas. The government started to convert the reclaimed land, which resulted in desertification, to pasture in 1980 while rotational grazing by fence (Kulun) was also tried in some places. Beginning in 1977, fly sowing project was started in Inner Mongolia, Shaanxi and Ningxia. By 1997, fly sowing rangeland areas reached 2.3 × 106 ha. From 1981 to 1995, the average annually cultivated and improved pasture amounted to 1.1 × 106 ha, 2.2 × 106 ha and 2.6 × 106 ha, respectively. Moreover, the nationwide pasture production contract responsibility akin to the agriculture production was generalized, which stimulate the incentives of the herdsmen to protect, construct and utilize the pasture resources in a rational way. Strategic adjustment was made in 1996 to meet the increasing demand for rangeland resources and the comprehensive development of the southern rangeland resources mainly located in the hills and slopes was implemented with improved seed of the grass and new breed of the livestock. Considering the vertical distribution of the grassland in the southern areas, the integrated ecological mode of “grain– grass–forest–drug” is proposed and developed to reconstruct the mountain ecological systems. In 2000, the government set down the National Ecological Construction Programme, promoting the natural rangeland protection measures which include rotational grazing by fence, conservation, tending and control of rodent and insect pests; propagating the pasture improvements which include after-culture, shallow-plowing, fertilization and irrigation; and construction methods which include fly-sowing, artificially cultivating, converting the cultured land to pasture and establishment of forage base, in order to raise the relative low level of the rangeland construction areas proportion, which accounted for only 3% to 30% of the total pasture areas. The investment of the central government in pasture

rehabilitation and reconstruction increased sharply in 2000. The Protection Project of Western Natural Grassland Vegetation (0.2 billion yuan invested) was started to establish 30 natural pasture protection and construction areas as demonstration projects in Inner Mongolia and Xinjiang. National Pasture Seed Base Construction Project (0.4 billion yuan invested) was also launched to set up five xerophytic pasture domestication and seed bases in western and northern areas. In addition, Prevention Project of Dust in Beijing and Its Surroundings (0.7 billion yuan invested) was initialed, of which 0.23 billion yuan was used to cultivate the grassland so as to protect Beijing against the terrible dust weather in spring. The herdsmen subsidized with the forage by the government were guided to transfer from the traditional production pattern, that is, moving to desert areas in winter and returning to the pasture for summer grazing, which depends on the status of the natural rangeland resources, to the rotationally graze coupled with stable breeding. Reynolds (2001) presented two case studies of the grassland ecosystems from China, of which the project of settling the Kazak herders with winter feed and transhumant systems in Altai Prefecture, which located in northern part of Xinjiang near the border with Kazakstan and Mongolia is analyzed in detail. It is indicated that, with the winter base and irrigation land for forage provided by the Kazak herder resettlement programme, the traditional life way of the nomad is deeply impacted. Thus, the increasing pressure imposed on the natural pasture is temporarily alleviated, albeit the fragile ecological balance is established which is difficult to maintain in the long term in the northern agro pastoral areas when the poor crop management and productivity, lack of water resources and overgrazing are considered. Despite the efforts made by the government, the degradation of the rangeland became still serious compared with the ecological construction, considering the degenerated rangeland areas summing up to 9 × 107 ha and 1% yield decline (Jiang, 1997; Wang et al., 2002). In addition, over grazing intensity leads to desertification, resulting in decline on the rangeland resources yield and 2.5 × 105 ha desertification areas increased each year, especially in agro pastoral transitional zones. For example, between 1949 and 1979, there were 3.5 × 106 ha rangeland reclaimed by the state farm system in Xinjiang and 2.1 × 106 ha in Inner Mongolia. It can be calculated that the EF or EEEF of the pasture sector has fluctuated around 0.12gha/cap or 0.24ha/cap during 1981 and 2001.

4.6.

Built-up land

Along with the increasing population and urbanization, the built-up area kept growing during the period 1981–2001. On one hand, since the boundary of the urban areas and the rural areas that was fixed in the 1950s has changed and the domain of the city keeps expanding, the hinterlands of the city have to be enlarged to effectively support the city itself, with more and more cropland and other types of lands being appropriated for built-up land so as to accommodate the additional people from the surrounding of the city. On the other hand, the farmers who encountered inequality economic problems in

EC O L O G IC A L E C O N O M IC S 6 1 ( 2 0 07 ) 35 5 –3 76

rural areas seek for migration to urban areas in search of employment.

5.

Comparison and discussion

Considering the different results based on conventional EF and the embodied exergy EF, the comparison and related discussion on EF, biocapacity and ecological overshoot, are presented as below.

5.1.

EF

As discussed in the section above, the conventional EF is calculated in the bioproduction view, whereas the EEEF is founded on three production, i.e., population production, economic production and environment production. Although the embodied exergy contents (Jc) of the products differ greatly from the weight (kg) of the yields from the bioproductive areas, the EF per capita varied in a similar trend as the EEEF per capita from 1981 to 2001, indicating a reasonably accordance between the results of these two methods. There are also some differences on more detailed level. The EEEF expanded by larger growth rate than the conventional EF. Also, considering the components, fossil energy and cropland contributed most to the total EF in conventional EF method, whereas fossil energy, cropland and fisheries are the major contents of the EEEF. The difference of the contribution can be explained by the products from the marine areas, although human have intensely explored as the land, which are assumed as a small fraction of human consumption and less manipulated by the human policy and management, are simplified and sometimes underestimated by the conventional EF based on the fundamental assumptions (Wackernagel and Rees, 1996).

5.2.

Biocapacity

Due to the different definitions of the biocapacity, the trends of the biocapacity of the conventional EF and EEEF are obviously distinguished. Along with the population growth, the embodied exergy biocapacity per capita has been steadily declining, from 11.45ha in 1981 to 8.98ha in 2001, as is shown in Fig. 6. The conventional biocapacity per capita fluctuates around the mean line (0.67gha). However, the point is not how to define the biocapacity, but to describe to what extent human use of natural capital, which is represented in the next subsection.

5.3.

Ecological overshoot

The EF per capita of the conventional EF always exceed the biocapacity in the study period. In contrast, the EEEF per capita started to exceed the biocapacity after 1990 due to the different definitions of biocapacity. However, the varying trends of the ecological overshoot based on conventional EF and EEEF are similar, although some principles of conventional EF and EEEF are quite different. To illustrate and demonstrate the possibility and actual occurrence of the ecological overshoot, which is the forgotten core concept of

373

sustainability (Wackernagel and Silverstein, 2000), EEEF, as a modification and complementary concept of the conventional EF, can help determine the overall depletion status of the natural capital based on the second law of thermodynamics. The consistent results of the ecological overshoot founded on conventional EF and EEEF show that the basic assumption of the conventional EF is reasonable and the extent to which human use of nature capital is not overestimated, but underestimated.

6.

Conclusions

Based on the second law of thermodynamics, the concept of embodied exergy is applied to ecological evaluation, resource accounting and environmental impact assessment. Embodied exergy, as a kind of embodied energy, further internalizes the impact external to the existing process of the earth, considering the cosmic exergy resulted in the thermodynamic difference between the solar and CBM radiation, part of which is intercepted by the earth and consumed in driving and sustaining the earth system. Since the anthropogenic exergy use is in the order-of-magnitude of 1% of the global exergy consumption of the material earth and can be dominant for some terrestrial processes (Chen, 2005), the budget of cosmic exergy can be regarded as a necessary indicator for ecological evaluation as it raises a unified thermodynamic metric for objectively evaluating resource depletion, environment degradation and ecological overshoot and provides an essential measure of “use scarcity” (Cleveland and Stern, 1999) of the real power driving the earth system. This paper introduces the embodied exergy method into EF calculation and makes a time series comparison study of China 1981–2001. Compared with the conventional EF, EF based on embodied exergy analysis avoids the disputable assumptions presumed by the conventional EF method, provides a consistent biophysical value to assess the resource, environment and buffering capacity in three production perspectives, including population production, economic production and environment production. The land area is reconstructed on the scarce factor of the ecological production, i.e., embodied exergy, offering an promoted and reliable measure of the development of the ecological system in the ecologically average sense over different time and space scales. Meanwhile, the difference between the EF and EEEF lies not only in the exergy or energy content of the products, but also in the “transformation” way concerning the exergy hierarchy existed in the general ecological system. The embodied exergy equivalent is obtained quite differently from the land equivalent calculated from the same products, although the results are similar. Since the results are similar while the prerequisite is quite different, this case study can validate the reasonability of the presumptions of EF that are criticized by some researchers. Moreover, associated with the concept of embodied exergy, EEEF intensity, defined as the ratio of the EEEF and the real status of the economic output, which is often represented in GDP, is used to depict the resource consumption intensity, also in the ecologically average sense, corresponding to the unit economic output.

374

EC O LO GIC A L E CO N O M ICS 6 1 ( 2 00 7 ) 3 5 5 –3 76

Acknowledgements This work was funded by the State Key Basic Research and Development Plan (973 Plan, Grant No. 2005CB724204), National Natural Science Foundation of China (Grant No. 1037226) and China Postdoctoral Science Foundation (Grant No. 2005038036).

REFERENCES Arrow, K., Bolin, B., Costanza, R., Dasgupta, P., Folke, C., Holling, C.S., Jansson, B.O., Levein, S., Maler, K.G., Perrings, C., Pimentel, D., 1995. Economic growth, carrying capacity, and the environment. Science 268 (5210), 520–521. Ash, R.F., 1998. Agricultural Development in China, 1949– 1989, The Collective Papers of Kenneth R. Walker (1931– 1989). Oxford University Press, New York, pp. 106–118, 227–256. Ayres, R.U., 2000. Commentary on the utility of the ecological footprint concept. Ecol. Econ. 32, 347–349. Ayres, R.U., Ayres, L.W., Martinas, K., 1998. Exergy, waste accounting and life-cycle analysis. Energy 23 (5), 353–363. Ayres, R.U., Ayres, L.W., Warr, B., 2003. Exergy, power and work in the US economy, 1900–1998. Energy 28, 219–273. Bergh, v.d., Verbruggen, H., 1999. Spatial sustainability, trade and indicators: an evaluation of the ‘ecological footprint’. Ecol. Econ. 29, 61–72. Campbell, D.E., 1997. Emergy analysis of human carrying capacity and regional sustainability: an example using the state of Maine. Eviron. Monit. Assess. 51, 531–569. CAY, China Agriculture Yearbook, 1982–2003. China Statistical Publishing House, Beijing. CCIY, China Coal Industry Yearbook, 1982–2002. China Coal Industry Publishing House, Beijing. CESY, China Energy Statistical Yearbook, 1986,1991,1991/ 1996,1997/1999, 2000/2002. China Statistical Publishing House, Beijing. CEY, China Environmental Yearbook, 1990–2003. China Environmental Yearbook Press, Beijing. CFY, China Forestry Yearbook, 1949/1986, 1987–2003. China Forestry Press, Beijing. Chen, G.Q., 2005. Exergy consumption of the earth. Ecol. Model. 184, 363–380. Chen, G.Q., 2006. Scarcity of exergy and ecological evaluation based on embodied exergy. Commun. Nonlinear Sci. Numer. Simul. 11, 531–552. Chen, B., Chen, G.Q., 2006. Exergy analysis for resource conversion of the Chinese society 1993 under the material product system. Energy 31, 1115–1150. Chen, D.J., Cheng, G.D., Xu, Z.M., Zhang, Z.Q., 2004. Ecological footprint of the Chinese population, environment and development. Environ. Conserv. 31 (1), 63–68. Christensen, P., 2004. Economic thought, history of energy in. In: Cleveland, C.J. (Ed.), Encyclopedia of Energy, 2. Elsevier, pp. 117–130. CIESY, China Industrial Economic Statistical Yearbook, 1988–1990, 1992 1995, 1998, 2001–2003. China Statistical Publishing House, Beijing. Cleveland, C.J., 1999. Biophysical economics: from physiocracy to ecological economics and industrial ecology. In: Mayumi, K., Gowdy, J.M. (Eds.), Bioeconomics and Sustainability: Essays in Honor of Nicholas Georgescu-Roegen. Edward Elgar, pp. 125–154.

Cleveland, C.J., Stern, D.I., 1999. Indicators of natural resource scarcity: a review and synthesis. In: van den Bergh, Jeroen C.J.M. (Ed.), Handbook of Environmental and Resource Economics. Edward Elgar, pp. 89–108. Cleveland, C.J., Costanza, R., Hall, C.A.S., Kaufmann, R., 1984. Energy and the US economy: a biophysical perspective. Science 225, 890–897. Costanza, R., 1980. Embodied energy and economic valuation. Science 210, 1219–1224. Costanza, R., 2000. The dynamics of the ecological footprint concept. Ecol. Econ. 32, 341–345. Costanza, R., Herendeen, R.A., 1984. Embodied energy and economic value in the United States economy: 1963, 1967 and 1972. Resour. Energy 6, 129–163. Costanza, R., Perrings, C., Cleveland, C.J., 1997. The Development of Ecological Economics. An Elgar Reference Collection. UK. Daily, G.C., Ehrlich, P.R., 1996. Socioeconomic equity, sustainability, and earth's carrying capacity. Ecol. Appl. 6 (4), 991–1001. Deutsch, L., Jansson, Å., Troell, M., Rönnbäck, P., Folke, C., Kautsky, N., 2000. The ‘ecological footprint’: communicating human dependence on nature's work. Ecol. Econ. 32, 351–355. Dincer, I., 2002. The role of exergy in energy policy making. Energy Policy 30, 137–149. Dincer, I., Hussain, M.M., Zahanah, I.A., 2004. Energy and exergy utilization in transportation sector of Saudi Arabia. Appl. Therm. Eng. 24, 525–538. Erb, K.-H., 2004. Actual land demand of Austria 1926–2000: a variation on ecological footprint assessments. Land Use Policy 21, 247–259. Ertesvåg, I.S., 2001. Society exergy analysis: a comparison of different societies. Energy 26, 253–270. Ertesvåg, I.S., 2005. Energy, exergy, and extended-exergy analysis of the Norwegian society 2000. Energy 30, 649–675. Ertesvåg, I.S., Mielnik, M., 2000. Exergy analysis of the Norway society. Energy 25, 953–957. Farber, S.C., Costanza, R., Wilson, M.A., 2002. Economic and ecological concepts for valuing ecosystem services. Ecol. Econ. 41, 375–392. Faucheux, S., O'Connor, M., 1998. Energy measures and their uses. In: Faucheux, S., O'Connor, M. (Eds.), Valuation for Sustainable Development. Edward Elgar, pp. 121–166. Fricker, A., 1998. The ecological footprint of New Zealand as a step towards sustainability. Futures 30 (9), 559–567. Haberl, H., Erb, K.-H., Krausmann, F., 2001. How to calculate and interpret ecological footprints for long periods of time: the case of Austri 1926–1995. Ecol. Econ. 38, 25–45. Herendeen, R.A., 2000. Ecological footprint is a vivid indicator of indirect effects. Ecol. Econ. 32, 357–358. Higgins, J.B., 2003. Emergy analysis of the oak openings region. Ecol. Eng. 21 (1), 75–109. Huettner, D.A., Costanza, R., 1982. Economic values and embodied energy. Science 216, 1141–1143. Jiang, S., 1997. Sustainable utilizations of grassland resources in China (in Chinese). Acta Agresia Sinca 5 (2), 73–79. Jin, S.X., Jiang, Y., et al., 1997. Present Situation and Rational Exploitation and Utilization of Coal Resources of China (in Chinese). Geological Publishing House, Beijing. Jørgensen, S.E., 1981. In: Mitsh, W.I., Bosserman, R.W. (Eds.), Exergy and Buffering Capacity in Ecological System in Energetics and Systems. Michigen, pp. 61–72. Jørgensen, S.E., 1992a. Parameters, ecological constraints and exergy. Ecol. Model. 60. Jørgensen, S.E., 1992b. Development of models able to account for changes in species composition. Ecol. Modelling 60. Jørgensen, S.E., 1994. Fundamentals of Ecological Modelling. Elsevier, Amsterdam. Jørgensen, S.E., 1999. State-of-the-art of ecological modeling with emphasis on development of structural dynamic models. Ecol. Model. 120, 75–96.

EC O L O G IC A L E C O N O M IC S 6 1 ( 2 0 07 ) 35 5 –3 76

Jørgensen, S.E., 2000. Application of exergy and specific exergy as ecological indicators of coastal areas. Aquat. Ecosyst. Health Manag. 3, 419–430. Jørgensen, SE., 2001. Thermodynamics and Ecological Modelling. CRC Press LLC, New York Washington, DC. Jørgensen, S.E., Nielsen, S., Mejer, H., 1995. Emergy, environ, exergy and ecological modelling. Ecol. Model. 77, 99–109. Jørgensen, S.E., Patten, B.C., Milan, S., 1999. Ecosystems emerging: 3. Openness. Ecol. Model. 117, 41–64. Jørgensen, S.E., Patten, B.C., Milan, S., 2000. Ecosystems emerging: 4. Growth. Ecol. Model. 126, 249–284. Kotas, T.J., 1985. The Exergy Method of Thermal Plant Analysis. Butterworths, London. Kratena, K., 2004. ‘Ecological value added’ in an integrated ecosystem–economy model—an indicator for sustainability. Ecol. Econ. 48, 189–200. Martinez-Alier, J., Schlüpmann, K., 1990. Ecological Economics: Energy, Environment and Society. Basil Blackwell, pp. 45–149. McDonald, G.W., Patterson, M.G., 2004. Ecological footprints and interdependencies of New Zealand regions. Ecol. Econ. 50, 49–67. Mejer, H.F., Jørgensen, S.E., 1979. Energy and ecological buffer capacity. In: Jørgensen, S.E. (Ed.), State-of-the-Art of Ecological Modelling. (Environmental Sciences and Applications, 7). Proc. of a Conference on Ecological Modelling, 28 August−2 September 1978, Copenhagen. International Society for Ecological Modelling, Copenhagen, pp. 829–846. Milia, D., Sciubba, E., 2006. Exergy-based lumped simulation of complex systems: an interactive analysis tool. Energy 31, 100–111. Moffatt, I., 2000. Ecological footprints and sustainable development. Ecol. Econ. 32, 359–362. Monfreda, C., Wackernagel, M., Deumling, D., 2004. Establishing national natural capital accounts based on detailed ecological footprint and biological capacity assessment. Land Use Policy 21, 231–246. Morris, D.R., Szargut, J., 1986. Standard chemical exergy of some elements and compounds on the planet earth. Energy 11, 733–755. Nelson, R.H., 1995. Sustainability, efficiency and God: economic values and the sustainability debate. Annu. Rev. Ecol. Syst. 26, 135–154. Odum, H.T., 1971. Environment, Power, and Society. John Wiley, p. 336. Odum, H.T., 1983. Systems Ecology: An Introduction. John Wiley, NY, p. 644. revised in 1994. Ecological and General Systems: An Introduction to Systems Ecology. Univ. Press of Colo., P.O. Box 849, Niwot, 80544. Odum, H.T., 1988. Self-organization, transformity and information. Science 242, 1132–1139. Odum, H.T., 1996. Environmental Accounting: Emergy and Environmental Decision Making. Johns & Wiley, New York, US. Odum, H.T., Brown, M.T., 1975. Carrying capacity for man and nature in South Florida. Final Report to the National Park Service, US Dept. Interior and State of Florida, Division of State Planning. Odum, H.T., Odum, E.C., Blisset, M., 1987a. Ecology and economy: emergy analysis and public policy in Texas, L.B. Johnson. School of Public Affairs and Texas Dept. of Agriculture, University of Texas, Austin. Odum, H.T., Wang, F.C., Alexander, J.F., Gilliland, M., Miller, M.A., Sendzimir, J., 1987b. Energy Analysis of Environmental Value. Center for Wetlands. University of Florida, Gainesville, FL. Opschoor, H., 2000. The ecological footprint: measuring rod or metaphor? Ecol. Econ. 32, 363–365. Pacca, S., Horvath, A., 2002. Greenhouse gas emissions from building and operating electric power plants in the Upper Colorado River Basin. Environ. Sci. Technol. 36 (14), 3194–3200.

375

Pillet, G., Odum, H.T., 1984. Energy externality and the economy of Switzerland. Swiss J. Pol. Econ. Stat. 120, 409–435. Rapport, D.J., 2000. Ecological footprints and ecosystem health: complementary approaches to a sustainable future. Ecol. Econ. 32, 367–370. Rees, W.E., 2000. Eco-footprint analysis: merits and brickbats. Ecol. Econ. 32, 371–374. Reynolds, S.G., 2001. Sustainable development of grassland ecosystems: two case studies from China. Presented at the International Symposium on Sustainable Development of Grassland Ecosystems, 27–30 August, Xilinhot, Inner Mongolia, China. Rosen, M.A., 1992. Evaluation of energy utilization efficiency in Canada using energy and exergy analyses. Energy 17 (4), 339–350. RSYC, Rural Statistical Yearbook of China, 1985–2003. China Statistical Publishing House, Beijing. Schaeffer, R., Wirtshafter, R.M., 1992. An exergy analysis of the Brazilian economy: from energy production to final energy use. Energy l7 (9), 841–855. Sciubba, E., 1995. Modelling the energetic and exergetic selfsustainability of societies with different structures. J. Eng. Res. Technol. 117 (6). Sciubba, E., 1998. A nested black-box exergetic method for the analysis of complex systems. In: Ulgiati, S., et al. (Ed.), Proc. of Adv. in Energy Studies. P. Venere, Italy, pp. 471–482. Sciubba, E., 1999. Exergy as a direct measure of environmental impact. AES-39. ASME. Sciubba, E., 2001a. Using exergy to evaluate environmental externalities. Invited lecture, IV NTVA Seminar on Industrial Ecology, Trondheim. Sciubba, E., 2001b. Beyond thermoeconomics? The concept of extended exergy accounting and its application to the analysis and design of thermal systems. Exergy Int. J. 1 (2), 68–84. Sciubba, E., 2003. Cost analysis of energy conversion systems via a novel resource-based quantifier. Energy 28, 457–477. Sciubba, E., 2004. Exergoeconomics. In: Cleveland, C.J. (Ed.), Encyclopedia of Energy, vol. 2. Elsevier, pp. 577–591. Sciubba, E., 2005. Exergo-economics: thermodynamic foundation for a more rational resource use. Int. J. Energy Res. 29, 613–636. Senbel, M., McDaniels, T., Dowlatabadi, H., 2003. The ecological footprint: a non-monetary metric of human consumption applied to North America. Glob. Environ. Changes 13, 83–100. Shambaugh, D., 2000. The Modern Chinese State. Cambridge University Press, Cambridge, U.K., pp. 207–215. Simmons, C., Lewis, K., Barrett, J., 2000. Two feet-two approaches: a component-based model of ecological footprinting. Ecol. Econ. 32, 375–380. Stöglehner, G., 2003. Ecological footprint—a tool for assessing sustainable energy supplies. J. Clean. Prod. 11, 267–277. SYC, Statistical Yearbook of China, 1980–2002. China Statistical Publishing House, Beijing. Szargut, J., 1980. International process in second law analysis. Energy 5, 709–718. Szargut, J., 1989. Chemical exergies of the elements. Appl. Energy 32, 269–286. Szargut, J., 2004. Exergy Method and Its Application in Ecology. WIT Press, Newcastle. Szargut, J., Dziedziniewicz, Csimir, 1971. Energie utilizable des substances chimiques inorganiques. Entropie 40, 14–23. Szargut, J., Morris, D.R., 1985. Calculation of the standard chemical exergy of some elements and their compounds, based upon sea water as the datum level substance. Bull. Pol. Acad. Sci., Tech. Sci. 33 (5–6), 292–305. Szargut, J., Ziebik, A., Stanek, W., 2002. Depletion of the nonrenewable natural exergy resources as a measure of the ecological cost. Energy Convers. Manag. 43, 1149–1163. Teather, D.C.B., Yee, H.S., 1999. China in Transition-Issues and Polices. Macmillan Press Ltd., London, pp. xvi–xxvii, 171–193.

376

EC O LO GIC A L E CO N O M ICS 6 1 ( 2 00 7 ) 3 5 5 –3 76

Templet, P.H., 2000. Externalities, subsidies and the ecological footprint: an empirical analysis. Ecol. Econ. 32, 381–383. Ulgiati, S., Brown, M.T., 1998. Monitoring patterns of sustainability in natural and man-made ecosystems. Ecol. Model. 108, 23–36. Ulgiati, S., Brown, M.T., 1999. Emergy accounting of humandominated, large scale ecosystems. In: Jørgensen, Kay (Ed.), Thermodynamics and Ecology. Ulgiati, S., Odum, H.T., Bastianoni, S., 1994. Emergy analysis, environmental loading and sustainability: an emergy analysis of Italy. Ecol. Model. 73, 215–268. Ulgiati, S., Brown, M.T., Bastianoni, S., Marchettini, N., 1995. Emergy based indices and ratios to evaluate the sustainable use of resources. Ecol. Eng. 5, 519–531. USDA, Nutrient Database, 2003. Beltsville Human Nutrition Center, USA. van Kooten, G.C., Bulte, E.H., 2000. The ecological footprint: useful science or politics? Ecol. Econ. 32, 385–389. van Vuuren, D.P., Bouwman, L.F., 2005. Exploring past and future changes in the ecological footprint for world regions. Ecol. Econ. 52, 43–62. van Vuuren, D.P., Smeets, E.M.W., 2000. Ecological footprints of Benin, Bhutan, Costa Rica and the Netherlands. Ecol. Econ. 34, 115–130. Vitousek, P.M., Ehrlich, P.R., Ehrlich, A.H., Matson, P.A., 1986. Human appropriation of the products of photosynthesis. BioScience 36 (6), 368–373. Vitousek, P.M., Mooney, H.A., Lubchenco, J., Melillo, J.M., 1997. Human domination of Earth's ecosystems. Science 277 (5325), 494–499. Wackernagel, M., Monfreda, C., 2004. Ecological footprints and energy. In: Cleveland, C.J. (Ed.). Encyclopedia of Energy, Elsevier, pp. 2, 1–11. Wackernagel, M., Rees, W.E., 1996. Our Ecological Footprint: Reducing Human Impact on the Earth. New Society, Gabrioala, BC, Canada. Wackernagel, M., Rees, W.E., 1997. Perceptual and structural barriers to investing in natural capital: economics from an ecological footprint perspective. Ecol. Econ. 20, 3–24.

Wackernagel, M., Richardson, D., 1998. How to calculate a household's ecological footprint, in preparation. Anáhuac University of Xalapa and University of Texas. Wackernagel, M., Silverstein, J., 2000. Big things first: focusing on the scale imperative with the ecological footprint. Ecol. Econ. 32, 391–394. Wackernagel, M., Onisto, L., Bello, P., Linares, A.C., Falfan, I.S.L., Garcia, J.M., Guerrero, A.I.S., Guerrero, M.G.S., 1999. National natural capital accounting with the ecological footprint concept. Ecol. Econ. 29, 375–390. Wackernagel, M., Monfreda, C., Schulz, N.B., Erb, K.H., Haberl, H., Schulz, N.B., 2004a. Ecological footprint time series of Austria, the Philippines, and South Korea for 1961–1999: comparing the conventional approach to an ‘actual land area’ approach. Land Use Policy 21, 261–269. Wackernagel, M., Monfreda, C., Schulz, N.B., Erb, K.H., Haberl, H., Krausmanh, F., 2004b. Calculating national and global ecological footprint time series: resolving conceptual challenges. Land Use Policy 21, 271–278. Wall, G., 1977. Exergy—A Useful Concept within Resource Accounting. Research Report no.77-42. Institute of Theoretical Physics, Göteborg, Sweden. Wall, G., 1986. Exergy—a useful concept, Thesis. Göteborg, Sweden: Chalmers University of Technology. Wall, G., 1990. Exergy conversion in the Japanese society. Energy 15 (5), 435–444. Wall, G., 1997. Exergy use in the Swedish society 1994. TAIES'97, June 10–13, Beijing, China. Wall, G., 1998. Exergetics. Mölndal, Sweden. See also: http:// exergy.se/. Wall, G., Gong, M., 2001a. On exergy and sustainable development: Part 1. Conditions and concepts. Exergy Int. J 1 (3), 128–145. Wall, G., Gong, M., 2001b. On exergy and sustainable development: Part 2. Indicators and methods. Exergy Int. J. 1 (4), 217–233. Wall, G., Sciubba, E., Naso, V., 1994. Exergy use in the Italian society. Energy 19 (12), 1267–1274. Wang, K., Han, J.G., Zhou, H., 2002. The current situation and developing strategy of Chinese grassland industry (in Chinese) Acta Agresia Sinca 10 (4), 293–297.