Exergy analysis of Chinese agriculture
Introduction
Agriculture, as a specific ecological entity at the interface between natural ecosystem and socio-economic system, is bounded with resource, environmental and economic dimensions. Natural resource inputs from the environment and purchased economic investments from the society are the essential prerequisite for sustaining the operation of agricultural ecological economic system and producing a certain level of economic output (Chen et al., 2009). The most distinct characteristic of modern agriculture is the intensive non-renewable resource use such as chemical fertilizer, pesticide, plastic film, electricity and diesel oil, due to the natural resource constraints. Traditional economic evaluation always underestimates the value of environmental inputs and ecosystem services provided by the natural ecosystem (Zhou et al., 2010). In order to optimize the structure and efficiency of resources use and reduce adverse environmental impacts, there is a growing concern on the sustainability of agricultural systems from the biophysical perspective (e.g., Chen et al., 2006b, Hoang and Prasada Rao, 2010, Perryman and Schramski, 2015, Zhang et al., 2016a, Zhang et al., 2016b, Zhang et al., 2016c, Zhang et al., 2016a, Zhang et al., 2016b, Zhang et al., 2016c, Zhang et al., 2016a, Zhang et al., 2016b, Zhang et al., 2016c, Wright and Østergård, 2016).
As an indicator of the distance from thermodynamic equilibrium based on the second law of thermodynamics, exergy provides a unified measure of various forms of energy carriers and materials (Szargut, 2005). The scarcity of exergy resources has been regarded as the fundamental feature for the ecosystem operation on the earth (Chen, 2005, Chen, 2006). Exergy can be played as a confluence of resource, environment and sustainable development (Rosen and Dincer, 2001, Zhang et al., 2012a, Zhang et al., 2012b). Exergy accounting as a basic medium has been carried out in various forms to qualify the exchange of ecological networks (Jørgensen and Fath, 2004, Dincer and Rosen, 2007). In the past two decades, the application of exergy method has been extended to the biophysical analyses on energy, resource and environmental problems in various scientific fields (Zhang and Chen, 2010). Exergy-based systems account has been widely used to assess societal exergy utilization in many countries or regions (e.g., Ertesvåg, 2005, Gasparatos et al., 2009, Dai et al., 2012, An et al., 2014, Gong and Wall, 2016), and concrete industrial sectors (e.g., Zhang et al., 2012a, Zhang et al., 2012b, BoroumandJazi et al., 2013, Bühler et al., 2016). The exploration and utilization of specific agricultural production systems can be systematically evaluated by the overall and unified accounting method, i.e., exergy analysis (e.g., Ahamed et al., 2011, Yang and Chen, 2014, Wu et al., 2015, Zisopoulos et al., 2017). Furthermore, exergy demand and exergy destruction have gained much attention for developing indicators or metrics related to sustainability assessment.
As a developing country with the world’s largest population, now up to 1.37 billion in 2015 (NBSC, 2017), agriculture plays a fundamental role in the Chinese society. The country’s agricultural issue such as food security has long been a focus for international organization, policy makers, researchers, and other groups around the world (Fukase and Martin, 2016). In history, Chinese agriculture was characterized by labor-intensive cultivation and relying heavily on free environmental resources (Chen et al., 2006b). Owing to the growing population scale and improving diet structure, the traditional agriculture with low productivity was no longer appropriate for the soaring demand of agricultural products. The self-sufficient family operation mode has been gradually substituted by the energy-intensive modern agriculture with higher agricultural productivity (Chen et al., 2009). In the past three decades, China has made tremendous progress in feeding its population with only 7% of the world’s arable land available (Piao et al., 2010). Along with soil degradation, the limited and diminished arable land and the acceleration of socio-economic transition, a great challenge still should be faced to ensure China’s food security by meeting its increasing food demand (Li et al., 2016a, Li et al., 2016b).
The diversity and complexity of Chinese agricultural system necessitates ecological analysis as an alternative to conventional economic analysis (Jiang et al., 2007, Chen et al., 2009, Tao et al., 2013). Chen and his colleagues have performed a series of studies on exergy accounting of the Chinese society covering the agricultural sector (e.g., Chen and Chen, 2006, Chen et al., 2006a, Chen and Chen, 2007a, Chen and Chen, 2007b, Chen and Chen, 2007c, Chen and Chen, 2007d, Chen and Qi, 2007, Zhang and Chen, 2010, Shao et al., 2013). For instance, Chen and Chen (2007c) performed a long time-series analysis of agricultural products of the Chinese society 1980–2002 based on exergy. Specifically, a detailed exergetic assessment by Chen et al. (2009) indicated that Chinese agriculture was experiencing a transition from the traditional self-supporting mode dependant on renewable resources to the pattern of increasing nonrenewable resource uses and heavy environmental impacts over the period of 1980–2000. Since the inception of the 21 st century, Chinese agriculture has undergone a rather dramatic change in the policy situation such as agricultural tax reform, and has continuously strengthened its resource, environmental and economic impacts such as the water-energy-food nexus. Nevertheless, its physical sustainability over this period remains to be systematically revealed.
To fill this gap, an overall exergy analysis of the Chinese agriculture during 2001–2015 will be presented. The resource use, economic yields and environmental impacts will be examined by accounting all the major exergy fluxes associated with agricultural activities. Systems structure of the exergy input/output, a variety of assessment indicators, and related resource, environmental and economic performances will be identified from a historical perspective. The ecological diagnosis of Chinese agriculture in fundamental biophysical term provides reliable and useful information to optimize resource utilization and alleviate environmental and climate impact (Rosen et al., 2008, Gasparatos and Scolobig, 2012), with essential implications to future agricultural sustainable development.
Section snippets
Methodology and data sources
Chinese agriculture comprises four interactive departments in terms of cropping, forestry, stockbreeding and fishery. The operation of this sector is sustained by various exergy resources input including free natural resources and purchased economic investments, while its yields mainly refer to the agricultural products as well as environmental emissions. With regard to the geographical scope of Chinese agriculture, only Mainland China is covered, and Hong Kong, Macao and Taiwan are excluded in
Resources input
Resource inputs into the agricultural system refer to free renewable resources (FR), free nonrenewable resources (FN), purchased renewable investment (PR) and purchased nonrenewable investment (PN). Fig. 2 presents the total resource input into Chinese agriculture during 2001–2015. The FR occupied a leading position, which increased slightly from 1.62 × 1020 J (88.24% of the total resource input) in 2001–1.67 × 1020 J (86.78%) in 2015. The PR took the second place with the share of 9.98% in 2001 and
Discussion
A better understanding of agricultural production pattern and structural transition is necessary for related stakeholders to address the evolution and driving forces of agricultural eco-economy. Exergy fluxes and indicators show that Chinese agriculture is a typical ecological economic system and its operation primarily depends on renewable resources input from natural ecosystem. Traditionally, land resource is a main productive factor associated with a large amount of free resources input. The
Concluding remarks
Achieving the nexus of economic development, population growth and food production–consumption balance has become a growing global challenge for sustainable development (Rask and Rask, 2011). The expansion of agricultural production and food consumption at the expense of environment is unsustainable. According to the sustainable development goals (SDGs) set by the United Nations for the next 15 years, agricultural sustainable development can directly contribute to achieving Goal 2 (End hunger,
Acknowledgements
This study has been supported by the National Natural Science Foundation of China (Grant nos. 71403270, 71774161 and 71373262), and the Foundation of State Key Laboratory of Coal Resources and Safe Mining, China University of Mining &Technology (Grant no. SKLCRSM16KFC06). Very helpful comments by the anonymous reviewers and the editor are highly appreciated.
References (99)
- et al.
An application of energy and exergy analysis in agricultural sector of Malaysia
Energy Policy
(2011) - et al.
Global footprints of water and land resources through China's food trade
Global Food Secur.
(2017) - et al.
Structural and regional variations of natural resource production in China based on exergy
Energy
(2014) - et al.
Energy and exergy analyses of the Danish industry sector
Appl. Energy
(2016) - et al.
A review on exergy analysis of industrial sector
Renew. Sustain. Energy Rev.
(2013) - et al.
Exergy analysis for resource conversion of the Chinese Society 1993 under the material product system
Energy
(2006) - et al.
Modified ecological footprint accounting and analysis based on embodied exergy–a case study of the Chinese society 1981–2001
Ecol. Econ.
(2007) - et al.
Resource analysis of the Chinese society 1980–2002 based on exergy–Part 2: renewable energy sources and forest
Energy Policy
(2007) - et al.
Resource analysis of the Chinese society 1980–2002 based on exergy–Part 3: agricultural products
Energy Policy
(2007) - et al.
Resource analysis of the Chinese society 1980–2002 based on exergy–Part 4: fishery and rangeland
Energy Policy
(2007)
Systems account of societal exergy utilization: china 2003
Ecol. Modell.
Exergy-based resource accounting for China
Ecol. Modell.
Emergy analysis of chinese agriculture. agriculture
Ecosyst. Environ.
Exergetic assessment for ecological economic system: chinese agriculture
Ecol. Modell.
Estimating nutrient releases from agriculture in China: an extended substance flow analysis framework and a modeling tool
Sci. Total Environ.
Exergy consumption of the earth
Ecol. Modell.
Scarcity of exergy and ecological evaluation based on embodied exergy
Commun. Nonlin. Sci. Numer. Simulat.
Constructing a network of the social-economic consumption system of China using extended exergy analysis
Renew. Sustain. Energy Rev.
Cropping system innovation for coping with climatic warming in China
Crop J.
Energy, exergy, and extended-exergy analysis of the Norwegian society 2000
Energy
Choosing the most appropriate sustainability assessment tool
Ecol. Econ.
Assessing the sustainability of the UK society using thermodynamic concepts: part 2
Renew. Sustain. Energy Rev.
Pesticide levels and environmental risk in aquatic environments in China–A review
Environ. Int.
Environmental impact of dietary change: a systematic review
J. Clean. Prod.
Measuring and decomposing sustainable efficiency in agricultural production: a cumulative exergy balance approach
Ecol. Econ.
Application of thermodynamic principles in ecology
Ecol. Complexity
Emergy account for biomass resource exploitation by agriculture in China
Energy Policy
China’s water scarcity
J. Environ. Manage.
Impacts of soil and water pollution on food safety and health risks in China
Environ. Int.
Management opportunities to mitigate greenhouse gas emissions from Chinese agriculture. Agriculture
Ecosyst. Environ.
Environmental costs of China’s food security. Agriculture
Ecosyst. Environ.
Evaluating the relationship between natural resource management and agriculture using embodied energy and eco-exergy analyses: a comparative study of nine countries
Ecol. Complexity
Economic development and food production–consumption balance: a growing global challenge
Food Policy
Exergy as the confluence of energy, environment and sustainable development
Exergy Int. J.
Role of exergy in increasing efficiency and sustainability and reducing environmental impact
Energy Policy
Exergy based ecological footprint accounting for China
Ecol. Modell.
Transforming agriculture in China: from solely high yield to both high yield and high resource use efficiency
Global Food Security
Provincial level-based emergy evaluation of crop production system and development modes in China
Ecol. Indic.
Greenhouse gas mitigation in Chinese agriculture: distinguishing technical and economic potentials
Global Environ. Change
Comparison of greenhouse gas emissions of chemical fertilizer types in China’s crop production
J. Clean. Prod.
Renewability and emergy footprint at different spatial scales for innovative food systems in Europe
Ecol. Indic.
Renewability and sustainability of biogas system: cosmic exergy based assessment for a case in China
Renew. Sustain. Energy Rev.
A comparative study on carbon footprints between plant- and animal-based foods in China
J. Clean. Prod.
Agriculture and crop science in China: innovation and sustainability
Crop J.
Carbon footprint of grain crop production in China −based on farm survey data
J. Clean. Prod.
Extended exergy-based sustainability accounting of a household biogas project in rural China
Energy Policy
Trends in the economic return on energy use and energy use efficiency in China’s crop production
Renew. Sustain. Energy Rev.
Mitigating greenhouse gas emissions in agriculture: from farm production to food consumption
J. Clean. Prod.
Utilization of straw in biomass energy in China
Renew. Sustain. Energy Rev.
Cited by (39)
Ecological accounting of the Chinese society 2012–2020 based on extended exergy
2023, Journal of Cleaner ProductionExergy analysis of China's transportation sector
2023, Sustainable Energy Technologies and AssessmentsSustainable wind energy planning through ecosystem service impact valuation and exergy: A study case in south-central Chile
2023, Renewable and Sustainable Energy ReviewsExploring provincial sustainable intensification of cultivated land use in China: An empirical study based on emergy analysis
2022, Physics and Chemistry of the Earth
- 1
These authors contributed equally to this paper.