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Environmental Modeling
Exploring future food provision scenarios for China Lin Ma, Zhaohai Bai, Wenqi Ma, Mengchu Guo, Rongfeng Jiang, Junguo Liu, Oene Oenema, Gerard L. Velthof, Andy Whitmore, John Crawford, Achim Dobermann, Marie Schwoob, and Fusuo Zhang Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.8b04375 • Publication Date (Web): 04 Jan 2019 Downloaded from http://pubs.acs.org on January 6, 2019
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Exploring future food provision scenarios for China
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Lin Ma*a†, Zhaohai Bai a†, Wenqi Ma a‡, Mengchu Guo∥, Rongfeng Jiang∥, Junguo
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Liu§, Oene Oenema⊥, Gerard L. Velthof ⊥, Andrew P. Whitmore ††, John Crawford ††,
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Achim Dobermann ††, Marie Schwoob ɸ, Fusuo Zhang*∥
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†
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Research, Institute of Genetics and Developmental Biology, Chinese Academy of
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Sciences, Shijiazhuang 050021, China;
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‡ College of Resources and Environmental Sciences, Hebei Agricultural University,
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Baoding, 071001, China;
Key Laboratory of Agricultural Water Resources, Center for Agricultural Resources
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∥Center for Resources, Environment and Food Security, China Agricultural
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University, Beijing 100193, China;
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§ School of Environmental Science and Engineering, South University of Science and
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Technology of China, Shenzhen, 518055, China;
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⊥Wageningen, Environmental Research P.O. Box 47, 6700 AA, Wageningen, The
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Netherlands;
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†† Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK;
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ɸ Institute for Sustainable Development and International Relations (IDDRI), 41, rue
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du Four 75006 Paris, France.
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a These authors contributed equally to this work.
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*Corresponding authors:
[email protected],
[email protected] 21 22
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ABSTRACT
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Developing sustainable food systems is essential, especially for emerging economies,
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where food systems are changing rapidly and afflict environment and natural
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resources. We explored possible future pathways for a sustainable food system in
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China, using multiple environmental indicators linked to 8 of the Sustainable
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Development Goals (SDGs). Forecasts for 2030 in a business as usual scenario (BAU)
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indicate increases in animal food consumption as well as increased shortages of the
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land available and the water needed to produce the required food in China. Associated
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greenhouse gas (GHG) emissions, and nitrogen and phosphorus losses could become
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10-42% of global emissions in 2010. We developed three main pathways besides
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BAU, [produce more and better-PMB, consume and waste less-CWL, and import
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more food-IMF], and analyzed their impacts and contributions to achieving one or
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more of the 8 SDGs. Under these scenarios, the demand for land and water, and the
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emissions of GHG and nutrients may decrease by 7-55% compared to BAU,
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depending on the pathway followed. A combination of PMB and CWL was most
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effective, while IMF externalizes impacts to countries exporting to China. Modestly
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increasing feed or food imports in a selective manner could ease the pressure on
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natural resources. Our modeling framework allows us to analyze the effects of
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changes in food production-consumption systems in an integrated manner, and the
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results can be linked to the 8 SDGs. Despite formidable technological, social,
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educational and structural barriers that need to be overcome, our study indicates that
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the ambitious targets of China’s new agricultural and environmental strategy appear to
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be achievable.
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TOC (Graphical Abstract) Consuming and Wasting Less
6 CLEAN WATER AND SANITATIO
1 NO POVERT Y
2 ZERO HUNGER
Sustainable food system 14 LIFE BELOW WATER
15 LIFE ON LAND
12 RESPONSIBLE CONSUMPTIO N AND PRODUCTION 13 CLIMATE ACTION
GHG emissions
Water use
3 GOOD HEALTH AND WELL-BEING
Produce More & Better
Import More Food
Food demand & supply
Fertilizer use
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Business as Usual
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INTRODUCTION
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Seventeen Sustainable Development Goals (SDGs) were approved by the United
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Nations in September 2015 1. Food systems are linked to at least eight SDGs (1 no
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poverty, 2 zero hunger, 3 good health and well-being, 6 clean water and sanitation, 12
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responsible consumption and production, 13 climate action, 14 life below water, 15 life
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on land). In short, achieving the specific targets embedded in these eight SDGs requires
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a more equitable distribution of nutritious food, more efficient use of resources, less
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pollution, and a drastic reduction of greenhouse gas (GHG) emissions and nitrogen (N)
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and phosphorus (P) losses. Success will therefore greatly depend on the organization
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and performance of food systems, particularly in those countries that account for the
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bulk of the global food system. Forecasts indicate that the demand for food will
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increase due to an increasing human population, while urbanization will lead to
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consumption of more resource-intensive food 2. Unless drastic improvements are made
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in resource use efficiency and emission mitigation in our food systems, there will be
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increasing scarcity of productive land 3 and fresh water resources 4, as well as negative
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impacts on air and water quality 5, biodiversity and climate change 2, 6.
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Transformative pathways towards more sustainable food systems are a global priority 7,
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8
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choices 9. This is particularly problematic in food systems in emerging economies,
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which are extremely complex and are evolving rapidly over time due to the interacting
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effects of changes in demography, economic growth and technology development,
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urbanization, transnational corporations and international trade 9. These emerging
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economies are populous and large, including countries, such as China, India, Brazil
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and also countries in Sub-Saharan Africa. Transitions in the food systems of emerging
, but policy makers and industry lack the tools and information to identify optimal
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economies have major global impacts, because of the sheer size of their populations
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and relatively poor regulatory framework
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quantitative analyses of possible pathways for transforming food systems will provide
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policy makers and industries with useful information for choosing actions to achieve
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more sustainable food systems.
10, 11
. We argue that harmonized and
79 80
With 19% of the World’s population and a rapidly developing economy, changes in
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food production and consumption patterns in China have significant global
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implications 12. China has increased both domestic food production and imports of both
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food and animal feed hugely during the past few decades, in order to keep pace with the
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large increase in demand for food products 12, 13. Increases in food production have been
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accompanied by significant increases in inputs, including water, nutrients and
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pesticides. Excessive inputs have, in turn, led to serious environmental damage as well
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as concerns about food safety and health 14. Deterioration of soil, water and air quality
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has become widespread throughout China 15-19. These issues will become even more
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critical by 2030 without appropriate interventions 11. The Chinese government has
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recognized the importance of sustainable food production and consumption. In March
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2015, it published the ‘National Plan on Sustainable Agricultural Development
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2015-2030’, with five clear targets. Policy makers and scientists are now challenged to
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find the right solutions for achieving the ambitious targets of this plan, including, for
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example, a target to achieve further growth of agricultural production without further
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increases in the area of land, water, fertilizers or pesticides used from 2020 onwards’.
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However, there is lack of quantitative analysis of the available pathways towards such
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a sustainable food system in China.
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Here, we develop and apply a quantitative food chain approach, to identify leverage
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points for principal interventions in the food production – consumption chain, to be
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used at national and regional levels. Using this approach, the objectives were (1) to
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quantify food and resources requirements for China in 2030, and (2) to analyze the
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system and provide key suggestions for more sustainable food production and
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consumption systems.
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MATERIALS AND METHODS
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Concept of the Food Chain
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The concept of a food system was formalized by sociologists decades ago 20. Sobal et
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al. (1998) identified four major model concepts: food chain, food cycles, food webs
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and food contexts, and developed a more integrated approach, the ‘food and nutrition
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system’ 21. Recently, the concept was expanded in the context of food security and its
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interactions with global environmental change 22. All these approaches and concepts
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contribute to a qualitative understanding of the food production – consumption chain,
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but they do not provide quantitative insight. In this study, an analytical food system
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approach was developed to link food production and consumption and their wider
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environmental impacts.
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Food systems consist of an interrelated set of compartments, here perceived as a
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‘pyramid’ with four main components (Figure 1), namely (i) crop production
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(including the root-able soil layer, i.e., the upper 1 meter of soil), (ii) animal
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production (including managed aquaculture), (iii) food processing and retail, and (iv)
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households. These components are connected through flows of energy, carbon (C) and
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nutrients, and virtual resources i.e. land and water. Each component suffers losses of 6 ACS Paragon Plus Environment
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energy, C, N, P, greenhouse gases (GHGs) and other substances to the environment
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(Figure 1, left panel). We used eight indicators to assess the success of possible future
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pathways for food systems, i.e. land, water and fertilizer N and P requirements, N and
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P use efficiencies, N and P losses, and GHG emissions (Figure 1, middle panel), and
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these were linked to the eight SDGs (Figure 1, right panel). We used the food chain
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model NUFER (Nutrient flows in Food chains, Environment and Resource use) to
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analyze the current and possible future (year 2030) food systems in China 23-25.
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Modeling Food Requirements in 2030
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The NUFER model quantifies land and water use, N and P flows and use efficiencies
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and losses within the whole food production – consumption chain 23-25 . Seven main
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crop categories (rice, wheat, maize, soybeans, vegetables, fruits and grassland; Figure
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S2) and six main animal product categories (pig meat, chicken meat, beef, mutton,
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eggs and milk; Figure S3) were distinguished. These products were allocated to food,
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animal feed, industrial products, and food waste (Figure S2, S3). In general, the main
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products are for consumption by humans, while the by-products may be used as
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animal feed or soil amendment or are wasted. Most of the plant-based food
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by-products are used as feedstuffs, such as rice chaff and wheat bran. In contrast, the
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by-products of animal-based foods after processing are rarely used as animal feeds
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because of the risks of animal diseases such as foot and mouth. This explains in part
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why there is relatively more plant source than animal source by-products used as feed
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(Figures S2, S3). Allocation of the various products between food, animal feed,
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industrial products and food waste were partially based on data from the FAO food
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balance, and partially on surveys and publications on food utilization and waste in
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The consumption of plant- and animal-based food by rural and urban populations in
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2010 was based on available statistics and literature data (Table S8). The projections
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of food requirements for 2030 were based on scenarios (described below). Feed
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requirements were estimated from the net energy and nutrient requirements of animals,
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as a function of animal category, production level and system, using the NUFER
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model (Table S9) 23-25.
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Scenarios for the Food System in 2030
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Six scenarios were developed to explore the effects of different possible food systems
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pathways. The assumptions related to the demand for domestic products per scenario
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are listed in Table S15 (crop production) and Table S16 (animal production).
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The ‘business as usual’ scenario (BAU) reflects the current Chinese diet. For this
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scenario, we assumed that there will be no changes in the diet of the urban population.
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However, due to rapid increase in incomes, we assume that the diets of rural and
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urban populations will have converged by 2030, with relatively more animal-derived
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food, vegetables and fruits being consumed overall. This will result in more intensive
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livestock, vegetable and fruit production. As a consequence, more cereals (mainly
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maize and wheat) and beans (mainly soybean) will be needed as animal feed, because
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industrial livestock production relies highly on concentrated feeds. We assumed that
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the percentage of feed concentrates will increase by about 30% compared with 2010,
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since this corresponds to the historical rate of change in the proportion of ingredients
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in feed concentrates to the total animal feed intake between 1980 and 2010.
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Scenario PMB (produce more and better) builds on BAU, and includes substantial
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technical improvements in crop and animal production efficiencies. According to
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recent field studies, yields of rice, wheat and maize could increase by 17%, 45% and
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70%, respectively without using more fertilizer and other inputs 10, 26 by adopting
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knowledge and technologies that are currently available. For soybean, vegetable and
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fruit production, we assumed that crop yields could be increased by 25% relative to
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2010 values 27. Losses due to ammonia emissions and nitrate leaching can be reduced
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by 50%, following improved low-emission nutrient management technology 28.
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Fertilizer rates used in vegetable and fruit production can be reduced by 30%,
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primarily by avoiding excess application of manure or synthetic fertilizers 29.
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In PMB, we expect that pig and broiler production will increase by 20% between
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2010 and 2030 (Table S9). Furthermore, we expect productivity increases of 40%
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between 2010 and 2030 for beef cattle, dairy cattle, and laying poultry (Table S9). The
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performance of livestock production can be improved in China through a combination
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of better management of grazing systems, precision animal feeding (e.g., phase
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feeding in pig production 30, total mix ration feeds in cattle production 31), animal
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breeding (using high performance breeding boars and bulls), and improved herd,
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disease and animal housing management.
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Significant amounts of animal manure are currently discharged into ponds and rivers
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32
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management were released in 2013 33. A recent study has indicated that N losses
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resulting from manure management could be decreased by 50% 28. We assumed that
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the recycling rate of the nutrients in the manure (estimated via the percent of total
, due to poor regulation and governance. However, the first regulations for manure
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manure produced that is recycled to crop land) will increase from 48% in 2005 to an
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average of 80% in 2030.
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Scenario CWL (consume and waste less; i.e., healthier and less resource-intensive
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diets and reduced food waste) also builds on BAU; it was designed to estimate the
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effects of adopting the Chinese dietary guidelines (CDG), alongside a reduction of
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food losses and waste by 20%. On the basis of CDG, the consumption of meat will
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decrease and that of milk, eggs, beans, and fruit will increase compared with 2010.
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For CWL, we assumed that diets of both urban and rural populations will change to
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the recommended diet by 2030 (Table S9). Food wastes will be reduced by 20%
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through a combination of new technology, improved food storage facilities and
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education. As a result, the percentage of food produced that is consumed by humans
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will increase (Table S14).
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Scenario PMB+CWL combines technology improvement (PMB) with dietary change
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and food waste reduction (CWL). It combines improvements on both the food
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production and consumption side.
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Scenario IMF (import more food) also builds on BAU, but assumes that much of the
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additional food required is imported from abroad. We assumed that the import of all
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plant-based and animal-based food and feeds will be 10% of total food demand in
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China in 2030, except for soybean and milk. In 2010, China imported 60% of traded
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world soybeans. For 2030, we assume that 84% of the total consumption of soybean
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in China comes from imports, based on the increase in imports between 2005 and
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2010. Milk imports increased quickly after the melamine scandal in 2008. For 2030, 10 ACS Paragon Plus Environment
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we assumed that imported milk is 20% of total consumption in China based on the
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increasing imports recorded during the last 10 years (Table S9). These are likely to be
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conservative estimates, since China’s soybean and milk import has continued to
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increase between 2010 and 2017.
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Scenario PMB+CWL+IMF is a combination of scenarios PMB, CWL and IMF. It
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represents a more integrated food system planning and management approach. In this,
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China would make large technical efficiency gains in food production, move towards
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healthier diets, and import feed and food items strategically to meet its overall food
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security goals.
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Our assumptions for the 2030 scenarios were adopted from peer-reviewed
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publications, and are assessed as achievable and internally consistent. Recent studies
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indicate that crop yields and land, water and nutrient use efficiencies can be increased
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greatly on smallholder farms in China through participatory research and extension 34.
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Yet, it remains a challenge to reach the other 200 million smallholder farms.
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Assumptions related to improvements in animal production were based on several
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studies (Table S17), and on the rapid changes in livestock production systems during
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the last few decades 35. Further, the NUFER model applies the mass balance approach
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throughout the food chain and thereby guarantees internal consistency.
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Land Requirements. The total land requirement per crop in 2030 is estimated from
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the total food and feed demand and the average productivity per crop. Baseline
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average crop yields between 2008 and 2013 are derived from the FAO data base
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Fertilizer Requirements. The N and P fertilizer requirements per crop in 2030 were
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derived from the total land requirement per crop and the average N and P fertilizer
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requirements per crop per hectare land. The average fertilizer N and P applications for
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different crops were derived from literature (Table S11).
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Water Requirements. The water requirement for food production was derived from
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the water footprint of different agriculture products 37. The water footprint is a
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measure of humans’ appropriation of freshwater resources and has three components:
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blue, green, and grey water 7,38. We expressed blue water footprint as derived from
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water-use by 7 main plant-based products, including feed for livestock and food for
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humans (Table S11). The drinking and service water demand by animals and humans
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were not considered, because these are relatively small compared to the blue water
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footprint of crops 39.
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Nutrient Losses and Nutrient Use Efficiency. The balances and use efficiencies of
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N and P of the food production – consumption chain, the gaseous loss of N via NH3
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and N2O and N2, denitrification and leaching, runoff and erosion losses of N & P were
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calculated by the NUFER model 23.
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Greenhouse Gas (GHG) Emissions. We estimated the non-CO2 GHG emissions,
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using the IPCC Tier 1 method. The CH4 emission from rice production was estimated
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to be 43.5 kg CH4 per ton of rice 40. We assumed that 20% of the rice, wheat, maize
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and soybean straw was burned with an emission factor of 4.6 g CH4 per kg burned
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straw 40. The CH4 emissions from enteric fermentation and manure management were 12 ACS Paragon Plus Environment
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derived from IPCC 41. Both direct and indirect N2O emissions from agriculture were
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calculated using the parameters listed in Tables S12-S13 along with methodology
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reported in the relevant citations.
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Contributions of China’s Food System to the Global Food System
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The contributions of China’s food chain to the global food chain in terms of resource
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use and environmental impacts in 2030 were derived from a comparison of results
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from this study and results from the literature for the baseline years 2009/2010. Data
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for 2009/2010 were used, since there are no solid or widely accepted predictions for
283
2030 yet. At the global level, the N fixation (both industrial and biological) was 150
284
Tg N in 2009 42. Reactive N losses from the global agricultural production systems
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have been estimated at 108 Tg in 2010 43. The annual losses of P from freshwater
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systems into the ocean has been estimated at 22 Tg P at the global level 42. The global
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area of agricultural land was 4893 million ha 36 and the annual blue water
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consumption was 2600 km3 in 2009 42. We used the global emissions reported by the
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IPCC for N2O and CH4, which were equivalent to 11 Gt CO2 in 2010 44.
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Uncertainty Analysis
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We used the Monte Carlo method to assess the uncertainty in resource use and
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emissions that result from the uncertainty in input parameters for food losses and
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waste management (Tables S3, S4), as well as the uncertainty in food demand
295
resulting from the uncertainty in population numbers expected in 2030 (Tables S15,
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S16). Mean values and standard deviations were used to describe the distribution of
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input parameters in the random sampling procedure in the Monte Carlo simulations
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(Tables S4, S5). There are also uncertainties in the assumptions underlying the 13 ACS Paragon Plus Environment
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suggested improvements in the food system (production, consumption and waste) but
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these are inherent to the scenarios and not considered further.
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RESULTS AND DISCUSSIONS
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Business as Usual (BAU).
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Both population (1.4-1.5 billion) and urbanization (60-80%) are expected to peak in
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2030 in China 27. If China follows current dietary trends (BAU), projected demands for
306
animal-derived food, vegetables, fruits, and animal feed cereals and grass in 2030 will
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increase by 45% to 105% relative to 2010 (Figure 2a-c, f). In contrast, the direct
308
consumption of cereals as human food will decrease by 14% (Figure 2) - a
309
compensating effect of the increasing consumption of animal products, vegetables and
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fruits. The required areas for arable land and grassland will increase by a factor of 1.4
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and 1.8, respectively, compared with the areas used in 2010.
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A major challenge in this scenario will be satisfying the requirement for ruminant
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fodder (grass, alfalfa), because of the increasing size of the dairy cattle herd and the
315
low productivity of Chinese grassland systems 45. Also, the demand for irrigation
316
water and fertilizer nutrients will increase further (Figure 2d, g, h), especially in
317
semi-arid areas. The scarcity of fertile agricultural land and fresh water has already
318
become severe over the last two decades 46, 47, and will increase further in the BAU
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scenario.
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Emissions of GHG from food production will increase by 28% in the BAU scenario.
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Total Nr losses will increase from 33 Tg to 46 Tg and P losses from 3.1 to 4.3 Tg 14 ACS Paragon Plus Environment
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between 2010 and 2030. These increases will have negative impacts on achieving
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SDG 13-climate action, SDG 6-clean water and sanitation, and SDG 14-life below
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water. NUE in the whole food system will decrease from 10% in 2010 to 8% in 2030
326
and PUE from 7% to 6% (Figure 3). By 2030, China’s food system will consume
327
around 30-45% of global fertilizer use, and contribute 40% of global Nr losses, 16%
328
of global P losses and 16% of global GHG emissions in the BAU scenario (Figure 4).
329
Evidently, BAU is not a sustainable pathway.
330 331
Produce More and Better (PMB). In this scenario, the required cropland area will
332
decrease from 164 Mha in BAU to 110 M ha in PMB, as a result of increased
333
productivity of both crop and livestock sectors. The required, grassland area is
334
expected to decline from 555 to 396 Mha (Figure 2). Increased crop yields and
335
increased feed use efficiency in livestock production both contribute to achieve SDG2
336
(zero hunger) and SDG1 (end poverty). PMB is a powerful strategy to achieve food
337
system related SDGs.
338 339
The increased crop and herd productivity will reduce total blue water consumption by
340
7% compared to BAU (Figure 2), which will contribute to the alleviation of water
341
scarcity 47. Improvements in crop and animal productivity are associated with increases
342
in NUE and PUE, and decreases of N, P and GHG losses (Figures 2, 3). This will
343
contribute to achieving SDG6 (clean water) and SDG12-15. We do not project an
344
increase in grassland productivity in PMB because most grassland in China has a
345
natural character 48, and about 90% has been degraded to a varying extent. However,
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sustainable grassland intensification remains an important area for further research
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and development.
348 349
The suggested improvements in the genetic potential of crops and animals, integrated
350
soil-crop system management 26, and integrated crop-livestock and manure
351
management 28 may greatly improve the agronomic and environmental performance of
352
the whole food production systems (Table S18). Such improvements have been
353
achieved already in field experiments, experimental farms and millions of small
354
house-hold farmers 34, but will require further integration, testing and upscaling
355
through, for example, the Science and Technology Backyard program 49. This requires
356
the joint efforts of policy makers, researchers, extension services, farmers, citizens,
357
industry and market organizations (Table 1). Chinese agriculture is already entering a
358
transition from the current system dominated by small-holder farms to larger farms,
359
which may enable better knowledge and technology transfer and provision of
360
professional services 11.
361 362
Consuming and Wasting Less (CWL). Diet manipulation and reducing food wastes
363
are key pillars of the CWL scenario. In CWL, consumption of milk products will
364
increase by 413%, but consumption of eggs, meat, and cereal-derived food products
365
will decrease by 4%, 34%, and 35%, respectively, relative to 2010 (Figure 2). In
366
comparison to BAU, this would result in a significant reduction of the requirements for
367
cropland (19%), grassland (46%), N fertilizer (7%), P fertilizer (26%) and water (23%)
368
in agriculture. Meanwhile, GHG emissions will decrease by 17%, and nutrient use
369
efficiencies of the whole food system will increase from 8.4 to 17% for N and from 5.5 16 ACS Paragon Plus Environment
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to 13% for P (Figure 3). These results are consistent with other findings, which indicate
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that dietary change can mitigate GHG emissions and benefit public health in China 50,
372
51
373
indirectly and to SDG6 and 12-15. Implementing CWL requires removing the range
374
of social barriers, listed in Table 1.
. The CWL scenario directly contributes to achieving SDG2 (zero hunger) and
375 376
Combinations of PMB and CWL. Together these have positive impacts on human
377
health, resource use efficiency and environmental sustainability (Figure 3), and might
378
alleviate land and water scarcity 46, 52. The demand for arable land under combinations
379
of these scenarios will reduce from 164 to 127 million ha and the demand for blue
380
water use will reduce from 293 to 197 billion m3 (Figure 2). This will contribute to
381
achieving the targets of the National Plan on Sustainable Agricultural Development
382
2015-2030. The land saved could be used for ecological preservation 52. The demand
383
for N and P fertilizers will reduce to 23 and 5.5 Tg, respectively, which equals 21%
384
and 26% of the world total N and P consumption in 2015 36. These projected
385
reductions will help to fulfill China’s central government’s target of zero fertilizer
386
increase from 2020 53. The formation of PM2.5 in air and water pollution will be
387
reduced by 61% and 66%, respectively compared to BAU (Figure 3).
388 389
Import More Food (IMF). If the food and feed demand in 2030 cannot be met through
390
domestic production, despite the PMB and/or CWL interventions, food and feed
391
imports may have to increase (or diets will have to change further). In the (IMF)
392
scenario, it was assumed that food and feed imports will increase by 10%. This will
393
decrease the required areas of domestic cropland and grassland, the demand for N 17 ACS Paragon Plus Environment
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394
fertilizer, as well as the water footprint and GHG emissions by 7-11% compared with
395
those in BAU (Figures 2 and 3). This would help to achieve SDG12-15 in China.
396 397
However, large increases in food and feed imports may distort international trade
398
balances, increase the environmental impacts of food production in exporting countries,
399
and increases the dependency of China’s food system on imports 56. The rapid
400
economic growth and changes in diet during recent decades has led to greatly
401
increased soybean imports from Latin America, which in turn has contributed
402
indirectly to the deforestation in the Brazilian Amazon 57. The import of maize and
403
soybean to China accounted for 6% and 58% of the global trade of these commodities
404
in 2010 36. In recent years, China has also emerged as a significant importer of dairy
405
products, commodities with a thin global market base 58. Further increases in
406
agricultural imports may have further negative consequences for food security and
407
environmental costs elsewhere 56. We argue that IMF alone cannot be a sustainable
408
pathway for large countries, especially in an era of increasing trade conflicts
409
throughout the world.
410 411
Towards a More Sustainable Food System. A targeted combination of PMB, CWL
412
and IMF would result in the greatest reduction in the impact of China’s food system on
413
resources use, emissions of N, P and GHG emissions at global level (Figure 4). Various
414
technologies for increasing productivity, resource use efficacy and waste recycling
415
have already been developed and tested (Tables S17 and S18). The adoption of
416
improved technologies in practice will require coordinated effort across different
417
stakeholders and sectors (i.e. policy makers, researchers, extension services, farmers 18 ACS Paragon Plus Environment
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and citizens, industry and market organizations) at several points in the food chain if
419
we are to achieve transformative change (Table 1). Such a coherent strategy must
420
include (1) incentives to adopt improved agronomic practices and technologies, (2)
421
incentives to support land-based animal production and pasture-based livestock
422
systems, so as to improve manure management and meet water quality standards
423
(which is included in the new Environmental Protection Law of China, EPL), (3)
424
subsidy reforms to ensure that subsidies reach their target stakeholders, and (4)
425
education and policies that promote a healthy diet and reduction of food waste.
426
Implementing such a strategy also commits China to sound monitoring and evaluation
427
so as to assess the impacts of action and to be able to adjust the strategy in a proactive,
428
evidence-based manner, taking account of constraints and barriers (Table 1). Despite
429
significant challenges, our analysis suggests that - in principle - the ambitious targets
430
embedded in China’s new agricultural and environmental strategies appear to be
431
achievable through an integrated transformation of the whole food system.
432 433
However, there are large spatial variations within China, which have not been
434
addressed by our national-scale analysis. Different regions face different key
435
challenges related to food security (such as resource scarcity and environmental
436
pollution), which suggests that specific regional strategies will have to be developed
437
and implemented. For example, identify zones that are more vulnerable to nitrogen
438
and phosphorus loss than others in order to help control water pollution 55. In these
439
zones stricter environmental control policies would be implemented than in other
440
regions. Hence, additional high-resolution spatial analyses are needed to explore
441
pathways for sustainable food system for different regions.
442
19 ACS Paragon Plus Environment
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443
Whole Food Chain Approach. Our modeling framework permits the analysis of the
444
effects of changes in the food production-consumption system of China in an
445
integrated manner, and the results can be linked to 8 SDGs. Our analyses also help to
446
identify knowledge gaps and priority innovations. The approach might be applied to
447
other emerging economies, such as Brazil and India, which face comparable changes
448
in demography and rapid urbanization as in China 60. The necessary input data and
449
parameters can be easily derived from FAO database and literatures. Transformative
450
pathways towards more sustainable food systems that simultaneously increase
451
nutritious food production and consumption, and enhance resource use efficiency and
452
environmental quality are a particular priority for emerging economies. Future studies
453
should address also economic and health effects 60.
454 455
ASSOCIATED CONTENT
456
Supporting information
457
The Supporting Information is available free of charge on the ACS Publications
458
website at DOI: ***. Detailed calculation methods, tables of additional data (Figures
459
S1 to S5, Tables S1 to S18, and References and note).
460
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AUTHOR INFORMATION
462
Corresponding Author
463
*Phone/Fax: 86-0-311-85810877. E-mail:
[email protected];
464
[email protected].
465
ORCID
466
Lin Ma: 0000-0003-1761-0158
467
Notes
468
The authors declare no competing financial interest.
469 470
ACKNOWLEDGMENTS
471
This work was financially supported by the National Key Research and Development
472
Program of China (2016YFD0800106), the Chinese National Basic Research Program
473
(2015CB150405), the National Natural Science Foundation of China (31572210), the
474
Hundred Talent Program of the Chinese Academy of Sciences, Distinguished Young
475
Scientists Project of Natural Science Foundation of Hebei (D2017503023),
476
President’s International Fellowship Initiative, PIFI of the Chinese Academy of
477
Science (2016DE008 and 2016VBA073), FACCE-JPI Surplus for the project Targets
478
for Sustainable And Resilient Agriculture - TSARA and Sustainable Development
479
Solutions Network (SDSN, http://unsdsn.org/).
480
21 ACS Paragon Plus Environment
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Atmosphere
N2, NH3, N2O, CH4
Human consumption Exports and losses
Food processing
imports
Animal production Crop production (soil accumulation)
N Leaching
481
Groundwater
NUFER model
Erosion and runoff
Resources requirement •
Land requirement
•
Water requirement
•
Fertilizer requirement
Resources use efficiency •
Nitrogen use efficiency
•
Phosphorus use efficiency
Environmental impacts • Nitrogen losses
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X
6 CLEAN WATER AND SANITATIO
14 LIFE BELOW WATER
• Phosphorus losses P
Surface waters
3 GOOD HEALTH AND WELL-BEING
1 NO POVERTY
2 ZERO HUNG ER
12 RESPONSIBLE CONSUMPTION AND PRODUCTION
13 CLIMATE ACTION
15 LIFE ON LAND
• GHG emissions
Indicators
Sustainable Development Goals (SDGs)
482
Figure. 1 Linking the food production and consumption chain (left panel) to the
483
Sustainable Development Goals (SDGs) (right panel) via a set of eight key indicators.
484
Food production and consumption is central to at least eight SDGs (1 no poverty, 2
485
zero hunger, 3 good health and well-being, 6 clean water and sanitation, 12
486
responsible consumption and production, 13 climate action, 14 life below water, 15
487
life on land – hereafter SDG-8. SDG 2 is in the center). The NUFER model (Nutrient
488
flows in Food chains, Environment and Resource use) was used to analyze the
489
impacts of changes in the food systems. X means evaluation.
490
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IMF
P+C+I
P+C
CWL
PMB
P+C+I
IMF
P+C
CWL
P+C
IMF
P+C+I
P+C
IMF
P+C+I
CWL
PMB
BAU
5 0
P+C+I
IMF
P+C
CWL
10
(g)
CWL
20
10
BAU
30
2010
P fertilizer (Tg P)
40
PMB
N fertilizer (Tg N)
50
0
(f)
15
PMB
(e)
700 600 500 400 300 200 100 0
2010
P+C+I
IMF
P+C
PMB
BAU
50 0
PMB
BAU
P+C+I
IMF
P+C
Grassland (million ha)
Cropland (million ha)
100
BAU
510
0
(d)
150
2010
509
100
Grass
200
506
508
200
(c)
505
507
CWL
PMB
0
BAU
Vegetable
300
2010
Soybean
200
Water use (billion m3)
Maize
400
2010
504
P+C+I
Wheat
600
501
503
IMF
800
500
502
400
Rice
2010
499
Milk Egg Mutton Beef Chicken Pork
(b)
1000
Feed production (Tg)
498
Fruit
(a)
496 497
P+C
PMB
495
CWL
Vegetable
BAU
Soybean
300 250 200 150 100 50 0
2010
Maize
Animal food production (Tg)
Wheat
CWL
494
Rice
BAU
493
1200 1000 800 600 400 200 0
2010
492
Plant food production (Tg)
491
(h)
512
Figure. 2 The demands for plant food (a), animal food (b), feed (c), fresh water (d),
513
crop land (e), grassland (f), nitrogen fertilizer (g), and phosphorus fertilizer (h) in the
514
food chain in China in 2010 and in 2030 for different scenarios. BAU: business as
515
usual; PMB: Improvements of crop and animal production; CWL: diet change based 23 ACS Paragon Plus Environment
Environmental Science & Technology
516
on recommended Chinese dietary guidelines; IMF: Increased food & feed imports.
517
P+C is the combination of PMB and CWL; P+C+I is the combination of PMB, CWL,
518
and IMF. The error bars reflect the expected lowest and highest projections in 2030.
24 ACS Paragon Plus Environment
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CWL
P+C
IMF
P+C+I
CWL
P+C
IMF
P+C+I
PMB
P+C+I
IMF
P losses (Tg P)
3.0 2.0
PMB
BAU
2010
P+C+I
IMF
P+C
CWL
0.0
(d)
GHG emissions (Tg CO2e)
1500 1000
IMF
P+C
P+C+I
(e)
535
CWL
0
BAU
500
2010
534
4.0
(c)
530
533
0
(b)
PMB
529
532
5
1.0 BAU
528
531
10
5.0
2010
527
60 50 40 30 20 10 0
Nr losses (Tg N)
526
15
(a)
524 525
P+C
523
CWL
0
PMB
5
20
BAU
P use efficiency in (%)
10
BAU
522
15
PMB
521
20
2010
520
25
N use efficiency (%)
519
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2010
Page 25 of 36
536
Figure. 3 Nitrogen use efficiency (NUE, a), phosphorus use efficiency (PUE, b),
537
reactive nitrogen losses (c), phosphorus losses (d), and GHG emissions (e) in the food
538
chain in China for 2010 and projected for 2030 for different scenarios; BAU: business
539
as usual; PMB: Improvements of crop and animal production. CWL: diet change
540
based on recommended Chinese dietary guidelines; IMF: Increased food & feed
541
imports. P+C is the combination of PMB and CWL; P+C+I is the combination of
542
PMB, CWL, and IMF. The error bars reflect the expected lowest and highest
543
projections in 2030. 25 ACS Paragon Plus Environment
China's global impacts (%)
Environmental Science & Technology
544
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60 50 40 30 20 10 0
2010 Agriculture land P fertilizer GHG emissions
BAU Water use N losses
PMB+CWL+IMF N fertilizer P losses
545
Figure. 4 Relative contribution of China’s food systems to the global food system in
546
2030, in terms of the uses of agricultural land, fresh water (blue water), N fertilizer, P
547
fertilizer, and the losses of N and P and GHG, for the scenarios BAU and the
548
combination of scenarios PMB, CWL and IMF. The error bars reflect the expected
549
lowest and highest projections in 2030.
550
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Environmental Science & Technology
Table 1 Action plan for more sustainable food production and consumption in China Actors Levers
Barriers
Benefits 552
Increasing crop productivity and resources use efficiency Incentives for more sustainable cropping systems and for improved management and technology. Enforcement of soil, water and air quality standards and regulations.
Increasing animal productivity and More healthy diets and reducing resources use efficiency food wastes and losses Policy Incentives for land- and pasture-based Incentives for choosing healthy makers animal production systems. diets and for reduction of food Incentives for improved manure wastes. management and technology. Enforcement of soil, water and Enforcement of soil, water and air quality air quality standards and standards and regulations. regulations. Researchers Design and development of Design and development of high-yielding Research linking nutrition, diet, and extension high-yielding and sustainable and sustainable animal production food wastes and behavior. services cropping systems. systems. Clear information and sound Clear information and sound Clear information and sound extension extension services. extension services. services. Farmers & Innovative networks and achieving Innovative networks and achieving Innovative networks and citizens targets. targets. achieving targets. Industry and Optimized logistics and increased Optimized logistics and increased Facilitation of consumers market utilization of wastes. utilization of wastes. associations, to reduce food Development of site-specific Development of site-specific technology, wastes. technology. especially for manure utilization. Lack of entrepreneurial skills; Shortage of land for feed production. Western influence on food Lack of education risk aversion Lack of experience with integrated habits. Number and age of farmers. crop-animal production systems. Lack of political willingness to Upscaling of innovative designs, Upscaling of innovative designs. influence consumption patterns. management & technology. management & technology. No poverty, Zero hunger, Good health and well-being, Clean water and sanitation, Responsible consumption and production, Climate action, Life below water, Life on land.
27
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