Global Human Appropriation of Net Primary Production and

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Global human appropriation of net primary production and associated resource decoupling: 2010-2050 Chuanbin Zhou, Ayman Elshkaki, and Thomas E. Graedel Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.7b04665 • Publication Date (Web): 10 Jan 2018 Downloaded from http://pubs.acs.org on January 10, 2018

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Environmental Science & Technology

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Global human appropriation of net primary production and associated resource

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decoupling: 2010-2050

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Chuanbin Zhoua,b,* Ayman Elshkakia, T.E. Graedela

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a

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Street, New Haven, Connecticut 06511, USA. bState Key Laboratory of Urban and Regional Ecology,

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Research Center for Eco- Environmental Science, Chinese Academy of Sciences, 18 Shuangqing Road,

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Haidian District, Beijing100085, China. * Email: [email protected]

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Abstract

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Human appropriation of net primary production (HANPP) methodology has previously been developed to

Center for Industrial Ecology, School of Forestry and Environmental Studies, Yale University, 195 Prospect

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assess the intensity of anthropogenic extraction of biomass resource. However, there is limited analysis

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concerning future trends of HANPP. Here we present four scenarios for global biomass demand) and

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HANPPharv (the most key component of HANPP) from 2010 to 2050 by incorporating data on expanded

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historical drivers and disaggregated biomass demand (food, wood material, and fuelwood). The results show

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that the biomass demand has the lowest value in the Equitability World scenario (an egalitarian vision) and the

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highest value in the Security Foremost scenario (an isolationist vision). The biomass demand for food and

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materials increases over time, while fuelwood demand decreases over time. Global HANPPharv rises to between

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8.5-10.1 Pg C/yr in 2050 in the four scenarios, 14% to 35% above its value in 2010, and some 50% of

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HANPPharv is calculated to be crop residues, wood residues, and food losses in the future. HANPPharv in

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developing region (Asia, Africa and Latin America) increases faster than that in more developed region (North

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America and Europe), due to urbanization, population growth, and increasing income. Decoupling of

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HANPPharv and socio-economic development is also discussed in this work.

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ACS Paragon Plus Environment


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TOC Global HANPPharv All biomass

Food

MW TR

Wood material SF

2050

2025

EW North America Latin America Europe Asia and Oceania Africa

2010

24

MW

TR

SF

EW

MW

TR

SF

Fuelwood

EW

1960 1970 1980 1990 2000 20102025 2020 2030 2040 2050 1960 2010 2050

25

2


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26 27


1. INTRODUCTION Biomass, resulting from the conversion of sunlight into organic matter by green plants1, is the most

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fundamental resource used during human history2. Biomass is used in many forms, including food, forage, fuel,

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feedstock, fiber, and fertilizer2-3. Global production of three primary biomass components: food, industrial

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round wood, and fuelwood, has increased between 30% and 200% in the last 50 years4-5, largely as a

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consequence of population growth and socio-economic development2,6. Global biomass demand is expected to

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continue to increase in the next three decades, owing to estimates that global population will grow to 9.7

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billion and the urban population will rise to 69% by 20507. Achieving specific United Nations Sustainable

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Development Goals (SDGs), such as ending malnutrition for around 0.8 billion people, providing affordable

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energy, and upgrading slums will require large amounts of biomass resources8-9. There is rising concern,

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however, regarding the demand and availability of biomass in coming decades. Long-term food demand is

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expected to increase by 50-100% between 2005 and 20506,10. In contrast, a decline in global wood production

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from natural forests is expected due to the wide-spread awareness of forestry conservation5, which will be a

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main constraint of industrial round wood and fuelwood supply. Concomitantly, biomass-oriented energy is

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expected to reach 130-270 EJ/y by 2050, equivalent to 15-25% of the global energy demand11-13. Secondary

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biomass (wasted biomass utilization) as a renewable energy source could be help to achieve this goal.

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Although projecting future biomass demand in separate sectors is useful, none of these studies depict the total

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human impacts on global biomass extraction in the next several decades, and whether biomass availability

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could limit growth.

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Human appropriation of net primary production (HANPP) has proven to be a useful methodology to

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integrate all types of biomass resources and to assess the upper limits of the biosphere’s capability of

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supplying humanity with biomass14-16. Global-17-18 regional-19-20 and national-scale21 studies on HANPP show

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a broad interest in quantifying human biomass extraction. Moreover, HANPP can be compared with total

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potential net primary production (NPP) so as to study the relative intensity of human impacts14. The estimated

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global level of HANPP varies greatly but ranges from 6.9 to 29.5 Pg C/y, thereby accounting for 13-39% of

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the total potential terrestrial NPP14. In general, global HANPP has shown an increasing correlation with

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socioeconomic development14,18. Most of the existing literature has analyzed HANPP in a specific year or

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period. One study, however, has shown that the global HANPP is expected to increase monotonically to 205018.

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The regional profiles and detailed composition of future HANPP remain unclear. The next three to four

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decades will probably be the epoch with the most intensive economic development and rapid urbanization

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throughout human history, so the 2010-2050 period merits further study directed toward anticipating HANPP

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changes and associated biomass resource decoupling in the future.

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According to the widely accepted definition of HANPP, there are two main components, i.e., human

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harvested biomass (HANPPharv) and the productivity change resulting from land use conversion (HANPPluc)14.

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HANPPluc was demonstrated to have decreased since 1955 and to have remained stable in the last decade,

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while HANPPharv has shown a sharp increase since 195518, making the latter the key factor in evaluating

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human biomass extraction. There are different measures to minimize both HANPPharv and HANPPluc, e.g.,

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changing human consumption patterns, improving the feed conversion ratio in livestock systems, and

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cascading the utilization of biomass22-24. Technological changes that increase crop yield can reduce pressure on

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HANPPluc, although this involves the intensive use of water, energy, chemical fertilizer, and pesticides, with a

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consequent increase in environmental impacts21,25. Food losses account for roughly one third of global food

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production, and the quantity of lost food grew by a factor of three between 1961 and 201026-27. Apart from

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food losses, onsite waste from agricultural and forestry production is a non-trivial fraction of HANPPharv. For

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example, crop residues and onsite wood residues account for 40-200% of directly used biomass products3.

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Despite the great potential for improving the sustainable level of HANPP by addressing the waste sector, few

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studies have examined the degree of decoupling of biomass resources that could be achieved by reducing

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biomass loss and recycling biomass waste.

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In the present study, four scenarios for the global HANPPharv to 2050 have been developed. They are based

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on the framework of the Fourth Global Environmental Outlook (GEO-4) scenarios of the United Nations

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Environment Program (UNEP)28 and regional and compositional analysis of historic biomass extraction. We

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present in this paper results for four physical resource scenarios that are expansive, but in different ways and to

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different degrees. The Market World (MW) scenario essentially posits that the emerging middle class will wish

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living standards similar to those of the more developed countries, and that market forces will enable that

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transition to happen. The Toward Resilience (TR) scenario is similar except that government policies more

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respectful of renewable energy and the environment will be in force. The Security Foremost (SF) scenario tilts

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toward confrontation rather than cooperation, with a consequent reduction in international commerce. The

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Equitability World (EW) scenario aims toward a more collaborative and inclusive world. The period of this

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work is 2010-2050, with one year time resolution. The global results are disaggregated into five regions:

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Africa, Asia and Oceania, Europe, Latin America, and North America.

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2. METHODOLOGY

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The scope of studied biomass (HANPPharv) includes all the biogenic matter extracted by humanity from

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forest, plantation, cropland and grazing land, including crop residues and onsite waste from wood cutting.

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From the perspective of human biomass utilization, the biomass resource was classified into four main

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categories, i.e., food, industrial round wood (material), fuelwood (energy), and waste and residue (SI, Fig. S2).

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The database provided by the Food and Agriculture Organization of the United Nations (FAOSTAT, 1961-

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2010) was the primary source of historic biomass demand and production information29. A detailed definition

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of biomass categories and dry-weight conversion factors can be found in the SI, as can methods for analyzing

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biomass extraction in livestock systems. Associated crop residues and wood residues were calculated for each

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category of biomass products and in each region, based on previous works 3,17 (SI). The historic data for

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primary biomass demand covered the period 1961 to 2010. The biomass data are presented on a dry weight

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(DM) basis in units of Pg/y, while the unit of HANPPharv is Pg C/y. The carbon content of biomass is 0.475

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(dry basis)17. To understand the regional divergence of biomass extraction, we addressed Africa, Asia and

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Oceania, Europe, Latin America, and North America according to the definition of the UNEP Global

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Environment Outlook (GEO-5)30.

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Regression analysis was carried out to analyze the historic biomass extraction in each category of biomass

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(food, material, and fuelwood) and in each region. The variables included in the analysis were population, per

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capita caloric intake, urbanization rate, urban population, rural population, and average income (per capita

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GDP 2005 US$), respectively. Historic data on population, food, wood material, and fuelwood were taken

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from FAOSTAT29, while historic data on urbanization rate and average income were taken from the World

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Bank database31. A detailed description of regression models, coefficients, and statistics is given in the SI.

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The initial foundation for this study is provided by the Global Scenario Group28,32, which assembled

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detailed historic data and outlined four visions of the future world. In the Market World (MW) scenario, the

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central element is the emphasis placed on economic investment and expanded trade to deliver economic, social,

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and environmental advances. The Toward Resilience (TR) scenario envisions a transition to a world of highly

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centralized approaches to balancing economic growth while enabling social and environmental advances. The

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Security Foremost (SF) scenario, in contrast, has the emphasis placed on security, which consistently

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overshadows other values, and conflict continues in many parts of the world. Finally, the Equitability World

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(EW) scenario is characterized by, at all levels and from all sectors, policies and actions to support the United

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Nations Sustainable Development Goals (SDGs) and to deliver economic, social, and environmental advances

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to all people in an equitable manner. From an energy perspective, all four scenarios include an assumption of

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reduced availability of crude oil, as well as variations on energy mix, GDP, population, and urbanization rate28.

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The use of four quite different scenarios thus provides a semi-quantitative sensitivity analysis as an integral

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part of the work. The input data of the biomass regression models in each region in 2025 and 2050, such as

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population, urbanization rate, per capita caloric intake, and per capita income, were taken from Electris et al.28.

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More detailed storylines and the fundamental data used in our regressions are found in the SI. The unique

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feature of the work reported herein is to employ driving force analysis to guide the development of the time-

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dependent magnitudes of food (in various forms), fuelwood, and wood-based materials. This information was

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then used in combination with the underlying scenario structures to define the rates of change of biomass

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parameters over the period 2010-2050.

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The method for analyzing food losses and waste is from references26-27. The food loss and waste in

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different stages of the food production systems, i.e., agricultural production, postharvest, processing,

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distribution and consumption, were calculated based on the food balance sheet from the FAOSTAT database29.

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The fraction of edible food losses in each region was taken from Gustavsson et al.26. Detailed methods on

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analyzing food loss and waste can be found in the SI. We added two analyses related to food loss reduction and

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biomass waste recycling in each scenario (Details were shown in SI): 1) reducing food losses and waste (RFL),

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in which no edible food losses occur throughout the food production and supply system, with the non-edible

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fractions of food and crop residues being reduced as a consequence; 2) replacing fuelwood with crop residues

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(RFC), in which we assume that all energy demands of fuelwood are fulfilled by combustion or gasification of

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crop residues.

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3. RESULTS

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3.1 The historic demand for biomass

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On a mass basis, biomass has historically been second only to construction minerals in terms of global

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extraction by humans (SI, Fig. S1)33. Eighteen main components make up the biomass utilization of human

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society (SI, Fig. S2); their historical patterns of use are shown in SI, Fig. S3. In total, the global biomass

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extraction in 2010 was 15.7 Pg (dry matter), 2.4 times the biomass used in 1961 (Fig. 1a). In contrast, per

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capita biomass demand has decreased from 1.4 to 1.3 Mg/(cap.y) during the last fifty years (Fig. 1b). Historical

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patterns of biomass demand show significant regional differences (SI, Fig. S3). The regional breakdown

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indicates that in the past five decades the biomass extraction of Asia and Oceania, Africa, and Latin America

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has increased rapidly, growing by factors of 3.4, 3.1, and 3.0, respectively, between 1961 and 2010. In contrast,

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North American extraction grew more slowly (1.8-times) than the developing regions, but still much higher

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than Europe, which increased only by 17% in the 50 year period. On a per capita basis, biomass demands in

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Africa, Asia and Oceania, Europe, Latin America, and North America were 1.1, 1.0, 1.8, 2.3, and 3.1

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Mg/(cap.y) (Fig. 1b). The per capita biomass extractions of North America and Europe have decreased since

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the 1990s, which may be resulted from a slower urbanization (less wood material extraction) and collapse of

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the U.S.S.R., respectively. However, they are still around three and two times higher than that of Africa and

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Asia, indicating their society has a higher dependency on biomass resources.

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The eighteen components of biomass utilization can be aggregated into five categories: biomass for food

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crops, biomass for livestock products, biomass for wood material (e.g., wood used in construction), biomass

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for fuelwood, and harvest residues (Fig. 1a). Biomass extraction for livestock products (meat, milk, and eggs)

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ranked first of all global biomass uses, growing 3.1 times between 1961 and 2010. This was followed by crops, 7



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which grew 2.5 times between 1961 and 2010. Global demand for wood material and fuelwood has increased

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by 1.6 and 1.3 times between 1961 and 2010. Interestingly, potentially available residues from wood and crop

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harvest account for roughly 40% of total biomass extraction. Part of these residues are used for energy, feed,

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and bedding material in soil, however, a large fraction of crop and wood residues are still not utilized by the

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human society. In particular, the quantity of crop residues is estimated to be 3.6 times larger than the total

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fuelwood demand in 2010, indicating the great potential of crop residues as a substitute of fuelwood. a

Biomass used by category (Pg/y )

18 16 Harvest residues

14 12

Biomass for food (livestock products) Biomass for food (crops) Biomass for fuelwood

10 8 6 4

Biomass for wood materials

2 0

1960

162

1970

1980

1990

2000

2010

4.5

b

Per capita biomass use (Pg/yr)

4.0 3.5

Africa

3.0

Asia and Oceania

2.5

Europe

2.0

Latin America

1.5

North America

1.0

World

0.5 0.0

163

1960

1970

1980

1990

2000

2010

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Figure 1 The historic flows of biomass. (a) Five principal categories of global biomass flows; (b) per

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capita biomass extraction of different regions (1961-2010).

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3.2 The future demand for biomass

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Total global biomass demand for the four scenarios is shown in Fig. 2a. Global total biomass demand

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(incl. food, wood material, fuelwood, and crop and wood residues) turns out to be 17.9-21.3 Pg/y in 2050,

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increasing by 14-35% compared to 2010. Of particular note is that biomass demand shows a sharp declining of 8


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increasing rate in the EW scenario. Total biomass demand in the EW scenario is 16% lower than that in the SF

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scenario.

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In the case of food, the results for the four scenarios are given in Fig. 2b. Primary biomass embodied in

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animal food products is included in the results. Overall, the global biomass demand for food is expected to

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increase by 20-43% in 2050 compared to the demand in 2010. This results largely from global population

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growth and rising calorie demand per capita. Among the four scenarios, biomass demand for food in the SF,

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MW and TR scenarios grows as fast as the historic demand, reaching 9.0-10.5 Pg/y by 2050, while in the EW

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scenario the growth rate is slower, remaining at around 8.4-8.8 Pg/y from 2025 to 2050.

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Demand for wood material biomass is shown in Fig. 2c. Urban population growth accounts for most of the

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increases of industrial round wood demand, especially in the regions under rapid urbanization. Urbanization

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encourages the construction of new buildings, and it is thus reasonable that wood products are correlated with

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urban population levels. The SF scenario has the highest demand for material biomass at 1.3 Pg/y. However,

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differences among the four scenarios are as significant as the food biomass results, which vary from 1.1 to 1.3

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Pg/y and thereby increase by 21-37% between 2010 and 2050.

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Biomass for fuelwood results appear in Fig. 2d. The percentages of rural population and average income

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largely account for the differences among the four scenarios because people tend to switch from fuelwood to

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fossil and renewable energy sources as their incomes increase. Thus, the global aggregated fuelwood demand

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shows a sharp decrease (by 15% to 34%), reaching 0.7-0.9 Pg/y by 2050. The differences among the scenario

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results are notable. The fuelwood demand of the SF scenario is 29% more than that of the EW scenario. This is

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because the SF world is increasingly dependent on local resources, and thus employs increasing amounts of

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biomass for cooking and heating, while the EW favors green energy technologies rather than biomass or fossil

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fuels.

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a

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b 25 12

Food

20 MW 15

TR SF

10

EW

5

Biomass demand for food (Pg/y)

Total biomass demand (Pg/y)

All biomass 10

MW

8

TR 6 SF EW

4

2

0 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050

0 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050

c

d

Biomass demand for materials (Pg/y)

Wood material 1.2 MW

1.0

TR

0.8

SF 0.6

EW

0.4

Biomass demand for fuelwood (Pg/y)

1.4

1.4

Fuelwood 1.2 MW

1.0

TR 0.8 SF 0.6

EW

0.4

0.2

0.2

0.0 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050

0.0 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050

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Figure 2 (a) Total biomass demand, historic (1961-2010) and for the four scenarios (2010-2050); (b) as

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for (a), but for food; (c) as for (b) but for wood material; (d) as for (b) but for fuelwood. MW, the Market

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World scenario; TR, the Toward Resilience scenario; SF, the Security Foremost scenario; EW, the

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Equitability World scenario. All the presented data are on a dry weight basis.

198 199 200

3.3 Composition of HANPPharv in the future Human harvested HANPP (HANPPharv) was estimated based on the biomass results, and then the

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compositions and regional fraction of HANPPharv was examined. In total, HANPPharv was calculated to range

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from 8.3 to 8.9 Pg C/y in 2025 and 8.5 to 10.1 Pg C/y in 2050 in the four scenarios (Fig. 3a); these totals

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represent the differing dynamics among the four quite different scenarios. The relative proportions in 2025 and

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2050 for the four scenarios, shown in Fig. 3a, demonstrate that food-related HANPPharv accounts for 83% of

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the total HANPPharv in 2050, while the ratio of food-related HANPPharv and wood-related HANPPharv increases

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4 to 5 times between 2010 and 2050. The rather startling message of this figure, however, is the large 10


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proportion of crop residues and food losses that still have great potential to be recovered or reduced.

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HANPPharv for crop residues, non-edible food losses, and edible food losses amounts to 2.8-3.4, 0.3-0.4, and

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0.5-0.6 Pg C/y in 2050, respectively. Biomass waste accounts for 49% of the food-associated HANPPharv,

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indicating that reducing and recycling of biomass waste could contribute significantly to the decoupling of

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HANPPharv from GDP.

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3.4 Regional variations of HANPPharv

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Fractions and future trends of regional HANPPharv are shown in Fig. 3b. HANPPharv of Asia and Oceania

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is calculated to account for 46% of global HANPPharv in 2050, while HANPPharv for the other four regions

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varies from 10% to 15%. HANPPharv, due to the biomass demands of Africa, Asia and Oceania, Europe, Latin

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America, and North America, increased by 45-72%, 8-28%, 8-37%, 14-31%, and 12-31% between 2010 and

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2050 in the four scenarios. In a change from the historic trend (1961 to 2010), HANPPharv in Africa surpasses

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that of Asia by 2050, becoming the region with the fastest increasing HANPPharv in the world. In the individual

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categories, Africa appears likely to increase most rapidly in food demand (increases by 75-100%) and wood

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material demand (increases by 48-54%), while Asia and Latin America demonstrate a relatively steady

221

increase in biomass demand due to their industrializing processes. Their trends in food and wood material

222

demand are similar, but that in fuelwood demand is different (Asia decreases 43-60%, while Latin America

223

maintains the same level in 2010). More industrialized regions show a similar trend in total HANPPharv but are

224

different in componential profiles. In North America wood material use increases rapidly, while fuelwood

225

demand of Europe decreases more slowly than that of North America.

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a 12

2050

2025

HANPPharv (Pg C/y)

10

Biomass demand for fuelwood

8

Biomass demand for material Onsite wood waste 6

Biomass demand for food Non-edible food waste Edible food losses

4

Crop residues 2

0 2010

MW

TR

SF

EW

MW

TR

SF

EW

b 12

2050

2025 10

HANPPharv (Pg C/y)

8

North America Latin America 6

Europe Asia and Oceania Africa

4

2

0

226

2010

MW

TR

SF

EW

MW

TR

SF

EW

227

Figure 3 (a) Comparative global demand of HANPPharv components in 2010, 2025 and 2050; (b)

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comparative demand of HANPPharv in each region. MW, the Market World scenario; TR, the Toward

229

Resilience scenario; SF, the Security Foremost scenario; EW, the Equitability World scenario.

230 231

3.5 Decoupling of HANPPharv and socio-economic development

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Biomass demand appears likely to become decoupled from socio-economic development as measured by

233

GDP, while an interesting feature of the results is that the decoupling accelerates in the four scenarios. Fig. 4

234

shows the decoupling of HANPPharv from both GDP and population in the four scenarios, with the EW

235

scenario leading to the highest resource productivity per unit of GDP. That scenario extracts 16% less biomass

236

resource and achieves 25% more GDP than the SF scenario, indicating that a possible relative decoupling of

237

HANPPharv could be obtained through a more equitably balanced human society (Fig. 4). The MW and TR 12


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scenarios show a synchronous increase of population and HANPPharv (Fig. 4a and Fig. 4b). However, the

239

HANPPharv of the SF and EW scenarios grows 3% more slowly than the population (Fig. 4c and Fig. 4d).

240

Comparing to MW and TR scenarios, lower per capita caloric intake is the main reason for this behavior. In the

241

SF scenario, countries become more isolationist, leading to a decreasing international trade of food products.

242

In contrast, in the EW scenario, food consumption and per capita calorie intake is reduced through lower

243

consumerism. a

b 3.0

3.0

TR

MW 2.5

2.5 GDP

2.0

GDP

2.0

Population

Population

HANPP harv

1.5

HANPPharv

1.5

HANPPharv(RFL)

HANPP harv(RFL) HANPP harv(RFC)

1.0

HANPPharv(RFC)

1.0

0.5

0.5

0.0 2010

2025

0.0 2010

2050

c

2025

2050

d 3.0

3.0

EW

SF 2.5

2.5 GDP

2.0

GDP

2.0

Population

Population

HANPP harv

1.5

HANPP harv

1.5

HANPP harv(RFL) HANPPharv(RFC)

1.0 0.5 0.0 2010

HANPP harv(RFL) HANPP harv(RFC)

1.0 0.5

2025

2050

0.0 2010

2025

2050

244 245

Figure 4 Decoupling of human appropriated net primary production (HANPPharv) with GDP and

246

population (2010-2050). (a) MW, the Market World scenario; (b) TR, the Toward Resilience scenario; (c)

247

SF, the Security Foremost scenario; (d) EW, the Equitability World scenario. HANPPharv(RFL) is a

248

scenario in which all edible food losses are reduced; HANPPharv(RFC) is a scenario in which fuelwood is

249

replaced with crop residues.

250

13



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In order to study the decoupling generated by reducing and recycling biomass waste, two revised

252

scenarios were developed: (1) reduce food losses (RFL), and (2) replace fuelwood with crop residues (RFC)

253

(details provided in SI). The results suggest that 11% and 7% reductions of biomass demand can be achieved

254

between 2010 and 2050 by these actions. However, in the MW, TR, and SF scenarios, 8%, 4%, and 11%

255

absolute increases of HANPPharv occur by 2050 even when RFL and RFC are employed. Only in the EW

256

scenario does an absolute reduction in HANPPharv take place (Fig. 4d) in the revised scenarios. In the most

257

optimistic vision, an even lower level of HANPPharv (HANPPharv2050: HANPPharv2010 = 0.94) can be obtained if

258

the fuelwood demand is fulfilled by crop residues.

259

4. DISCUSSION

260

4.1 Future trend of HANPPharv

261

The only other study on global future HANPP projected that total HANPP could increase by 25-29%

262

between 2005 and 2050 based on projections of GDP and population18. This finding is close to the future trend

263

of HANPPharv in the MW scenario in our work. In comparison to that research, a higher-resolution profile of

264

future HANPPharv under four scenarios with regional and compositional breakdown is provided in the present

265

work. We demonstrate that the most important driver for future HANPPharv is the amount of biomass extracted

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for food. This result meets the future trend suggested by other food and wood demand studies: food demand

267

increases sharply and wood demand grows slowly or even decreases by the middle of this century5,10. There is

268

rising concerns on limited availability of crude oil to 205034. According to our results, the energy oriented

269

from secondary biomass resource could play a vital role in global energy supplies in the future, although the

270

primary fuelwood demand may not increase accordingly. Furthermore, our study highlights the differences in

271

regional profiles, which could be vital for HANPPharv decoupling. We envision that food biomass demand by

272

the developing world will increase much more rapidly than that of the developed world. Africa will become

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the region with the most dramatic increase of HANPPharv, but with the fewest biomass resources. The more

274

developed regions, North America and Europe, show much more modest changes in future HANPPharv because

275

of the maturity of their biomass industries and the slowing of their population growth. Increasing HANPPharv

276

may synchronously raise HANPPluc, the other component of HANPP: 1) farmland expansion may lead to

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deforestation and conversion of natural grassland; 2) intensification of current farmland may throw negative

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impacts on habitats, biodiversity, carbon storage, and soil conditions25, 35, and thereby drive up HANPPluc in a

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long term. Therefore, it still calls for further studies on the future trend of HANPPluc, although it remained

280

stable in the last decade18.

281

4.2 Factors related to future HANPPharv

282

An important attribute of HANPPharv is that it is a direct consequence of population size, which is

283

expected to be the largest in 2050 (9.5 billion) in the SF scenario. This aspect can be thought of as a result of

284

countries assigning low importance to female education and thus to family planning32. In sharp contrast, the

285

EW scenario leads to only about 8 billion people in 2050 and thus to about a 16% lower food demand than in

286

the SF scenario.

287

Economic growth is another crucial factor for HANPPharv. The consumption of high protein food, such as

288

meat and dairy products, is known to be related to per capita income36-37, and per capita income is anticipated

289

to grow steadily in the coming decades32. In the four scenarios, per capita GDP increases by a factor of 1.8-2.6

290

between 2010 and 2050. Consequently, global average per capita caloric intake is estimated to be 4-7% higher

291

in 2050. Another point related to income growth is that as one becomes wealthier fuelwood is increasingly

292

replaced by cleaner and more convenient fossil fuels and electricity38, owing to the fact that collecting

293

fuelwood is a labor-consuming task for the households in developing countries39. This may be one reason for

294

the decreased fuelwood demand by 15-34% to 2050.

295

The level of urbanization is another factor influencing food, material biomass, and fuelwood40-41. The

296

principal use of industrial round wood is in constructing and furnishing buildings, an activity closely related to

297

urbanization. Studies on urban material stocks suggest that around 90% of industrial round wood is used for

298

buildings and furniture42-43. In contrast, urbanization may reduce the extraction of fuelwood, owing to easier

299

access to urban energy facilities. This feature can be demonstrated by fuelwood production data from China,

300

Indonesia, Brazil, and the U.S., in which wood fuel use decreased by 50%, 80%, 13%, and 60% from the peak

301

historical year to year 201344.

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302

International trade plays an increasingly important role in the global supply chain of biomass, because

303

although historically most food was produced locally, international trade in food is now essential if the planet’s

304

population is to be fed. Areas with very large population densities, especially those with poor agricultural

305

prospects, cover large fractions of Africa, East Asia, and South America, and are challenged to generate their

306

own food45. It is anticipated that by 2050 there will be well over a billion people totally dependent on

307

international trade for the food that they require45-46. In the SF scenario, the large food demand (due to the

308

largest population among scenarios) and the low accessibility to international trade suggest a high risk for the

309

maintenance of adequate food supplies in the future.

310

4.3 Decoupling potential of HANPPharv

311

Accelerated decoupling of human welfare from biomass resources extraction is thought to be vital to both

312

human society and natural ecosystems47. We have discussed three ideas for decoupling of biomass resource

313

demand from socio-economic development (GDP and population). First, in a well-balanced society (the EW

314

scenario) HANPPharv can be reduced by reasonable population size, increased urbanization, and transformed

315

diets. Second, reducing food losses and waste, especially edible food losses, can lower HANPPharv. In

316

developing countries, a large fraction of food is lost in postharvest and distribution stages, owing to inadequate

317

handling and storage facilities. In more developed countries, large portions of food are wasted during the

318

consumption stage due to living styles and values26. Third, cascading the utilization of biomass resources, such

319

as replacing fuelwood with crop residues, can also contribute to decoupling. Multiple methods for converting

320

primary and secondary biomass waste to bioenergy have proven practical in rural areas, e.g., household biogas,

321

straw gasification, and bio-charcoal from nut shells1,48-49. The frequent inadequacy of facilities, education,

322

incentives, and local governance are responsible for the low rate of use of biomass waste48. In particular,

323

spatial mismatch and lacking information between residues production and energy conversion facilities also

324

create barriers on the way to use the residues. In addition to the energy aspect of biomass resources, biomass

325

waste can be useful in replacing industrial round wood with straw-compressed bricks in building construction,

326

replacing wood pulp with straw in the paper production industry, and recycling biogenetic carbon and nutrients

327

to improve the long term yield of cropland. Reducing biomass waste is challenging in both developing and

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developed countries50-51, but the benefits of waste reduction over the next few decades are obvious. Apart from

329

these three decoupling methods, shifting to more sustainable diets (e.g., reducing meat consumption, especially

330

beef), improving the feed conversion ratio of the livestock system52, and reusing wood materials are also

331

possible routes to decoupling.

332

4.4 A final note

333

The purpose of these scenarios is not to forecast the future, but rather to imagine what can happen. In

334

carrying out this work, the goal has been to set the framework for a better informed and more nuanced outlook

335

on the evolution of the human use of biomass, the associated consequences, and the potential for resource

336

availability going forward. Accordingly, the results presented in this study should not be viewed as predictions.

337

Rather, our scenarios are designed with the goal with potentially influencing the course of events through

338

consideration of the consequence of alternative visions of the future. Our work will allow the sustainability

339

research community to better understand the intensity of human biomass use and the associated consequences

340

in the future.

341

ASSOCIATED CONTENT

342

Supporting Information

343

Definition of regions, methodology for analyzing biomass demand, data sources, regression of biomass

344

demand, methodology of scenarios, method for analyzing decoupling, and error analysis. This material is

345

available free of charge via the Internet at http://pubs.acs.org.

346

AUTHOR INFORMATION

347

Corresponding Author

348

* Phone: +86 10 62849147; email: [email protected]

349

Author Contributions

17



350

The manuscript was written through contributions of all authors. All authors have given approval to the

351

final version of the manuscript.

352

Notes

353

The authors declare no competing financial interest.

354

ACKNOWLEDGEMENT

355

We thank the United Nations Environment Programme, the US National Science Foundation (Grant No.

356

CBET-1336121), National Key R&D Program of China (2016YFC0502800), Youth Innovation Promotion

357

Association CAS (2017061), and National Natural Science Foundation of China (Grant No. 71533004) for

358

financial support. Thanks also due to Barbara Reck, Tomer Fishman, Daqian Jiang, and Benjamin Sprecher for

359

helpful comments.

360

REFERENCES

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(1) McKendry, P. Energy production from biomass (part 1): overview of biomass. Bioresour. Technol. 2002,

362 363 364 365 366 367

83(1), 37-46. (2) Hall, D.; Rosillo-Calle, F.; Woods, J. Biomass utilization in households & industry: Energy use and development. Chemosphere. 1994, 29(5), 1099-1119. (3) Rosillo-Calle, F.; De Groot, P.; Hemstock, S.L.; Woods, J. The Biomass Assessment Handbook: Energy for a Sustainable Environment. Routledge. 2015. (4) Godfray, H.C.J.; Beddington, J.R.; Crute, I.R.; Haddad, L.; Lawrence, D.; Muir, J.F.; Pretty, J.; Robinson,

368

S.; Thomas, S.M.; Toulmin, C. Food security: the challenge of feeding 9 billion people. Science. 2010,

369

327(5967), 812-818.

370 371 372 373

(5) Warman, R.D. Global wood production from natural forests has peaked. Biodivers. Conserv. 2014, 23(5), 1063-1078. (6) Alexandratos, N.; Bruinsma, J. World agriculture towards 2030/2050: the 2012 revision. ESA Working paper Rome, FAO. 2012.

18


Page 18 of 22

Page 19 of 22

374 375


(7) United Nations. World Population Prospects. United Nations Department of Economics and Social Affairs. 2015.

376

(8) Assembly UN General. Transforming our world: the 2030 Agenda for Sustainable Development. 2015.

377

(9) FAO. The state of food insecurity in the world. 2015.

378

(10) Bodirsky, B.L.; Rolinski, S.; Biewald, A.; Weindl, I.; Popp, A.; Lotze-Campen, H. Global Food Demand

379 380 381 382 383 384 385 386 387 388 389 390 391 392

Scenarios for the 21st Century. PloS one 2015, 10, e0139201. (11) Beringer, T.; Lucht, W.; Schaphoff, S. Bioenergy production potential of global biomass plantations under environmental and agricultural constraints. Gcb Bioenergy 2011, 3, 299-312. (12) Fischer, G.; Schrattenholzer, L. Global bioenergy potentials through 2050. Biomass Bioenergy 2001, 20(3), 151-159. (13) Haberl, H., Erb, K. H., Krausmann, F., Running, S., Searchinger, T. D., mith, W. K. Bioenergy: how much can we expect for 2050?, Environ. Res. Lett., 2013. 8(3), 031004. (14) Haberl, H.; Erb, K.H.; Krausmann, F. Human appropriation of net primary production: patterns, trends, and planetary boundaries. Annu. Rev. Environ. Resour. 2014, 39, 363-391. (15) Rojstaczer, S.; Sterling, S.M.; Moore, N.J. Human appropriation of photosynthesis products. Science 2001, 294(5551), 2549-2552. (16) Vitousek, P.M.; Mooney, H.A.; Lubchenco, J.; Melillo, J.M. Human domination of Earth's ecosystems. Science 1997, 277(5325), 494-499. (17) Haberl, H.; Erb, K.H.; Krausmann, F.; Gaube, V.; Bondeau, A.; Plutzar, C.; Gingrich, S.; Lucht, W.;

393

Fischer-Kowalski, M. Quantifying and mapping the human appropriation of net primary production in

394

earth's terrestrial ecosystems. Proc. Natl. Acad. Sci. USA 2007, 104(31),12942-12947.

395

(18) Krausmann, F.; Erb, K.H.; Gingrich, S.; Haberl, H.; Bondeau, A.; Gaube, V.; Lauk, C.; Plutzar, C.;

396

Searchinger, T.D. Global human appropriation of net primary production doubled in the 20th century.

397

Proc. Natl. Acad. Sci. USA 2013, 110(25), 10324-10329.

398

(19) Fetzel, T.; Niedertscheider, M.; Haberl, H.; Krausmann, F.; Erb, K.H. Patterns and changes of land use

399

and land-use efficiency in Africa 1980–2005: an analysis based on the human appropriation of net

400

primary production framework. Reg. Environ. Change. 2016, 16(5),1507-1520. 19



401

(20) Plutzar, C.; Kroisleitner, C.; Haberl, H.; Fetzel, T.; Bulgheroni, C.; Beringer, T.; Hostert, P.; Kastner, T.;

402

Kuemmerle, T.; Lauk, C. Changes in the spatial patterns of human appropriation of net primary

403

production (HANPP) in Europe 1990–2006. Reg. Environ. Change 2016, 16(5), 1225-1238.

404

(21) Krausmann, F.; Gingrich, S.; Haberl, H.; Erb, K.H.; Musel, A.; Kastner, T.; Kohlheb, N.; Niedertscheider,

405

M.; Schwarzlmüller, E. Long-term trajectories of the human appropriation of net primary production:

406

Lessons from six national case studies. Ecol. Econ. 2012, 77, 129-138.

407 408 409 410 411 412 413 414 415 416 417 418 419 420

(22) Erb, K.H.; Krausmann, F.; Lucht, W.; Haberl, H. Embodied HANPP: Mapping the spatial disconnect between global biomass production and consumption. Ecol. Econ. 2009, 69(2), 328-334. (23) Haberl, H.; Geissler, S. Cascade utilization of biomass: strategies for a more efficient use of a scarce resource. Ecol. Eng. 2000, 16, 111-121. (24) Imhoff, M.L.; Bounoua, L.; Ricketts, T.; Loucks, C.; Harriss, R.; Lawrence, W.T. Global patterns in human consumption of net primary production. Nature 2004, 429(6994), 870-873. (25) Westhoek H.; Ingram J.; van Berkum S.; Hajer M. Food systems and natural resources. United Nations Environment Programme, International Resource Panel. 2016. (26) Gustavsson, J.; Cederberg, C.; Sonesson, U.; Van Otterdijk, R.; Meybeck, A. Global food losses and food waste. Food and Agriculture Organization of the United Nations, Rome. 2011. (27) Porter, S.D.; Reay, D.S.; Higgins, P.; Bomberg, E. A half-century of production-phase greenhouse gas emissions from food loss & waste in the global food supply chain. Sci. Total Environ. 2016, 571, 721-729. (28) Electris, C.; Raskin, P.; Rosen, R.; Stutz, J. The century ahead: four global scenarios. Tellus Institute, Technical Documentation. 2009.

421

(29) FAOSTAT. Database of the Food and Agriculture Organization of the United Nations. 2016.

422

(30) UNEP. Global Environment Outlook 5. 2012.

423

(31) World Bank. Database of World Bank Open Data. 2016.

424

(32) UNEP. Global Environment Outlook 4: Environment for Development. 2007.

425

(33) Schandl H., et al. Global material flows and resource productivity (United Nations Environment

426

Programme, International Resource Panel, in preparation, United Nations, New York). (In preparation).

20


Page 20 of 22

Page 21 of 22


427

(34) Ahmed, N.M. Failing States, Collapsing Systems. 2017.

428

http://www.springer.com/gp/book/9783319478142

429

(35) Foley, J.A.; Ramankutty, N.; Brauman, K.A.; Cassidy, E.S.; Gerber, J.S.; Johnston, M.; Mueller, N.D.;

430

O’Connell, C.; Ray, D.K.; West, P.C. Solutions for a cultivated planet. Nature 2011, 478(7369), 337-342.

431

(36) Kastner, T.; Rivas, M.J.I.; Koch, W.; Nonhebel, S. Global changes in diets and the consequences for land

432 433 434

requirements for food. Proc. Natl. Acad. Sci. USA 2012, 109(18), 6868-6872. (37) Tilman, D.; Balzer, C.; Hill, J.; Befort, B.L. Global food demand and the sustainable intensification of agriculture. Proc. Natl. Acad. Sci. USA 2011, 108(50), 20260-20264.

435

(38) Mead, D.J. Forests for energy and the role of planted trees. Crit. Rev. Plant Sci. 2005, 24(5-6), 407-421.

436

(39) McMichael, A.J.; Powles, J.W.; Butler, C.D.; Uauy, R. Food, livestock production, energy, climate

437 438 439 440 441 442

change, and health. The Lancet 2007, 370(9594), 1253-1263. (40) Clair, P.C.S. Community forest management, gender and fuelwood collection in rural Nepal. J. Forest Econ. 2016, 24, 52-57. (41) Seto, K.C., Ramankutty, N. Hidden linkages between urbanization and food systems. Science 2016, 352(6288), 943-945. (42) Fishman, T.; Schandl, H.; Tanikawa, H. Stochastic Analysis and Forecasts of the Patterns of Speed,

443

Acceleration, and Levels of Material Stock Accumulation in Society. Environ. Sci. Technol. 2016, 50,

444

3729-3737.

445 446

(43) Fishman, T.; Schandl, H.; Tanikawa, H.; Walker, P.; Krausmann, F. Accounting for the material stock of nations. J. Ind. Ecol. 2014, 18, 407-420.

447

(44) FAO. Yearbook of Forest Products 2013. 2015.

448

(45) Pradhan, P.; Lüdeke, M.K.; Reusser, D.E.; Kropp, J.P. Food self-sufficiency across scales: how local can

449

we go? Environ. Sci. Technol. 2014, 48(16), 9463-9470.

450

(46) Fader, M.; Gerten, D.; Krause, M.; Lucht, W.; Cramer, W. Spatial decoupling of agricultural production

451

and consumption: quantifying dependences of countries on food imports due to domestic land and water

452

constraints. Environ. Res. Lett. 2013, 8(1), 014046.

21



453 454 455 456 457 458 459 460 461 462

(47) Fischer-Kowalski, M.; Swilling, M. Decoupling: natural resource use and environmental impacts from economic growth. United Nations Environment Programme. 2011. (48) Chen, Y.; Yang, G.; Sweeney, S.; Feng, Y. Household biogas use in rural China: a study of opportunities and constraints. Renewable Sustainable Energy Rev. 2010, 14(1), 545-549. (49) Zhou, X.; Wang, F.; Hu, H.; Yang, L.; Guo, P.; Xiao, B. Assessment of sustainable biomass resource for energy use in China. Biomass Bioenergy 2011, 35(1), 1-11. (50) Girotto, F.; Alibardi, L.; Cossu, R. Food waste generation and industrial uses: a review. Waste Manag. 2015, 45, 32-41. (51) Nahman, A.; De Lange, W.; Oelofse, S.; Godfrey, L. The costs of household food waste in South Africa. Waste Manage. 2012, 32(11), 2147-2153.

463

(52) Herrero, M.; Havlík, P.; Valin, H.; Notenbaert, A.; Rufino, M.C.; Thornton, P.K.; Blümmel, M.; Weiss, F.;

464

Grace, D.; Obersteiner, M. Biomass use, production, feed efficiencies, and greenhouse gas emissions

465

from global livestock systems. Proc. Natl. Acad. Sci. USA 2013, 110(52), 20888-20893.

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