Global inequalities in food consumption,cropland demand and land-use efficiency: A decomposition analysis

The world population is expected to rise to 9.7 billion by 2050 and to ~11 billion by 2100, and securing its healthy nutrition is a key concern. As global fertile land is limited, the question arises whether growth in food consumption associated with increased affluence surmounts increases in land-use efficiency (measured as food supply per cropland area) associated with technological progress. Furthermore, substantial inequalities prevail in the global food system: While overly rich diets represent a serious health issue for many of the world’s most affluent inhabitants and constitute a critical climate-change driver, undernourishment and hunger still threaten a considerable fraction of the world population, mostly in low-income countries. We here analyze trajectories in cropland demand and their main basic drivers food consumption (measured by a food index reflecting the share of animal products in diets) and land-use efficiency, for 123 countries (clustered in four income groups, covering 94% of the world population). We cover the period 1990–2013 and assess if these trajectories are associated with changes in inequality between countries. We find that while all groups of countries converged towards the high level of the per-capita food consumption of high-income countries, differences between income groups remained pronounced. Overall, cropland demand per capita declined over the entire period in all regions except low income countries, resulting in a tendency towards global convergence. However, the trend slowed in the last years. In contrast, land-use efficiency increased in all income groups with a similar trend, hence international inequalites in land-use efficiency remained almost unaltered. Because population and food requirements per capita are expected to grow in all income groups except the richest ones, failure to improve land efficiency sufficiently could lead to a less unequal but at the same time less ecologically sustainable world. Avoiding such outcomes may be possible by reducing the consumption of animal products in the richer countries and raising land-use efficiency in the poorer countries.     

Interaction effects between economic development and forest cover determine deforestation rates

Recent work on global patterns of deforestation has shown that countries with high per capita GDP or low remaining forest cover are more likely to be experiencing afforestation than deforestation. Here, I show that the relationship is more complex than previously described, because the effect of one variable is dependent upon the value of the other. As a result, high-income nations exhibit the opposite response to disappearing forest cover than low-income nations. In an analysis of 103 countries, I found that high-income countries with low forest cover have the highest rates of afforestation, typically through the establishment of new plantations. In contrast, low-income countries with little forest are more likely to consume that remaining portion at a faster proportional rate than do low-income countries with more forest. Nations with large amounts of forest have approximately equal deforestation rates, regardless of national wealth. These results highlight for the first time that there is a strong interaction between forest cover and economic development that determines rates of forest change among nations.     

Contraction and convergence of in-use metal stocks to meet climate goals

The foundations of modern society are based on metals, yet their production is currently placing considerable strain on the Earth’s carrying capacity. Here, we develop a century-long scenario for six major metals (iron, aluminum, copper, zinc, lead, and nickel) harmonized with climate goals, with the goal of establishing science-based targets. We show that for the metal sector to contribute proportionally to emission reductions targets of the industrial sector, global in-use metal stocks need to converge from the current level of around 4 t/capita to about 7 t/capita. This will require today’s high-income countries to contract their per capita stock from current levels of about 12 t/capita to make room for growth in countries that are presently classified as middle- and low-income countries. In such a contraction and convergence scenario, primary production of all six metals will peak by 2030, and secondary production will surpass primary production by at least 2050. Consequently, cumulative ore requirements over the 21st century will remain below currently identified resources, implying that natural ore extraction will be limited by emissions budgets before existing resources can be depleted. Importantly, realizing such system changes will require urgent and concerted international efforts involving all countries, but specific responsibilities will vary according to income level. Namely, wealthy countries will need to use existing metal stocks more intensively and for longer periods to reduce stock replacement demand, while poor countries will need to develop long-lasting and material-efficient infrastructure to curtail stock expansion demand in the first half of the 21st century.     

Economic and political drivers of environmental impact shifting between countries

There is mounting evidence that major improvements in environmental quality in high-income countries over the past decades may have been achieved to a large degree through relocation of environmental impacts of consumption to other, usually poorer countries. While political and academic debates on appropriate policy interventions to address this challenge are gaining ground, we still know rather little about the drivers of international environmental impact shifting, other than international trade flows per se. We address this issue by focusing on the effects of economic inequality and political factors. We argue that income inequality between and within countries as well as variation in political institutions, environmental clauses in preferential trade agreements (PTAs), and participation in international environmental treaties could be important drivers or mitigators of environmental impact shifting between countries. We use novel panel data on five types of environmental impact flows between country dyads (187 countries, 1990–2015) to assess these arguments. We find that richer countries and countries with higher domestic economic equality tend to be the “outsourcers”, and poorer, domestically more unequal countries the “insourcers” of environmental impacts. Discrepancies in democracy levels aggravate the outsourcing from more equal to more unequal societies. In turn, environmental clauses in PTAs have a mitigating effect on environmental impact shifting, but participation in international environmental agreements has no such effect. Our findings highlight the need for green economy policies that reduce environmental footprints of consumption not only within high-income democracies, but also make their global supply chains more sustainable.     

Air conditioning and global inequality

As global temperatures go up and incomes rise, air conditioner sales are poised to increase dramatically. Recent studies explore the potential economic and environmental impacts of this growth, but relatively little attention has been paid to the implications for inequality. In this paper we use household-level microdata from 16 countries to characterize empirically the relationship between climate, income, and residential air conditioning. We show that both current and future air conditioner usage is concentrated among high-income households. Not only do richer countries have much more air conditioning than poorer countries, but within countries adoption is highly concentrated among high-income households. The pattern of adoption is particularly stark in relatively low-income countries such as Pakistan, where we show that the vast majority of adoption between now and 2050 will be concentrated among the upper income tercile. We use our model to forecast future adoption, show how patterns vary across countries and income levels, and discuss what these patterns mean for health, productivity, and educational inequality.     

Land use biodiversity impacts embodied in international food trade

Agricultural land use to meet the demands of a growing population, changing diets, lifestyles and biofuel production is a significant driver of biodiversity loss. Globally applicable methods are needed to assess biodiversity impacts hidden in internationally traded food items. We used the countryside species area relationship (SAR) model to estimate the mammals, birds, amphibians and reptiles species lost (i.e. species ‘committed to extinction’) due to agricultural land use within each of the 804 terrestrial ecoregion. These species lost estimates were combined with high spatial resolution global maps of crop yields to calculate species lost per ton for 170 crops in 184 countries. Finally, the impacts per ton were linked with the bilateral trade data of crop products between producing and consuming countries from FAO, to calculate the land use biodiversity impacts embodied in international crop trade and consumption. We found that 83% of total species loss is incurred due to agriculture land use devoted for domestic consumption whereas 17% is due to export production. Exports from Indonesia to USA and China embody highest impacts (20 species lost at the regional level each). In general, industrialized countries with high per capita GDP tend to be major net importers of biodiversity impacts from developing tropical countries. Results show that embodied land area is not a good proxy for embodied biodiversity impacts in trade flows, as crops occupying little global area such as sugarcane, palm oil, rubber and coffee have disproportionately high biodiversity impacts.     

Economic development and natural disasters: A satellite data analysis

In this study we examine the impact of large-scale natural disasters on economic development. A major obstacle in exploring this relationship is the poor data quality on GDP per capita in low-income countries, while at the same time more than 90% of all disasters that happen worldwide occur in these particular countries. To overcome this problem, we use data based on satellite images of the night-time light intensity in a specific country or region which is shown to be highly correlated with income per capita. After testing for the sensitivity of the results, our main findings suggest that natural disasters reduce the amount of lights visible from outer space significantly in the short run. To be more precise, we demonstrate that climatic and hydrological disasters cause a large drop in the luminosity in developing and emerging market countries, while geophysical and meteorological disasters decrease light intensity more in industrialized countries. It turns out that using reported real GDP per capita figures underestimates the true impact. Besides, a large part of the economic consequences of the natural events is explained by their regional impact. However, in the long run most of the disaster effect has disappeared. Finally, the impact of a disaster depends partly on the size and scope of the natural catastrophe, the geographical location, the degree of financial development of a country and the quality of the political institutions present.     

Measuring income and projecting energy use

Energy is a key requirement for a healthy, productive life and a major driver of the emissions leading to an increasingly warm planet. The implications of a doubling and redoubling of per capita incomes over the remainder of this century for energy use are a critical input into understanding the magnitude of the carbon management problem. A substantial controversy about how the Special Report on Emissions Scenarios (SRES) measured income and the potential implications of how income was measured for long term levels of energy use is revisited again in the McKibbin, Pearce and Stegman article appearing elsewhere in this issue. The recent release of a new set of purchasing power estimates of national income, and the preparations for creating new scenarios to support the IPCC’s fifth assessment highlight the importance of the issues which have arisen surrounding income and energy use. Comparing the 1993 and 2005 ICP results on Purchasing Power Parity (PPP) based measures of income reveals that not only do the 2005 ICP estimates share the same issue of common growth rates for real income as measured by PPP and US $, but the lack of coherence in the estimates of PPP incomes, especially for developing countries raises yet another obstacle to resolving the best way to measure income. Further, the common use of an income term to mediate energy demand (as in the Kaya identity) obscures an underlying reality about per capita energy demands, leading to unreasonable estimates of the impact of changing income measures and of the recent high GDP growth rates in India and China. Significant new research is required to create both a reasonable set of GDP growth rates and long term levels of energy use.     

Income,consumer preferences,and the future of livestock-derived food demand

In recent decades there has been a sustained and substantial shift in human diets across the globe towards including more livestock-derived foods. Continuing debates scrutinize how these dietary shifts affect human health, the natural environment, and livelihoods. However, amidst these debates there remain unanswered questions about how demand for livestock-derived foods may evolve over the upcoming decades for a range of scenarios for key drivers of change including human population, income, and consumer preferences. Future trends in human population and income in our scenarios were sourced from three of the shared socioeconomic pathways. We used scenario-based modeling to show that average protein demand for red meat (beef, sheep, goats, and pork), poultry, dairy milk, and eggs across the globe would increase by 14% per person and 38% in total between the year 2020 and the year 2050 if trends in income and population continue along a mid-range trajectory. The fastest per person rates of increase were 49% in South Asia and 55% in sub-Saharan Africa. We show that per person demand for red meat in high-income countries would decline by 2.8% if income elasticities of demand (a partial proxy for consumer preferences, based on the responsiveness of demand to income changes) in high-income countries decline by 100% by 2050 under a mid-range trajectory for per person income growth, compared to their current trajectory. Prices are an important driver of demand, and our results demonstrate that the result of a decline in red meat demand in high-income countries is strongly related to rising red meat prices, as projected by our scenario-based modeling. If the decline in the income elasticity of demand occurred in all countries rather than only in high-income countries, then per person red meat demand in high-income countries would actually increase in 2050 by 8.9% because the income elasticity-driven decline in global demand reduces prices, and the effect of lower prices outweighs the effect of a decline in the income elasticity of demand. Our results demonstrate the importance of interactions between income, prices, and the income elasticity of demand in projecting future demand for livestock-derived foods. We complement the existing literature on food systems and global change by providing quantitative evidence about the possible space for the future demand of livestock-derived foods, which has important implications for human health and the natural environment.     

A novel analysis of consumption-based carbon footprints in China: Unpacking the effects of urban settlement and rural-to-urban migration

Urbanization in developing countries greatly contributes to growing carbon emissions. Although studies have documented the urbanization effect, the science of consumption-based footprint assessments has yet to unpack various effects during the process of urbanization. Based on household expenditure data, this study innovatively proposes a methodology to conceptually and statistically deconstruct the observed urbanization effects on carbon footprint into selection effects and migration effects, which consist of human settlement effects and purposeful changes of migration (such as income and residential location). Applying propensity score matching and regression on the 2010 China Family Panel Study, we find that the apparent carbon-footprint difference between rural residents and migrants is about 1.5 t CO₂e per capita. The migration effects account for about 2/3 of the apparent difference and the remaining 1/3 is due to selection effects. Urban settlement effects and the purposeful changes account for 73% and 27% of the migration effects, respectively. Transport sector is the key driver of carbon-footprint growth: it accounts for 60% of the migration effects. We conclude that travel behavior of rural migrants, currently in scarcity in the lite rature, merits further investigation, and policies should emphasize transit-oriented land use and transportation to achieve low-carbon urbanization.     

A global comparison of carbon-water-food nexus based on dietary consumption

Exploring the environmental impact of dietary consumption has become increasingly important to understand the carbon-water-food nexus, vital to achieving UN sustainable development goals. However, the research on diet-based nexus assessment is still lacking. Here, we developed an Environmentally Extended Multi-Regional Input-Output (EE-MRIO) model with compiling a global MRIO table based on the latest Global Trade Analysis Project (GTAP) 10 database, where we specifically constructed a water withdrawal account and matched it to each economy at the sectoral level. The regional heterogeneity and synergy of carbon-water nexus affected by dietary patterns in nine countries was explored. The results show that: (1) Dietary consumption is the main use of water withdrawal for each country; Japan, the US, South Korea, and India have a high per capita dietary water footprint. Mainly due to consumption of processed rice, Japan has the highest per capita value of 488 M³/year, accounting for 63.4% of the total water footprint. (2) The total dietary carbon footprints in China, India, and the US are high, which is mainly caused by the high consumption of animal products (including dairy) either due to the large population (China, India) or animal-based diet (the US). Americans have the highest per capita dietary carbon footprint, reaching 755.4 kg/year, 2.76 times that of the global average. (3) Generally, imported/foreign footprints account for a greater share in dietary water and carbon footprints of developed countries with an animal-based diet. (4) In the nexus analysis, the US, Japan, and South Korea are key-nexus countries, vegetables, fruit and nuts, tobacco and beverages, and other food products are selected as key-nexus sectors with relatively high dietary water and carbon footprint. Furthermore, dietary consumption choices lead to different environmental impacts. It is particularly important to find a sustainable dietary route adapted to each country considering that heterogeneity and synergism exist in key-nexus sectors to achieve the relevant Sustainable Development Goals.     

Climate change and international tourism: A simulation study

The literature on tourism and climate change lacks an analysis of the global changes in tourism demand. Here, a simulation model of international tourism is presented that fills that gap. The current pattern of international tourist flows is modelled using 1995 data on departures and arrivals for 207 countries. Using this basic model the impact on arrivals and departures through changes in population, per capita income and climate change are analysed. In the medium to long term, tourism will grow, however, the change from climate change is smaller than from population and income changes.     

县域生态足迹动态变化分析——以内蒙古和林格尔县为例

采用生态足迹的理论和分析方法对和林格尔县可持续发展进行了评价分析。结果表明：1997--2007年间,和林格尔县二、三产业发展水平偏低,导致人均生态赤字越来越大,和林格尔县发展需要所占用的生态服务已经超出了其本身可承载的能力;和林格尔县每万元GDP所消耗的生态足迹呈逐年下降趋势;从历年生态足迹构成来看,耕地和化石能源用地占整个生态足迹的比重很大,是影响和林格尔县生态足迹变化的最重要因素。     

Out of sight,out of mind: Plastic waste exports,psychological distance and consumer plastic purchasing

Per capita consumption of plastic continues to increase and remains at high levels in high-income countries, despite obvious contributions to the global problem of plastics pollution. This paper attempts to provide an explanation for this phenomenon based on construal level theory, positing that plastic waste is a problem that is perceived as “out of sight and out of mind” for consumers in high plastic consumption (typically high income) countries and that this is influenced by the export of plastic waste to other (typically lower income and lower consumption) countries for disposal – shifting the burden of mismanaged plastic waste and perceptions of plastics pollution in the countries creating the majority of plastic waste. The apparent lack of plastics pollution in a local environment becomes a mediator, influenced by the export of plastic waste, which may then contribute to further plastics consumption. The theory is tested using structural equation modelling using rare, available matched data for mismanaged plastic waste, plastic waste exports, and plastics consumption at an aggregate country level. All study hypotheses are supported. The paper concludes with recommendations for future research and practice, including potential changes to government policy aimed at reducing future plastics consumption and pollution.     

The effect of industrialization and globalization on domestic land-use: A global resource footprint perspective

Land-use activities are increasingly globalized and industrialized. While this contributes to a reduction of pressure on domestic ecosystems in some regions, spillover effects from these processes represent potential obstacles for global sustainable land-use. This contribution scrutinizes the complex global resource nexus of national land-use intensity, international trade of biomass goods, and resource footprints in land-use systems. Via a systematic account of the global human appropriation of net primary production (HANPP) and input–output modelling, we demonstrate that with growing income countries reduce their reliance on local renewable resources, while simultaneously consuming more biomass goods produced in other countries requiring higher energy and material inputs. The characteristic 'outsourcing' country appropriates 43% of its domestic net primary production, but net-imports a similar amount (64 gigajoules per capita and year) from other countries and requires energy (11 GJ/cap/yr) and material (~400 kg/cap/yr) inputs four to five times higher as the majority of the global population to sustain domestic land-use intensification. This growing societal disconnect from domestic ecological productivity enables a domestic conservation of ecosystems while satisfying growing demand. However, it does not imply a global decoupling of biomass consumption from resource and land requirements.     

Tele-connecting local consumption to global land use

Globalization increases the interconnectedness of people and places around the world. In a connected world, goods and services consumed in one country are often produced in other countries and exchanged via international trade. Thus, local consumption is increasingly met by global supply chains oftentimes involving large geographical distances and leading to global environmental change. In this study, we connect local consumption to global land use through tracking global commodity and value chains via international trade flows. Using a global multiregional input–output model with sectoral detail allows for the accounting of land use attributed to “unusual” sectors – from a land use perspective – including services, machinery and equipment, and construction. Our results show how developed countries consume a large amount of goods and services from both domestic and international markets, and thus impose pressure not only on their domestic land resources, but also displace land in other countries, thus displacing other uses. For example, 33% of total U.S. land use for consumption purposes is displaced from other countries. This ratio becomes much larger for the EU (more than 50%) and Japan (92%). Our analysis shows that 47% of Brazilian and 88% of Argentinean cropland is used for consumption purposes outside of their territories, mainly in EU countries and China. In addition, consumers in rich countries tend to displace land by consuming non-agricultural products, such as services, clothing and household appliances, which account for more than 50% of their total land displacement. By contrast, for developing economies, such as African countries, the share of land use for non-agricultural products is much lower, with an average of 7%. The emerging economies and population giants, China and India, are likely to further increase their appetite for land from other countries, such as Africa, Russia and Latin America, to satisfy their own land needs driven by their fast economic growth and the needs and lifestyles of their growing populations.     

How does carbon dioxide emission change with the economic development? Statistical experiences from 132 countries

Issues concerning what measures should be adopted to achieve a sustainable world with less carbon dioxide emission and in what magnitude should we reduce our emission have been on agenda in both international negotiations and countries’ policy making aimed at coping with potential global climate change. These issues cannot be easily addressed unless comprehensive understanding about the countries’ status quo as well as historical relationship between economic development and carbon dioxide emission are gained. In this paper, we examine the historical relationship between economic development and carbon dioxide emission; the ex ante restrictions on function forms and the poorly handled robustness issues rife in economics literature are synthetically addressed. Evidence from recent four decades indicates that per capita carbon dioxide emission first significantly and monotonously increase at low income level and flattens after per capita income reaches at about 22,000 $ (2005 constant price). We perform various robustness checks by employing different data sources, different model specifications and different econometric estimates. The captured development–emission relationship is robust. Our empirical results indicate factors such as urbanization, population density, trade, energy mix and economic environment impact the absolute level of carbon dioxide emission not the overall income elasticity structure of carbon dioxide emission.     

Identifying regional drivers of future land-based biodiversity footprints

Biodiversity footprints quantify the impacts on ecosystems caused by final consumption in a region, accounting for imports and exports. Up to now, footprint analyses have typically been applied to analyze past or present consumption patterns. Here, we quantify future land-based biodiversity footprints associated with three diverging Shared Socio-economic Pathways (SSPs), using loss in Biodiversity Intactness Index (BII) as an indicator of biodiversity loss. For each SSP, we retrieved socio-economic and land use projections to 2100 from the IMAGE-MAGNET model and calculated associated biodiversity footprints for seven aggregated world regions. We then compared these with the functional diversity component of the biosphere integrity planetary boundary. Our results indicate that the global land-based biodiversity impact stays below the boundary (tentatively set at 90% of original BII) in all scenario-year combinations. Contrastingly, the per capita boundary is transgressed in one, four and five out of the seven world regions in 2100 for SSP1 (‘sustainability’), SSP2 (‘middle of the road’) and SSP3 (‘regional rivalry’), respectively. These results indicate a strong difference in the biodiversity impact of final consumption between the regions and between SSPs. Even in the ‘sustainability’ scenario, the per capita biodiversity footprint of consumption in North America needs to be reduced to meet the per capita boundary. Thus, policy-making to safeguard the environment would benefit from adopting region-specific strategies: focusing on realizing agricultural efficiency gains in regions with unexploited potential, while focusing on promoting dietary changes towards less animal-based consumption in regions with limited potential for additional efficiency gains.     

Exchange Rates and Climate Change: An Application of Fund

As economic and emissions scenarios assume convergence of per capita incomes, they are sensitivity to the exchange rate used for international comparison. Particularly, developing countries are project to grow slower with a purchasing power exchange rate than with a market exchange rate. Different exchange rates may lead to scenarios with very different per capita incomes. However, these scenarios also assume convergence of energy intensities, which at least partly offsets the income effect, so that scenarios with different exchange rates would differ less in greenhouse gas emissions. Differences become smaller still if atmospheric concentrations and global warming is considered. However, differences become larger again if one considers the costs of meeting a certain stabilisation target, as the gap between baseline and target is more sensitive to the exchange rate used than the baseline itself. Differences also grow larger if one looks at climate change impacts, which are determined not just by climate change but also by development. The sensitivity to the exchange rate is purely due to imperfect data, imperfect statistical analysis of data, a crude spatial resolution, and imperfect models.     

Sharing the burden of financing adaptation to climate change

Climate change may cause most harm to countries that have historically contributed the least to greenhouse gas emissions and land-use change. This paper identifies consequentialist and non-consequentialist ethical principles to guide a fair international burden-sharing scheme of climate change adaptation costs. We use these ethical principles to derive political principles – historical responsibility and capacity to pay – that can be applied in assigning a share of the financial burden to individual countries. We then propose a hybrid ‘common but differentiated responsibilities and respective capabilities’ approach as a promising starting point for international negotiations on the design of burden-sharing schemes. A numerical assessment of seven scenarios shows that the countries of Annex I of the United Nations Framework Convention on Climate Change would bear the bulk of the costs of adaptation, but contributions differ substantially subject to the choice of a capacity to pay indicator. The contributions are less sensitive to choices related to responsibility calculations, apart from those associated with land-use-related emissions. Assuming costs of climate adaptation of USD 100 billion per year, the total financial contribution by the Annex I countries would be in the range of USD 65–70 billion per year. Expressed as a per capita basis, this gives a range of USD 43–82 per capita per year.