Spatially-explicit footprints of agricultural commodities: Mapping carbon emissions embodied in Brazil's soy exports

Reliable estimates of carbon and other environmental footprints of agricultural commodities require capturing a large diversity of conditions along global supply chains. Life Cycle Assessment (LCA) faces limitations when it comes to addressing spatial and temporal variability in production, transportation and manufacturing systems. We present a bottom-up approach for quantifying the greenhouse gas (GHG) emissions embedded in the production and trade of agricultural products with a high spatial resolution, by means of the integration of LCA principles with enhanced physical trade flow analysis. Our approach estimates the carbon footprint (as tonnes of carbon dioxide equivalents per tonne of product) of Brazilian soy exports over the period 2010–2015 based on ~90,000 individual traded flows of beans, oil and protein cake identified from the municipality of origin through international markets. Soy is the most traded agricultural commodity in the world and the main agricultural export crop in Brazil, where it is associated with significant environmental impacts. We detect an extremely large spatial variability in carbon emissions across sourcing areas, countries of import, and sub-stages throughout the supply chain. The largest carbon footprints are associated with municipalities across the MATOPIBA states and Pará, where soy is directly linked to natural vegetation loss. Importing soy from the aforementioned states entailed up to six times greater emissions per unit of product than the Brazilian average (0.69 t t⁻¹). The European Union (EU) had the largest carbon footprint (0.77 t t⁻¹) due to a larger share of emissions from embodied deforestation than for instance in China (0.67 t t⁻¹), the largest soy importer. Total GHG emissions from Brazilian soy exports in 2010–2015 are estimated at 223.46 Mt, of which more than half were imported by China although the EU imported greater emissions from deforestation in absolute terms. Our approach contributes data for enhanced environmental stewardship across supply chains at the local, regional, national and international scales, while informing the debate on global responsibility for the impacts of agricultural production and trade.     

全球贸易隐含碳变化及其影响分析

基于最新的GTAP8 (Global Trade Analysis Project）数据库,使用投入产出法,分析了2004年到2007年全球贸易变化下南北集团贸易隐含碳变化及对全球碳排放的影响。结果显示,随着发展中国家进出口规模扩张,全球贸易隐含碳流向的重心逐渐向发展中国家转移。2004年到2007年,发达国家高端设备制造业和服务业出口以及发展中国家资源、能源密集型行业及中低端制造业出口的趋势加强,该过程的生产转移导致全球碳排放增长4.15亿t,占研究时段全球贸易隐含碳增量的63%。未来发展中国家的出口隐含碳比重还将进一步提高。贸易变化带来的南北集团隐含碳流动变化对全球应对气候变化行动的影响日益突出,发达国家对此负有重要责任。     

The land cover and carbon cycle consequences of large-scale utilizations of biomass as an energy source

The use of modern biomass for energy generation has been considered in many studies as a possible measure for reducing or stabilizing global carbon dioxide (CO₂) emissions. In this paper we assess the impacts of large-scale global utilization of biomass on regional and grid scale land cover, greenhouse gas emissions, and carbon cycle. We have implemented in the global environmental change model IMAGE the LESS biomass intensive scenario, which was developed for the Second Assessment Report of IPCC. This scenario illustrates the potential for reducing energy related emission by different sets of fuel mixes and a higher energy efficiency. Our analysis especially covers different consequences involved with such modern biomass scenarios. We emphasize influences of CO₂ concentrations and climate change on biomass crop yield, land use, competition between food and biomass crops, and the different interregional trade patterns for modern biomass based energy. Our simulations show that the original LESS scenario is rather optimistic on the land requirements for large-scale biomass plantations. Our simulations show that 797 Mha is required while the original LESS scenario is based on 550 Mha. Such expansion of agricultural land will influence deforestation patterns and have significant consequenses for environmental issues, such as biodiversity. Altering modern biomass requirements and the locations where they are grown in the scenario shows that the outcome is sensitive for regional emissions and feedbacks in the C cycle and that competition between food and modern biomass can be significant. We conclude that the cultivation of large quantities of modern biomass is feasible, but that its effectiveness to reduce emissions of greenhouse gases has to be evaluated in combination with many other environmental land use and socio-economic factors.     

Towards meaningful consumption-based planetary boundary indicators: The phosphorus exceedance footprint

The idea of measuring humanity’s footprint against planetary boundaries has attracted wide academic attention but methods to implement the theory in sustainability accounting remain underexplored. To help nations take collective actions to stay within a safe operating space, footprinting approaches need to be revised to accommodate biophysical limits. Here we develop a novel sustainability indicator, the phosphorus exceedance footprint (PEF) that measures countries’ contributions to the transgression of the planetary boundaries for phosphorus. Adopting a consumption-based perspective reveals how nations contribute to environmentally unsustainable phosphorus pollution in their trading partners. This captures country-specific transgression through supply chains in a way that complements conventional footprinting. In 2011, 27% of the world’s PEF was associated with international trade flows. Wealthier countries tend to reduce their domestic phosphorus fertiliser exceedance, thus preserving their own natural environment, while increasing their share of imported P-embodied products through trade. A pattern of highly uneven distribution of phosphorus-compromised economies is revealed, with 76% of the worldwide exceeded phosphorus embodied in exports supplied by only four countries: China (42%), Brazil (19%), India (10%) and New Zealand (54%). All countries transgress phosphorus planetary boundaries, even those that do not exceed their own territorial boundaries. Our findings highlight that mitigation strategies need to include international cooperation on increasing the efficiency of fertiliser use and reducing the demand of products that cause phosphorus exceedance.     

China's carbon emissions and international trade: implications for post-2012 policy

Growing international trade has been one of the most important drivers for China's recent economic growth. This growth has fed rapid increases in energy demand and carbon emissions since 2000. China is now the world's largest emitter of carbon dioxide. There is mounting pressure from some in the international community for China to take specific actions to mitigate its emissions as part of a post-2012 climate regime. However, emissions embodied in internationally traded goods have not been given enough attention in this debate. This article discusses the results of research to quantify the emissions stemming from goods that are exported from China to other countries. It finds that these emissions accounted for 23% of China's national total in 2004. The article sets out how this result has been obtained and compares it to the results of several other pieces of research to demonstrate the importance of this issue. Some pointers for international climate policy are then discussed, including the advantages and difficulties of moving to consumption-based emissions accounting, and implications for international trade rules.     

基于多区域投入产出模型中美贸易隐含能源、碳排放的测算

采用多区域投入产出模型（MRIO）,利用欧盟资助开发的世界投入产出表和环境账户数据,测算了1995—2009年中国与美国的增加值贸易规模及净值,在此基础上利用环境账户中的能源消耗和碳排放数据测算出中美外贸隐含能源和隐含碳排放总体水平及其行业结构。研究表明：1995—2009年,中国对美国的增加值出口保持持续增长的态势,尤其是在中国加入世界贸易组织（WTO）后,但随后受2008年全球经济危机的影响,中国增加值出口规模有所减小;相比于美国,中国单位增加值能耗和碳排放水平较高,从而导致较大规模的隐含能源和隐含碳出口,长期处于隐含能源和隐含碳净输出国地位,且净输出规模呈现出上升的趋势;从行业结构来看,电力、燃气及水的供应业等能源行业是中国出口隐含能源和隐含碳排放的主要行业来源。     

Pollution embodied in trade: The Norwegian case

With the increase in international trade, it is becoming increasingly important to accurately determine environmental impacts resulting from pollution embodied in trade. Many previous studies have unrealistically assumed that imports are produced with the technology of the importing country. For countries with diverging technology and energy mixes the likely errors are significant. This study uses a model that explicitly includes regional technology differences to the case of Norway. It is found that CO₂ emissions embodied in imports was 67% of Norway's domestic emissions. Around a half of this embodied pollution originates in developing countries, yet they represent only 10% of the value of Norwegian imports. In addition the carbon leakage from non-Annex I countries was at least 30%. We then argue that basing emission inventories on consumption, rather than production, may resolve not only issues related to international trade, but also provide greater flexibility towards pollution intensive resource endowments, emission reductions, and participation levels.     

Land-use futures in the shared socio-economic pathways

In the future, the land system will be facing new intersecting challenges. While food demand, especially for resource-intensive livestock based commodities, is expected to increase, the terrestrial system has large potentials for climate change mitigation through improved agricultural management, providing biomass for bioenergy, and conserving or even enhancing carbon stocks of ecosystems. However, uncertainties in future socio-economic land use drivers may result in very different land-use dynamics and consequences for land-based ecosystem services. This is the first study with a systematic interpretation of the Shared Socio-Economic Pathways (SSPs) in terms of possible land-use changes and their consequences for the agricultural system, food provision and prices as well as greenhouse gas emissions. Therefore, five alternative Integrated Assessment Models with distinctive land-use modules have been used for the translation of the SSP narratives into quantitative projections. The model results reflect the general storylines of the SSPs and indicate a broad range of potential land-use futures with global agricultural land of 4900 mio ha in 2005 decreasing by 743 mio ha until 2100 at the lower (SSP1) and increasing by 1080 mio ha (SSP3) at the upper end. Greenhouse gas emissions from land use and land use change, as a direct outcome of these diverse land-use dynamics, and agricultural production systems differ strongly across SSPs (e.g. cumulative land use change emissions between 2005 and 2100 range from −54 to 402 Gt CO₂). The inclusion of land-based mitigation efforts, particularly those in the most ambitious mitigation scenarios, further broadens the range of potential land futures and can strongly affect greenhouse gas dynamics and food prices. In general, it can be concluded that low demand for agricultural commodities, rapid growth in agricultural productivity and globalized trade, all most pronounced in a SSP1 world, have the potential to enhance the extent of natural ecosystems, lead to lowest greenhouse gas emissions from the land system and decrease food prices over time. The SSP-based land use pathways presented in this paper aim at supporting future climate research and provide the basis for further regional integrated assessments, biodiversity research and climate impact analysis.     

Climate change and agriculture: A perspective on priorities for economic policy

Research on the effects of climate change on U.S. agriculture and world grain markets suggests that adaptation will occur with relatively small effects on total production. Additional research shows that reducing emission of greenhouse gases from U.S. agricultural production is relatively expensive compared to encouraging reforestation as an offset to emissions of carbon dioxide. Nevertheless, continued population growth and the increasing inequality of income across countries are likely to exacerbate the adverse effects of climate change. Concepts of sustainability should be expanded to cover industrial as well as agricultural production, and promote the efficient use of fossil fuels in general. Dealing with climate change effectively will require international cooperation and a willingness to address population growth and the divergence of incomes between rich and poor countries.     

Deforestation in the Ayeyarwady Delta and the conservation implications of an internationally-engaged Myanmar

Myanmar is a country of huge biodiversity importance that is undergoing major political change, bringing with it new international engagement. This includes access to international markets, which will likely spur investment in export-oriented agriculture, leading to increased pressures on already threatened ecosystems. This scenario is illustrated in the Ayeyarwady Delta, the country's agricultural heartland sustaining high deforestation rates. Using the Delta as a model system, we use an integrated approach to inquire about whether and how imminent agricultural reforms associated with an internationally-engaged Myanmar could introduce new actors and incentives to invest in agricultural expansion that could affect deforestation rates. We use a novel remote sensing analysis to quantify deforestation rates for the Delta from 1978 to 2011, develop business-as-usual deforestation scenarios, and contextualize those results with an analysis of contemporary policy changes within Myanmar that are expected to alter the principal drivers of land-cover change. We show that mangrove systems of Myanmar are under greater threat than previously recognized, and that agriculture has been the principle driver of deforestation on the Delta. The centrality of agriculture to the Myanmar economy indicates that emerging policies are likely to tip the scales towards agricultural expansion, agro-industrial investment and potentially greater rates of deforestation due to the introduction of well-funded investors, insufficient land tenure agreements, and low governance effectiveness. The broad national challenge is to initiate environmental governance reforms (including safeguards) in the face of significant pressures for land grabbing and opportunistic resource extraction.     

The role of soybean production as an underlying driver of deforestation in the South American Chaco

South America’s tropical dry forests and savannas are under increasing pressure from agricultural expansion. Cattle ranching and soybean production both drive these forest losses, but their relative importance remains unclear. Also unclear is how soybean expansion elsewhere affects deforestation via pushing cattle ranching to deforestation frontiers. To assess these questions, we focused on the Chaco, a 110 million ha ecoregion extending into Argentina, Bolivia, and Paraguay, with about 8 million ha of deforestation in 2000–2012. We used panel regressions at the district level to quantify the role of soybean expansion in driving these forest losses using a wide range of environmental and socio-economic control variables. Our models suggest that soybean production was a direct driver of deforestation in the Argentine Chaco only (0.08 ha new soybean area per ha forest lost), whereas cattle ranching was significantly associated with deforestation in all three countries (0.02 additional cattle per hectare forest loss). However, our models also suggested Argentine soybean cultivation may indirectly be linked to deforestation in the Bolivian and Paraguayan Chaco. We furthermore found substantial time-delayed effects in the relationship of soybean expansion in Argentina and Paraguay (i.e., soybean expansion in one year resulted in deforestation several years later) and deforestation in the Chaco, further suggesting that possible displacement effects within and between Chaco countries may at least partly drive forest loss. Altogether, our study showed that deforestation in the Chaco appears to be mainly driven by the globally surging demand for soybean, although regionally other proximate drivers are sometimes important. Steering agricultural production in the Chaco and other tropical dry forests onto sustainable pathways will thus require policies that consider these scale effects and that account for the regional variation in deforestation drivers within and across countries.     

Sharing responsibility for trade-related emissions based on economic benefits

How to share responsibility for greenhouse gas emissions between consumers and producers is a highly sensitive question in international climate policy negotiations. Traditional ‘Production-Based Accounting’ (PBA), which assigns responisibility to the region where emissions are released, has frequently been challenged by ‘Consumption-Based Accounting’ (CBA) schemes that suggest that greenhouse gas emissions generated to produce traded goods and services should be attributed to their final consumers. PBA and CBA both lack a sound foundation in economic theory as they do not consider the economic benefits accruing to producers or consumers if carbon emissions do not carry a price that reflects their social costs. We build on well-established economic theory to derive how to share responsibility for trade-related emissions between producers and consumers and apply this novel approach for the most prominent bilateral trade relationships using multi-regional input–output data. We propose an ‘Economic Benefit Shared Responsibility’ (EBSR) scheme, in which China is attributed significantly higher responsibility for emissions than in CBA, while lower emissions and responsibility are attributed to both the US and the EU.     

Estimating the CDM market under the Marrakech Accords

Abstract

The agreement on implementation of the Kyoto Protocol achieved at COP7 in Marrakech has important implications for investment in greenhouse gas emission reduction projects in developing countries through the Clean Development Mechanism (CDM). The required actual emission reductions for participating Annex B countries overall will be relatively small, as the United States do not intend to ratify the protocol and significant amounts of carbon sequestered in domestic sinks can be credited. In addition, the potential supply of surplus emission permits (hot air) from Russia and other economies in transition may be as high as total demand in the first commitment period. Thus, even under restraint of hot air sellers, CDM demand will be limited, and a low demand, low price carbon market scenario appears likely.

The magnitude of the CDM will be influenced by a host of factors both on the demand and the supply-side. We analyse these using a quantitative model of the global carbon market, based on marginal abatement cost curves. Implementation and transaction costs, as well as baseline and additionality rules affect the CDM's share in the carbon market. Demand for the CDM is sensitive to changes in business-as-usual emissions growth in participating Annex B countries, and also to crediting for additional sinks. Permit supply from Russia and other economies in transition is possibly the most crucial factor in the carbon market.     

International trade undermines national emission reduction targets: New evidence from air pollution

Many developed countries in Annex B of the Kyoto Protocol have been able to report decreasing emissions, and some have officially fulfilled their CO₂ reduction commitments. This is in part because current reporting and regulatory regimes allow these countries to displace emissions intensive production offshore. Using a new highly detailed account of emissions embodied in international trade we investigate this phenomenon of emissions leakage. We independently confirm previous findings that adjusting for trade, developed countries emissions have increased, not decreased. We find that the sectors successfully holding or lowering their domestic emissions are often the same as those increasing their imports of embodied CO₂. We also find that the fastest growing flow paths of embodied CO₂ largely originate outside the Kyoto Annex B signatory nations. Finally, we find that historically the same phenomenon of emissions displacement has already occurred for air pollution, with the result that despite aggressive legislation in major emitters total global air pollution emissions have increased. If regulatory policies do not account for embodied imports, global emissions are likely to rise even if developed countries emitters enforce strong national emissions targets.     

世界排放大国CO2排放和GDP的格兰杰因果分析及其对国际气候治理的影响和意义

基于1990—2015年世界前20个排放大国碳排放量和国内生产总值（GDP）的时间序列数据,采用协整分析、格兰杰因果检验,对主要排放大国碳排放与经济增长之间的关系进行了实证分析。通过协整分析得出大多数国家的碳排放量与经济增长之间存在长期均衡关系;碳排放量和GDP的格兰杰检验结果显示,大多数世界排放大国碳排放与经济增长之间存在单向因果关系。发达国家主要表现为经济增长是碳排放的格兰杰原因,发展中国家则主要表现为碳排放是经济增长的格兰杰原因。研究结果反映了发达国家和发展中国家在碳减排问题上的阶段性特征,碳减排对发展中国家经济发展的负面影响明显大于发达国家。基于格兰杰因果分析结果,国际气候治理进程中关于要求发展中国家现阶段提出大幅减排目标的诉求不符合发展中国家发展阶段特征,可能影响发展中国家经济发展的正常秩序和规律。发达国家基于历史排放责任、发展阶段和能力,都应该带头开展减排行动,并帮助发展中国家实现转型、升级发展,降低经济发展对碳排放的依赖。国际气候治理需要根据并考虑不同国家的发展需求和特征,形成国际合作制度安排,实现社会经济发展与全球气候治理的协同。     

The impact of biofuel-induced food-price inflation on dietary energy demand and dietary greenhouse gas emissions

Dramatic increases in liquid biofuel production have led to concerns about associated impacts on food prices, with many modeling studies showing significant biofuel-related price inflation. In turn, by changing patterns of food demand, biofuel production may indirectly influence greenhouse gas emissions. We estimated changes to dietary energy (calorie) demand and greenhouse gas emissions embodied in average diets under different biofuel-related food-price scenarios for Brazil, China and the United States, using food-price projections and food-price elasticities. Average energy demand decreased in all countries, from about 40 kcal per person per day in Brazil under a moderate price inflation scenario – a reduction of 1% relative to the (2009) reference scenario – to nearly 300 per day in the United States with high price inflation – almost 8% of reference levels. However, emissions per calorie increased slightly in all three countries. In terms of total greenhouse gas emissions, the results are suggestive of overall reductions only in the United States, where average reductions ranged from about 40 to 110 kg of carbon dioxide equivalent emissions per person per year. In China, the direction of impact is unclear, but the net change is likely to be small. Brazilian results were sensitive to parameter values and the direction and magnitude of impact is therefore uncertain. Despite the uncertainty, even small changes (positive or negative) in individual dietary emissions can produce large changes at the population level, arguing for the inclusion of the dietary pathway in greenhouse gas accounting of liquid biofuels.     

The Australia clause and REDD: a cautionary tale

If a binding agreement can be reached on a post-2012 international climate regime, it is likely to include the phased introduction of a market-linked mechanism for reducing emissions from deforestation and forest degradation in developing countries (REDD). Under such a scheme, countries that reduce net REDD emissions below a pre-set baseline would receive credits that could be sold in carbon markets and used by purchasing nations to meet their international mitigation obligations. This paper draws on the Australian experience with deforestation to identify some of the issues that might obstruct progress on REDD. For the past 20 years, Australia has had the highest rate of deforestation in the developed world; ~416,000 ha of forests were cleared annually between 1990 and 2009, resulting in the emission of almost 80 MtCO₂-e/yr. It is also the only developed country that will rely on reduced deforestation emissions as the primary way of meeting its quantified emissions target under the Kyoto Protocol. Australia’s approach to deforestation issues provides valuable insights into the difficulties an international REDD scheme might encounter.     

The global environmental paw print of pet food

Global pet ownership, especially of cats and dogs, is rising with income growth, and so too are the environmental impacts associated with their food. The global extent of these impacts has not been quantified, and existing national assessments are potentially biased due to the way in which they account for the relative impacts of constituent animal by-products (ABPs). ABPs typically have lower value than other animal products (i.e. meat, milk and eggs), but are nevertheless associated with non-negligible environmental impacts. Here we present the first global environmental impact assessment of pet food. The approach is novel in applying an economic value allocation approach to the impact of ABPs and other animal products to represent better the environmental burden. We find annual global dry pet food production is associated with 56–151 Mt CO₂ equivalent emissions (1.1%−2.9% of global agricultural emissions), 41–58 Mha agricultural land-use (0.8–1.2% of global agricultural land use) and 5–11 km³ freshwater use (0.2–0.4% of water extraction of agriculture). These impacts are equivalent to an environmental footprint of around twicethe UK land area, and would make greenhouse gas emission from pet food around the 60th highest emitting country, or equivalent to total emissions from countries such as Mozambique or the Philippines. These results indicate that rising pet food demand should be included in the broader global debate about food system sustainability.     

减少发展中国家毁林排放谈判进展

减少毁林可为减缓大气温室气体浓度上升做出重要贡献,因此减少毁林的议题已被提上气候公约谈判的议事日程（议题6）,将成为今后相当长时间内谈判的重要议题之一。通过调研和分析各缔约方提交的对减少毁林提案的意见及附属科学技术咨询机构（SBSTA）第24届会议的谈判情况,对各国的观点进行了归纳总结和剖析。     

Corrigendum to “Meeting the food security challenge for nine billion people in 2050: What impact on forests?” [Global Environ. Change 62 (2020) 102056]

As the world’s population continues to grow, agricultural expansion is expected to increase to meet future food demand often at the expense of other land uses. However, there are limited studies examining the degree to which forest cover will change and the underlying assumptions driving these projections. Focusing on food and forest scenarios for the middle to the end of the current century, we review 63 main scenarios and 28 global modelling studies to address variations in land use projections and evaluate the potential outcomes on forest cover. Further, their potential impacts on greenhouse gases (GHG) emission/sequestration and global temperature are explored. A majority (59%) of scenarios expected a reduction in both forests and pasturelands to make way for agricultural expansion (particularly reference and no mitigation scenarios). In most scenarios, the extent of forest loss is proportional to that of crop gain, which is associated with higher GHG emission and global temperature, loss of carbon sequestration potential and increase in soil erosion. However, 32% of scenarios predicted that meeting food security objectives is possible without leading to further deforestation if there is a global reduction in the demand for energy intensive foods, and improvements in crop yields. Forest gain and lower rates of deforestation are needed to achieve ambitious climate targets over the next decade. Our analysis also highlights carbon taxes (prices), reforestation/afforestation and bioenergy as important variables that can contribute to maintaining or increasing global forest area in the future.