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1.
Human appropriation of land for food production has fundamentally altered the Earth system, with impacts on water, soil, air quality, and the climate system. Changes in population, dietary preferences, technology and crop productivity have all played important roles in shaping today’s land use. In this paper, we explore how past and present developments in diets impact on global agricultural land use. We introduce an index for the Human Appropriation of Land for Food (HALF), and use it to isolate the effects of diets on agricultural land areas, including the potential consequences of shifts in consumer food preferences. We find that if the global population adopted consumption patterns equivalent to particular current national per capita rates, agricultural land use area requirements could vary over a 14-fold range. Within these variations, the types of food commodities consumed are more important than the quantity of per-capita consumption in determining the agricultural land requirement, largely due to the impact of animal products and in particular ruminant species. Exploration of the average diets in the USA and India (which lie towards but not at global consumption extremes) provides a framework for understanding land use impacts arising from different food consumption habits. Hypothetically, if the world were to adopt the average Indian diet, 55% less agricultural land would be needed to satisfy demand, while global consumption of the average USA diet would necessitate 178% more land. Waste and over-eating are also shown to be important. The area associated with food waste, including over-consumption, given global adoption of the consumption patterns of the average person in the USA, was found to be twice that required for all food production given an average Indian per capita consumption. Therefore, measures to influence future diets and reduce food waste could substantially contribute towards global food security, as well as providing climate change mitigation options.  相似文献   

2.
Agriculture is responsible for 25?C30% of global anthropogenic greenhouse gas (GHG) emissions but has thus far been largely exempted from climate policies. Because of high monitoring costs and comparatively low technical potential for emission reductions in the agricultural sector, output taxes on emission-intensive agricultural goods may be an efficient policy instrument to deal with agricultural GHG emissions. In this study we assess the emission mitigation potential of GHG weighted consumption taxes on animal food products in the EU. We also estimate the decrease in agricultural land area through the related changes in food production and the additional mitigation potential in devoting this land to bioenergy production. Estimates are based on a model of food consumption and the related land use and GHG emissions in the EU. Results indicate that agricultural emissions in the EU27 can be reduced by approximately 32 million tons of CO2-eq with a GHG weighted tax on animal food products corresponding to ?60 per ton CO2-eq. The effect of the tax is estimated to be six times higher if lignocellulosic crops are grown on the land made available and used to substitute for coal in power generation. Most of the effect of a GHG weighted tax on animal food can be captured by taxing the consumption of ruminant meat alone.  相似文献   

3.
IPCC特别报告SRCCL关于气候变化与粮食安全的新认知与启示   总被引：3，自引：0，他引：3  
气候变化对粮食安全的影响是广泛的,不但影响粮食产量和品质,还会影响到农户的生计以及农业相关的产业发展等;而粮食系统在保障粮食安全的同时,又会产生一系列的环境问题,其中农业源温室气体（GHG）的排放加剧全球变暖。IPCC在2019年8月份发布的《气候变化与土地特别报告》（SRCCL）,从粮食生产、加工、储存、运输及消费的各个环节评估气候变化对粮食安全的影响及粮食系统的温室气体排放对气候系统的影响;系统梳理粮食系统供给侧和需求侧的适应与减缓措施、适应与减缓的协同和权衡问题,以及气候变化条件下保障粮食安全的政策环境等。SRCCL评估结论认为,由于大量施用氮肥和消耗水资源,目前粮食系统GHG排放占全球总排放的21%~37%;农业和粮食系统是全球应对气候变化的重要方面,供给侧和需求侧的综合措施可以减少食物浪费、减少GHG排放、增加粮食系统的恢复力。未来工作的重点应丰富和扩展气候变化影响评估内容,量化适应效果,加深对适应、减缓及其协同和权衡的科学认知,大力加强应对气候变化能力建设。  相似文献   

4.
Diets lower in meat could reduce agricultural expansion and intensification thereby reducing biodiversity impacts. However, land use requirements, associated with alternate diets, in biodiverse regions across different taxa are not fully understood. We use a spatially explicit global food and land system model to address this gap. We quantify land-use change in locations important for biodiversity across taxa and find diets low in animal products reduce agricultural expansion and intensity in regions with high biodiversity. Reducing ruminant meat consumption alone however was not sufficient to reduce fertiliser and irrigation application in biodiverse locations. The results differed according to taxa, emphasising that land-use change effects on biodiversity will be taxon specific. The links shown between global meat consumption and agricultural expansion and intensification in the biodiverse regions of the world indicates the potential to help safeguard biodiverse natural ecosystems through dietary change.  相似文献   

5.
Today, the agricultural sector accounts for approximately 15% of total global anthropogenic emissions, mainly methane and nitrous oxide. Projecting the future development of agricultural non-CO2 greenhouse gas (GHG) emissions is important to assess their impacts on the climate system but poses many problems as future demand of agricultural products is highly uncertain. We developed a global land use model (MAgPIE) that is suited to assess future anthropogenic agricultural non-CO2 GHG emissions from various agricultural activities by combining socio-economic information on population, income, food demand, and production costs with spatially explicit environmental data on potential crop yields. In this article we describe how agricultural non-CO2 GHG emissions are implemented within MAgPIE and compare our simulation results with other studies. Furthermore, we apply the model up to 2055 to assess the impact of future changes in food consumption and diet shifts, but also of technological mitigation options on agricultural non-CO2 GHG emissions. As a result, we found that global agricultural non-CO2 emissions increase significantly until 2055 if food energy consumption and diet preferences remain constant at the level of 1995. Non-CO2 GHG emissions will rise even more if increasing food energy consumption and changing dietary preferences towards higher value foods, like meat and milk, with increasing income are taken into account. In contrast, under a scenario of reduced meat consumption, non-CO2 GHG emissions would decrease even compared to 1995. Technological mitigation options in the agricultural sector have also the capability of decreasing non-CO2 GHG emissions significantly. However, these technological mitigation options are not as effective as changes in food consumption. Highest reduction potentials will be achieved by a combination of both approaches.  相似文献   

6.
Approaches to reconciling food production with climatic and environmental protection often require agricultural intensification. The production of more food per unit of agricultural land through “sustainable intensification” is intended to enable the protection of natural ecosystems elsewhere (land sparing). However, there are problems associated with agricultural intensification; such as soil erosion, eutrophication or pollution of water bodies with chemicals, landscape homogenization and loss of biodiversity; for which solutions have not yet been found. Reuse of abandoned agricultural lands – which are abundant throughout the world – to address the rising demand for food is a potentially important alternative, which up to now has been widely ignored. To test the power of this alternative, equilibrium economic land allocation to various land-use practices by risk-avoiding tropical farmers in Ecuador was simulated. The reestablishment of pastures on abandoned cattle lands lowered prices for pasture products, and also triggered conversion of existing pasture into cropland. The resulting land-use change increased total annual food production in a moderate scenario from the current level of 17.8–23.1 petacalories (1015 calories), which amounted to a production increase of 30%. At the same time, there was a 19% reduction in the amount of payments to farmers required to preserve tropical forests – one of the world's greatest terrestrial carbon stores.  相似文献   

7.
Meeting the food needs of the growing and increasingly affluent human population with the planet’s limited resources is a major challenge of our time. Seen as the preferred approach to global food security issues, ‘sustainable intensification’ is the enhancement of crop yields while minimizing environmental impacts and preserving the ability of future generations to use the land. It is still unclear to what extent sustainable intensification would allow humanity to meet its demand for food commodities. Here we use the footprints for water, nitrogen, carbon and land to quantitatively evaluate resource demands and greenhouse gas (GHG) emissions of future agriculture and investigate whether an increase in these environmental burdens of food production can be avoided under a variety of dietary scenarios. We calculate average footprints of the current diet and find that animal products account for 43–87% of an individual’s environmental burden – compared to 18% of caloric intake and 39% of protein intake. Interestingly, we find that projected improvements in production efficiency would be insufficient to meet future food demand without also increasing the total environmental burden of food production. Transitioning to less impactful diets would in many cases allow production efficiency to keep pace with growth in human demand while minimizing the food system’s environmental burden. This study provides a useful approach for evaluating the attainability of sustainable targets and for better integrating food security and environmental impacts.  相似文献   

8.
Western diets are characterised by a high intake of meat, dairy products and eggs, causing an intake of saturated fat and red meat in quantities that exceed dietary recommendations. The associated livestock production requires large areas of land and lead to high nitrogen and greenhouse gas emission levels. Although several studies have examined the potential impact of dietary changes on greenhouse gas emissions and land use, those on health, the agricultural system and other environmental aspects (such as nitrogen emissions) have only been studied to a limited extent. By using biophysical models and methods, we examined the large-scale consequences in the European Union of replacing 25–50% of animal-derived foods with plant-based foods on a dietary energy basis, assuming corresponding changes in production. We tested the effects of these alternative diets and found that halving the consumption of meat, dairy products and eggs in the European Union would achieve a 40% reduction in nitrogen emissions, 25–40% reduction in greenhouse gas emissions and 23% per capita less use of cropland for food production. In addition, the dietary changes would also lower health risks. The European Union would become a net exporter of cereals, while the use of soymeal would be reduced by 75%. The nitrogen use efficiency (NUE) of the food system would increase from the current 18% to between 41% and 47%, depending on choices made regarding land use. As agriculture is the major source of nitrogen pollution, this is expected to result in a significant improvement in both air and water quality in the EU. The resulting 40% reduction in the intake of saturated fat would lead to a reduction in cardiovascular mortality. These diet-led changes in food production patterns would have a large economic impact on livestock farmers and associated supply-chain actors, such as the feed industry and meat-processing sector.  相似文献   

9.
The global use of and pressure on land resources will continue to rise in tandem with the predicted rise in global population and food demand. Addressing unavoidable trade-offs between satisfying human needs and biodiversity conservation for future generations is of paramount importance when tackling the global environmental challenges of land use. Food consumption patterns are inextricably linked to land-use and land-use changes. The domestic supply and final use of food by humans and feed by animals within the borders of a country have environmental impacts overseas. Countries like Denmark, with considerably high livestock production, import “virtual” land needed to produce cereals and other fodder crops. Denmark's high meat and dairy consumption and trade levels make it a compelling case for this study. The overarching question is: how much land is required to support food and feed consumption in Denmark? This paper assesses the global cropland footprint of Danish food and feed supply from 2000 to 2013 using a consumption-based physical accounting approach. In addition to domestic croplands for local food and supply, we estimate the hectares of cropland displaced in other countries to satisfy Danish demand for food and feed in this period. Secondly, we calculate Denmark's global cropland requirements for the supply of specific livestock products, namely; pork, eggs, beef, milk, and mutton. Globally, animals provide a third of the protein in human diets and agricultural GDP. The total global cropland footprint of Danish food and feed supply decreased by 18% from 1568 kha in 2000 to 1282 kha in 2013 because of a reduction in the consumption of ruminant livestock products. A high share of this reduction can be attributed to increased local self-sufficiency in feed supply as opposed to rising food imports. The share of cropland used for feed in total cropland declined by 5% whereas the share of cropland used for food increased from 28% in 2000 to 32% by 2013. Our findings suggest that reducing domestic meat consumption coupled with local self-sufficiency policies for both food and feed supply could be a means of lowering ecological degradation in exporting countries.  相似文献   

10.
Low-meat and no-meat diets are increasingly acknowledged as sustainable alternatives to current Western food consumption patterns. Concerns for the environment, individual health or animal welfare are raising consumers’ willingness to adopt such diets. Dietary shifts in Western countries may modify the way human-environment systems interact over distances, primarily as a result of existing trade flows in food products. Global studies have focused on the amount of water, land, and CO2 emissions embodied in plant-based versus animal-based proteins, but the potential of alternative diets to shift the location of environmental impacts has not yet been investigated. We build on footprint and trade-based analyses to compare the magnitude and spatial allocation of the impacts of six diets of consumers in the United States of America (USA). We used data on declared diets as well as a stylized average diet and a recent dietary guideline integrating health and environmental targets. We demonstrate that low-meat and no-meat diets have a lower demand for land and utilize more crops with natural nitrogen fixation potential, yet also rely more widely on pollinator abundance and diversity, and can increase impacts on freshwater ecosystems in some countries. We recommend that governments carefully consider the local impacts of the alternative diets they promote, and minimize trade-offs between the global and local consequences of dietary shifts through regulation or incentives.  相似文献   

11.
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.  相似文献   

12.
Both supply and demand side changes are necessary to achieve a sustainable food system. However, the weight accorded to these depends on one’s view of what the priority goals are for the food system and the extent to which production systems versus consumption patterns are open to change. Some stakeholders see the problem as one of ‘not enough food’ and focus on the need to sustainably increase supply, while others consider the resource demanding and ‘greedy’ consumption patterns of the Western world as the main problem and emphasize the need to shift diets. In this study global land use and greenhouse gas emissions are estimated for a set of scenarios, building on four ‘livestock futures’ reflecting these different perspectives. These scenarios are: further intensification of livestock systems; a transition to plant-based eating; a move towards artificial meat and dairy; and a future in which livestock production is restricted to the use of ‘ecological leftovers’ i.e. grass from pastures, food waste and food and agricultural byproducts. Two dietary variants for each scenario are modelled: 1) a projected diet following current trends and 2) a healthy diet with more fruits and vegetables and fewer animal products, vegetable oils and sugar. Livestock production in all scenarios (except the baseline scenario) was assumed to intensify to current levels of intensive production in North-Western Europe. For each scenario, several variant assumptions about yield increases and waste reductions were modelled. Results show that without improvements in crop productivity or reductions on today’s waste levels available cropland will only suffice if production of all protein currently supplied by animal foods is replaced by (hypothetical) artificial variants not requiring any land. With livestock intensities corresponding to current ones in North-Western Europe and with yield gaps closed by 50% and waste reduced by 50%, available cropland will suffice for all scenarios that include a reduction of animal products and/or a transition to poultry or aquaculture. However, in the scenario based on an extrapolation of current consumption patterns (animal product amounts and types consumed in proportions corresponding to the current average consumption in different world regions) and with livestock production based on feed from cropland, available cropland will not be enough. The scenario that makes use of pastures for ruminant production and food waste for pigs, uses considerably less cropland and could provide 40–56 kg per capita per year of red meat. However, such a livestock future would not reduce GHG emissions from agriculture on current levels. This study confirms previous research that to achieve a sustainable food future, action is needed on all fronts; improved supply and reduced demand and waste.  相似文献   

13.
This paper presents three baseline scenarios of no policy action computed by the IMAGE 2 model. These scenarios cover a wide range of coupled global change Indicators, including: energy demand and consumption; food demand, consumption, and production; changes in land cover including changes in extent of agricultural land and forest; emissions of greenhouse gases and ozone precursors; and climate change and its impacts on sea level rise, crop productivity and natural vegetation. Scenario information is available for the entire world with regional and grid scale detail, and covers from 1970 to 2100. The scenarios indicate that the coming decades could be a period of relatively rapid global environmental change as compared to the period before and after. The natural vegetation in industrialized regions could be threatened by climate change, but abandonment of agricultural lands could also make new lands available for reforestation and revegetation. The opposite is true for most of Asia and Africa. Here the impacts of climate change on vegetation may not be as significant as in temperate climates, but the demand for food will lead to a significant expansion of agricultural lands at the expense of remaining forests and other natural areas.  相似文献   

14.
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.  相似文献   

15.
Bioenergy with carbon capture and storage (BECCS) and afforestation are key negative emission technologies suggested in many studies under 2 °C or 1.5 °C scenarios. However, these large-scale land-based approaches have raised concerns about their economic impacts, particularly their impact on food prices, as well as their environmental impacts. Here we focus on quantifying the potential scale of BECCS and its impact on the economy, taking into account technology and economic considerations, but excluding sustainability and political aspects. To do so, we represent all major components of BECCS technology in the MIT Economic Projection and Policy Analysis model. We find that BECCS could make a substantial contribution to emissions reductions in the second half of the century under 1.5 and 2 °C climate stabilization goals, with its deployment driven by revenues from carbon dioxide permits. Results show that global economic costs and the carbon prices needed to hit the stabilization targets are substantially lower with the technology available, and BECCS acts as a true backstop technology at carbon prices around $240 per tonne of carbon dioxide. If driven by economics alone, BECCS deployment increases the use of productive land for bioenergy production, causing substantial land use changes. However, the projected impact on commodity prices is quite limited at the global scale, with global commodity price indices increasing by less than 5% on average. The effect is larger at the regional scale (up to 15% in selected regions), though significantly lower than previous estimates. While BECCS deployment is likely to be constrained for environmental and/or political reasons, this study shows that the large-scale deployment of BECCS is not detrimental to agricultural commodity prices and could reduce the costs of meeting stabilization targets. Still, it is crucial that policies consider carbon dioxide removal as a complement to drastic carbon dioxide emissions reductions, while establishing a credible accounting system and sustainable limits on BECCS.  相似文献   

16.
The volume of agricultural trade increased by more than ten times throughout the past six decades and is likely to continue with high rates in the future. Thereby, it largely affects environment and climate. We analyse future trade scenarios covering the period of 2005–2045 by evaluating economic and environmental effects using the global land-use model MAgPIE (“Model of Agricultural Production and its Impact on the Environment”). This is the first trade study using spatially explicit mapping of land use patterns and greenhouse gas emissions. We focus on three scenarios: the reference scenario fixes current trade patterns, the policy scenario follows a historically derived liberalisation pathway, and the liberalisation scenario assumes a path, which ends with full trade liberalisation in 2045.Further trade liberalisation leads to lower global costs of food. Regions with comparative advantages like Latin America for cereals and oil crops and China for livestock products will export more. In contrast, regions like the Middle East, North Africa, and South Asia face the highest increases of imports. Deforestation, mainly in Latin America, leads to significant amounts of additional carbon emissions due to trade liberalisation. Non-CO2 emissions will mostly shift to China due to comparative advantages in livestock production and rising livestock demand in the region. Overall, further trade liberalisation leads to higher economic benefits at the expense of environment and climate, if no other regulations are put in place.  相似文献   

17.
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.  相似文献   

18.
Understanding potential future influence of environmental, economic, and social drivers on land-use and sustainability is critical for guiding strategic decisions that can help nations adapt to change, anticipate opportunities, and cope with surprises. Using the Land-Use Trade-Offs (LUTO) model, we undertook a comprehensive, detailed, integrated, and quantitative scenario analysis of land-use and sustainability for Australia’s agricultural land from 2013–2050, under interacting global change and domestic policies, and considering key uncertainties. We assessed land use competition between multiple land-uses and assessed the sustainability of economic returns and ecosystem services at high spatial (1.1 km grid cells) and temporal (annual) resolution. We found substantial potential for land-use transition from agriculture to carbon plantings, environmental plantings, and biofuels cropping under certain scenarios, with impacts on the sustainability of economic returns and ecosystem services including food/fibre production, emissions abatement, water resource use, biodiversity services, and energy production. However, the type, magnitude, timing, and location of land-use responses and their impacts were highly dependent on scenario parameter assumptions including global outlook and emissions abatement effort, domestic land-use policy settings, land-use change adoption behaviour, productivity growth, and capacity constraints. With strong global abatement incentives complemented by biodiversity-focussed domestic land-use policy, land-use responses can substantially increase and diversify economic returns to land and produce a much wider range of ecosystem services such as emissions abatement, biodiversity, and energy, without major impacts on agricultural production. However, better governance is needed for managing potentially significant water resource impacts. The results have wide-ranging implications for land-use and sustainability policy and governance at global and domestic scales and can inform strategic thinking and decision-making about land-use and sustainability in Australia. A comprehensive and freely available 26 GB data pack (http://doi.org/10.4225/08/5604A2E8A00CC) provides a unique resource for further research. As similarly nuanced transformational change is also possible elsewhere, our template for comprehensive, integrated, quantitative, and high resolution scenario analysis can support other nations in strategic thinking and decision-making to prepare for an uncertain future.  相似文献   

19.
Providing food and other products to a growing human population while safeguarding natural ecosystems and the provision of their services is a significant scientific, social and political challenge. With food demand likely to double over the next four decades, anthropization is already driving climate change and is the principal force behind species extinction, among other environmental impacts. The sustainable intensification of production on current agricultural lands has been suggested as a key solution to the competition for land between agriculture and natural ecosystems. However, few investigations have shown the extent to which these lands can meet projected demands while considering biophysical constraints. Here we investigate the improved use of existing agricultural lands and present insights into avoiding future competition for land. We focus on Brazil, a country projected to experience the largest increase in agricultural production over the next four decades and the richest nation in terrestrial carbon and biodiversity. Using various models and climatic datasets, we produced the first estimate of the carrying capacity of Brazil's 115 million hectares of cultivated pasturelands. We then investigated if the improved use of cultivated pasturelands would free enough land for the expansion of meat, crops, wood and biofuel, respecting biophysical constraints (i.e., terrain, climate) and including climate change impacts. We found that the current productivity of Brazilian cultivated pasturelands is 32–34% of its potential and that increasing productivity to 49–52% of the potential would suffice to meet demands for meat, crops, wood products and biofuels until at least 2040, without further conversion of natural ecosystems. As a result up to 14.3 Gt CO2 Eq could be mitigated. The fact that the country poised to undergo the largest expansion of agricultural production over the coming decades can do so without further conversion of natural habitats provokes the question whether the same can be true in other regional contexts and, ultimately, at the global scale.  相似文献   

20.
Rapidly increasing populations coupled with increased food demand requires either an expansion of agricultural land or sufficient production gains from current resources. However, in a changing world, reduced water availability might undermine improvements in crop and grass productivity and may disproportionately affect different parts of the world. Using multi-model studies, the potential trends, risks and uncertainties to land use and land availability that may arise from reductions in water availability are examined here. In addition, the impacts of different policy interventions on pressures from emerging risks are examined.Results indicate that globally, approximately 11% and 10% of current crop- and grass-lands could be vulnerable to reduction in water availability and may lose some productive capacity, with Africa and the Middle East, China, Europe and Asia particularly at risk. While uncertainties remain, reduction in agricultural land area associated with dietary changes (reduction of food waste and decreased meat consumption) offers the greatest buffer against land loss and food insecurity.  相似文献   

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