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1.
There is widespread concern that biomass energy policy that promotes forests as a supply source will cause net carbon emissions. Most of the analyses that have been done to date, however, are biological, ignoring the effects of market adaptations through substitution, net imports, and timber investments. This paper uses a dynamic model of forest and land use management to estimate the impact of United States energy policies that emphasize the utilization of forest biomass on global timber production and carbon stocks over the next 50 years. We show that when market factors are included in the analysis, expanded demand for biomass energy increases timber prices and harvests, but reduces net global carbon emissions because higher wood prices lead to new investments in forest stocks. Estimates are sensitive to assumptions about whether harvest residues and new forestland can be used for biomass energy and the demand for biomass. Restricting biomass energy to being sourced only from roundwood on existing forestland can transform the policy from a net sink to a net source of emissions. These results illustrate the importance of capturing market adjustments and a large geographic scope when measuring the carbon implications of biomass energy policies.  相似文献   

2.
Comprehensive life cycle assessments show that current transport biofuels often do worse than conventional fossil transport fuels as to the emission of greenhouse gases. Biofuels from microalgae grown with present technology and lignocellulosic biofuels from current arable land or land that is to be deforested are unlikely to do better regarding the emission of greenhouse gases than fossil transport fuels. When crops characterized by relatively low fossil fuel inputs and relatively high biomass yields are grown on abandoned agricultural and marginal soils which currently sequester little carbon, cropping for transport biofuels may help in limiting climate change without an impact on food prices. For such cropping one probably has to go beyond the market mechanism. Worldwide, there is some scope for the use of harvest residues in biofuel production. However, European arable soils show on average large losses of soil carbon and this rather favors increased addition of such residues to soils. Received: November 17, 2008; accepted: December 3, 2008  相似文献   

3.
Fen D. Beed 《Food Security》2014,6(2):169-186
Global crop production needs to double by 2050 in order to meet demands from rising populations, diet shifts and biofuels. Production must increase through more efficient use of currently available arable land to prevent encroachment on land that otherwise provides vital services to the earth and its people (i.e. through increased biodiversity and reduced carbon emissions). Significant improvements can be realised through enhanced management of critical diseases of crops that are pivotal to food security and income generation. To achieve this, the dynamic and complex interactions between crops and beneficial or antagonistic organisms that characterise the biological environment, must be understood. For Sub-Saharan Africa (SSA) a crop healthcare system is required that encompasses national responsibility and regional cooperation, and which harnesses global excellence in terms of the knowledge and methods that are available for implementation. This system would be able to control crop diseases in a pre-emptive and cost efficient manner and avoid the current scenario of belatedly combating largescale epidemics. Components would include: risk assessment to predict impacts on food and feed value chains; targeted surveillance; fit-for-purpose diagnostics; control intervention packages; extension mechanisms; and enabling policy environments. Each component would be refined, based on practical feedback and results from research targeted to address knowledge gaps. Specific examples are presented for viruses of cassava, viral and bacterial diseases of banana, stem rust of wheat and a new viral disease complex of maize. Finally, the links among disease control and improved crop quality, consumer health and safe trade are discussed through biological control interventions for aflatoxin in SSA.  相似文献   

4.
Increasingly, developing nations which are land rich are sanctioning the sale or transfer of user rights of large tracts of farmland for foreign investment. While this issue is of relatively recent origin, caused in large measure by the recent global food crisis and related to desires by food importing countries to have greater control over their food supply, the impact on food security could be very significant. Because of the newness of the matter, most of the available evidence is found outside traditional academic literature. Poor, smallholder farmers without formal land titles currently occupy much of the land sold in these transactions, threatening the internal food security of the lessor state. Factors driving the global acquisition of land include development aid shortfalls, the global food crisis, the burgeoning middle class in middle- and high-income nations, and the increasing acceptance of biofuels as a viable alternative source of fuel by governments of these nations. The risks associated with the global acquisition of land on food security of the seller country are manifold. This article reviews the current literature available on the subject and makes policy suggestions for equitable investment and benefit-sharing for all stakeholders. Opportunities and risks abound but if the risks are mitigated, then the global acquisition of land has the potential to be an unparalleled development opportunity for lessor states.  相似文献   

5.
Recent U.S. climate change policy developments include aggressive proposals to reduce greenhouse gas emissions, including cap-and-trade legislation with a goal of an 83% reduction below 2005 levels by 2050. This study examines behavioral and technological changes required to achieve this reduction within the light-duty vehicle (LDV) sector. Under this "fair share" sectoral assumption, aggressive near-term actions are necessary in three areas: vehicle miles traveled (VMT), vehicle fuel economy (FE), and fuel carbon intensity (FCI). Two generic scenarios demonstrate the important role of FCI in meeting the 2050 goal. The first scenario allows deep reductions in FCI to compensate for relatively modest FE improvements and VMT reductions. The second scenario assumes optimistic improvements in FE, relatively large reductions in VMT and less aggressive FCI reductions. Each generic scenario is expanded into three illustrative scenarios to explore the theoretical implications of meeting the 2050 goal by relying exclusively on biofuels and hybrid vehicles, biofuels and plug-in hybrid vehicles, or hydrogen fuel cell electric vehicles. These scenarios inform a discussion of resource limitations, technology development and deployment challenges, and policy goals required to meet the 2050 GHG goal for LDVs.  相似文献   

6.
During the period 2006–2008, general inflation around the world was pressed upwards by food inflation. An important reason for concern about the impact of high food prices arises from the fact that the poorest people spend approximately three quarters of their income on staple foods. In Mexico, meals are based on maize, with tortillas providing much of the caloric intake in rural areas. Prices of maize along with nearly every agricultural commodity sharply increased creating a global food price bubble. Using the Household Income and Expenditure National Survey (Encuesta Nacional de Ingresos y Gastos de los Hogares ENIGH) conducted in 2006 and 2008, it was found that higher prices for maize affected Mexican household living standards and food security both in urban and rural areas. There is an evident decay in household living standards from year 2006 to year 2008. In regional terms, urban areas are better off than rural areas. The poorest rural and urban households—net buyers of maize—were the most affected as their budget share on maize increased significantly. However, higher prices provided direct benefits to maize producers in rural areas at all levels of living. Another effect of higher maize prices was to redistribute income towards maize producer households in the middle and bottom of the rural income distribution.  相似文献   

7.
Using marginal agricultural lands to grow energy crops for biofuel feedstocks is a promising option to meet the biofuel needs in populous China without causing further food shortages or environmental problems. Here we quantify the effects of growing switchgrass and Miscanthus on Chinese marginal agricultural lands on biomass production and carbon emissions with a global-scale biogeochemical model. We find that the national net primary production (NPP) of these two biofuel crops are 622 and 1546 g C m(-2) yr(-1), respectively, whereas the NPP of food crops is about 600 g C m(-2) yr(-1) in China. The net carbon sink over the 47 Mha of marginal agricultural lands across China is 2.1 Tg C yr(-1) for switchgrass and 5.0 Tg C yr(-1) for Miscanthus. Soil organic carbon is estimated to be 10 kg C m(-2) in both biofuel ecosystems, which is equal to the soil carbon levels of grasslands in China. In order to reach the goal of 12.5 billion liters of bioethanol in 2020 using crop biomass as biofuel feedstocks, 7.9-8.0 Mha corn grain, 4.3-6.1 Mha switchgrass, or 1.4-2.0 Mha Miscanthus will be needed. Miscanthus has tremendous potential to meet future biofuel needs, and to benefit CO(2) mitigation in China.  相似文献   

8.
In the wake of recent food price spikes, plus growing demands for food in emerging Asia and for biofuels in Europe and the United States, governments are re-examining their strategies for dealing with both short-term and long-term food security concerns. This paper argues that long-run trends in real agricultural prices have policy implications for food security that are at least as important as those related to short-lived spikes around trend prices. The paper therefore summarizes recent projections of markets to 2030 under various scenarios, and then reviews evidence on how trade policy restrictions typically are altered to insulate domestic markets from short-run fluctuations in international prices around their long-run trends. That provides a firm empirical basis for re-examining the effectiveness and efficiency of various policy options for ensuring food security in Asia and elsewhere. Those options include boosting agricultural productivity growth rates to deal with long-run concerns, and using more-appropriate domestic policy measures rather than trade policies to cope with price volatility.  相似文献   

9.
Maize is one of the most important food crops in the world and, together with rice and wheat, provides at least 30% of the food calories to more than 4.5 billion people in 94 developing countries. In parts of Africa and Mesoamerica, maize alone contributes over 20% of food calories. Maize is also a key ingredient in animal feed and is used extensively in industrial products, including the production of biofuels. Increasing demand and production shortfalls in global maize supplies have worsened market volatility and contributed to surging global maize prices. Climatic variability and change, and the consequent rise in abiotic and biotic stresses, further confound the problem. Unless concerted and vigorous measures are taken to address these challenges and accelerate yield growth, the outcome will be hunger and food insecurity for millions of poor consumers. We review the research challenges of ensuring global food security in maize, particularly in the context of climate change. The paper summarizes the importance of maize for food, nutrition and livelihood security and details the historical productivity of maize, consumption patterns and future trends. We show how crop breeding to overcome biotic and abiotic stresses will play a key role in meeting future maize demand. Attention needs to be directed at the generation of high yielding, stress-tolerant and widely-adapted maize varieties through judicious combination of conventional and molecular breeding approaches. The use of improved germplasm per se will not, however, be enough to raise yields and enhance adaptation to climate change, and will need to be complemented by improved crop and agronomic practices. Faced with emasculated state extension provision and imperfect markets, new extension approaches and institutional innovations are required that enhance farmers’ access to information, seeds, other inputs, finance and output markets. Over the long-term, large public and private sector investment and sustained political commitment and policy support for technology generation and delivery are needed to overcome hunger, raise the incomes of smallholder farmers and meet the challenges of growing demand for maize at the global level.  相似文献   

10.
The 2007–2008 food crisis and subsequent economic recession have severely undermined food security and agricultural sustainability worldwide. Failures in market functioning and trade openness have posed particularly high risks to the import-dependent countries in the Arab region. Many of the global causes of the price spikes are still in place, creating uncertainty about food availability and access in the future. Especially in the Arab region, these uncertainties are compounded by water scarcity. A long-term outlook is essential for formulating appropriate policy and investment strategies in order to ensure future food security for the region. After a brief discussion of trends in agricultural growth and investment, this paper presents projections by the International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT) on agriculture production, trade, demand, prices, and food security up to 2025 and 2050. Simulations are used to compare a baseline scenario (with climate change) with two scenarios incorporating increased investment and supportive policies. The results highlight the key role of agricultural research, as well as expanded irrigation, improved natural resource management, and enhanced market efficiency, in improving food security. Four priority areas are proposed: investments in agricultural research and development, rural infrastructure, and rural institutions; more open regional and international trade to facilitate commodity flows and alleviate supply shortages; pro-poor food and nutrition interventions; and cross-cutting issues of policy coherence, gender dimensions, inclusion of traditional populations, and coordination mechanisms to deal with climate change and ecosystem challenges.  相似文献   

11.
In a rapidly transitioning China, urban land use has changed dramatically, both spatially and in terms of magnitude; these changes have significantly affected the natural environment. This paper reports the development of an Integrated Environmental Assessment of Urban Land Use Change (IEA-ULUC) model, which combines cellular automata, scenario analysis, and stochastic spatial sampling with the goal of exploring urban land-use change, related environmental impacts, and various uncertainties. By applying the IEA-ULUC model to a new urban development area in Dalian in northeastern China, the evolution of spatial patterns from 1986 to 2005 was examined to identify key driving forces affecting the changing trajectories of local land use. Using these results, future urban land use in the period 2005-2020 was projected for four scenarios of economic development and land-use planning regulation. A stochastic sampling process was implemented to generate industrial land distributions for each land expansion scenario. Finally, domestic and industrial water pollution loads to the ocean were estimated, and the environmental impacts of each scenario are discussed. The results showed that the four urban expansion scenarios could lead to considerable differences in environmental responses. In principle, urban expansion scenarios along the intercity transportation rail/roadways could have higher negative environmental impacts than cluster-developing scenarios, while faster economic growth could more intensely aggravate the environment than in the moderate growth scenarios.  相似文献   

12.
The ongoing debate over the impact of biofuels on food security makes it difficult for governments to develop clear policies for an industry that can enhance rural employment and help to alleviate rural poverty, but may also reduce food availability and raise food prices. Whilst there have been many studies reporting a wide range of global commodity price impacts arising from the sharp rise in biofuel use over the past decade, there has been less evidence on food security impacts at a local level in developing countries. Where evidence does exist the impact is difficult to assess, often due to different types of production models and feedstocks, but also due to weaknesses in the methodologies and measures of food security used. This paper aims to help address this evidence gap by analysing household survey data from sites close to different types of biofuel operations in Mozambique and Tanzania, using an index that measures key macronutrient and micronutrient deficits at the household level. The results show that those households with employees in medium to large-scale biofuel feedstock operations achieved significantly higher food security outcomes than other households in the same locations. Furthermore, most of the households with better food security outcomes reported an improvement in food security since the biofuel operations had been established and attributed this mainly to increased and more regular income from salaried employment.  相似文献   

13.
Rapid escalation in biofuels consumption may lead to a trade regime that favors exports of food-based biofuels from tropical developing countries to developed countries. There is growing interest in mitigating the land-use impacts of these potential biofuels exports by converting biorefinery waste streams into cellulosic ethanol, potentially reducing the amount of land needed to meet production goals. This increased land-use efficiency for ethanol production may lower the land-use greenhouse gas emissions of ethanol but would come at the expense of converting the wastes into bioelectricity which may offset fossil fuel-based electricity and could provide a vital source of domestic electricity in developing countries. Here we compare these alternative uses of wastes with respect to environmental and energy security outcomes considering a range of electricity production efficiencies, ethanol yields, land-use scenarios, and energy offset assumptions. For a given amount of waste biomass, we found that using bioelectricity production to offset natural gas achieves 58% greater greenhouse gas reductions than using cellulosic ethanol to offset gasoline but similar emissions when cellulosic ethanol is used to offset the need for more sugar cane ethanol. If bioelectricity offsets low-carbon energy sources such as nuclear power then the liquid fuels pathway is preferred. Exports of cellulosic ethanol may have a small impact on the energy security of importing nations while bioelectricity production may have relatively large impacts on the energy security in developing countries.  相似文献   

14.
The challenges of desertification and food insecurity share considerable common ground, not only in terms of their myriad biophysical, political and socioeconomic drivers and links to the productivity of the land and soil, but also in the discourses and approaches that have informed their management. This paper reviews the elements common to both challenges and argues that due to their cross-cutting nature and the parallel pathways along which each issue has evolved, there is a strong case to be made for taking a synergistic approach towards the development of future solutions. In particular, it is argued that livelihoods and vulnerability approaches could be used as a common platform to inform more integrated interventions. This could enable multiple benefits to be harnessed for both challenges.
Lindsay C. StringerEmail:

Lindsay Stringer   is a Lecturer in Environmental Social Sciences at the University of Leeds Sustainability Research Institute. Lindsay’s research focuses largely on the socioeconomic and policy dimensions of desertification and global change, with regional focus in Southern Africa and Eastern Europe. Her current research is exploring the links between desertification, land use change and other important global challenges, including food insecurity, the increasing cultivation of biofuels and adaptation to future climate change.   相似文献   

15.
A resilient US dairy industry will be underpinned by forage and crop production systems that are economically, environmentally, and socially sustainable. Land use for production of perennial and annual forages and grains for dairy cattle must evolve in response to multiple food security and environmental sustainability issues. These include increasing global populations; higher incomes and demand for dairy and other animal products; climate change with associated temperature and moisture changes; necessary reductions in carbon and water footprints; maintenance of soil quality and soil nutrient concerns; and competition for land. Likewise, maintaining producer profitability and utilizing practices accepted by consumers and society generally must also be considered. Predicted changes in climate and water availability will likely challenge current feed and dairy production systems and their national spatial distribution, particularly the western migration of dairy production in the late 20th century. To maintain and stabilize profitability while reducing carbon footprint, particularly reductions in methane emission and enhancements in soil carbon sequestration, dairy production will need to capitalize on genetic and management innovations that enhance forage and grain production and nutritive value. Improved regional and on-farm integration of feed production and manure utilization is needed to reduce environmental nitrogen and phosphorus losses and mitigate greenhouse gas emissions. Resilient and flexible feed production strategies are needed to address each of these challenges and opportunities to ensure profitable feeding of dairy cattle and a sustainable dairy industry.  相似文献   

16.
Ensuring global food security for a growing population remains a major challenge. This is especially true against the background of increasing food prices paired with growing income levels and changing demand patterns in the developing world. At the same time, climate change and the occurrence of more frequent and extreme natural disasters increase the vulnerability of rural farm households, negatively affecting agricultural production. Given the many dimensions of food security, no simple solution can be found. Promoting productivity of farming and increasing the efficiency of the food marketing system are effective measures contributing to rural development in developing countries. Policy reforms in agriculture and beyond help to reduce distortions and change consumers’ awareness with respect to food waste and resource use inefficiencies related to human diets. What is new in this context is the increasing link of agriculture with other sectors such as the energy and the financial markets. This calls for further research as additional pressure is being put on the global food system.  相似文献   

17.
Achieving food security in the face of climate change is a major challenge for humanity in the 21st century but comprehensive analyses of climate change impacts, including global market feedbacks are still lacking. In the context of uneven impacts of climate change across regions interconnected through trade, climate change impact and adaptation policies in one region need to be assessed in a global framework. Focusing on four Eastern Asian countries and using a global integrated modeling framework we show that i) once imports are considered, the overall climate change impact on the amount of food available could be of opposite sign to the direct domestic impacts and ii) production and trade adjustments following price signals could reduce the spread of climate change impacts on food availability. We then investigated how pressure on the food system in Eastern Asia could be mitigated by a consumer support policy. We found that the costs of adaptation policies to 2050 varied greatly across climate projections. The costs of consumer support policies would also be lower if only implemented in one region but market price leakage could exacerbate pressure on food systems in other regions. We conclude that climate adaptation should no longer be viewed only as a geographically isolated local problem.  相似文献   

18.
不断调整的国内外经济政策,不仅对我国利用国际市场资源带来挑战,还可能通过价格传导的形式影响国内粮食价格,甚至粮食生产。在广泛搜集影响粮食价格波动相关因素的基础上,采用主成分分析和时变参数因子增强向量自回归模型(TVP-FAVAR)相结合的方法,分析了供求因素、金融及能源因素以及全球经济政策不稳定性对我国粮食价格的影响。主要研究发现如下:全球经济政策不确定性对国内粮食价格有显著的负向冲击;不同种类粮食价格对不确定性冲击的响应是有差异的。针对模型结果,提出如下政策建议:在中美贸易战愈演愈烈的今天,面对来自国际市场的不确定性冲击,政策制定者应该采取组合策略平抑国际市场的冲击;政策制定者应针对不同粮食品种实施有差别的价格政策和调节手段;加强粮食市场信息监测系统建设,提高根据价格监测信息准确解读市场行情的能力,制定多样化价格调整政策来抵消外部市场的不确定性冲击;我国可以通过与更多具有粮食出口潜力的国家实施更多的贸易自由协定,为国民寻求更加稳定的外部供给渠道,减缓主要国家贸易政策不稳定性带来的不利影响。  相似文献   

19.
Recent spikes in world food and energy prices have fostered renewed momentum for agricultural investment in lower and middle-income countries. Governments in some food-importing countries are promoting the acquisition of land overseas as a means to ensure long-term national food security. Businesses are recognizing new opportunities for strong returns from international investments in agriculture for food, fuel and other agricultural commodities. Dubbed ‘land grabs’ in the media, land-based investments have kindled much international debate, in which strong positions are taken on the impacts of such investments on environment, rights, sovereignty, livelihoods, development and conflict at local, national and international levels. Depending on how they are structured, agricultural investments may deliver local benefits and include small-scale producers in value chains, or carry environmental and social risks that fall disproportionately on local people. Vigorous public debate in recipient countries, effective screening of proposed investments, including robust environmental and social impact assessments, secure local land and resource rights, local voice in decision-making, skillfully negotiated and regulated contracts and effective policy incentives for business models that favor working with local farmers over large plantations can help make the renewed momentum in agricultural investment work for development.  相似文献   

20.
In addition to available country or site-specific life cycle studies on Jatropha biodiesel we present a generic, location-independent life cycle assessment and provide a general but in-depth analysis of the environmental performance of Jatropha biodiesel for transportation. Additionally, we assess the influence of changes in byproduct use and production chain. In our assessments, we went beyond the impact on energy requirement and global warming by including impacts on ozone layer and terrestrial acidification and eutrophication. The basic Jatropha biodiesel system consumes eight times less nonrenewable energy than conventional diesel and reduces greenhouse gas emissions by 51%. This result coincides with the lower limit of the range of reduction percentages available in literature for this system and for other liquid biofuels. The impact on the ozone layer is also lower than that provoked by fossil diesel, although eutrophication and acidification increase eight times. This study investigates the general impact trends of the Jatropha system, although not considering land-use change. The results are useful as a benchmark against which other biodiesel systems can be evaluated, to calculate repayment times for land-use change induced carbon loss or as guideline with default values for assessing the environmental performance of specific variants of the system.  相似文献   

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