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1.
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
2.
Andrew Challinor Tim Wheeler Chris Garforth Peter Craufurd Amir Kassam 《Climatic change》2007,83(3):381-399
Africa is thought to be the region most vulnerable to the impacts of climate variability and change. Agriculture plays a dominant
role in supporting rural livelihoods and economic growth over most of Africa. Three aspects of the vulnerability of food crop
systems to climate change in Africa are discussed: the assessment of the sensitivity of crops to variability in climate, the
adaptive capacity of farmers, and the role of institutions in adapting to climate change. The magnitude of projected impacts
of climate change on food crops in Africa varies widely among different studies. These differences arise from the variety
of climate and crop models used, and the different techniques used to match the scale of climate model output to that needed
by crop models. Most studies show a negative impact of climate change on crop productivity in Africa. Farmers have proved
highly adaptable in the past to short- and long-term variations in climate and in their environment. Key to the ability of
farmers to adapt to climate variability and change will be access to relevant knowledge and information. It is important that
governments put in place institutional and macro-economic conditions that support and facilitate adaptation and resilience
to climate change at local, national and transnational level. 相似文献
3.
Philip K. Thornton Peter G. Jones Gopal Alagarswamy Jeff Andresen 《Global Environmental Change》2009,19(1):54-65
There is general consensus that the impacts of climate change on agriculture will add significantly to the development challenges of ensuring food security and reducing poverty, particularly in Africa. While these changes will influence agriculture at a broad scale, regional or country-level assessments can miss critical detail. We use high-resolution methods to generate characteristic daily weather data for a combination of different future emission scenarios and climate models to drive detailed simulation models of the maize and bean crops. For the East African region, there is considerable spatial and temporal variation in this crop response. We evaluate the response of maize and beans to a changing climate, as a prelude to detailed targeting of options that can help smallholder households adapt. The results argue strongly against the idea of large, spatially contiguous development domains for identifying and implementing adaptation options, particularly in regions with large variations in topography and current average temperatures. Rather, they underline the importance of localised, community-based efforts to increase local adaptive capacity, take advantage of changes that may lead to increased crop and livestock productivity where this is possible, and to buffer the situations where increased stresses are likely. 相似文献
4.
R. K. Mall Ranjeet Singh Akhilesh Gupta G. Srinivasan L. S. Rathore 《Climatic change》2006,78(2-4):445-478
During the recent decade, with the growing recognition of the possibility of climate change and clear evidence of observed
changes in climate during 20th century, an increasing emphasis on food security and its regional impacts has come to forefront of the scientific community.
In recent times, the crop simulation models have been used extensively to study the impact of climate change on agricultural
production and food security. The output provided by the simulation models can be used to make appropriate crop management
decisions and to provide farmers and others with alternative options for their farming system. It is expected that in the
coming decades with the increased use of computers, the use of simulation models by farmers and professionals as well as policy
and decision makers will increase. In India, substantial work has been done in last decade aimed at understanding the nature
and magnitude of change in yield of different crops due to projected climate change. This paper presents an overview of the
state of the knowledge of possible effect of the climate variability and change on food grain production in India.
An erratum to this article can be found at 相似文献
5.
The study focuses on economic and food security implications of projected climate change on Malian agriculture sector. Climate change projections made by two global circulation models are considered. The analysis focuses on the effects on crops, forages, and livestock and the resultant effects on sectoral economics and risk of hunger in Mali. Results show that under climate change, crop yield changes are in the range of minus 17% to plus 6% at national level. Simultaneously, forage yields fall by 5 to 36% and livestock animal weights are reduced by 14 to 16%. The resultant economic losses range between 70 to $142 million, with producers gaining, but consumers losing. The percentage of population found to be at risk of hunger rises from a current estimate of 34% to an after climate change level of 64% to 72%. A number of policy and land management strategies can be employed to mitigate the effects of climate change. In particular, we investigate the development of heat resistant cultivars, the adoption of existing improved cultivars, migration of cropping pattern, and expansion of cropland finding that they effectively reduce climate change impacts lowering the risk of hunger to as low as 28%. 相似文献
6.
Historical increases in agricultural production were achieved predominantly by large increases in agricultural productivity. Intensification of crop and livestock production also plays a key role in future projections of agricultural land use. Here, we assess and discuss projections of crop yields by global agricultural land-use and integrated assessment models. To evaluate these crop yield projections, we compare them to empirical data on attainable yields by employing a linear and plateauing continuation of observed attainable yield trends. While keeping in mind the uncertainties of attainable yields projections and not considering future climate change impacts, we find that, on average for all cereals on the global level, global projected yields by 2050 remain below the attainable yields. This is also true for future pathways with high technological progress and mitigation efforts, indicating that projected yield increases are not overly optimistic, even under systemic transformations. On a regional scale, we find that for developing regions, specifically for sub-Saharan Africa, projected yields stay well below attainable yields, indicating that the large yield gaps which could be closed through improved crop management, may also persist in the future. In OECD countries, in contrast, current yields are already close to attainable yields, and the projections approach or, for some models, even exceed attainable yields by 2050. This observation parallels research suggesting that future progress in attainable yields in developed regions will mainly have to be achieved through new crop varieties or genetic improvements. The models included in this study vary widely in their implementation of yield progress, which are often split into endogenous (crop management) improvements and exogenous (technological) trends. More detail and transparency are needed in these important elements of global yields and land use projections, and this paper discusses possibilities of better aligning agronomic understanding of yield gaps and yield potentials with modelling approaches. 相似文献
7.
《Global Environmental Change》2003,13(1):51-59
The impacts of climate change on agriculture may add significantly to the development challenges of ensuring food security and reducing poverty. We show the possible impacts on maize production in Africa and Latin America to 2055, using high-resolution methods to generate characteristic daily weather data for driving a detailed simulation model of the maize crop. Although the results indicate an overall reduction of only 10% in maize production to 2055, equivalent to losses of $2 billion per year, the aggregate results hide enormous variability: areas can be identified where maize yields may change substantially. Climate change urgently needs to be assessed at the level of the household, so that poor and vulnerable people dependent on agriculture can be appropriately targeted in research and development activities whose object is poverty alleviation. 相似文献
8.
The climate change research community’s shared socioeconomic pathways (SSPs) are a set of alternative global development scenarios focused on mitigation of and adaptation to climate change. To use these scenarios as a global context that is relevant for policy guidance at regional and national levels, they have to be connected to an exploration of drivers and challenges informed by regional expertise.In this paper, we present scenarios for West Africa developed by regional stakeholders and quantified using two global economic models, GLOBIOM and IMPACT, in interaction with stakeholder-generated narratives and scenario trends and SSP assumptions. We present this process as an example of linking comparable scenarios across levels to increase coherence with global contexts, while presenting insights about the future of agriculture and food security under a range of future drivers including climate change.In these scenarios, strong economic development increases food security and agricultural development. The latter increases crop and livestock productivity leading to an expansion of agricultural area within the region while reducing the land expansion burden elsewhere. In the context of a global economy, West Africa remains a large consumer and producer of a selection of commodities. However, the growth in population coupled with rising incomes leads to increases in the region’s imports. For West Africa, climate change is projected to have negative effects on both crop yields and grassland productivity, and a lack of investment may exacerbate these effects. Linking multi-stakeholder regional scenarios to the global SSPs ensures scenarios that are regionally appropriate and useful for policy development as evidenced in the case study, while allowing for a critical link to global contexts. 相似文献
9.
Building on previous work quantitative estimates of climate change impacts on global food production have been made for the UK Hadley Centre's HadCM2 greenhouse gas only ensemble experiment and the more recent HadCM3 experiment (Hulme et al., 1999). The consequences for world food prices and the number of people at risk of hunger as defined by the Food and Agriculture Organisation (FAO, 1988) have also been assessed. Climate change is expected to increase yields at high and mid-latitudes, and lead to decreases at lower latitudes. This pattern becomes more pronounced as time progresses. The food system may be expected to accommodate such regional variations at the global level, with production, prices and the risk of hunger being relatively unaffected by the additional stress of climate change. By the 2080s the additional number of people at risk of hunger due to climate change is about 80 million people (±10 million depending on which of the four HadCM2 ensemble members is selected). However, some regions (particularly the arid and sub-humid tropics) will be adversely affected. A particular example is Africa, which is expected to experience marked reductions in yield, decreases in production, and increases in the risk of hunger as a result of climate change. The continent can expect to have between 55 and 65 million extra people at risk of hunger by the 2080s under the HadCM2 climate scenario. Under the HadCM3 climate scenario the effect is even more severe, producing an estimated additional 70+ million people at risk of hunger in Africa. 相似文献
10.
J Alcamo GJJ Kreileman JC Bollen GJ van den Born R Gerlagh MS Krol AMC Toet HJM de Vries 《Global Environmental Change》1996,6(4):261-303
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
11.
One of the issues with respect to climate change involves its influence on the distribution of future crop yields. Many studies have been done regarding the effect on the mean of such distributions but few have addressed the effect on variance. Furthermore, those that have been done generally report the variance from crop simulators, not from observations. This paper examines the potential effects of climate change on crop yield variance in the context of current observed yields and then extrapolates to the effects under projected climate change. In particular, maximum likelihood panel data estimates of the impacts of climate on year-to-year yield variability are constructed for the major U.S. agricultural crops. The panel data technique used embodies a variance estimate developed along the lines of the stochastic production function approach suggested by Just and Pope. The estimation results indicate that changes in climate modify crop yield levels and variances in a crop-specific fashion. For sorghum, rainfall and temperature increases are found to increase yield level and variability. On the other hand, precipitation and temperature are individually found to have opposite effects on corn yield levels and variability. 相似文献
12.
X-C Zhang 《Climatic change》2007,84(3-4):337-363
Spatial downscaling of climate change scenarios can be a significant source of uncertainty in simulating climatic impacts
on soil erosion, hydrology, and crop production. The objective of this study is to compare responses of simulated soil erosion,
surface hydrology, and wheat and maize yields to two (implicit and explicit) spatial downscaling methods used to downscale
the A2a, B2a, and GGa1 climate change scenarios projected by the Hadley Centre’s global climate model (HadCM3). The explicit
method, in contrast to the implicit method, explicitly considers spatial differences of climate scenarios and variability
during downscaling. Monthly projections of precipitation and temperature during 1950–2039 were used in the implicit and explicit
spatial downscaling. A stochastic weather generator (CLIGEN) was then used to disaggregate monthly values to daily weather
series following the spatial downscaling. The Water Erosion Prediction Project (WEPP) model was run for a wheat–wheat–maize
rotation under conventional tillage at the 8.7 and 17.6% slopes in southern Loess Plateau of China. Both explicit and implicit
methods projected general increases in annual precipitation and temperature during 2010–2039 at the Changwu station. However,
relative climate changes downscaled by the explicit method, as compared to the implicit method, appeared more dynamic or variable.
Consequently, the responses to climate change, simulated with the explicit method, seemed more dynamic and sensitive. For
a 1% increase in precipitation, percent increases in average annual runoff (soil loss) were 3–6 (4–10) times greater with
the explicit method than those with the implicit method. Differences in grain yield were also found between the two methods.
These contrasting results between the two methods indicate that spatial downscaling of climate change scenarios can be a significant
source of uncertainty, and further underscore the importance of proper spatial treatments of climate change scenarios, and
especially climate variability, prior to impact simulation. The implicit method, which applies aggregated climate changes
at the GCM grid scale directly to a target station, is more appropriate for simulating a first-order regional response of
nature resources to climate change. But for the site-specific impact assessments, especially for entities that are heavily
influenced by local conditions such as soil loss and crop yield, the explicit method must be used. 相似文献
13.
14.
Climate change and critical thresholds in China’s food security 总被引：2，自引：0，他引：2
Identification of ‘critical thresholds’ of temperature increase is an essential task for inform policy decisions on establishing
greenhouse gas (GHG) emission targets. We use the A2 (medium-high GHG emission pathway) and B2 (medium-low) climate change
scenarios produced by the Regional Climate Model PRECIS, the crop model – CERES, and socio-economic scenarios described by
IPCC SRES, to simulate the average yield changes per hectare of three main grain crops (rice, wheat, and maize) at 50 km ×
50 km scale. The threshold of food production to temperature increases was analyzed based on the relationship between yield
changes and temperature rise, and then food security was discussed corresponding to each IPCC SRES scenario. The results show
that without the CO2 fertilization effect in the analysis, the yield per hectare for the three crops would fall consistently as temperature rises
beyond 2.5 ^C; when the CO2 fertilization effect was included in the simulation, there were no adverse impacts on China’s food production under the projected
range of temperature rise (0.9–3.9 ^C). A critical threshold of temperature increase was not found for food production. When the socio-economic scenarios, agricultural
technology development and international trade were incorporated in the analysis, China’s internal food production would meet
a critical threshold of basic demand (300 kg/capita) while it would not under A2 (no CO2 fertilization); whereas basic food demand would be satisfied under both A2 and B2, and would even meet a higher food demand
threshold required to sustain economic growth (400 kg/capita) under B2, when CO2 fertilization was considered. 相似文献
15.
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
16.
Impacts of extreme weather on wheat and maize in France: evaluating regional crop simulations against observed data 总被引：2，自引：0，他引：2
Marijn van der Velde Francesco N. Tubiello Anton Vrieling Fay?al Bouraoui 《Climatic change》2012,113(3-4):751-765
Extreme weather conditions can strongly affect agricultural production, with negative impacts that can at times be detected at regional scales. In France, crop yields were greatly influenced by drought and heat stress in 2003 and by extremely wet conditions in 2007. Reported regional maize and wheat yields where historically low in 2003; in 2007 wheat yields were lower and maize yields higher than long-term averages. An analysis with a spatial version (10?×?10?km) of the EPIC crop model was tested with regards to regional crop yield anomalies of wheat and maize resulting from extreme weather events in France in 2003 and 2007, by comparing simulated results against reported regional crops statistics, as well as using remotely sensed soil moisture data. Causal relations between soil moisture and crop yields were specifically analyzed. Remotely sensed (AMSR-E) JJA soil moisture correlated significantly with reported regional crop yield for 2002–2007. The spatial correlation between JJA soil moisture and wheat yield anomalies was positive in dry 2003 and negative in wet 2007. Biweekly soil moisture data correlated positively with wheat yield anomalies from the first half of June until the second half of July in 2003. In 2007, the relation was negative the first half of June until the second half of August. EPIC reproduced observed soil dynamics well, and it reproduced the negative wheat and maize yield anomalies of the 2003 heat wave and drought, as well as the positive maize yield anomalies in wet 2007. However, it did not reproduce the negative wheat yield anomalies due to excessive rains and wetness in 2007. Results indicated that EPIC, in line with other crop models widely used at regional level in climate change studies, is capable of capturing the negative impacts of droughts on crop yields, while it fails to reproduce negative impacts of heavy rain and excessively wet conditions on wheat yield, due to poor representations of critical factors affecting plant growth and management. Given that extreme weather events are expected to increase in frequency and perhaps severity in coming decades, improved model representation of crop damage due to extreme events is warranted in order to better quantify future climate change impacts and inform appropriate adaptation responses. 相似文献
17.
Integrating global and regional analyses of the effects of climate change: A case study of land use in England and Wales 总被引：3，自引：0，他引：3
M. L. Parry J. E. Hossell P. J. Jones T. Rehman R. B. Tranter J. S. Marsh C. Rosenzweig G. Fischer I. G. Carson R. G. H. Bunce 《Climatic change》1996,32(2):185-198
The purpose of this paper is to exemplify a means by which an integrated assessment can be made of global and regional effects on land use of climate change. This is achieved by use of data on the effects of climate change on world food prices as inputs to a regional land use allocation model.Data on world prices are drawn from a recent global study of climate change and crop yields. In a case study of England and Wales a land allocation model is used to infer changes of land use that are the product of the integrated effect of climate-induced global price changes and climate-related changes of yield in England and Wales. This combination of changed prices and yield potential is used to calculate the land use providing the highest returns for each of 155,235 1 km2 cells of land in England and Wales for a future assumed for the year 2060 (without climate change) and then for that same environment with climate change. The difference between these two is then treated as an estimated effect resulting from climate change. 相似文献
18.
The aim of this paper is to improve understanding of the adaptive capacity of European agriculture to climate change. Extensive
data on farm characteristics of individual farms from the Farm Accountancy Data Network (FADN) have been combined with climatic
and socio-economic data to analyze the influence of climate and management on crop yields and income and to identify factors
that determine adaptive capacity. A multilevel analysis was performed to account for regional differences in the studied relationships.
Our results suggest that socio-economic conditions and farm characteristics should be considered when analyzing effects of
climate conditions on farm yields and income. Next to climate, input intensity, economic size and the type of land use were
identified as important factors influencing spatial variability in crop yields and income. Generally, crop yields and income
are increasing with farm size and farm intensity. However, effects differed among crops and high crop yields were not always
related to high incomes, suggesting that impacts of climate and management differ by impact variable. As farm characteristics
influence climate impacts on crop yields and income, they are good indicators of adaptive capacity at farm level and should
be considered in impact assessment models. Different farm types with different management strategies will adapt differently. 相似文献
19.
Agricultural risk management policies under climate uncertainty 总被引：1，自引：0，他引：1
Jesús Antón Andrea Cattaneo Shingo Kimura Jussi Lankoski 《Global Environmental Change》2013,23(6):1726-1736
Climate change is forecasted to increase the variability of weather conditions and the frequency of extreme events. Due to potential adverse impacts on crop yields it will have implications for demand of agricultural risk management instruments and farmers’ adaptation strategies. Evidence on climate change impacts on crop yield variability and estimates of production risk from farm surveys in Australia, Canada and Spain, are used to analyse the policy choice between three different types of insurance (individual, area-yield and weather index) and ex post payments. The results are found to be subject to strong uncertainties and depend on the risk profile of different farmers and locations; the paper provides several insights on how to analyse these complexities. In general, area yield performs best more often across our countries and scenarios, in particular for the baseline and marginal climate change (without increases in extreme events). However, area yield can be very expensive if farmers have limited information on how climate change affects yields (misalignment in expectations), and particularly so under extreme climate change scenarios. In these more challenging cases, ex post payments perform well to increase low incomes when the risk is systemic like in Australia; Weather index performs well to reduce the welfare costs of risks when the correlation between yields and index is increased by the extreme events. The paper also analyses the robustness of different instruments in the face of limited knowledge of the probabilities of different climate change scenarios; highlighting that this added layer of uncertainty could be overcome to provide sound policy advice under uncertainties introduced by climate change. The role of providing information to farmers on impacts of climate change emerges as a crucial result of this paper as indicated by the significantly higher budgetary expenditures occurring across all instruments when farmers’ expectations are misaligned relative to actual impacts of climate change. 相似文献
20.
Adaptation to climate change through the choice of cropping system and sowing date in sub-Saharan Africa 总被引：1，自引：0，他引：1
K. Waha C. Müller A. Bondeau J.P. Dietrich P. Kurukulasuriya J. Heinke H. Lotze-Campen 《Global Environmental Change》2013,23(1):130-143
Multiple cropping systems provide more harvest security for farmers, allow for crop intensification and furthermore influence ground cover, soil erosion, albedo, soil chemical properties, pest infestation and the carbon sequestration potential. We identify the traditional sequential cropping systems in ten sub-Saharan African countries from a survey dataset of more than 8600 households. We find that at least one sequential cropping system is traditionally used in 35% of all administrative units in the dataset, mainly including maize or groundnuts. We compare six different management scenarios and test their susceptibility as adaptation measure to climate change using the dynamic global vegetation model for managed land LPJmL. Aggregated mean crop yields in sub-Saharan Africa decrease by 6–24% due to climate change depending on the climate scenario and the management strategy. As an exception, some traditional sequential cropping systems in Kenya and South Africa gain by at least 25%. The crop yield decrease is typically weakest in sequential cropping systems and if farmers adapt the sowing date to changing climatic conditions. Crop calorific yields in single cropping systems only reach 40–55% of crop calorific yields obtained in sequential cropping systems at the end of the 21st century. The farmers’ choice of adequate crops, cropping systems and sowing dates can be an important adaptation strategy to climate change and these management options should be considered in climate change impact studies on agriculture. 相似文献