The effect of climate change on the water and food nexus in China

A country level food security approach called PODIUMSim model was applied in this paper to analyse the likely food surplus/deficit in China in the years 2030 and 2050 based on population growth and irrigation area development scenarios. PODIUMSim is an interactive policy planning and scenario analysis tool, which explores the trade-offs and future demands on water resources at a national scale. Changes in precipitation and evapotranspiration estimated from climate models are used to represent climate change. A decision support tool for stochastic analysis called @RISK was used to perform stochastic analysis on future water availability and water demand. Without climate change the results indicate that total grain demand in China would increase from 427 million tons in 2000 to 609 million tons by 2030 and 714 million tons by 2050 while the total grain production was 400 million tons in 2000 and would increase to 521 million tons and 629 million tons in 2030 and 2050, respectively. There was a 27 million ton grain deficit in the year 2000 and there would be an 88 million ton and 85 million ton grain deficit in 2030 and 2050, respectively, under medium population growth and irrigation area development scenarios. To meet the total food demand in 2030 and 2050 in the high population growth scenario, 107.8 and 104.7 million ha of gross irrigated area need to be reached respectively, which requires 48% and 73% of surface water and groundwater irrigation efficiencies in the year 2030 and 49% and 75% of surface water and groundwater irrigation efficiencies in the year 2050, subject to the constraint of irrigation water use being between 400 and 420 billion m³, as set by the Chinese government. Achieving these gains in both gross irrigated area and irrigation efficiency at the country levels is a formidable task, requiring further intensification of land and water use. To meet the total food, domestic and industrial demand, the total water production will have to increase from 564 billion m³ in 2000 to 600 and 615 billion m³ in 2030 and 2050, respectively. In addition, climate change will have significant impacts on future water availability and irrigation water demand. Under climate change (precipitation increased by 3% and evapotranspiration increased by 0.03 mm day⁻¹) in 2030, the surface water availability would decrease from 951 billion m³ to 914 billion m³ and groundwater availability would decrease from 383 billion m³ to 378 billion m³. To cope with the impacts from climate change, some mitigation measures such as investing in drought resistant crops, expanding water storage schemes, and increasing irrigation water use efficiencies should be adopted.     

Global food markets,trade and the cost of climate change adaptation

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.     

Skyfarming an ecological innovation to enhance global food security

Population growth increases the demand for food and thus leads to expansion of cultivated land and intensification of agricultural production. There is a definite limit to both of these options for food security and their multiple negative effects on the environment undermine the aim for sustainability. Presently the impact of the Green Revolution on crop production is levelling off at high yields attained and even the potential of large scale irrigation programmes and transgenic crops seem to be limited in view of the expected increase in demand for food. Moreover, climate change threatens to affect agricultural production across the globe. Skyfarming represents a promising approach for food production that is largely environment independent and therefore immune to climate change. Optimal growing conditions, shielded from weather extremes and pests are aimed at raising plant production towards the physiological potential. Selecting rice as a pioneer crop for Skyfarming will not only provide a staple for a large part of the global population, but also significantly reduce the greenhouse gas emission caused by paddy cultivation. Multiplication of the benefits could be achieved by stacking production floors vertically. In Skyfarming the crop, with its requirements for optimal growth, development and production, determines the system??s design. Accordingly, the initial development must focus on the growing environment, lighting, temperature, humidity regulation and plant protection strategies as well as on the overall energy supply. For each of these areas potentially suitable technologies are presented and discussed.     

Skyfarming an ecological innovation to enhance global food security

Population growth increases the demand for food and thus leads to expansion of cultivated land and intensification of agricultural production. There is a definite limit to both of these options for food security and their multiple negative effects on the environment undermine the aim for sustainability. Presently the impact of the Green Revolution on crop production is levelling off at high yields attained and even the potential of large scale irrigation programmes and transgenic crops seem to be limited in view of the expected increase in demand for food. Moreover, climate change threatens to affect agricultural production across the globe. Skyfarming represents a promising approach for food production that is largely environment independent and therefore immune to climate change. Optimal growing conditions, shielded from weather extremes and pests are aimed at raising plant production towards the physiological potential. Selecting rice as a pioneer crop for Skyfarming will not only provide a staple for a large part of the global population, but also significantly reduce the greenhouse gas emission caused by paddy cultivation. Multiplication of the benefits could be achieved by stacking production floors vertically. In Skyfarming the crop, with its requirements for optimal growth, development and production, determines the system’s design. Accordingly, the initial development must focus on the growing environment, lighting, temperature, humidity regulation and plant protection strategies as well as on the overall energy supply. For each of these areas potentially suitable technologies are presented and discussed.     

The impact of climate change on disease constraints on production of oilseed rape

Weather data generated for different parts of the UK under five climate change scenarios (baseline, 2020s low CO₂ emissions, 2020s high emissions, 2050s low emissions, 2050s high emissions) were inputted into weather-based models for predicting oilseed rape yields and yield losses from the two most important diseases, phoma stem canker and light leaf spot. An economic analysis of the predictions made by the models was done to provide a basis to guide government and industry planning for adaptation to effects of climate change on crops to ensure future food security. Modelling predicted that yields of fungicide-treated oilseed rape would increase by the 2020s and continue to increase by the 2050s, particularly in Scotland and northern England. If stem canker and light leaf spot were effectively controlled, the value of the crop was predicted to increase above the baseline 1980s value by ￡13 M in England and ￡28 M in Scotland by the 2050s under a high CO₂ emissions scenario. However, in contrast to predictions that phoma stem canker will increase in severity and range with climate change, modelling indicated that losses due to light leaf spot will decrease in both Scotland and England. Combined losses from both phoma stem canker and light leaf spot are predicted to increase, with yield losses of up to 40% in southern England and some regions of Scotland by the 2050s under the high emission scenarios. For this scenario, UK disease losses are predicted to increase by ￡50 M (by comparison with the baseline losses). However, the predicted increases in fungicide-treated (potential) yield and phoma stem canker/light leaf spot yield losses compensate for each other so that the net UK losses from climate change for untreated oilseed rape are small.     

Application of the TOA-MD model to assess adoption potential of improved sweet potato technologies by rural poor farm households under climate change: the case of Kabale district in Uganda

Sweet potato technologies that increase productivity, such as drought resistant varieties and virus free planting material are being promoted in order to reduce the vulnerability of poor farm households to climate change. In this paper, the Trade-off Analysis, Minimum Data Model Approach (TOA-MD) was used to assess the adoption potential of these technologies by resource poor farmers under climate change in Uganda. The model was calibrated and validated using household survey data collected in 2009 from Kabale district. To simulate adoption potential, the base system data was generated from household data and adjusted to reflect impact of climate change on crop yields and prices by 2050. The percentage increase in yields resulting from the use of climate resilient sweet potato technologies were used to estimate yields for alternative systems based on the results from sweet potato trials by the National Agricultural Research Organization (NARO), Uganda. Adoption potential of sweet potato technologies varied across altitudes. Compared with the high and lower altitudes, adoption potential is lowest at moderate altitude despite higher yields and lower costs of production. Paying farmers to adopt new sweet potato technologies is economically rational at the higher and moderate altitudes but not at the lower altitudes. The provision of free planting material (subsidy) for the evaluated technologies resulted in a modest increase of 2 % in adoption potential. Therefore, providing this as a way of increasing adoption of sweet potato technologies to reduce vulnerability of poor farm households to climate change will have a very small impact. Instead, climate change adaptation policy should focus on creating enabling environments for farmers to market their produce so as to raise returns and reduce the opportunity costs of climate change adaptation strategies.     

The relative importance of drought and other water-related constraints for major food crops in South Asian farming systems

Variation in water availability is a major source of risk for agricultural productivity and food security in South Asia. Three hundred and thirty expert informants were surveyed during 2008-09 to determine the relative importance of drought and water-related constraints compared with other constraints limiting the production of four major food crops (wheat, rice, sorghum, chickpea) in five broad-based South Asian farming systems. Respondents considered drought an important constraint to crop yield in those farming systems that are predominantly rainfed, but associated it with low yield losses (well below 10% of all reported losses) for crops in farming systems with well-developed irrigation. In these systems, other water-related constraints (including difficult access to sufficient irrigation water, the high cost of irrigation, poor water management, waterlogging and flooding of low-lying fields) were more important. While confirming the importance of drought and water constraints for major food crops and farming systems in South Asia, this study also indicated they may contribute to no more than 20–30% of current yield gaps. Other types of constraint, particularly soil infertility and the poor management of fertilizer and weeds for the cereals, and pests and diseases for chickpea, contributed most yield losses in the systems. Respondents proposed a wide range of interventions to address these constraints. Continued investments in crop-based genetic solutions to alleviate drought may be justified for food crops grown in those South Asian farming systems that are predominantly rainfed. However, to provide the substantial production, sustainability and food security benefits that the region will need in coming decades, the study proposed that these be complemented by other water interventions, and by improvements to soil fertility for the cereals and plant protection with chickpea.     

Application of DSSAT Crop Simulation Model to Identify the Changes of Rice Growth and Yield in Nilwala River Basin for Mid-centuries under Changing Climatic Conditions

Changes of climate will be one of the deciding factors that affect for future food production in the world because crop growth is highly sensitive to any changes of climatic conditions. As the rice is staple food of Sri Lankans, it is essential to identify the impacts of climate changes on country's rice production. This study was conducted to identify the yield and growth changes of most popular two rice varieties (At362 and Bg357) cultivated in Nilwala river basin at Yala season under the global climate change scenario Representative Concentrate Pathway (RCP) 8.5. The Decision Support System for Agro technology Transfer (DSSAT) software is used to forecast the rice yield for Yala season in mid-centuries. To simulate the rice yield DSSAT requires data sets of crop growth and management, daily weather data and soil data. Crop management data were obtained from an experiment which was conducted in Palatuwa area at Nilwala downstream in Matara district. Daily weather data were collected from Mapalana weather station and soil data were collected from wet zone soil classification. Model was calibrated using experimental data for Yala season 2014 and model was validated using collected data in Yala season 2013. Future yield was predicted using forecasted weather data under climate change scenario RCP 8.5 for Mapalana area. The results show that increasing temperature and solar radiation and decreasing rainfall in mid-centuries affects both yield and growth of rice. Grain yield in mid-centuries shows decreasing trend in both varieties by 25% to 35% than the yield at 2014 and growth period will be shorter than the present conditions.     

Crops that feed the world 7: Rice

Fears about global food security led to a spike in food prices in 2008, social unrest and pushed a further 100 million people into poverty. Prices remain high and volatile. In this paper we take a closer look at rice, a crop that feeds billions of people in the world, and focus in particular on Asia and Africa. On both continents, rice is grown in a wide range of climatic conditions, from river deltas to mountainous regions. Irrigated systems dominate in Asia and rainfed systems in Africa. Predicted demands for rice remain strong. An additional 116 million tons of rice will be needed by 2035 to feed growing populations. In Africa, where rice is the most rapidly growing food source, about 30 million tons more rice will be needed by 2035, representing an increase of 130% in rice consumption from 2010. About one-third of this extra rice will be needed in Nigeria alone. In Asia, per capita consumption of rice may go down in some mid- and high-income countries. Rice farming will need to produce about 8–10 million tons more paddy per year over the next decade. Without area expansion this will require an annual yield increase of about 1.2–1.5%, equivalent to an average yield increase of 0.6 t ha⁻¹ world-wide. Improving global food security will, therefore, necessitate concerted efforts to increase the productivity of rice per unit of land, water and/or labor in Asia and Africa, and the development of new land and water resources in a responsible and equitable manner to counteract losses due to urbanization and industrialization. During 2007–2011, productivity increases in Africa have been leading the way, with paddy rice production levels increasing by 9.5% per year, compared to 1.6% in Asia. Priorities for rice sector development include (i) continued and increased research efforts to close yield gaps and raise yield ceilings across rice growing environments through varietal development and improved rice production methods, and coping with climate change in both continents and (ii) strengthened and equitable public-private sector partnerships and conducive policy environments in Africa, with special emphasis on mechanization of rice farming from land preparation to harvest and rice processing practices.     

Future threats to agricultural food production posed by environmental degradation,climate change,and animal and plant diseases – a risk analysis in three economic and climate settings

Global food security is one of the most pressing issues for humanity, and agricultural production is critical for achieving this. The existing analyses of specific threats to agricultural food production seldom bring out the contrasts associated with different levels of economic development and different climatic zones. We therefore investigated the same biophysical threats in three modelled types of countries with different economic and climatic conditions. The threats analysed were environmental degradation, climate change and diseases and pests of animals and plants. These threats were analysed with a methodology enabling the associated risks to be compared. The timeframe was 2012–2050 and the analysis was based on three underlying assumptions for 2050: the world population will have increased to 9 billion people, there will be a larger middle class in the world and climate change will be causing more extreme weather events, higher temperatures and altered precipitation. It is suggested that the risks, presented by the biophysical threats analysed, differ among the three modelled types of countries and that climate zone, public stewardship and economic strength are major determinants of these differences. These determinants are far from evenly spread among the world’s major food producers, which implies that diversification of risk monitoring and international assessment of agricultural production is critical for assuring global food security in 2050.     

Climate change and food safety: A review

Climate change and variability may have an impact on the occurrence of food safety hazards at various stages of the food chain, from primary production through to consumption. There are multiple pathways through which climate related factors may impact food safety including: changes in temperature and precipitation patterns, increased frequency and intensity of extreme weather events, ocean warming and acidification, and changes in contaminants’ transport pathways among others. Climate change may also affect socio-economic aspects related to food systems such as agriculture, animal production, global trade, demographics and human behaviour which all influence food safety.This paper reviews the potential impacts of predicted changes in climate on food contamination and food safety at various stages of the food chain and identifies adaptation strategies and research priorities to address food safety implications of climate change. The paper concludes that there is a need for intersectoral and international cooperation to better understand the changing food safety situation and in developing and implementing adaptation strategies to address emerging risks associated with climate change.     

Agricultural productivity in the lower Mekong Basin: trends and future prospects for food security

This paper examines the spatial and temporal variability and trends of agricultural productivity in the Lower Mekong River Basin. We also show the future productivity requirements for both food security and the maintenance of the basin’s export potential at the current level for the projected increase in population by 2030. We considered both rice and upland crops grown in the basin and estimated physical and economic productivity in terms of land and population. Both physical and economic productivity of rice in terms of land area and population is highest in Vietnam, moderate in Laos and lowest in Thailand and Cambodia. However, the physical productivity of upland crops such as sugarcane and maize is highest in Thailand. Economic productivity of upland crops is highest in Laos followed by Vietnam, Cambodia and Thailand, respectively and is much higher than that of rice. Total economic productivity is dominated by rice in all countries except Laos. In general, productivity has increased in all four riparian countries between 1993 and 2004 and there appears to be considerable scope for further increases, which will allow maintenance of the current level of rice export in the future, despite population growth.

A Monte Carlo analysis on the impact of climate change on future crop choice and water use in Uzbekistan

Central Asia is considered a hot spot for severe water stress. According to the Intergovernmental Panel on Climate Change (IPCC), over the next century this region is expected to see a rise in temperatures and experience lower amounts of rainfall, creating a more arid climate. Regional agricultural policies have dominated water resource use. The impact of climate change coupled with market distorting economic policies, inefficient irrigation systems, and lack of water rights, could lead to social instability in the region. This analysis employs two downscaled climate projections and two Relative Concentration Pathway (RCP) scenarios (4.5 and 8.5) to simulate the impact of climate change on crop production, water use, and future crop allocations in the Khorezm region of Uzbekistan. Drought scenarios show drastic changes in crop productivity and producer profitability. If production quotas are removed, this region has the ability to become self-sufficient in wheat production, increasing its capacity to achieve food security.     

Adapting maize production to climate change in sub-Saharan Africa

Given the accumulating evidence of climate change in sub-Saharan Africa, there is an urgent need to develop more climate resilient maize systems. Adaptation strategies to climate change in maize systems in sub-Saharan Africa are likely to include improved germplasm with tolerance to drought and heat stress and improved management practices. Adapting maize systems to future climates requires the ability to accurately predict future climate scenarios in order to determine agricultural responses to climate change and set priorities for adaptation strategies. Here we review the projected climate change scenarios for Africa’s maize growing regions using the outputs of 19 global climate models. By 2050, air temperatures are expected to increase throughout maize mega- environments within sub-Saharan Africa by an average of 2.1°C. Rainfall changes during the maize growing season varied with location. Given the time lag between the development of improved cultivars until the seed is in the hands of farmers and adoption of new management practices, there is an urgent need to prioritise research strategies on climate change resilient germplasm development to offset the predicted yield declines.     

Household food security in the face of climate change in the Hindu-Kush Himalayan region

This study attempts to understand local people’s perceptions of climate change, its impacts on agriculture and household food security, and local adaptation strategies in the Hindu-Kush Himalayan (HKH) region, using data from 8083 households (HHs) from four river sub-basins (SBs), i.e. Upper Indus (Pakistan), Eastern Brahmaputra (India), Koshi (Nepal) and Salween and Mekong (China). The majority of households in SBs, in recent years, have perceived that there have been more frequent incidences of floods, landslides, droughts, livestock diseases and crop pests, and have attributed these to climate change. These changes have led to low agricultural production and income, particularly in Eastern Brahmaputra (EB) where a substantial proportion of HHs reported a decline in the production of almost all staple and cash crops, resulting in very low farm income. Consequently, households’ dependency on external food items supplied from plain areas has increased, particularly in the Upper Indus (UI) and EB. After hazards, households face transitory food insecurity owing to damage to their local food systems and livelihood sources, and constrained food supply from other areas. To cope with these, HHs in SBs make changes in their farming practices and livestock management. In EB, 11 % of HHs took on new off-farm activities within the SB and in SM, 23 % of HHs chose out-migration as an adaptation strategy. Lastly, the study proposes policy instruments for attaining sustainable food security, based on agro-ecological potential and opportunities for increasing agricultural resilience and diversity of livelihoods.     

Impacts of climate change and inter-annual variability on cereal crops in China from 1980 to 2008

BACKGROUND: Negative climate impacts on crop yield increase pressures on food security in China. In this study, climatic impacts on cereal yields (rice, wheat and maize) were investigated by analyzing climate‐yield relationships from 1980 to 2008. RESULTS: Results indicated that warming was significant, but trends in precipitation and solar radiation were not statistically significant in most of China. In general, maize is particularly sensitive to warming. However, increase in temperature was correlated with both lower and higher yield of rice and wheat, which is inconsistent with the current view that warming results in decline in yields. Of the three cereal crops, further analysis suggested that reduction in yields with higher temperature is accompanied by lower precipitation, which mainly occurred in northern parts of China, suggesting droughts reduced yield due to lack of water resources. Similarly, a positive correlation between temperature and yield can be alternatively explained by the effect of solar radiation, mainly in the southern part of China where water resources are abundant. CONCLUSION: Overall, our study suggests that it is inter‐annual variations in precipitation and solar radiation that have driven change in cereal yields in China over the last three decades. Copyright © 2011 Society of Chemical Industry     

Physical limitations and challenges to Grain Security in China

China’s grain security is a global issue. In this paper, grain production and consumption in China from 1981 to 2011 are analyzed empirically, and the physical limitations and strategic options for future sustainable grain production are discussed. China’s population is estimated to reach 1.4 billion in 2020 and to peak at about1.43 billion around 2030. With rapid urbanization, grain consumption per capita for food and feed will decrease slightly, and the total grain demand will increase to 525.4 Mt in 2020 and 546.3 Mt in 2030, accounting for increments of 31.9 and 52.8 Mt, respectively from a base of 493.6 Mt, the average of 2009–2011 production. Increased industrial use is the dominant factor, which will drive increase in grain demand in the future. Increase in grain production over the period 1981–2011 occurred mainly as a result of increases in yield per unit area but the significant increase in maize has been due to both cultivated area and yield. Limited arable land, declining area of cultivated grain and water shortage in the North China Plain are the most critical resources limiting further grain production, while the impacts of growing urbanization, rural aging and climate change are less significant. In order to ensure future grain security in China, the following strategic options must be adopted: optimizing existing population policy, strictly protecting cultivated land and ensuring conservation of grain crop areas, raising the ratio of agricultural use to other uses of water in the North China Plain, adjusting grain self-sufficiency ratio, reducing pressure on resources and increasing investments in agriculture and in developing agricultural technologies.     

The potential of small-scale rainfed agriculture to strengthen food security in Arab countries

In most Arab countries, domestic agricultural production is insufficient. The gap between production and demand is likely to increase due to climate change and other factors. This review paper examines the challenges and possible solutions to ensuring food security in the future. It focuses on rainfed agriculture, which accounts for two-thirds of the region’s cropland, the bulk of its food staples, and almost all its rangelands. Given the scarcity of water and arable land, there are few opportunities in the region to expand cultivated area. But numerous effective, proven technologies are available that can increase productivity per unit area of land or volume of water. Crop technologies include, for example, new stress-tolerant varieties, supplemental irrigation and other techniques to increase water productivity, and conservation agriculture and other land management methods. Livestock nutrition and productivity could be increased with new forage or dual-purpose varieties, and greater use of alternative feed sources such as feed blocks made from crop by-products. The paper describes some of these technologies, and summarizes results obtained from on-station and on-farm testing. The key issue is poor adoption of available technologies. The priority for researchers and policy makers must therefore be to scale up investments in research and extension; encourage private sector participation; and create enabling policies to encourage technology adoption, market participation and more sustainable use of natural resources, by smallholder farmers.     

The impact of the homestead food garden programme on food security in South Africa

The South African government has implemented homestead food garden (HFG) programmes directed at enhancing food production in order to reduce food insecurity, malnutrition, poverty and hunger. The present paper evaluated the impact of this programme on household food insecurity using surveys of 500 households. Endogenous switching regression, propensity score matching and household food insecurity average scores were employed in our analysis. Our findings demonstrated that participation in an HFG programme could significantly enhance the food security status of participants by increasing household food supply and consumption as well as by income derived from selling any excess production from the garden. Specifically, our empirical findings showed that participation in the HFG programme significantly reduced food insecurity among rural households by as much as 41.5%. Therefore, we recommend that policy makers should encourage more rural households to participate in the programme in order to reduce their food insecurity. Facilitating easy access to credit, extension services, fertilizer, irrigation facilities and land are policy options needed to promote farmers participation in HFG programmes. Furthermore, the formation of farmer-based organizations and the building of positive perceptions about HFGs are some of the key policy options that can be employed to improve households’ participation in the programme. Promotion of education, participating in off-farm activities, access to market, irrigation, extension and credit, and adoption of fertiliser are some policy interventions that can reduce food insecurity among rural house holds whether or not they participate in the HFG programme.     

Arsenic in soil and irrigation water affects arsenic uptake by rice: complementary insights from field and pot studies

Groundwater rich in arsenic (As) is extensively used for dry season boro rice cultivation in Bangladesh, leading to long-term As accumulation in soils. This may result in increasing levels of As in rice straw and grain, and eventually, in decreasing rice yields due to As phytotoxicity. In this study, we investigated the As contents of rice straw and grain over three consecutive harvest seasons (2005-2007) in a paddy field in Munshiganj, Bangladesh, which exhibits a documented gradient in soil As caused by annual irrigation with As-rich groundwater since the early 1990s. The field data revealed that straw and grain As concentrations were elevated in the field and highest near the irrigation water inlet, where As concentrations in both soil and irrigation water were highest. Additionally, a pot experiment with soils and rice seeds from the field site was carried out in which soil and irrigation water As were varied in a full factorial design. The results suggested that both soil As accumulated in previous years and As freshly introduced with irrigation water influence As uptake during rice growth. At similar soil As contents, plants grown in pots exhibited similar grain and straw As contents as plants grown in the field. This suggested that the results from pot experiments performed at higher soil As levels can be used to assess the effect of continuing soil As accumulation on As content and yield of rice. On the basis of a recently published scenario of long-term As accumulation at the study site, we estimate that, under unchanged irrigation practice, average grain As concentrations will increase from currently ～0.15 mg As kg(-1) to 0.25-0.58 mg As kg(-1) by the year 2050. This translates to a 1.5-3.8 times higher As intake by the local population via rice, possibly exceeding the provisional tolerable As intake value defined by FAO/WHO.