In this study, the water footprint (blue, green and grey WF) and virtual water theory were used to uniform measure the new challenges (population growth, population urbanization, dietary structure change, energy industry development, grain trade and climate change) of food security in Northwest China. Moreover, this study quantified the demand for new challenges to water resources from 2000 to 2016, and then evaluated their impact on water resources and food security in Northwest China. The results showed that in 2000–2016, population growth caused the food consumption WF to increase from 153.8 Gm³ to 159.6 Gm³, with an average annual growth rate of 0.4%. The ratio of per capita consumption of WF of urban residents to rural areas has increased from 80.3% to 120%. The per capita food consumption in the region increased by 1.3% annually due to changes in dietary structure. However, with the increase of water use efficiency, the WF decreased by 0.3% per year. Among them, the total consumption WF of food rations decreased by 51.9%, with an average annual decrease of 4.4%, and that of meat, dairy products and aquatic products increased by 2.4%, 10.8% and 3.0% per year, respectively. From the economic point of view, the development of the energy industry has increased the competition index of energy-grain to water resources from 0.22 to 0.49. Due to climate change, although the precipitation increased at a rate of 3.2 mm/yr, the increase in ET₀ was 3.3 mm/yr, and thus the demand for water resources in agricultural production increased. Based on the results, this paper suggests to carry out measures such as optimizes crop planting structure, adopts effective biological, agricultural technologies, guides healthy food consumption structure, strengthens international food trade and biofuel use and so on to reduce the WF of grain crops and energy industry. Ultimately, the goal of reducing regional water stress and ensuring food security is achieved.

This study aimed to assess the holistic impacts of climate change and irrigation management on food centric water-energy-land interlinkages in the Food-Energy-Water (FEW) nexus specialized in agriculture. Accordingly, we analyzed the trends and variation in productivity, irrigation requirement, and energy input for paddy rice production, which is the representative crop in Korea, from 1990 to 2099 with eight general circulation models (GCMs) as climate change scenarios. Results showed that the productivity of paddy rice would decrease owing to climate change, and its variation would increase. Irrigation requirement under the MIROC-ESM scenario was estimated as 849 mm year⁻¹ in 2020−2099, which was 37 mm year⁻¹ greater than that in 1990−2018. The change in irrigation management from continuous to intermittent irrigation would affect the interlinkages in the agricultural FEW nexus. Intermittent irrigation could positively influence irrigation water savings but lower productivity under climate change, and would increase the variation in both productivity and irrigation requirement. Finally, we analyzed the blue water and land footprints as interlinkage indicators in the FEW nexus. In particular, we classified the simulation results from eight GCMs in 2020−2099 based on footprints and precipitation through K-means clustering to assess the differences between footprints under various precipitation conditions. The largest number of cases was classified in the cluster characterized by large blue water footprints but small land footprints under low precipitation. These results could help develop the agricultural FEW nexus platform considering the various impacts of climate change and irrigation management.

Abstract While water–energy–food (WEF) nexus is a major livelihood sources for local community, its security issues grow continually and there is limited information on how nexus resource management is effective at delivering livelihoods and food security. These difficulties are related to the lack of local community knowledge of the use and exploitation of water, energy, and food resources; this limited awareness leads to trade‐offs, especially in local and marginalized areas. On the basis of data collected from a local community through a survey‐based approach, this study examines local community perception of nexus resources and their contribution to livelihoods. The results indicate that community perceptions of nexus resources can be understood through social, natural, economic, human, physical, and environmental livelihood indicators. According to our findings, the perception of nexus resources is based on the benefits of individual resources rather than their interlinkages. This could be the result of community perceptions of a particular nexus resource from three nexus sector, that is, food. Food is the center of nexus resources for the community in the study area. This indicates, that there is a missing link between cross‐sectorial resource utilization and management, and full‐scale adoption of the WEF nexus to enhance living conditions. Our findings suggest that there is a low understanding of WEF nexus resource use and management, and the livelihood benefit of individual nexus resources is the primary focus in the studied community. From these results, we recommend more action to be taken by the government and other stakeholders to improve the local community perception of nexus resources for their livelihoods.

A spatial mismatch in water and arable land availability results in large virtual water transfers through interprovincial food trade in China. Accurately identifying and measuring water-saving links in interprovincial food trade can help to relieve water resources pressure in main grain-producing areas. We use a multiregional input-output table combined with the CROPWAT model to build China's interprovincial virtual water transfer network embedded in food trade in 2012. Then, water saving and scarce water saving are measured. Both consider the difference in water productivity among provinces, but the latter also pays attention to the scarcity of water resources. Finally, we adopt a water footprint to recalculate the scarce water savings without precipitation (green water). Our results indicate that the amount of virtual water transfer embedded in food trade is 74.9 billion m³, which is equivalent to 12.22% of the total water use in 2012. We observe large variations in the relationship between water resources abundance and agricultural water-use efficiency across provinces. Especially, there is a virtual water transfer from provinces with high water productivity but a lack of water to provinces with low water productivity but an abundance of water. The scarce water saving can identify sustainable food trade links, which can alleviate water scarcity in consuming provinces without exacerbating water shortage in producing provinces. In addition, interprovincial food trade results in 15 billion m³ of scarce gray water saving, which is equivalent to 59.76% of the scarce blue water saving. Scarce water saving based on blue water and gray water provides a basis for establishing an interprovincial compensation mechanism to balance the cost of water redistribution caused by food trade.

The increase in world population and the resulting demand for food, water, and energy are exerting increasing pressure on soil, water resources, and ecosystems. Identification of approaches to reduce the related cross-sectoral environmental impacts for the water–energy–food nexus is, therefore, crucial. The purpose of the review was to discuss the circular economy approaches devoted to understand the interdependencies among these three sectors. In particular, the review focuses on the importance of the application of life cycle thinking and life cycle assessment for understanding the interconnections in the nexus along the whole supply chains. Moreover, researches related to water and energy use in the agrifood sector are presented, addressing food waste management alternatives in a circular economy perspective.

In the context of China’s rapid and perennial urbanization, it is of profound importance to understand how to enable and accelerate progress towards achieving the country’s sustainable water-energy-food nexus by 2030. In this study, a quantitative spatial scenario analysis was performed to identify the provinces that are expected to experience changes in water stress, under the competition for water between food and energy sectors. The results manifested an imbalance of water availability for meeting the demand between those two sectors. First, food sector played the leading role in the baseline water stress. Second, energy sector dominates the increases of the projected water stress index. Third, urbanization is projected to substantially affect the extent of water availability, especially in the eastern provinces. Tackling imbalanced sectoral water demand is the key to China’s sustainable water-energy-food nexus, which shall require some corresponding changes in national policy-making. China needs, first, policy coherence and synergies, second, ensuring the adequacy of any follow-up procedures, and third, embracing greater participation and transparency in policy-making.

Copyright © The Author(s) 2020.Background: Ultra-processed foods (UPF) have been associated with major diet-related public health issues that share underlying drivers with climate change. Both challenges require major changes to the food system and so the potential benefits to health and the environment present a double motivation for transformation. Our aim is to assess the impacts of UPF on total greenhouse gas emissions (GHGE), water and ecological footprints in Brazil food purchases. Methods: We have used data from 4 Brazilian Household Budget Surveys (1987, 1996, 2003, 2009). Each food item was classified into NOVA food groups (unprocessed/minimally processed, culinary ingredients, processed and ultra-processed). The information was linked to nutrition and footprint data. Purchases were converted into grams per capita per day to estimate total energy (kcal), percentage of energy from UPF, as well as total GHGE, water and ecological footprints. We performed linear regression to calculate year-adjusted means of footprints per 1000 Kcal by year-specific quintiles of UPF participation in the total energy. The data were analysed in R v.3.6.1 and STATA SE 14.1. Results: The mean UPF participation in total energy varied from 13% (SD 2.4) in the 1st UPF quintile to 29% (SD 5.1) in the 5th quintile. The footprints increased linearly across quintiles: the mean g CO2eq varied from 1312 in the 1st to 1721 in the 5th UPF quintile (p-trend<0.001); the mean litres of water varied from 1420 in the 1st to 1830 in the 5th quintile (p-trend<0.001); the mean m2 varied from 9.4 in the 1st to 12.3 in the 5th quintile (p < 0.001). Conclusions: The environmental impacts were higher for Brazilian diets with a larger fraction of energy from UPF. Specifically, low UPF diets seem to have lower GHGE, water and ecological footprints. Our findings offer new motivators for dietary change to simultaneously healthier and more sustainable eating patterns and will be of relevance to consumers and policymakers. Key messages: * Diets high in UPF cause more climate impact than diets with lower levels of UPF. * Healthy and sustainable dietary patterns should be low in ultra-processed foods.