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Understanding dryland dynamics is essential to predict future climate trajectories. However, there remains large uncertainty on the extent to which drylands are expanding or greening, the drivers of dryland vegetation shifts, the relative importance of different hydrological processes regulating ecosystem functioning, and the role of land-use changes and climate variability in shaping ecosystem productivity. We review recent advances in the study of dryland productivity and ecosystem function and examine major outstanding debates on dryland responses to environmental changes. We highlight often-neglected uncertainties in the observation and prediction of dryland productivity and elucidate the complexity of dryland dynamics. We suggest prioritizing holistic approaches to dryland management, accounting for the increasing climatic and anthropogenic pressures and the associated uncertainties.

The role of water resources in conflict has been the centre of a polarized scientific debate on the connections between environmental and social sustainability. We investigate whether and how water availability, also in relation to water demand, increases the likelihood of violent conflict, and we analyse how hydrological factors influence social conflict dynamics involving non-state armed groups in the Lake Chad Basin. We combine hydrological and biophysical factors with information on socio-political processes. We use a novel physically based agro-hydrological model to produce water-availability and water-demand indicators to explore the conflict potential. By coupling a critical modelling perspective with a novel rendition of hydrological dynamics and statistical tools, we explore water–conflict interconnections in a broader hydrosocial framework. Our results show that, although water scarcity alone does not directly drive violent conflict, complex water-related interdependencies exist on multiple space–time scales. Analytical integration of fine-scale hydrological indicators may help deconstruct both mechanistic and relativist narratives, improve understanding of socio-hydrological complexity and move towards a comprehensive vision of socially and environmentally sustainable use of water and land.

Rising interest in large-scale afforestation and reforestation as a strategy for climate change mitigation has recently motivated research efforts aiming at the identification of areas suitable for the plantation of trees. An often-overlooked aspect of agroforestry projects for carbon sequestration is their impact on water resources. It is often unclear to what extent the establishment of forest vegetation would be limited by water availability, whether it would engender competition with other local water uses or induce water scarcity. Here we use global water models to study the hydrologic constraints and impacts of afforestation in tropical biomes. We find that 36% of total suitable and available afforestation areas are in areas where the rain alone can meet just up to the 40% of total plant water requirement. Planting trees will substantially increase water scarcity and possible dispossession (green water grab) especially in dryland regions of Africa and Oceania. Moreover, the combination of tree restoration and irrigation expansion to rainfed agricultural areas is expected to further exacerbate water scarcity, with about half of the global suitable areas for tree restoration experiencing water scarcity at least 7 months per year. Thus, the unavailability of water can overall limit climate change adaptation strategies. This article is part of the theme issue ‘Ecological complexity and the biosphere: the next 30 years’.

The goal of limiting the use of natural resources and combatting climate change has led to the improvement of agricultural techniques and the development of some Carbon Dioxide Removal (CDR) techniques, given their proficiency to sequester carbon from the atmospheric CO2 and to store it in more stable forms within oceans, plants, soil, or other terrestrial environments. Among them, Enhanced Weathering (EW) is regarded as one of the most promising. This consists of amending soils with silicate minerals, such as olivine, so as to speed up the weathering process that naturally occurs in soils. This work aims to couple a model for the resolution of the agro-hydrological balance in the active soil layer of croplands (i.e., WATNEEDS model) and a dynamic mass balance model that explores ecohydrological, biogeochemical, and olivine dissolution dynamics, also estimating carbon sequestration rates (i.e., EW model). This latter is composed of different interacting components and takes into account important processes, such as the cation exchange.From the operational point of view, the EW model is fed by rainfall data, and the outputs of the soil water balance (i.e., infiltration, evapotranspiration, leaching, and runoff rates) estimated by the WATNEEDS at the global scale at a 5 arcminute resolution. In this study, a regional application of both models is proposed to explore EW efficiency in various cropland areas in Sicily (Italy), the largest island of the Mediterranean basin, which is considered a hot spot of climate change. The methodological approach will be developed and tested for four different crops (i.e., olive and citrus groves, vineyards, and fruit trees) that are particularly widespread and profitable in the selected region. Apart from facing climate change, the goal of this study is also to preserve water, thus selecting the most suitable irrigation strategies in the context of a changing climate and olivine amendment prescription. This study may also provide a tool to decision-makers for an actual future application of EW, which can be valid for Sicily and for other parts of the world with similar climatic conditions, soil, and vegetation.

Animal foods play an important role in human nutrition providing essential micro and macronutrients. In addition, animal-source foods cover 16% of the global food supply, so contribute to global food security. However, livestock consumes about 70% of the global agricultural land and one-third of the freshwater available for agriculture, thus fueling the debate on the competition between the food and the feed sector for the use of increasingly scarce natural resources. Several studies suggest that more efficient management in the food system can reduce competition and increase the global food supply without further pressure on resources. Here we propose a strategy consisting in the replacement of energy-rich food-competing feeds, such as cereals and tubers, with agricultural by-products and residues. Thus, we analyze both the current impact on land and water use for animal-source foods and the natural resources (i.e. land and water) saving associated with the replacement. To this aim, we collected data on regional feed use and the potential replacement of these feeds with actually available by-products and residues. Then, the collected data are combined with countries-specific crop yields and a dynamic spatially distributed and physically based agro-hydrological model to analyze the difference in the land and water use between the current baseline condition and the substitution scenario. Considering the replacement of five major cereals and cassava estimated to range between 11% to 16% of their feed use, the potential amount of fertile land and green water volume that could be saved ranges from 10% to 14%, while from 11% to 17% for the blue water volume. While Eastern Asia and North America would reduce their energy-rich feed crop consumption the most, would be Southern, Eastern, and South-Eastern Asia, and Eastern Europe that would benefit the most from the use of agricultural by-products and residues to save land and green water resources. As far as blue water is concerned, the highest savings are expected to occur in Asia, where cereal production is traditionally irrigated, although linked to unsustainable water withdrawals. Furthermore, the effect of trade on the consumption of natural resources, namely virtual land and water trade, is also explored, with feed crop production relocated through virtual resource flows. While Eastern Europe, Northern America, and South America appear as net land and green water exporters, Eastern and Western Asia and Southern Europe appear as net importers, and Western Europe, instead, as both an importer and exporter region through feed trade. On the other hand, Asia and Northern America appear to be net freshwater exporters. As the demand for livestock products grows over the next half-century, any strategy aimed at curbing the demand for primary commodities and making the food system more resilient has the benefit of reducing environmental impacts on both local and distant areas of the world but also the trade dependency of countries, in a time where global food security is threatened by several factors.

The global production of vegetable oils exceeds 200 million tonnes per year, with almost 40% for food use, and around 330 M hectares occupied by oil crops. The most produced is palm (40% if palm kernel oil is included), followed by soybean oil (28%), rapeseed oil (12%) and sunflower oil (9%). Some of these oil crops, particularly oil palm plantations and soy cultivations, are among the main drivers of global land use changes (LUC) and deforestation. In particular palm oil has been one of the most highly criticized due to the link between oil palm cultivation expansion and the loss of primary tropical forests, observed in recent decades. This issue has generated two different responses in the food sector: some players decided to produce and/or use deforestation-free palm oil. Other actors chosen to replace palm oil with other vegetable oils, such as soybean, rapeseed and sunflower oil.Considering the importance of a proper land management in view of the food-ecosystems-resources nexus, this study assesses the potential LUC and the related GHG emissions that can occur by using sustainable palm oil or replacing it with the other oils for food use. A methodology was developed to assess the potential GHG emissions from the LUC due to alternative oil crops expansion at detrimental of high carbon content areas, such as forests or perennial croplands, and the GHG emissions from the production process though a Life Cycle Assessment (LCA).Under the scenario of 100% replacement of palm and palm kernel oil globally, the extra-land needed to produce the additional alternative oils was determined in their three top producer countries using yield data from literature. An expansion algorithm considering suitability and distance from roads and existing oil crops was developed to determine the potential LUC which may occur in the selected countries. The potential GHG emissions from deforestation and other LUC were calculated from the carbon stock data of the FAO Forest Resource Assessment and IPCC; the field production of the four oils was reconstructed to calculate anthropogenic GHG emissions using relevant LCA existing databases. Results show that deforestation-free palm oil is the less impacting in terms of GHG emissions per oil ton thanks to its far highest oil yield. Replacing sustainable palm oil with any other alternative oil is never a favourable solution (Fig. 1), entailing a potential GHG emissions increase from 0.94-0.96 Mg CO2 per ton of palm oil replaced by sunflower oil produced in Ukraine or in Russia (where deforestation is unlikely), to 4.38 Mg CO2 per ton of palm oil replaced by soybean oil produced in Brazil, up to 13.65 Mg CO2 per ton of palm oil replaced by soybean oil produced in Argentina. Figure 1. GHG emissions in Mg CO2eq t-1 from LCA (blue bars) and LUC (green bars) with 100% palm oil replacement. Based on national trends and forest policies, potential deforestation can be likely (full green), likely with limitation (dense dots), likely with offset (oblique lines), unlikely (scattered dots). Vertical lines for palm oil include deforestation.

The introduction of participatory processes directly and actively involving stakeholders has been steadily gaining importance also in the definition of water management policies. Moreover, for policies to be sustainable, the decision-making process has to keep a multisectorial vision of water management, for instance taking into account the mutual interactions between water, agriculture and energy production, while being careful to move within the limits of the ecosystem. This inclusive approach to the water-energy-food-ecosystem nexus (WEFE Nexus) is the way in which a community of practice made by both technicians and stakeholders can make conscious and sustainable decisions. In this context, the use of hydrological models takes on a key role, not only to describe the current state of resources use, but also to evaluate the impact on resources of different management strategies. However, it is fundamental to properly structure the information pathway from the stakeholders to the model, as well as the return pathway of model results to the stakeholders. On this depends the successful creation of a fruitful and transparent interaction between technicians and stakeholders. An instance of how models can be applied to this context is the use, within the PRIMA NEXUS-NESS project, of the spatially distributed hydrological model WATNEEDS, developed at Politecnico di Milano,. The project aims at co-creating WEFE Nexus management strategies in 4 different case studies, defined as Nexus Ecosystem Labs (NELs) in 4 different countries of the Mediterranean area: Spain, Italy, Tunisia, and Egypt. The 4 NELs are very different from each other in terms of characterizations and problématiques, but they all present major sustainability challenges that can be conceptualized in terms of WEFE Nexus. In the context of NEXUS NESS, WATNEEDS has been enhanced in terms of spatial ductility and range of possible model scenarios, with the aim to describe the current status of water resources in each NEL and to evaluate the management alternatives proposed by the different stakeholders. Among the alternatives the model can analyse, we report changing the crop calendar, implementing new crops or redistributing the existing crops in the territory, changing or modernizing the irrigation systems, and moving towards indoor cultivation techniques. As an example, we report the results relative to some of the interventions proposed by the stakeholders during the first set of project Workshops, held between May and June 2022. The final results will be provided to the stakeholders in November, to illustrate the different impacts that each choice can lead to, not only in terms of water use, but also of WEFE Nexus in general. In this way, using hydrological models in the evaluation of co-created and participatory policy decisions demonstrates its crucial role in the definition of shared and sustainable management strategies.

The search for innovative approaches to agricultural production is fundamental to face the challenge of providing sustainable food production without depleting natural resources for growing population. Therefore, an accurate assessment of the green and blue water needs of cultivated land under different agricultural strategies is essential for systematic water management in agriculture. Among the limits to global food production, water availability, and soil and water salinity play key roles, especially in semi-arid and arid regions. In those areas, a possible solution for a sustainable increase in crop production while preserving natural resources is shifting small vegetable crop productions in a controlled environment, as greenhouses, where temperature, humidity, light, and other factors can be adjusted to meet the plant's needs. Here, we propose a method to estimate the water needed to grow small vegetables under different crop production techniques, from the more traditional approach in the field to innovative soilless cultivation techniques in greenhouses, with a case study in Egypt. To do so, we use the spatially distributed agro-hydrological model WATNEEDS to simulate the plant growth, including the effect of greenhouse production on crop water demand. Moreover, we simulate the possible use of brackish water for irrigation. Results show that by shifting to protected cultivation, the reduction in crop water requirement is 60%,65%, and 30% for tomato, watermelon, and pepper, respectively. This model could be used for irrigation planning and resource management policies. Besides, it can be helpful on multiple scales, from farm to global scale.

Providing healthy food from a sustainable food system, while satisfying the demand of a growing population, is one of the major challenges of the century. The limited agricultural land and water represent the main boundaries to meet the food demand of a growing population (Davis et al., 2014, 2017). Moreover, availability of natural freshwater is expected to furtherly decline in future due to climate change (Rodell et al., 2018) – especially in arid regions – and, thus, there is an urgent need to reshape the agricultural system to sustainably feed a global population approaching 9 billion people in the next century (Godfray et al., 2010).Food security in the Nile Basin is strictly related to the availability of freshwater resources, which are increasingly threatened by climate change and future demographic trends. Currently, food production is insufficient to meet the population food demand, and all Nile countries are currently net food importers. Healthy food is also needed to address malnutrition within the poorest rural communities in the Nile countries. Countries in the Basin are highly affected by undernourishment - linked low dietary energy - iron-deficiency-induced anemia and diabetes. The agricultural sector is the largest consumer of the Nile waters and, thus, the state of the food system has profound implications for attaining water security in the Nile Basin (NBI, 2020).In this study we suggest a sustainable agricultural strategy to enhance sustainable a food system within the Nile River Basin. We couple the WATNEEDS hydro-agrological (Chiarelli et al., 2020) model with a linear optimization algorithm to reshape the current cropland with the aim of producing more healthy food, with several benefits for the ecosystem (e.g., reduced irrigation water consumption) and human health. Cropland redistribution can be coupled with agricultural intensification and diet shift generating, at the meso-scale, benefits in terms of irrigation water savings and increase in food self-sufficiency. We first evaluated the amount of irrigation water and the crop production related to the current crop distribution and second, we identified potential differences in food production and water consumption between the current and optimized crop distributions. We use the WATNEEDS model to quantify spatially distributed crop water requirements, - namely blue and green water requirements - which are the volumes of water needed to compensate crop water losses through evapotranspiration. Our results show that crop redistribution increases food availability and, thus, the percentage of population sustained sustainably with the local agricultural production, reducing the pressure on the currently available renewable freshwater resources of the Nile.

Water availability can be linked to a country's stability, internal security, and the occurrence of violence and governability, in the environmental change context. For instance, lack of access to water resources can trigger political conflicts, be used as a tool for political negotiation or attacks on water infrastructure can be used as a source of intimidation. The potential political risks associated with water availability take particular relevance at the scale of international and transboundary hydrological basins and under conditions of water-food scarcity or political instability. To date, although water risks occurring within the boundaries of the hydrological basin have been studied across several case studies in the literature, the issue of risks arising from water upwind-downwind dependency has been overlooked. For instance, precipitation in a hydrological basin or agricultural centre regions with a high dependency on terrestrial moisture recycling may originate in upwind terrestrial areas outside of the basin boundaries. Here we study geopolitical risk related to this water dependency by analizing terrestrial moisture recycling. Our analysis shows that some hydrological basins in Africa, Asia and South America present a high risk of experiencing geopolitical conflicts when there is a large extension of croplands, high moisture recycling dependency and their precipitationsheds extend over warmongering countries. Hence, our results indicate that addressing transboundary water security from a surface perspective can underlook potential geopolitical conflicts that may threaten regional water-food security and peace. These risks need special international attention to guarantee global peace and agricultural production.

Both natural and social science have been debating the existence, nature, and relevance of the interconnections between water and conflict. The intrinsic complexity of these interconnections makes representing them in a quantitative way a challenging task. Yet, there are actors in intra-state conflicts allegedly taking advantage of environmental stress, often in contexts where resources such as water and land have a primal role in the local population’s livelihoods. In this regard, the environmental aspects of conflicts become of special interest. We investigate these aspects and interconnections for conflict events occurring in the Lake Chad Basin from 2000 to 2015. We use custom-made spatially distributed hydrological simulations to construct and quantify water availability indicators explicitly accounting for human dimensions of water demand and water utilization, focusing in particular on agriculture as a key sustenance mean. Then, spatial econometric regression models are employed to test conflict occurrence against a set of covariates including water scarcity, but also other biophysical and social stress variables, and accounting for space- and time-specific conflict mechanisms through ad-hoc modeling structures. As a complement to this analysis, we develop a methodology to spatially cluster conflicts in association to water scarcity and so identify specific patterns of water availability recurring in specific conflict dynamics. While from the spatial econometric analysis we find that, in line with previous literature, the self-feeding mechanisms of conflict play a stronger role as conflict drivers than water scarcity, from the clustering analysis emerge complex, context-specific interconnections between water availability, water scarcity and conflict, with particular water utilization processes and specific conflictual mechanisms as intermediary processes. More in general, advanced hydrological simulations and statistical analyses are combined with a critical approach to how socio-hydrological processes are described, making quantitative results able to support qualitative insights. This approach can contribute to close the gap between biophysical environmental stress modeling and qualitative social stress representations, so to build more comprehensive knowledge frameworks for complex socio-environmental issues.

Tree restoration plays a key role in curbing climate change by storing carbon. However, the impacts these strategies have on water resources is still unclear. While more and more areas are afforested every year, the extent to which these trees can grab rainwater and displace it from other uses while inducing water scarcity should be further investigated. Here, we examine the hydrological limits to tree restoration in tropics and the impacts of these strategies on water availability locally and downstream. We consider tropical biomes as case study since water is the main limiting factor to plant growth there. First, we use the spatially distributed agro-hydrological model WATNEEDS to evaluate the tree water requirement in suitable and available areas for tree restoration at pixel scale. Available areas for tree restoration are shrub areas not yet occupied by agricultural purposes or urbanization. Then, we compute the hydrological balance for different land use scenarios starting from present conditions (i.e., current land use) to tree restoration with and without yield gap closure (i.e., expansion of irrigation on currently rainfed areas).We find that more than one third of suitable and available areas for tree restoration are in zones at high water stress for the plant, where rain alone can meet just up to the 40% of plant water requirement. Here, tree restoration causes substantial increase in water scarcity conditions, especially in the Horn of Africa and in Oceania. When accounting for both tree restoration and agricultural yield gap closure, water scarcity on these areas is exacerbated. Here, more than half of suitable and available areas for tree restoration will experience water scarcity conditions for at least six months per year.It appears clear how competition for water resources reduces the benefits of tree restoration practices as plant growth is overall constrained by the lack of water.

At the heart of the vision of sustainable development and intergenerational responsibility lies the prudent use of natural resources. Agriculture is a key sector both in terms of resources consumed and of goods and services provided. Recently Its intensification and expansion have been studied and their sustainability evaluated, often with a particular focus on water management. While, in literature, possible agricultural strategies have been based on local water availability and, in some cases, downstream effects of such strategies have been evaluated, a method to identify and quantify hydrologically sustainable land use and crop use changes directly accounting for downstream effects is yet to be defined. Here we propose a framework to assess hydrological sustainability of land use and crop use changes, preventing both in situ and downstream effects. We apply this framework on the case study of coffee plantations expansion in Kenya, a sector that is seeing, and is planned to see, a rapid growth, given its potential in promoting agricultural, economic, and social development, not without risks associated to hydroclimatic change. We simulate the hydrological alterations caused by coffee plantation expansion onto available suitable areas, and use these simulations to identify areas where the expansion does not generate water scarcity either in situ or downstream. The assessment of hydrological suitability proves effective in preventing water availability reduction. Areas selected for expansion present similar total water footprints as currently used areas, but with higher precipitation-generated water availability. The proposed methodology identifies and quantifies areas in a physically robust, and thus transparent, way, also maintaining flexibility to the selected expansion scenario and low data intensity. This makes this framework a potentially easily replicable methodology for planning sustainable agricultural development within planetary boundaries.

Climate change mitigation is becoming increasingly important for curbing severe hydrological events and at the same time for effectively managing natural resources. The nexus among water, energy, food, and ecosystem has recently evolved as a resource-management concept to cope with this interlinked set of resources, their complex interactions and their effect on the natural, innovation and social ecosystems. The transitioning towards the Water-Energy-Food-Ecosystem (WEFE) Nexus for climate change mitigation requires knowledge exchange and co-production among resource managers, policymakers, farmers and other societal-stakeholders, and scientists. For such WEFE-NEXUS transformation and adoption, it is necessary for actors and stakeholders to actively participate in the WEFE-NEXUS transition process and to take co-ownership of the transition. In this respect, the concept of Responsible Research and Innovation (RRI) and its application through the RRI Roadmap is very suitable for facilitating the transition towards WEFE-Nexus. The RRI Roadmap applies an interactive process, where societal stakeholders, scientists andpolicymakers actively engage to share knowledge and to together co-define, co-design and co-construct a WEFE-Nexus Transition vision and plan with solutions and services. This paper will illustrate how the RRI Roadmap has been applied for creating interdisciplinary knowledge co-production collaborations for co-designing and co-agreeing a WEFE-Nexus transition. The paper shows how individual disciplinary perspectives can converge and how these converged perspectives have fed the adaptation of hydrological models to specific conditions. This is part of the work executed in the EU PRIMA-funded project NEXUS-NESS, where the RRI Roadmap has been applied for transitioning towards WEFE-Nexus. The paper exemplifies the preliminary results of activities where social stakeholders together with scientists and policymakers have been actively engaged to co-produce knowledge in four locations: a) Cornia watershed, in coastal Tuscany, Italy; b) Duero watershed, Spain, c) Wadi Jir watershed in Tunisia and d) Wadi Naghamishwatershed, Egypt.

Humanity’s capacity to live without irreversibly compromising the environmental and biophysical conditions on which it depends is at stake. The expanding societal needs for food and energy add an unsustainable pressure on limited amounts of freshwater resources. In this context, the recent global economic and food security crisis, the adoption of new bioenergy policies, trends of water and land commodification, have been described as the drivers of a fast escalation in transnational land investments. A phenomenon described as a new ‘global land rush’. This process is favoring a strong transformation of the rural landscapes in large parts of Latin America, Southeast Asia and Sub-Saharan Africa, with small-scale farming, the most diffused system of production, being displaced by large-scale commercial intensified agriculture. Such land deals may result in the dispossession of traditional users, subsistence and small-holder farmers by large-scale commercial agriculture, as well as expansion of agricultural land at the expense of savannas, forests, or other ecosystems. Here, we bring together the insights from distinct studies conducted on these different dimensions using the (to our knowledge) largest available sample of georeferenced global transnational land deals. We synthesize these studies with the objective to identify and highlight the interconnectedness of the phenomenon and how different interdependencies and trade-offs play out. Using data from the Demographic and Health Survey Program we then investigate the livelihood, health and food security dynamics associated with this phenomenon. We identified the main archetypes such large-scale transitions and defined their temporal trajectories (e.g., before and after the deals). We found that a significant portion of such deals, especially located in Southeast Asia, showed strong simultaneous increases in deforestation, crop cover and probability of export/trade, severely undermining the food security in such areas. Our approach offers a robust methodology to understand the multi-sectoral implications of the global land rush in a systematic, multi-dimensional and integrated way that we believe is helpful to inform policy.

Land grabbing typically leads to social and environmental harms

Shallow landslides (SLs) are rapid soil mass movements, typically occurring in the mountain areas, involving the most superficial soil layers up to 5 to 10 m in depth. Damages, and casualties due to shallow landslides are recorded globally, and in literature a variety of models to study landslides have been implemented hitherto. Often times, shallow landslides occur in the wake of snowfall events, when sudden temperature increase triggers fast snow thaw, and soil moisture increases thereby. Several models studied the influence of intensity, and duration of rainfall upon shallow landslides, but the effect of snow melt in spring/summer was little considered so far. Thus, we developed a simple but robust, and parameter-wise parsimonious model, that mimics the triggering mechanism of SLs, accounting for the combined effect of precipitation duration and intensity, and snowmelt at thaw. The model is here applied to the case study of the high altitude Tartano basin, paradigmatic of SLs in the Alps of Lombardia. Our results showed that about 26 % of the Tartano basin slopes display unstable conditions. Using a traditional (i.e. rainfall-based) approach, the occurrence of shallow landslides was predicted in ca. 19 % of the basin, mainly during storms in October and November. In contrast, when snowmelt was included, the model was able to mimic potential SLs even during April and May, when snow melt rate is the highest, and may increase SLs triggering potential, to ca. 26 % of the treated area. With better spatial and temporal description of slope failure as achieved here, validated against observed failures, a public authority may be prepared to implement emergency plans, to prevent injuries, causalities, and damages to infrastructures even during springtime, when shallow landslides may occur in response to fast snowmelt, even during dry, clear sky days, and with scarce/null precipitation.

The emergence of SARS-like coronaviruses is a multi-stage process from wildlife reservoirs to people. Here we characterize multivariate indicators associated with the risk of zoonotic spillover of SARS-like coronaviruses in different areas to help inform surveillance and mitigation activities. We consider direct and indirect transmission pathways by modeling four scenarios with livestock and mammalian wildlife as potential and known reservoirs, before examining how access to healthcare varies within areas. We found 19 multivariate clusters that had differing risk factor contributions. High-risk areas were mostly close (11-20%) rather than far (TeaserMultivariate clusters of stressors associated with SARS-like coronavirus spillover risk.

Aiming at facing climate change, some CDR (Carbon Dioxide Removal) techniques are currently studied given their capability to sequester carbon from the atmospheric CO2 and to store it within oceans, plants, soil, or other terrestrial environments. Among them, Enhanced Weathering (EW), that acts in speeding up the chemical weathering naturally occurring in soils through the amendments of highly reactive silicate minerals, is referred to as one of the most promising. Hot and humid climates provide the best conditions for EW, since reactions are faster at high temperature, high soil water content and low soil pH. This study presents a dynamic mass balance model that explores ecohydrological, biogeochemical and olivine dissolution dynamics. Through the application of this model, which is composed of different interconnected components, it is possible to explore the role of hydrological processes on olivine dissolution and, therefore, to compute carbon sequestration rates. The model is coupled with a spatially distributed crop specific agro-hydrological model named WATNEEDS, able to solve the soil water balance at the global scale at a 5 arcminute resolution. Input of rainfall data, along with the outputs components of the soil water balance (i.e., infiltration, evapotranspiration, leaching and runoff rates) for each crop, estimated the WATNEEDS are used as input in estimating EW yields at large scale. Here a current application at the regional scale for agriculture, is proposed to explore EW yields in various cropland areas in Italy. The spatial extension of the study area, i.e., the whole Italian territory, allows to explore the EW dynamics under different climate conditions and crop and soil types, defining the importance of such factors in the EW dynamics. This allows to extract olivine dissolution dynamics in places characterized by significant differences in terms of rainfall seasonality, crop phenology, soil type and composition. A future enhancement of this study may be the application of the EW model at the global scale, so as to provide a tool to decision makers for an actual future application of EW.

Foreign investors have acquired approximately 90 million hectares of land for agriculture over the past two decades. The effects of these investments on local food security remain unknown. While additional cropland and intensified agriculture could potentially increase crop production, preferential targeting of prime agricultural land and transitions toward export-bound crops might affect local access to nutritious foods. We test these hypotheses in a global systematic analysis of the food security implications of existing land concessions. We combine agricultural, remote sensing, and household survey data (available in 11 sub-Saharan African countries) with georeferenced information on 160 land acquisitions in 39 countries. We find that the intended changes in cultivated crop types generally imply transitions toward energy-rich, but nutrient-poor, crops that are predominantly destined for export markets. Specific impacts on food production and access vary substantially across regions. Deals likely have little effect on food security in eastern Europe and Latin America, where they predominantly occur within agricultural areas with current export-oriented crops, and where agriculture would have both expanded and intensified regardless of the land deals. This contrasts with Asia and sub-Saharan Africa, where deals are associated with both an expansion and intensification (in Asia) of crop production. Deals in these regions also shift production away from local staples and coincide with a gradually decreasing dietary diversity among the surveyed households in sub-Saharan Africa. Together, these findings point to a paradox, where land deals can simultaneously increase crop production and threaten local food security.

Recently, vast tracts of land have been acquired by foreign and domestic–foreign partnerships to satisfy an increasing demand for agricultural products, often resulting in the conversion of forested landscapes into agricultural fields. Those conversions often occur in areas characterized by high slope angles with the potential to cause mass wasting and shallow landslides. An interesting case‐study is the Licungo basin in Mozambique, where from 2000 nearly 160,000 ha of forest were converted, 17% of which occurred in areas acquired through large‐scale land acquisitions (LSLAs). This study analyses the relationship between deforestation occurring within LSLA areas and the likelihood of landslide occurrence. To this end, we use a spatially distributed physically based model that couples the assessment of slope stability with hillslope‐scale hydrological processes and evaluates the change in slope stability associated with remotely sensed forest loss. Relative to conditions where no human modification of land cover has occurred, we find that LSLAs have the potential to increase the extent of areas susceptible to slope failure by as much as 15,000 ha. We also quantified potential direct and indirect implications of such events for the food supply of local populations, estimating that 4,000 people could lose approximately 700 kcal cap⁻¹ d⁻¹ if all LSLAs are put under production. This study demonstrates the linkages between LSLAs, slope instability, and knock‐on environmental and societal impacts. Governments should therefore take such impacts into account (in addition to those related to habitat destruction and carbon emissions) when issuing permits and concessions within forested lands.

Significance Water’s ability to generate value in irrigated agriculture remains poorly quantified at the global scale. The valuation of irrigation water is an important piece of information not only for agribusiness investors interested in the acquisition of land and water entitlements but also for farmers and rural communities that are negotiating with such investors. To make an informed decision about the acquisition or relinquishment of water rights or about investments in irrigation infrastructure there is a need for a better understanding of the value generated by irrigation water in agriculture using methods that rely on globally available data. This study provides a high-resolution global assessment of irrigation water value as a function of crop type and geographic location., Major environmental functions and human needs critically depend on water. In regions of the world affected by water scarcity economic activities can be constrained by water availability, leading to competition both among sectors and between human uses and environmental needs. While the commodification of water remains a contentious political issue, the valuation of this natural resource is sometime viewed as a strategy to avoid water waste. Likewise, water markets have been invoked as a mechanism to allocate water to economically most efficient uses. The value of water, however, remains difficult to estimate because water markets and market prices exist only in few regions of the world. Despite numerous attempts at estimating the value of water in the absence of markets (i.e., the “shadow price”), a global spatially explicit assessment of the value of water in agriculture is still missing. Here we propose a data-parsimonious biophysical framework to determine the value generated by water in irrigated agriculture and highlight its global spatiotemporal patterns. We find that in much of the world the actual crop distribution does not maximize agricultural water value.

Shallow landslides (SLs) imply downhill movements of soil, rocks, debris. These typically occur on steep terrains, in mountainous, and hilly areas, representing a major risk for people and infrastructures. Properly mapping of shallow landslides in space and time is fundamental for prediction, forecast, and setting up of countermeasures. However, modelling of shallow landslides is complex, given (very) local nature of the phenomenon. Recently investigation started about the role of snow melt in triggering shallow landslides, displaying increasing evidence of catastrophic events at thaw. Little was done hitherto in modelling snow melt triggered SLs, especially in terms of physically based modeling. Under the umbrella of the recent project MHYCONOS, funded by Fondazione CARIPLO of Italy, we developed a robust, and parameter-wise parsimonious model, able to mimic triggering of SLs accounting for the combined effect of precipitation duration and intensity, and snowmelt at thaw. In our model, when temperature is below 0 °C, precipitation is stored as snowpack on the soil surface, and released later in thaw season. Storage of melting water during springtime increases soil moisture, so creating potential for SLs. The model is demonstratively applied to the Tartano river valley, in the Alps of Lombardia region of Italy. In this region mass movements and flash-floods in the wake of intense storms are common. Currently from our model about 26% of the Tartano valley displays (permanent) unstable conditions, more than 40% of it influenced by soil moisture changes. Conversely, by applying a traditional rainfall-based analysis, only 19% of the basin is predicted as potentially unstable, mainly in fall, when intense rainfall occurs. When including snowmelt as a cause of SLS triggering, one finds anticipation of the (modeled) peak of instability to springtime, during April and May. Forcing the model under 6 different climate change scenarios of IPCC at 2050, and 2100, an increase is expected in temperature (i.e. with rapider snow melt), and extreme precipitation events, further aggravating SLs hazard. Mapping zones prone to instability in space and time under present conditions, and future scenarios, will help to prevent casualties, and damages in the short-term, while providing base for structural mitigation measures in the long term, during periods of potential instability, even at low to medium rainfall rates.

Diets are simultaneously connected with population health and environment. The EAT-Lancet Commission proposed a sustainable reference diet to improve population health and respect the planetary boundaries. Recently, the Planetary Health Diet Index (PHDI) has been developed to assess the adherence to this reference diet. In the present study, we aimed to evaluate the adherence to the EAT-Lancet diet through the PHDI in a nationwide population-based study carried out in Brazil. We used data from the National Dietary Survey conducted through the Household Budget Survey in 2017–2018, with 46,164 Brazilians aged over 10 years old. Food consumption was evaluated with a 24 h dietary recall. The average PHDI total score in the Brazilian population was 45.9 points (95% CI 45.6:46.1) on a total score that can range from 0 to 150 points. The adherence to EAT-Lancet diet was low among all Brazilian regions. Women, elderly, those overweighed/obese, with higher per capita income and living in the urban area had higher scores in the PHDI. In general, the Brazilian population presented low adherence to a healthy and sustainable dietary pattern and seems far from meeting the EAT-Lancet recommendations.

Global changes in response to human encroachment into natural habitats and carbon emissions are driving the biodiversity extinction crisis and increasing disease emergence risk. Host distributions are one critical component to identify areas at risk of viral spillover, and bats act as reservoirs of diverse viruses. We developed a reproducible ecological niche modelling pipeline for bat hosts of SARS-like viruses (subgenus Sarbecovirus ), given that several closely related viruses have been discovered and sarbecovirus–host interactions have gained attention since SARS-CoV-2 emergence. We assessed sampling biases and modelled current distributions of bats based on climate and landscape relationships and project future scenarios for host hotspots. The most important predictors of species distributions were temperature seasonality and cave availability. We identified concentrated host hotspots in Myanmar and projected range contractions for most species by 2100. Our projections indicate hotspots will shift east in Southeast Asia in locations greater than 2°C hotter in a fossil-fuelled development future. Hotspot shifts have implications for conservation and public health, as loss of population connectivity can lead to local extinctions, and remaining hotspots may concentrate near human populations.