Olli Varis

Lost food, wasted resources: global food supply chain losses and their impacts on freshwater, cropland, and fertiliser use.

Reducing food losses and waste is considered to be one of the most promising measures to improve food security in the coming decades. Food losses also affect our use of resources, such as freshwater, cropland, and fertilisers. In this paper we estimate the global food supply losses due to lost and wasted food crops, and the resources used to produce them. We also quantify the potential food supply and resource savings that could be made by reducing food losses and waste. We used publically available global databases to conduct the study at the country level. We found that around one quarter of the produced food supply (614 kcal/cap/day) is lost within the food supply chain (FSC). The production of these lost and wasted food crops accounts for 24% of total freshwater resources used in food crop production (27 m(3)/cap/yr), 23% of total global cropland area (31 × 10(-3)ha/cap/yr), and 23% of total global fertiliser use (4.3 kg/cap/yr). The per capita use of resources for food losses is largest in North Africa & West-Central Asia (freshwater and cropland) and North America & Oceania (fertilisers). The smallest per capita use of resources for food losses is found in Sub-Saharan Africa (freshwater and fertilisers) and in Industrialised Asia (cropland). Relative to total food production, the smallest food supply and resource losses occur in South & Southeast Asia. If the lowest loss and waste percentages achieved in any region in each step of the FSC could be reached globally, food supply losses could be halved. By doing this, there would be enough food for approximately one billion extra people. Reducing the food losses and waste would thus be an important step towards increased food security, and would also increase the efficiency of resource use in food production.

Is physical water scarcity a new phenomenon? Global assessment of water shortage over the last two millennia

In this letter we analyse the temporal development of physical population-driven water scarcity, i.e. water shortage, over the period 0 AD to 2005 AD. This was done using population data derived from the HYDE dataset, and water resource availability based on the WaterGAP model results for the period 1961‐90. Changes in historical water resources availability were simulated with the STREAM model, forced by climate output data of the ECBilt‐CLIO‐VECODE climate model. The water crowding index, i.e. Falkenmark water stress indicator, was used to identify water shortage in 284 sub-basins. Although our results show a few areas with moderate water shortage (1000‐1700 m 3 /capita/yr) around the year 1800, water shortage began in earnest at around 1900, when 2% of the world population was under chronic water shortage (<1000 m 3 /capita/yr). By 1960, this percentage had risen to 9%. From then on, the number of people under water shortage increased rapidly to the year 2005, by which time 35% of the world population lived in areas with chronic water shortage. In this study, the effects of changes in population on water shortage are roughly four times more important than changes in water availability as a result of long-term climatic change. Global trends in adaptation measures to cope with reduced water resources per capita, such as irrigated area, reservoir storage, groundwater abstraction, and global trade of agricultural products, closely follow the recent increase in global water shortage.

From food insufficiency towards trade dependency: a historical analysis of global food availability

Achieving global food security is one of the major challenges of the coming decades. In order to tackle future food security challenges we must understand the past. This study presents a historical analysis of global food availability, one of the key elements of food security. By calculating national level dietary energy supply and production for nine time steps during 1965–2005 we classify countries based on their food availability, food self-sufficiency and food trade. We also look at how diets have changed during this period with regard to supply of animal based calories. Our results show that food availability has increased substantially both in absolute and relative terms. The percentage of population living in countries with sufficient food supply (>2500 kcal/cap/d) has almost doubled from 33% in 1965 to 61% in 2005. The population living with critically low food supply (<2000 kcal/cap/d) has dropped from 52% to 3%. Largest improvements are seen in the MENA region, Latin America, China and Southeast Asia. Besides, the composition of diets has changed considerably within the study period: the world population living with high supply of animal source food (>15% of dietary energy supply) increased from 33% to over 50%. While food supply has increased globally, food self-sufficiency (domestic production>2500 kcal/cap/d) has not changed remarkably. In the beginning of the study period insufficient domestic production meant insufficient food supply, but in recent years the deficit has been increasingly compensated by rising food imports. This highlights the growing importance of food trade, either for food supply in importing countries or as a source of income for exporters. Our results provide a basis for understanding past global food system dynamics which, in turn, can benefit research on future food security.

How Close Do We Live to Water? A Global Analysis of Population Distance to Freshwater Bodies

Traditionally, people have inhabited places with ready access to fresh water. Today, over 50% of the global population lives in urban areas, and water can be directed via tens of kilometres of pipelines. Still, however, a large part of the worlds population is directly dependent on access to natural freshwater sources. So how are inhabited places related to the location of freshwater bodies today? We present a high-resolution global analysis of how close present-day populations live to surface freshwater. We aim to increase the understanding of the relationship between inhabited places, distance to surface freshwater bodies, and climatic characteristics in different climate zones and administrative regions. Our results show that over 50% of the worlds population lives closer than 3 km to a surface freshwater body, and only 10% of the population lives further than 10 km away. There are, however, remarkable differences between administrative regions and climatic zones. Populations in Australia, Asia, and Europe live closest to water. Although populations in arid zones live furthest away from freshwater bodies in absolute terms, relatively speaking they live closest to water considering the limited number of freshwater bodies in those areas. Population distributions in arid zones show statistically significant relationships with a combination of climatic factors and distance to water, whilst in other zones there is no statistically significant relationship with distance to water. Global studies on development and climate adaptation can benefit from an improved understanding of these relationships between human populations and the distance to fresh water.

Diet change—a solution to reduce water use?

Water and land resources are under increasing pressure in many parts of the globe. Diet change has been suggested as a measure to contribute to adequate food security for the growing population. This paper assesses the impact of diet change on the blue and green water footprints of food consumption. We first compare the water consumption of the current diets with that of a scenario where dietary guidelines are followed. Then, we assess these footprints by applying four scenarios in which we gradually limit the amount of protein from animal products to 50%, 25%, 12.5% and finally 0% of the total protein intake. We find that the current water use at the global scale would be sufficient to secure a recommended diet and worldwide energy intake. Reducing the animal product contribution in the diet would decrease global green water consumption by 6%, 11%, 15% and 21% within the four applied scenarios, while for blue water, the reductions would be 4%, 6%, 9% and 14%. In Latin America, Europe, Central and Eastern Asia and Sub-Saharan Africa, diet change mainly reduces green water use, while in the Middle East region, North America, Australia and Oceania, both blue and green water footprints decrease considerably. At the same time, in South and Southeast Asia, diet change does not result in decreased water use. Our results show that reducing animal products in the human diet offers the potential to save water resources, up to the amount currently required to feed 1.8 billion additional people globally; however, our results show that the adjustments should be considered on a local level.

Water Resources Development in the Lower Senegal River Basin: Conflicting Interests, Environmental Concerns and Policy Options

The Senegal River is the lifeline of the westernmost part of the Sahelian zone in Africa. This zone has extreme problems with high population growth, rapid and uncontrolled urbanization, climate changes, widespread poverty, growing inequity, ethnic confrontations and stagnant economic development. This paper analyses the management system of Lac de Guiers--one of the largest lakes in West Africa--which is among the Senegal Rivers key management entities. A Bayesian network model is used to study the conflicting interests among the various stakeholders, the environmental and social concerns in the region and the viability of a series of policy options for water resources development.

Integrated Water Resources Management along the Senegal River: Introducing an Analytical Framework

Integrated water resources management has become a trendy paradigm, although the issue is anything but new. In West Africa the past few decades have been rich with such attempts. Along the Senegal River their success has been very limited. The situation has instead polarized strongly across the dilemma of whether to prioritize a few macro-scale development goals or to develop the livelihood of the poor along the river. One of the crucial steps to move on is to develop a clear and transparent formulation of the problem. An approach that uses Bayesian networks is presented and applied in this study.

Myanmar under reform: Emerging pressures on water, energy and food security

Myanmars water‐related sectors are subject to intensive changes, as the countrys abundant land and water resources provide substantial scope for development. Recent steps towards economic reform in Myanmar have led to a surge of foreign investment directed towards intensified natural resource extraction. Both the agricultural and the energy sector are increasingly affected by foreign investments that will impact the status of water, energy and food security in the country. With these on‐going developments, Myanmars future is largely dependent on how its natural resources are managed and how the benefits from the resource extraction are shared. With various institutional changes and new actors welcomed to the sectors, existing livelihoods and ecosystems dependent on the land and water resources are to face increasing competition for the shared resources, while lacking secured access to them. There are increasing concerns that this sectoral development is occurring at the expense of environmental and social sustainability. As one way to tackle these challenges, the water‐energy‐food nexus approach could help in finding synergies and co‐benefits across sectors by addressing the imbalances along the nexus and externalities derived from the on‐going intensification.

Over the hills and further away from coast: global geospatial patterns of human and environment over the 20th–21st centuries

Proximity to the coast and elevation are important geographical considerations for human settlement. Little is known, however, about how spatial variation in these factors exactly relates to human settlements and activities, and how this has developed over time. Such knowledge is important for identifying vulnerable regions that are at risk from phenomena such as food shortages and water stress. Human activities are a key driving force in global change, and thus detailed information on population distribution is an important input to any research framework on global change. In this paper we assess the global geospatial patterns of the distribution of human population and related factors, with regard to the altitude above sea level and proximity to the coast. The investigated factors are physical conditions, urbanisation, agricultural practices, economy, and environmental stress. An important novel element in this study, is that we included the temporal evolution in various factors related to human settlements and agricultural practices over the 20th century, and used projections for some of these factors up to the year 2050. We found population pressure in the proximity of the coast to be somewhat greater than was found in other studies. Yet, the distribution of population, urbanisation and wealth are evolving to become more evenly spread across the globe than they were in the past. Therefore, the commonly believed tendency of accumulation of people and wealth along coasts is not supported by our results. At the same time, food production is becoming increasingly decoupled from the trends in population density. Croplands are spreading from highly populated coastal zones towards inland zones. Our results thus indicate that even though people and wealth continue to accumulate in proximity to the coast, population densities and economic productivity are becoming less diverse in relation to elevation and distance from the coast.

The major central asian river basins: An assessment of vulnerability

Central Asias hydrological systems and environment have undergone incomparable changes during recent decades. By using various geospatial and national databases, the socio-economic-environmental vulnerability of the regions major river basins with regard to stress factors related to governance, economy, social issues, environment, hazards, and water scarcity was assessed. A vulnerability profile for each basin was produced and compared with those of the Asia-Pacifics 10 major river basins. Each of the factors appeared quite important for the overall vulnerability. It is thus crucial to focus attention holistically on all the analyzed sectors when trying to solve the challenges in Central Asian waters.