世界経済・社会統計 = World development indicators

Continuing population and consumption growth will mean that the global demand for food will increase for at least another 40 years. Growing competition for land, water, and energy, in addition to the overexploitation of fisheries, will affect our ability to produce food, as will the urgent requirement to reduce the impact of the food system on the environment. The effects of climate change are a further threat. But the world can produce more food and can ensure that it is used more efficiently and equitably. A multifaceted and linked global strategy is needed to ensure sustainable and equitable food security, different components of which are explored here.

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Food Security: The Challenge of Feeding 9 Billion People

This chapter discusses leading problems linked to energy that the world is now confronting and to propose some ideas concerning possible solutions. Oil deserves special attention among all energy sources. Since the beginning of 1981, it has merely been continuing and enhancing the downward movement in consumption and prices caused by excessive rises, especially for light crudes such as those from Africa, and the slowing down of worldwide economic growth. Densely-populated oil-producing countries need to produce to live, to pay for their food and their equipment. If the economic growth of the industrialized countries were to be 4%, even if investment in the rational use of energy were pushed to the limit and the development of nonpetroleum energy sources were also pursued actively, it would be extremely difficult to prevent a sharp rise in prices. It is evident that it is absolutely necessary to pursue actively the development of coal, natural gas, and nuclear power if a physical shortage of energy is not to block economic growth.

World energy outlook

Ecosystem management that attempts to maximize the production of one ecosystem service often results in substantial declines in the provision of other ecosystem services. For this reason, recent studies have called for increased attention to development of a theoretical understanding behind the relationships among ecosystem services. Here, we review the literature on ecosystem services and propose a typology of relationships between ecosystem services based on the role of drivers and the interactions between services. We use this typology to develop three propositions to help drive ecological science towards a better understanding of the relationships among multiple ecosystem services. Research which aims to understand the relationships among multiple ecosystem services and the mechanisms behind these relationships will improve our ability to sustainably manage landscapes to provide multiple ecosystem services.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1461-0248.2009.01387.x

Understanding relationships among multiple ecosystem services.

Agricultural ecosystems provide humans with food, forage, bioenergy and pharmaceuticals and are essential to human wellbeing. These systems rely on ecosystem services provided by natural ecosystems, including pollination, biological pest control, maintenance of soil structure and fertility, nutrient cycling and hydrological services. Preliminary assessments indicate that the value of these ecosystem services to agriculture is enormous and often underappreciated. Agroecosystems also produce a variety of ecosystem services, such as regulation of soil and water quality, carbon sequestration, support for biodiversity and cultural services. Depending on management practices, agriculture can also be the source of numerous disservices, including loss of wildlife habitat, nutrient runoff, sedimentation of waterways, greenhouse gas emissions, and pesticide poisoning of humans and non-target species. The tradeoffs that may occur between provisioning services and other ecosystem services and disservices should be evaluated in terms of spatial scale, temporal scale and reversibility. As more effective methods for valuing ecosystem services become available, the potential for ‘win–win’ scenarios increases. Under all scenarios, appropriate agricultural management practices are critical to realizing the benefits of ecosystem services and reducing disservices from agricultural activities.

https://royalsocietypublishing.org/doi/pdf/10.1098/rstb.2010.0143

Ecosystem services and agriculture: tradeoffs and synergies.

Agricultural soils in the tropics have undergone significant declines in their native carbon stock through the long-term use of extractive farming practices. However, these soils have significant capacity to sequester CO2 through the implementation of improved land management practices. This paper reviews the published and grey literature related to the influence of improved land management practices on soil carbon stock in the tropics. The review suggests that the implementation of improved land management practices such as crop rotation, no-till, cover crops, mulches, compost, or manure can be effective in enhancing soil organic carbon pool and agricultural productivity in the tropics. The benefits of such amendments were, however, often short-lived, and the added organic matters were usually mineralized to CO2 within a few cropping seasons leading to large-scale leakage. We found that management of black carbon (C), increasingly referred to as biochar, may overcome some of those limitations and provide an additional soil management option. Under present circumstances, recommended crop and land management practices are inappropriate for the vast majority of resource constrained smallholder farmers and farming systems. We argue that expanding the use of biochar in agricultural lands would be important for sequestering atmospheric CO2 and mitigating climate change, while implementing the recommended crop and land management practices in selected areas where the smallholder farmers are not resource constrained.

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The Role of Biochar in Ameliorating Disturbed Soils and Sequestering Soil Carbon in Tropical Agricultural Production Systems

The Indochinese section of the Mekong Basin has been subjected to major environmental disturbances over the last half century. The Vietnam War is invoked as a central explanation for the extensive deforestation in specific areas while conflictinduced exoduses caused the abandonment of cultivated lands, followed by forest regeneration. Although the socio-economical consequences of these episodes have been analysed, their hydrological impacts remain unknown. This paper investigates hydrological changes in two catchments of the lower Mekong Basin that were either heavily bombed (in southern Laos) or depopulated (in northern Laos). This analysis is based on the widely and independently recognized fact that vegetation, via evapotranspiration, is a central driver of basin water yield. The analysis of the most complete Vietnam War air mission database and of available hydro-meteorological data over the period 1960–2004 reveals a sharp runoff increase in the southern catchment when bombing climaxed in the early 1970s while no hydrological change is observed in the northern catchment over the same period. From 1995 onwards, the northern and southern catchment's runoff productions are significantly lower and higher than in the pre-war conditions, respectively. Although causalities could not be ascertained because of data limitations, these short- and long-term hydrological shifts were found to be consistent, in terms of occurrence, spatial distribution and magnitude, with the expected changes in the vegetation cover, either denser in the north (in response to abandonment of cultivated lands) or sparser in the south (as a result of bomb-induced deforestation and soil degradations).

Conflict, migration and land-cover changes in Indochina: A hydrological assessment

Soil acidification and carbon storage in fertilized pastures of Northeast Thailand

Rethinking agriculture in the Greater Mekong Subregion: how to sustainably meet food needs, enhance ecosystem services and cope with climate change

In Ethiopia, exclosures in landscapes have become increasingly important to improving ecosystem services and reversing biodiversity losses. The present study was conducted in Gomit watershed, north...

Andrew Noble

Papers

The Role of Biochar in Ameliorating Disturbed Soils and Sequestering Soil Carbon in Tropical Agricultural Production Systems

Conflict, migration and land-cover changes in Indochina: A hydrological assessment

Soil acidification and carbon storage in fertilized pastures of Northeast Thailand

Rethinking agriculture in the Greater Mekong Subregion: how to sustainably meet food needs, enhance ecosystem services and cope with climate change

Restoring aboveground carbon and biodiversity: a case study from the Nile basin, Ethiopia