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Delhi Sustainable Development Summit 2002
Ensuring sustainable livelihoods:

challenges for governments, corporates, and civil society at Rio+10
8 - 11 February 2002, New Delhi

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DSDS 2002: Plenary session 7, 9 February 2002

Food security and basic human needs
GŁnther Fischer
Project Leader, Land Use and Land Cover Project, International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria


In the coming decades of this millennium, the world community of nations will face an enormous challenge concerning food security, environmental conservation, and preservation of genetic resources.

The need for food for an increasing population often threatens natural resources as people strive to get the most out of land already in production or push into virgin territory for new agricultural land. The damage is increasingly evident: arable lands lost to erosion, salinity, desertification, and urban spread; water shortages; disappearing forests; and threats to biodiversity. The situation is likely to be further worsened by the potential impacts of global warming and climate change on growing conditions. Hence, sustainable agricultural development is not just an option, it is an imperative in a world of interdependence, interpenetration, and reciprocity.

Between now and the year 2050, the world’s population will most likely increase by some three billion people. Almost all of this growth will occur in developing countries. Currently, some 800 million people go hungry every day and over a billion live on less than US$1 per day. If no progress is made against hunger, by the year 2050, half the world’s population of some nine billion could be living in conditions of malnutrition and poverty.


Given the complex and interlinked components of the food security challenge in the 21st century, it is clear that solutions that deal with one part only—for example, crop productivity, land use, water conservation, or forest protection—will not be sufficient. The issues are connected and must be dealt with as an interlinked holistic system to ensure sustainable management of natural resources. Each country must assign the highest priority to the assessment of land, water, and climate resources and create an integrated spatial information system to apply the best science, technology, and knowledge for sustainable agricultural development through effective public and private policies.

The Food and Agriculture Organization of the United Nations (FAO), in collaboration with the International Institute for Applied Systems Analysis (IIASA), has developed the Agro-ecological Zones (AEZ) methodology and a worldwide spatial land resources database. AEZ provides a standardized framework for characterizing climate, soil, and terrain conditions relevant to agricultural production, and employs crop modeling and environmental matching procedures to identify crop-specific limitations of the land under different levels of inputs and management conditions.

In essence, the Global AEZ assessment has provided a comprehensive and spatially explicit database of crop production potential and related factors. The results are a valuable source of information and input to various global, regional and national applications. The AEZ computations were completed for a range of climatic conditions, including a reference climate (average of period 1961-1990), individual historical years of 1901 to 1996, and scenarios of future climate based on the outputs of various global climate models, with a global land surface database comprising of more than 2.2 million grid-cells at 5-minutes latitude/longitude.

The results of the Global AEZ assessment include identification of areas with specific climate, soil, and terrain constraints to crop production; estimation of the extent and productivity of rain-fed and irrigated cultivable land and potential for expansion; quantification of cultivation potential of land currently in forest ecosystems; and impacts of climate change on food production, geographical shifts of cultivable land, and implications for food security:

  • More than three-quarters of the global land surface is unsuitable for crop cultivation, suffering severe constraints of being too cold (13%), too dry (27%), or too steep (12%), or having poor soils (40%). Also, multiple constraints occur in some locations.

  • Over 80% of potentially cultivable land reserves are located in just two regions, South America and sub-Saharan Africa. In contrast, most of the cultivable land in Asia is already in use, and the population increase expected by 2050 will reduce per capita availability of cultivable land to below the critical level of 0.1 ha per person.

  • In both the developed and developing worlds, some 1.4 billion ha each constitute forest ecosystems, of which 12% and 30%, respectively, have good potential for crop cultivation. However, cultivation in these forest areas would result in severe environmental consequences.

  • Intensification of agriculture will be the most likely means to meet food needs for a world population of some nine billion people in 2050. The study asserts that enough food can be produced on currently cultivated land if sustainable management and adequate inputs are applied. However, this will require substantial improvements of socioeconomic conditions in many developing countries to enable access to inputs and technology.

  • The projected climate change will result in mixed and geographically varying impacts on crop production. Developed countries substantially gain production potential, while many developing countries lose. In some 40 poor developing countries with a combined current population of 2 billion, including 450 million undernourished people, production losses due to climate change may drastically increase the number of undernourished, severely hindering progress against poverty and food insecurity.


Article 2 of the Framework Convention on Climate Change asserts that impacts on world food supply should be a key area to decide at which point climate change might imply dangerous anthropogenic interference with the climate system. A recent IIASA study examined the effects of climate change on regional agricultural production potential. Climate change data from transient GCM experiments were systematically applied to derive crop production potential using the recently completed spatial databases and methodologies of the Global Agro-ecological Zone Assessment.

Furthermore, a scaled scenario approach was used to characterize trajectories of plausible future climate states and to derive climate impact response functions based on climate change data derived from simulation experiments at the German Climate Research Center of the Max-Planck-Institute for Meteorology.

Results highlight the regional differences in climate impact responses of agriculture. Heterogeneity of climate change impacts, uncertainty of magnitude and geographical detail of impacts and effectiveness of adaptation and mitigation measures, imbalance of adaptive capacity among countries, and disconnection of causes and impacts of climate change are intrinsic characteristics of the greenhouse gas debate. In addition, in a setting based primarily on exploiting comparative advantages, climate change impacts tend to be accentuated by the socioeconomic and trade system.

Integrating climate change mitigation and adaptation policies with sustainable development policies improves prospects of achieving long-term environmental goals and meeting immediate development needs. The world community of nations must fairly and equitably meet the challenge of addressing climate change mitigation policies. This must take into account differences between nations in their past and future emissions, as well as socioeconomic considerations. The timely implementation of economically efficient and environmentally effective international agreements on climate change and national adaptive measures will be critical in the context of achieving societal goals of equity and sustainable development.