Food security and farming
Naturally occurring climate variability and human-induced climate change are transforming the landscape for agriculture and food production, and threatening water resources in some areas, while expanding the growing season in others. Reliable weather, climate and water information is essential to guide the food and agriculture sector.
For a billion people or more, most of whom live in sub-Saharan Africa and South Asia, hunger accompanied by poverty is a harsh reality. The regions affected are generally densely populated, with low agricultural productivity due to poor fertilization and water resources. Other stresses arise from environmental degradation, pollution, desertification, and competition from expanding urban areas for land, water and labour.
The United Nations Food and Agriculture Organization predicts that world food demand will double by 2050 due to population growth (an estimated 9 billion people) and socio-economic development. Climate change will add pressure to the already stressed food market. The use of sustainable land management practices is an important measure in responding to this challenge.
Agriculture as the foundation of economic growth
For several billion people, agriculture provides a way of life, their livelihood and their only source of nutrition. For some developing countries, agriculture may comprise as much as 50 per cent of the Gross Domestic Product (GDP).
There have been huge strides in agricultural productivity in the past five decades, thanks to improvements in plant breeding, irrigation and fertilizers, coupled with national policy initiatives. For example, the productivity of irrigated land can be three times greater than that of rain-fed land. From 1960–2007, global food production nearly tripled, while per capita availability of food increased from 2300 kcal/day to more than 2800 kcal/day, despite rapid population growth.
A recent study on the potential for agriculture in Africa concluded that, in many African countries, only agriculture has sufficient scale to increase economic growth significantly over the near future. The New Partnership for Africa’s Development (NEPAD) has identified agriculture as a priority sector with a US$ 250 billion programme of investments between 2002–2015.
Feeding agriculture with information
Ask any farmer whether they would like more information on weather, climate and water, and invariably the answer is yes – provided it is understandable and accurate.
Agriculture and food security are among the priorities of the Global Framework for Climate Services, which will increase the availability and relevance of climate information, especially for vulnerable communities like subsistence farmers. The Framework envisages a user-interface platform to link providers of weather and climate information with users in the agricultural community. This will ensure that scientists understand what farmers want and that farmers know how to access and use the information.
The need for the Framework has become more pressing in the face of climate change owing to the effects on agriculture of carbon dioxide enrichment, temperature increases and changes in the amount and the timing of rainfall.
It is likely that arid and semi-arid regions, mainly in continental areas, will experience increased water stress. This will affect food production, markets and food security. Historical climate data and scenarios of future climate, coupled with agricultural data, are already in high demand to identify hotspots and to explore agricultural alternatives. In order to be relevant, this information must be downscaled to meet national and community needs.
The Framework will be especially useful for long-term planning: big decisions such as the purchase of land; the design of irrigation schemes; the adoption of new farming systems; the introduction of more drought-resistant seed; or a move from pastoral farming to higher-value horticulture.
On a larger scale, satellite imagery can be combined with ground-based observations to provide mapped information such as the Normalised Difference Vegetation Index – the index for monitoring vegetation and assessing and forecasting crop yield over regions and countries. Geographic information systems can also incorporate social and economic data to explore issues such as the vulnerability of rural populations to climatic risks.
Weather forecasts and climate predictions
Global numerical weather forecasts, especially useful in anticipating rapidly changing atmospheric conditions, have improved by more than one day per decade. The 7–8-day weather forecasts of today are as reliable as the three-day forecasts of the 1970s. This success is due to scientific and technological progress, such as more powerful computers and increased observing capacities by satellites.
Scientific advances have boosted the availability and reliability of monthly and seasonal climate predictions, especially at a national and regional level. The main signal in seasonal to inter-annual predictions is correlated to the El Niño Southern Oscillation (ENSO) phenomenon – the coupling of sea-surface temperatures and atmospheric conditions - which has a major impact on climate conditions in tropical and sub-tropical parts of the world.
The economic consequences of ENSO are huge. From 1997–1998, the world experienced a severe El Niño event. This was followed by a strong La Niña in 1998-1999, which led to severe economic losses in the United States of America. Some studies put the value of a perfect ENSO forecast at several hundreds of millions of US dollars per year.
It is hoped that seasonal to decadal climate predictions will improve further to take advantage of more advanced knowledge of upper-ocean heat content, soil moisture, snow cover, polar sea ice and other factors.
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