Agriculture and climate change: FAO's role

As world leaders meet in Kyoto to hammer out legally binding targets for reducing greenhouse gas emissions, we take a look at the known and future possible effects of long-term climate change on world agriculture.

The Kyoto conference venue with the conference logo

People's ability to grow enough to feed themselves and their animals is determined to a large extent by the weather - by temperature, light and water. Short or long-term fluctuations in weather patterns - climate variability and climate change - can have extreme impacts on agricultural production, slashing crop yields and forcing farmers to adopt new agricultural practices in response to altered conditions. Climate, therefore, has a direct impact on food security. For this reason, FAO is concerned with the issues of global warming and climate change and variability.

Climate change could hit agriculture in many ways
Climate change over the long-term, in particular global warming, could affect agriculture in a number of ways - the majority of which would threaten food security for the world's most vulnerable people:

  • The overall predictability of weather and climate would decrease, making planning of farm operations more difficult.
  • Climate variability might increase, putting additional stress on fragile farming systems.
  • Climate extremes - which are almost impossible to plan for - might become more frequent.
  • The sea-level would rise, threatening valuable coastal agricultural land, particularly in low-lying small islands.
  • Biological diversity would be reduced in some of the world's most fragile environments, such as mangroves and tropical forests.
  • Climatic and agro-ecological zones would shift, forcing farmers to adapt, as well as threatening natural vegetation and fauna.
  • The current imbalance of food production between cool and temperate regions and tropical and subtropical regions could worsen.
  • Distribution and quantities of fish and seafoods could change dramatically, wreaking havoc in established national fishery activities.
  • Pests and vector-borne diseases would spread into areas where they were previously unknown.

Global warming might also have some positive effects for farmers. Increases in carbon dioxide have a fertilizing effect for many crops, increasing growth rates and water use efficiency. But experts point out that the many question marks that remain over this scenario outweigh the possible benefits.

Climate variability is farmers' greatest challenge today
The natural variability of rainfall, temperature and other conditions is the main factor behind variability in agricultural production, which in turn is one of the main factors behind food insecurity. Some areas of the world are particularly prone to such variability - the Sahel, northeast Brazil, central Asia, and Mexico, for instance.

Climate extremes - violent and unusual events such as floods, drought, and storms - though by nature more apparently dramatic, have less overall effect on agricultural production than chronic climate deficiencies. Both climate variability and climate extremes may increase as a result of global warming.

FAO works on two levels to reduce the impact of climate variability and climate change on food security. The Organization aims to increase farmers' ability to cope with variability:

  • encouraging a "no-regrets" approach to agricultural development - options that increase agricultural efficiency and flexibility under current conditions, and that will also stand farmers in good stead should conditions shift over the long term.

Promoting farming practices that withstand climate variability - the use of drought-resistant crop varieties, for instance, or more efficient use of water resources - also builds up farmers' capacity to adapt to long-term change.

FAO also works with national decision-makers and the scientific community to improve monitoring of both current conditions and long-term climate change, and to encourage foresighted development choices:

But agriculture is not only a victim of global warming. At present, it is also a contributory factor, and in the future, it could make a major contribution to reduction of global climate change. Some 25 percent of carbon dioxide emissions come from land use change (mainly deforestation in the tropics), and fertilizer use is one of the main humanmade sources of nitrous oxides. As part of the "no-regrets" approach, FAO encourages farmers to reduce excessive use of nitrogenous fertilizers - which is costly, inefficient and harmful to the environment - and to choose livestock breeds that are efficient converters of feed into meat and milk, thus reducing methane emissions.

The Organization works with planners to reduce rates of deforestation and promote reforestation, as one of the ways to remove carbon dioxide from the atmosphere. FAO also advocates the use of biomass energy (SD Dimensions Energy for Development) as a means of reducing fossil fuel consumption - the main source of carbon dioxide emissions. Using biofuels instead of fossil fuels is a way of "closing the carbon cycle" so that carbon dioxide absorbed by plants is released back into the atmosphere when they are used as fuel, but the carbon stored in fossil fuels is not added to that already in circulation (interview with FAO's Gustavo Best).

5December 1997

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©FAO, 1997