Climate change affects everyone. But the worst hit will be hundreds of millions of small-scale farmers, fishers and forest-dependent people who are already vulnerable and food insecure. By affecting the availability of land, water and biodiversity, and the price of food, the rising demand for biofuels produced from food crops also has an impact on the poor.
Climate change will affect the suitability of land for different types of crops, livestock, fish and pasture. It will also have an impact on the health and productivity of forests, the incidence of pests and diseases, biodiversity and ecosystems. Changes in temperatures and precipitation as well as more frequent extreme weather are expected to result in crop and livestock production shortfalls and other asset losses, thereby threatening food production and also access, stability and utilization of food resources.
LAND: Climate change threatens to uproot many rural communities. Rising sea levels may force many communities in low-lying coastal areas and river deltas to move to higher ground. Similarly, increasingly frequent droughts brought on by climate change may leave farmers and pastoralists who rely on rainfall to raise their crops and livestock in conflict over land and water. This displacement of people is likely to result in competition between migrants and established communities for access to land. Reconciling diverse land use needs presents daunting challenges for governments at all levels. In cases where land rights are informal and different customary land tenure systems coexist, governments will need to work closely with local communities to establish fair and equitable systems of land tenure and develop mechanisms for resolving disputes. For many displaced communities, it may be impossible to maintain their farming and pastoral traditions. Land tenure policies designed to facilitate resettlement will need to be incorporated into a broader program that provides opportunities for the displaced to earn livelihoods outside the agricultural sector.
WATER: As a consequence of climate change, farmers will face growing unpredictability and variability in water supplies and increasing frequency of droughts and floods. Hardest hit will be rain fed agriculture – which covers 96% of all cultivated land in sub-Saharan Africa, 87% in South America and 61% in Asia. In marginal semi-arid zones with prolonged dry seasons, the risk of crop failures will increase. Where stability of production cannot be assured, people will be forced to migrate.
Irrigation in large river basins and deltas are also at risk from a combination of reduced runoff, salinity (Indus), increased flooding, sea level rise (Nile, Ganges-Brahmaputra, Mekong, Yangtse), and urban and industrial pollution. These stresses on some of the prime productive land will reduce the agricultural output, biodiversity and the natural ability of ecosystems to recover – with possible negative impacts on millions of farmers and consumers across the world as food supply becomes progressively constrained. Areas projected to experience lower precipitation will need to improve water storage, management and productivity. Large irrigation schemes will need to adapt to changes in water supply regimes and support will be needed for small-scale, field-based water control measures.
BIODIVERSITY: The 2005 Millennium Ecosystem Assessment estimates that by the end of this century, climate change will be the main cause of biodiversity loss. But as climate changes, the value of biodiversity for food and agriculture will increase. Genetic resources are the living material that local communities, researchers and breeders use to adapt food and agricultural production to changing needs. Maintaining and using this reservoir of genetic diversity will be the foundation for coping with climate change. Many researchers advise caution in the use of genetically modified resources.
TRANSBOUNDARY PESTS AND DISEASES: While there is clear evidence that climate change is altering the distribution of animal and plant pests and diseases, the full effects are difficult to predict. Changes in temperature, moisture and atmospheric gases can fuel growth and generation rates of plants, fungi and insects, altering the interactions between pests, their natural enemies and their hosts. Changes in land cover, such as deforestation or desertification, can make remaining plants and animals increasingly vulnerable to pests and diseases. New farming practices, different crops and animal breeds, and integrated pest management principles must be developed to help stem the spread of pests. Countries may need to consider the introduction of biological control agents or new pests or disease-resistant crops and breeds. Governments also need to strengthen national animal and plant health services as a priority.
FISHERIES AND AQUACULTURE: Impacts of climate change will affect fisheries and aquaculture-dependent people as production and marketing costs increase, buying power and exports decrease and dangers from harsher weather conditions rise. Small fishing communities in some areas will face greater uncertainty as availability, access, stability and use of aquatic food and supplies diminish and as work opportunities dwindle. Now accounting for 45% of global seafood consumption, aquaculture production will continue rising to meet future demand. Climate change offers new opportunities. Production in warmer regions will likely increase because of better growth rates, a long growing season and the availability of new fish farming areas where it was once too cold. Therefore, aquaculture development opportunities will increase in particular in tropical and sub-tropical regions, such as in Africa and Latin American.
MANAGING THE RISK: Much can be done now and in the next decades to lessen the worst effects of global warming. These include:
1) developing climate and climate impact models that give a better understanding of how climate change may affect farming and forestry at a local level;
2) diversifying livelihoods and adapting agricultural, fishing and forestry practices by encouraging better water management, soil conservation, resilient crops and trees;
3) improving and expanding weather and climate forecasting;
4) improving monitoring and early warning systems;
5) developing disaster risk management.
To better adapt to climate change impacts:
1) land use plans, food security programs, fisheries and forestry policies must all be adjusted;
2) cost/benefit analyses are needed to take account of climate change risks for irrigation or coastal protection;
3) farmers’ best practices should be promoted through capacity building and networking;
4) contingency plans need to cover new and evolving risk scenarios.