The report looks at the ecological and economic impacts on agriculture, and particularly the food systems, of the climate change projections of four general circulation models (GCMs), for a range of socio-economic future development paths It offers an ecological-economic assessment of the impacts of climate change on agriculture across all countries and regions of the world. The study looks at:
climate-change induced environmental constraints to crop agriculture
shifts in potential agricultural land
changes in crop production patterns
changes of cereal production potential.
The report integrates spatial agro-ecological evaluation of all countries, developed and developing, into a world economy and trade policy general equilibrium model framework. The models find that developed countries substantially gain in agricultural production due to climate change, while many developing countries lose. Individual country results are reason for concern.
some 40 least developed countries, with a projected population of some 3 billion in the 2080s, may lose on average 10-20% of their cereal-production potential due to climate change.
the situation in sub-Saharan Africa is of concern. For example, Sudan, Nigeria, Senegal, Mali, Burkina Faso, Somalia, Ethiopia, Zimbabwe, Chad, Sierra Leone, Angola, Mozambique, and Niger lose cereal-production potential for three of the climate models, across all the emission scenarios
In contrast, Zaire, Tanzania, Kenya, Uganda, Madagascar, Côte d’Ivoire, Benin, Togo, Ghana, and Guinea all gain cereal-production potential.
China, the world’s largest cereal producer, gains substantially, up to 25% for three of the GCM climate models and all emission scenarios. For India, the second-largest cereal producer, Brazil, and Thailand, results vary according to climate model. Argentina gains production potential by up to 25% for two of the climate models and loses in the other two climate models. South Africa substantively loses production potential for three climate models and all emission scenarios.
Developing countries lose in the range of 15-45% rain-fed wheat production potential for all scenarios and climate models. The decline is substantial in South Asia (wide range up to 75%), South East Asia (wide range up to 95%) and South America (up to 30%) and wheat virtually disappears in Africa.
Shortfalls in food production, caused by climate change, create market imbalances, which affect international prices and provide incentives for reallocation of capital and human resources, thus mitigating climate change impacts by economic adjustments. For two of the GCMs, international prices for cereals rise between 10- 30%.
Agricultural GDP in the developed world benefits, while developing countries, with the exception of Latin America, are confronted with negative impacts on agricultural GDP. In the 2080s Asia’s GDP declines by 4%, Africa’s by up to 8%, depending on the climate models and the IPCC scenario. In contrast, North America’s agricultural GDP increases up to 13%, the Russian Federation up to 23%.
developing countries will face a growing dependence on net cereal imports, with these growing by 10-40% according to development paths scenario and GCM climate change projections
Most of the discussion on climate change has focused on mitigation measures, for example the Kyoto Protocol. Not much attention has been given to climate-change adaptation, which will be critical for many developing countries. It is critical that developing countries recognize the urgency to put this issue of adaptation to climate change on the global agenda:
For agricultural research to respond in a timely manner, a worldwide concerted policy action is necessary. Networking of researchers, priority setting, allocation of funding, inter-regional and inter-country technology transfer, institutional development and strengthening are among the decisions that need to be made so that agricultural research can contribute toward mitigation and adaptation of agriculture to climate change
National governments and the international aid community must give agriculture and rural sector a high priority in terms of resource allocation and adoption of development polices that are locally relevant and globally consistent, to respond to the threat of future climate change. Only then can progress be made to eradicate hunger and poverty in the world.
Many of the food-insecure and poor developing countries are socially, economically and environmentally vulnerable and climate change may exacerbate the situation, and make it difficult to realize the goals of poverty and hunger eradication. Added to this are other confounding factors such as land degradation, water scarcity, pest and disease epidemics, and, in some cases, political instability, all of which constrain the achieving of sustainable development.
The report raises issues of equity and fairness. Poor developing countries have so far contributed relatively little to the causes of global warming. Yet many of these countries will bear the brunt of climate change through loss of food production. The burden will undoubtedly fall disproportionately on the poorest and most vulnerable.