Climate change is likely to affect all sectors of the economy, but nowhere does it matter so supremely as in agriculture for the developing world.

Climate change and agriculture are interrelated processes, both of which take place on a global scale. Global warming is projected to have significant impacts on conditions affecting agriculture, including temperature, carbon dioxide, glacial run-off, precipitation and the interaction of these elements (Frazer, 2008). These conditions determine the carrying capacity of the biosphere to produce enough food for the human population and domesticated animals. The overall effect of climate change on agriculture will depend on the balance of these effects. Assessment of the effects of global climate changes on agriculture might help to properly anticipate and adapt farming to maximize agricultural production.

Land use change such as deforestation and desertification, together with use of fossil fuels, are the major anthropogenic sources of carbon dioxide; agriculture itself is the major contributor to increasing methane and nitrous oxide concentrations in Earth’s atmosphere (UN report on climate change, 2007).

Despite technological advances, such as improved varieties, genetically modified organisms, and irrigation systems, weather is still a key factor in agricultural productivity, as well as soil properties and natural communities. The effect of climate on agriculture is related to variabilities in local climates rather than in global climate patterns. The Earth’s average surface temperature has increased by 1.5 °F (0.83 °C) since 1880. Consequently, agronomists consider any assessment has to be individually considering each local area.

On the other hand, agricultural trade has grown in recent years, and now provides significant amounts of food, on a national level to major importing countries, as well as comfortable income to exporting ones. The international aspect of trade and security in terms of food implies the need to also consider the effects of climate change on a global scale.

A study published in Science suggests that, due to climate change, “southern Africa could lose more than 30% of its main crop, maize, by 2030. In South Asia losses of many regional staples, such as rice, millet and maize could top 10%” (Lobell, 2008).

In the long run, the climatic change could affect agriculture in several ways:

• Productivity, in terms of quantity and quality of crops
• Agricultural practices, through changes of water use (irrigation) and agricultural inputs such as herbicides, insecticides and fertilizers
• Environmental effects, in particular in relation of frequency and intensity of soil drainage (leading to nitrogen leaching), soil erosion, reduction of crop diversity
• Rural space, through the loss and gain of cultivated lands, land speculation, land renunciation, and hydraulic amenities.
• Adaptation, organisms may become more or less competitive, as well as humans may develop urgency to develop more competitive organisms, such as flood resistant or salt resistant varieties of rice.

Droughts have been occurring more frequently because of global warming and they are expected to become more frequent and intense in Africa, southern Europe, the Middle East, many parts of America, Australia, and Southeast Asia (Dal et el, 2011). Their impacts are aggravated because of increased water demand, population growth, urban expansion, and environmental protection efforts in many areas (Mishra et el, 2011). Droughts result in crop failures and the loss of pasture grazing land for livestock (Ding et el, 2011).

Impact in Africa

In Africa, IPCC (2007:13) projected that climate variability and change would severely compromise agricultural production and access to food. This projection was assigned “high confidence.”

Africa’s geography makes it particularly vulnerable to climate change, and seventy per cent of the population relies on rain-fed agriculture for their livelihoods. Tanzania’s official report on climate change suggests that the areas that usually get two rainfalls in the year will probably get more, and those that get only one rainy season will get far less. The net result is expected to be that 33% less maize—the country’s staple crop—will be grown (Vidal, 2005).

Impact in Asia

In East and Southeast Asia, IPCC (2007:13) projected that in Central and South Asia, projections suggested that yields might decrease by up to 30%, over the same time period. These projections were assigned “medium confidence.” Taken together, the risk of hunger was projected to remain very high in several developing countries.

More detailed analysis of rice yields by the International Rice Research Institute forecasts 20% reduction in yields over the region per degree Celsius of temperature rise. Rice becomes sterile if exposed to temperatures above 35 degrees for more than one hour during flowering and consequently produces no grain.

A 2013 study by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) aimed to find science-based, pro-poor approaches and techniques that would enable Asia’s agricultural systems to cope with climate change, while benefitting poor and vulnerable farmers. The study’s recommendations ranged from improving the use of climate information in local planning and strengthening weather-based agro-advisory services, to stimulating diversification of rural household incomes and providing incentives to farmers to adopt natural resource conservation measures to enhance forest cover, replenish groundwater and use renewable energy (ICRISAT, 2014). A 2014 study found that warming had increased maize yields in the Heilongjiang region of China had increased by between 7 and 17% per decade as a result of rising temperatures (Lobell et el, 2014).

Mitigation and adaptation in developing countries

The Intergovernmental Panel on Climate Change (IPCC, 2007) has reported that agriculture is responsible for over a quarter of total global greenhouse gas emissions. Given that agriculture’s share in global gross domestic product (GDP) is about 4 percent, these figures suggest that agriculture is highly Green House Gas intensive. Innovative agricultural practices and technologies can play a role in climate mitigation and adaptation. This adaptation and mitigation potential is nowhere more pronounced than in developing countries where agricultural productivity remains low; poverty, vulnerability and food insecurity remain high; and the direct effects of climate change are expected to be especially harsh. Creating the necessary agricultural technologies and harnessing them to enable developing countries to adapt their agricultural systems to changing climate will require innovations in policy and institutions as well. In this context, institutions and policies are important at multiple scales.

Travis Lybbert and Daniel Sumner (2010) suggest six policy principles:

1. The best policy and institutional responses will enhance information flows, incentives and flexibility.
2. Policies and institutions that promote economic development and reduce poverty will often improve agricultural adaptation and may also pave the way for more effective climate change mitigation through agriculture.
3. Business as usual among the world’s poor is not adequate.
4. Existing technology options must be made more available and accessible without overlooking complementary capacity and investments.
5. Adaptation and mitigation in agriculture will require local responses, but effective policy responses must also reflect global impacts and inter-linkages.
6. Trade will play a critical role in both mitigation and adaptation, but will itself be shaped importantly by climate change.