The climate in East Africa is changing, as it is throughout the world. The timing and duration of the rainy seasons have altered, becoming highly unpredictable. Profound climate shocks, such as floods and droughts, are already evident (Cook & Vizy, 2012). Arid and semi-arid regions are predicted to increase over the next century and temperatures will rise (IPCC, 2014). However, the effects of climate change in East Africa are, and will continue to be, highly spatially variable. As a result of this variability, biological communities (biomes) will be altered with widespread range-shifts in animals and plants. The majority of agriculture is rain-fed and climate change has already proved to have a profound effect on farmers’ ability to grow food. Modelling predicts that the number of days suitable for growing food will decline dramatically in some regions, and shifting biomes will make crop yield changes spatially patchy. However, there are a number of practical strategies that farmers can use to build intrinsic resilience within agricultural systems. Resilience is the ability to withstand climate shocks and in the long-term adapt to a changing environment. Resilience-thinking focuses on reducing risks by increasing the adaptive capacity of people and the agriculture ecosystems on which they depend. This will enable farmers to meet current and future food needs whilst coping with uncertainty and change (Adger, 2003). In this report we provide a detailed review of current literature that discusses, and tests, practical ways in which farmers in East Africa can build resilience to climate change into agricultural systems. Greenpeace considers these practices as part of ecological farming and we provide detailed case studies in an accompanying report (Building Environmental Resilience: A Snapshot of Farmers Adapting to Climate Change in Kenya). Taken together, these two reports focus on positive steps that farmers, businesses and policy-makers can take to enhance longterm resilience in the context of climate change. These ecological farming strategies fundamentally build on four key elements within agricultural systems: soil, water, diversity and communities. Healthy soils underpin healthy food, and agricultural yields (Amundsen et al., 2015). African soil is geologically very old, and extremely weathered. Natural tropical ecosystems involve a nutrient cycle that relies on a critical relationship between forest and micro-fungi. When these forests are removed, nutrients leach quickly from the soil, leaving it highly vulnerable to even more leaching and erosion. With the organic content and physical structure of the soils destroyed, the ability for rain to permeate, and water to be retained, declines. Ecological agriculture focuses on returning nutrients to the soils through practices such as agroforestry, intercropping with nitrogen fixing crops, animal manure, and green manure. Minimum tillage ensures that the physical structure of the soil is retained. Soils that are not left bare but are covered, using cover crops or mulching with residues, have protection from erosion and leaching (Garrity et al., 2010). All these soil-focused strategies also serve to increase water penetration and retention, making more water available for crops. Traditional methods of soil conservation, particularly terracing on sloped land, also serve to increase water retention. Crop yields are constrained by the availability of water in East Africa (Lobell and Gourdji, 2012). To build resilience to fluctuations in rainfall, farmers focus on strategies that will harvest water that can be stored in the long-term to cover periods of drought. Macro-catchments include community dams, with localised drip feed irrigation directly to crop plants, with no water wastage. In communities where these projects are not possible, many farmers aim to collect water in smaller-scale micro-catchments that are lined water pans, or tanks. The main limitation in farmers adopting these water catchment strategies is the financial investment it takes to acquire liners that prevent seepage of stored water. Another way of harvesting available water is through certain planting strategies, where crops are planted in pits and mulched so that water evaporation rates are minimised, and plant water uptake is maximised. On-farm diversity assists farmers in spreading risk across time, and space, building redundancy into agricultural systems and leading to long-term resilience (Martin & Magne 2015). Drought resilient crop varieties and livestock breeds increase the likelihood of returns for farmers during unpredictable periods of rainfall. Retaining indigenous practices, and seeds, also serves to provide a mosaic of crops and varieties giving dietary diversity that is locationspecific (Cernansky, 2015). Temporal diversity – by adjusting sowing and planting times – staggers harvests so that if one crop fails, the farmer can rely on food from another. Physical diversity of plants can be used successfully in pest protection in the push-pull system, avoiding the need for costly external inputs. Community learning, and participatory research, builds individual farmer knowledge that can then spread throughout the region. Farmer field schools provide training in ecological farming approaches that are locationspecific, and ensure that communities are working together to ensure the best price for their harvests. Access to global information technology means that farmers, and communities, can directly participate in learning, climate warnings, marketing and advocacy.
This review provides the scientific rationale for the adaptive practices that are being used successfully in the field (Table 1) (examples of which are listed in Thompson et al. (2015)). The way forward must include investment in multiple elements that will improve soil health, water resources, diversity and communities. The adoption of adaptive practices is a transition process for farmers and is more likely to take hold with education and continued support that minimises individual risk. To ensure food and nutritional security in the longterm, it is vital that resilience building be farmerfocused with climate adaptation, and mitigation, that is highly context-specific with constant learning and evaluation to ensure its long-term success.