Introduction: adaptation, resilience, conservation of resources and prevention

1Under the framework of UNFCCC, the Paris agreement (December 2015), in place of the almost expired Kyoto Protocol, aims to limit the increase of the global temperature to below 2°C. Article 2.1 stresses the need “to strengthen the global response to the threat of climate change, in the context of sustainable development efforts to eradicate poverty”, including actions aimed at “increasing the ability to adapt to adverse impacts of climate change and foster climate resilience and low greenhouse gas emission development, in a manner that does not threaten food production.” The need to pursue mitigation and adaptation in tandem is therefore widely acknowledged.

2Although humankind has always adapted to diverse weather and climate conditions using a wide range of practices (irrigation, water management, crop diversification, etc.), there is an urgent need to take action to consolidate and accelerate adaptation strategies, particularly in agriculture. This need is borne out by the following factors (Howden et al. 2007):

• A 0.1°C increase in world temperature during the past decade,
• More rapid than expected climate change because of increases in greenhouse gas (GHG)
• Lack of agreement for the reduction of GHG emissions.

3Although adaptation has different meanings in ecology, climate policy and evolutionary biology (see Glossary IPPC, 2014), a broad definition would be “an adjustment to actual and expected climate conditions to reduce the risk and vulnerability of ecosystems and society and to seek opportunities to cope with climate change”. Adaptation strategies must be formulated in response to well identified risks and vulnerabilities1. Two main categories of adaptation can be identified:

• Ecosystem-Based Adaptation (EBA) is the use of biodiversity and ecosystem services as part of an overall strategy to help people adapt to the adverse effects of climate change (SCBD, 2009),
• Community-Based Adaptation (CBD) refers to the participatory identification and implementation of community-based development activities that strengthen the capacity of local people to adapt to climate change (see in Archer et al. 2014).

4Africa is the world’s second most populous continent after Asia. Most African regions have faced an increase in extreme temperature (Seneviratne et al. 2012). Toward the end of the century, heat waves and extreme temperatures will increase whereas–except in East Africa–projected heavy precipitation will not increase. Observed and projected data lack sufficient scope.

5Africa as a whole is the most vulnerable continent due to its high exposure and low adaptive capacity. Because of the lack of observations, the detection and attribution of observed climate change in Africa to anthropogenic emissions is not sufficiently clear-cut (Niang et al. 2014). This therefore reduces the effectiveness of any adaptive strategy, although action is urgently needed. Agriculture – the main economic domain in terms of employment – has witnessed stagnant yields relative to the population growth (FAO, 2002). Recent improvements (2000-2010) have not impacted significantly on the overall pattern, since they have been recorded from the lowest productive countries. Reliance on rainfed crop production (98% of the production relied on rainfed crops un SSA), high intra-and inter-seasonal climate variability, recurrent droughts or floods and persistent poverty limit the capacity to adapt. Africa’s food production is therefore at risk. Simulations of main crop yields point to the consistently negative effect of climate change on major cereal crops in Africa. A study by Eid et al. (2007) stressed the high vulnerability of wheat production in North Africa. The temperature increases in West Africa are estimated to counteract the positive impact of rainfall increase (Sultan et al. 2013).

6Climate uncertainties, lack of real-time and future climate projections, and complex interacting barriers at local, national and international levels need to be addressed to build long term and multi-scale adaptive plans for actions. The National Adaptation Plan for Action (NAPA) and the Comprehensive African Agriculture Development Program (CAADP) highlight the political will to enrich economic growth through agriculture. CAADP focuses on four pillars: land and water management, market access, food supply and hunger and agricultural research (NEPAD, 2010). For Africa, reduced crop productivity has been identified as one of nine key regional risks (Niang et al., 2014).

7Research has demonstrated that no single adaptation can meet the needs of all communities in Africa. Moreover, adaptation and mitigation must be integrated in policy. For agriculture, sustainable land management techniques are particularly vital for Africa. This chapter explores the situation with a particular focus on soil functioning. It sets out to present a short review of (i) the general context of land degradation under the framework of UNCCD – the international convention on desertification with a specific focus on Land Degradation Neutrality, and (ii) examples of the main processes responsible for soil degradation (e.g. surface crusting, runoff and water erosion, tillage erosion, wind erosion, and salinization), along with the principles of desertification control and land rehabilitation, in light of the socioeconomic context and ecological conditions and processes. It also focuses on two other key considerations for land restoration: the conservation/increase of soil carbon stocks (see Tunisian example), and the biological restoration of functioning soil through the management of mycorrhizal fungi.