IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group II: Impacts, Adaptation and Vulnerability

9.6 Case studies

9.6.1 Food insecurity: the role of climate variability, change and other stressors

It has long been recognised that climate variability and change have an impact on food production, (e.g., Mendelsohn et al., 2000a, b; Devereux and Maxwell, 2001; Fischer et al., 2002; Kurukulasuriya and Rosenthal, 2003), although the extent and nature of this impact is as yet uncertain. Broadly speaking, food security is less seen in terms of sufficient global and national agricultural food production, and more in terms of livelihoods that are sufficient to provide enough food for individuals and households (Devereux and Maxwell, 2001; Devereux, 2003; Gregory et al., 2005). The key recognition in this shifting focus is that there are multiple factors, at all scales, that impact on an individual or household’s ability to access sufficient food: these include household income, human health, government policy, conflict, globalisation, market failures, as well as environmental issues (Devereux and Maxwell, 2001; Marsland, 2004; Misselhorn, 2005).

Building on this recognition, three principal components of food security may be identified:

  • i. the availability of food (through the market and through own production);
  • ii. adequate purchasing and/or relational power to acquire or access food;
  • iii. the acquisition of sufficient nutrients from the available food, which is influenced by the ability to digest and absorb nutrients necessary for human health, access to safe drinking water, environmental hygiene and the nutritional content of the food itself (Swaminathan, 2000; Hugon and Nanterre 2003).

Climate variability, such as periods of drought and flood as well as longer-term change, may – either directly or indirectly – profoundly impact on all these three components in shaping food security (Ziervogel et al., 2006; Figure 9.6).

Figure 9.6

Figure 9.6. Linkages identified between climate change in Africa and three major components of food security. Adapted from inputs of (1) Swaminathan, 2000; Fischer et al., 2002; Turpie et al., 2002; Rosegrant and Cline, 2003; Slingo et al., 2005. (2) Fischer et al., 2002; Slingo et al., 2005. (3) Turpie et al., 2002; African Union, 2005. (4) Piot and Pinstrup-Anderson, 2002; Turpie et al., 2002; Mano et al., 2003; USAID, 2003; Gommes et al., 2004; van Lieshout et al., 2004. (5) Adger and Vincent, 2005; Brooks et al., 2005; Gregory et al., 2005; Thomas and Twyman, 2005; O’Brien, 2006. (6) Slingo et al., 2005. (7) Swaminathan, 2000; Schulze et al., 2001; Gommes et al., 2004.

The potential impacts of climate change on food access in Figure 9.6 may, for example, be better understood in the light of changes in Africa’s livelihoods landscape. A trajectory of diversification out of agricultural-based activities – ‘deagrarianisation’ – has been found in the livelihoods of rural people in many parts of sub-Saharan Africa. Less reliance on food production as a primary source of people’s food security runs counter to the assumption that people’s food security in Africa derives solely (or even primarily) from their own agricultural production (Bryceson, 2000, 2004; Bryceson and Fonseca, 2006). At the same time, however, for the continent as a whole, the agriculture sector, which is highly dependent on precipitation, is estimated to account for approximately 60% of total employment, indicating its crucial role in livelihoods and food security derived through food access through purchase (Slingo et al., 2005).

There are a number of other illustrative impacts that climate variability and change have on livelihoods and food access, many of which also impact on food availability and nutrient access aspects of food security. These include impacts on the tourism sector (e.g., Hamilton et al., 2005), and on market access, which both affect the ability of farmers to obtain agricultural inputs, sell surplus crops, and purchase alternative foods. These impacts affect food security through altering or restraining livelihood strategies, while also affecting the variety of foods available and nutritional intake (Kelly et al., 2003). Market access is influenced not only by broader socio-economic and political factors, but also by distance from markets and the condition of the infrastructure, such as roads, which can be damaged during climate events (e.g., Abdulai and Crolerees, 2001; Ellis, 2003).

The key issues, therefore, in relation to the potential impacts of climate variability and change on food security in Africa encompass not only a narrow understanding of such impacts on food production but also a wider understanding of how such changes and impacts might interact with other environmental, social, economic and political factors that determine the vulnerability of households, communities and countries, as well as their capacity to adapt (Swaminathan, 2000; Adger and Vincent, 2005; Brooks et al., 2005). The impact of climate variability and change on food security therefore cannot be considered independently of the broader issue of human security (O’Brien, 2006). The inclusion of climate variability and change in understanding human vulnerability and adaptation is being increasingly explored at household and community levels, as well as though regional agro-climatological studies in Africa (e.g., Verhagen et al., 2001).

A number of studies have been undertaken that show that resource-poor farmers and communities use a variety of coping and adaptive mechanisms to ensure food security and sustainable livelihoods in the face of climate change and variability (see also Table 9.2). Adaptive capacity and choices, however, are based on a variety of complex causal mechanisms. Crop choices, for example, are not based purely on resistance to drought or disease but on factors such as cultural preferences, palatability, and seed storage capacity (Scoones et al., 2005). Research elsewhere in the world also indicates that elements of social capital (such as associations, networks and levels of trust) are important determinants of social resilience and responses to climate change, but how these develop and are used in mitigating vulnerability remains unclear.

While exploring the local-level dynamics of people’s vulnerability to climate change, of which adaptive capacity is a key component, it is important to find ways to embed such findings into wider scales of assessment (e.g., country and regional scales) (Brooks et al., 2005). A number of recent studies are beginning to probe the enormous challenges of developing scenarios of adaptive capacity at multiple scales. From these studies, a complex range of factors, including behavioural economics (Grothmann and Patt, 2005), national aspirations and socio-political goals (Haddad, 2005), governance, civil and political rights and literacy, economic well-being and stability, demographic structure, global interconnectivity, institutional stability and well-being, and natural resource dependence (Adger and Vincent, 2005), are all emerging as powerful determinants of vulnerability and the capacity to adapt to climate change. Such determinants permeate through food ‘systems’ to impact on food security at various levels. Attainment of the Millennium Development Goals, particularly the first goal of eradicating extreme poverty and hunger, in the face of climate change will therefore require science that specifically considers food insecurity as an integral element of human vulnerability within the context of complex social, economic, political and biophysical systems, and that is able to offer usable findings for decision-makers at all scales.