Environmental change

In the literature on environmental change, different terminologies are used for describing the change that has occurred in the environment over the past century or more. This includes „environmental change‟ itself, often used to describe the changed phenomenon in general terms. It also includes „global environmental change‟ often used to emphasize the global nature of the phenomenon and „regional environmental change‟ denoting the

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regional dimensions in the change phenomenon. Although all these terminologies are taken to mean the same thing, the context of usage may vary. For instance, Adger et al.

(2001) observe that the term „global environmental change‟ is contested and problematic in the context of semantics. This is because all forms of environmental change are in some sense global or universal. For instance, „global environmental change‟ as represented by climate change is described as systemic, in that environmental change at any locale can either affect the environment anywhere else or even affect the characteristics of the global environmental system (Turner et al., 1990; kasperski et al., 2001:2). The choice of terminology underlines or frames the way risk and response to environmental change is perceived in public policy. For instance, the use of the terminology „global environmental change‟ underlines perceptions of the transnational nature, or global public-good nature, of „environmental change‟ as justification for exclusively global and market-oriented solutions. This is exemplified by reference to bio-diversity loss, desertification and climate change as „global environmental problems‟

(Adger et al., 2001; in Adger and Brooks, 2003:19). Dolman and Verhagen (2003:3) explain that changes in land use and land cover have contributed substantially to increased concentration of carbon dioxide in the atmosphere, exacerbated shortages of water, substantially changed biogeochemical cycles on the earth, and are causing dramatic losses of biodiversity around the globe. The combined effects of these forces on global climate, biodiversity, water availability and ecosystem are generally denoted as global environmental change. In the international front, the two interrelated problems of depletion of the stratospheric ozone layer and global climate change in particular dominated international attention in the domain of environmental problems since the 1990s. They have underpinned many international environmental agreements (e.g., the Earth Summit 1992, the Kyoto Convention, 1997) and spurred scientific networking and efforts at political-consensus within the scientific community (See Clark et al., 2001;

Kasperson et al., 2001; Adger and Brooks, 2003).

In addition to these are the discussions of two types of global environmental change originally proposed by Turner et al. (1990) and discussed by others (e.g., Kasperson et al., 2001; Adger and Brooks, 2003). This range of global environmental problems as

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represented by a two-way typology of systemic and cumulative change (Table 1.1) come with them hugely different implications for environmental risk and hazard, for which global science and policy-making must deal with (Adger and Brooks, 2003).

Table 1.1: Types of global environmental change

Type Characteristics Example

Systemic Direct impact on globally functioning system

(a) Industrial and land- use emissions of greenhouse gases

(b) Industrial and consumer emissions of ozone-depleting gases

(c) Land-cover changes in albdeo Cumulative Impact through world-wide

distribution of change

(a) Groundwater pollution and depletion (b) Species depletion/genetic alteration

(biodiversity) Impact through magnitude of

change (share of global resources)

(a) Deforestation

(b) Industrial toxic pollutants

(c) Soil depletion on prime agricultural lands

Source: Turner et al, 1990:15; see Kasperson et al., 2001:3; Adger and Brooks, 2003:20 Global environmental change as represented by “systemic risks are those which impact on an environmental system operating at the planetary scale; cumulative global environmental change is that which becomes important because it occurs everywhere”

(Adger and Brooks, 2003:20). In this respect, climate change, stratospheric ozone depletion and biodiversity loss associated with natural ecosystem, groundwater resources and forest cover change as humanly induced perturbations arising from social, economic and political context eclipse systemic global environmental change (Kasperski et al, 2001:2; Adger and Brooks, 2003:20). However, cumulative environmental change may well eclipse „localized‟ systemic changes in both long-term and short-term consequences.

This type of global environmental change refers to the accumulation of regional and localized changes that are distributed throughout the world. Such changes include ecosystem degradation such as coral reefs, groundwater resources, rain forests, soil loss but also the accumulative contamination of air, water and land under the pressures of population increase and economic growth (Kasperski et al., 2001; 2-3). Kasperson and colleagues (2001:3) argue that both types of environmental change pose distinctive challenges to the creation of an adequate knowledge on both drivers and processes of environmental perturbations and the vulnerability of human and ecological systems, and

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in the framing and enhancement of effective societal response capability. Since global environmental change arises from environment and human interactions, social vulnerability to these global environmental risks is a construct of both the physical and social worlds (Adger and Brooks, 2003:21). One important issue pertaining to environmental change is the overwhelming focus on the global scale debates to the relative neglect of local level perturbation processes and efforts at addressing social vulnerability at the local level. Adger and Brooks (2003:21) make this point in their assessment that global environmental change discussions and action are shaped by an

“unshakable belief in the necessity of global-scale action to the exclusion of locally determined sustainable development priorities.” It is against this backdrop that it is relevant for scientific enquiries to focus on environmental change and how communities are responding to these changes for addressing vulnerabilities at the local level. In the ensuing discussions, I shall turn my attention to regional environmental change, focusing on West Africa and the Sahel since this has a more direct bearing on my study. In doing so, I will focus on two broad domains of environmental change: (1) land cover change, desertification and land and soil degradation and; (2) climate change, especially changing rainfall patterns. The physical environment in Sub-Saharan Africa poses many challenges for the arable farmer but the two most serious factors that reinforce each other and adversely affect food production are rainfall and soils (Jones, 1986). This still holds true today. My discussion on environmental change draws on literature in general and research output under the GVP³ in this chapter and in subsequent chapters.

Environmental change is a broader regional phenomenon – evidenced both at the regional and country levels. A historical literature of pessimism about deforestation, erosion,

3The GLOWA Volta Project (GVP) was an inter-disciplinary research project launched in May 2000. Its objective was to support sustainable water resource management in the riparian countries of the Volta Basin, West Africa. It analyzed the physical and socio-economic dominants of the hydrological cycle in the basin in the context of global environmental change. it also developed scientifically sound Decision Support Resources for institutions in the region.

The GVP ended in May 2009 and is now replaced by a new project – “Sustainable Development of Research Capacity based on the GLOWA Volta Project” implementable from June 2009 to November 2010.

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declining soil fertility in Sub-Saharan Africa dates back to the 1920s (Wiggens, 1999).

Sub-Saharan Africa‟s estimated forest cover of 679 million ha in 1980 is said to have been diminishing at about 2.9 % per annum. The rate of deforestation has since been increasing. Studies and documentation under the GLOWA Volta Project (eg., Vlek and Rodgers, 2005; Rodgers et al., 2007) corroborates evidence of land cover conversions, deforestation, and degradation of the natural ecosystem spanning the period 1990 to 2000 in the Volta basin. The findings reveal that the natural vegetation is converted into agricultural land uses and settlements combined with deforestation as facilitated by anthropogenic factors such as firewood harvesting and perennial fire hazards across the Volta Basin⁴ of West Africa. Similarly, Rodgers and colleagues attest to a decrease in tree cover density over the same period as occurring mainly in northern Ghana, and described as a transition from closed woodland to open woodland. In addition, they suggest a decrease in woody stock volumes and vegetation structure, that is, a change from woody to woody scrublands. This conversion is most noticeably occurring in northern Burkina Faso. Furthermore, there is an expansion of agricultural areas, often at the margins of natural wetlands at the expense of woodlands, especially in northern Ghana and southern Burkina Faso (Rodgers et al., 2007: 59). The findings also suggest that degradation of natural vegetation is caused by climate variability or change over decades whiles the degradation of pastureland is widespread and caused primarily by intensive farming systems. The areas worst affected by deforestation include the southern parts of Burkina Faso while in the UER of Ghana, minor land conversions took place (Vlek and Rodgers, 2005: 12). As a result, soil degradation and erosion has affected about half of its farmland while as much as 80 % of its pasture range shows signs of degradation (Wiggens, 1999). While the causes of deforestation, land degradation and poor soil fertility remains a subject of debate, the review so far attributes much of this phenomenon mainly to anthropogenic factors. This incidence of deforestation has also adversely affected regional and local rainfall hydrological systems; and some effects have been prolonged periods of below average rainfall in the Sahel in the 1970‟s and 1980s

4The Volta Basin, a major part of West Africa, covers 400,000 km² of which more than 80% lies in Ghana and Burkina Faso. The other riparian countries are Côte d‟Ivoire, Mali, Benin, and Togo.

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(Cleaver and Screiber,1994). At this point, I will turn my attention to the specific issue of regional climate change.

Climate change as represented by temperature, rainfall changes, runoff, evapotranspiration and soil moisture are the key components of regional climate change that affect food crop production and other livelihoods in West Africa. Issues of climate change in West Africa and the Sahel predates the Sahelian droughts of 1970s but has persisted since then. Rainfall in the region is described as characteristically low and variable, falling erratically and randomly. For most years, rainfall is either abnormally high or continuous to support cropping or drought sets in and crops fail (Foster, 1986).

The distribution rather than the total amount of precipitation affects food production the most (Wilhite and Glantz, 1985; Yaro, 2004), so that in this context dry spells and drought or excessive rainfall occurs at different times of the production season. The

„Sahelian region‟ originating from the southern fringe of the Sahara and stretching from the West African coast to the East African highlands has gained notoriety for dry conditions and drought dating back to the late 1960s. Since the catastrophic drought of the early 1970s during which hundreds of thousands of people and millions of animals died (de Waal 1997; Mortimore 1998), dry conditions have persisted to date with some amelioration coming in the 1990s (Adger and Brooks, 2003:26). In the West African Sub-region, the Volta Basin is described as climatically sensitive so that any small changes in the water balance can have a profound influence on livelihoods extensively dependant on rain fed agriculture. Analysis of historical climatic data from the northern Volta Basin suggests increasing temperature and decreasing rainfall trends (Vlek and Rodgers, 2005:3). In West Africa, choice of crop, sowing dates and resulting yields strongly depend on the temporal and spatial distribution of rainfall, and on the date of onset of the rainy season. A shift in the onset time of rains has been widely reported within the last few decades. Temporal variability of rainfall has made prediction of the onset time of rains crucial to farmers. This is because the successes in prediction directly influence farmers' livelihoods and regional food security. While planting too early may cause crop failure, planting too late may equally lead to crop failure or reduce crop yields (Vlek and Rodgers, 2005:6; Rodgers et al., 2007:46). These observed climatic changes

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are consistent with scenarios of human-induced climate changes as described in modelling studies (eg. IPCC, 1996; Rodgers et al., 2007) and hence, they likely represent manifestations of systemic change driven by emissions of greenhouse gases from twentieth –century industrialization.

Regional environmental change as represented by climate and weather variability, deforestation and land degradation are significant constraining factors in human development (Adger and Brooks, 2003). This is particularly so for the West African sub-region and northern Ghana. Dealing with the challenges of sub-regional environmental change in the search for livelihood sustainability is a major concern in policy debate at the regional level. These debates can draw on some historical experiences in adaptation as a means for dealing with environmental change. For instance, agriculture is a primary sector through which climate plays a role in economic development. In this arena, there is a long history of analysis of the adaptation of human societies to climate change in food production (Lamb, 1995; Adger and Brooks, 2003:23). However, sustainable adaptation rest on the contribution of a paradigm shift for understanding „natural disasters‟ and

„livelihood‟ interactions. This new perspective draws on vulnerability analysis. Some authors distinguish between social vulnerability⁵ on the one hand and biophysical vulnerability⁶ on the other hand. The former is examined later in my discussion in view of its appropriateness for this study.