ment, land slope, inadequate land grading and hydraulic structures. Rational use of water will not be practiced in the short to medium term, so water-use efficiency will deteriorate. A different technology mix will be required to optimize the efficiency, which will be possible by developing AKST (Penning de Vries et al., 2003; IWMI, 2006).

3.3.1.5 Climate change

Climate change in the past century has already had a measurable effect on ecosystems. The earth?s climate system has changed since the pre-industrial era, in part because of human activity, and it is projected to continue to change throughout the twenty-first century.

The many challenges global climate change poses, from increased temperatures and extreme weather events to rises in sea level, are now widely recognized in both scientific and policy circles (Smit, 1993; McCarthy et al., 2001). The global mean surface air temperature is projected to increase from 1990 to 2100 by 1.4-6.4?C, accompanied by more heat waves (IPCC, 2007). Precipitation patterns are projected to change, with most arid and semiarid areas becoming drier but with an increase in heavy precipitation events, leading to increased incidence of floods and droughts. The Millennium Ecosystem Assessment scenarios project a sea level rise of 9-88 cm.

In this respect, the fourth report of the Intergovernmental Panel on Climate Change (IPCC) estimates that a global temperature rise during the century of between 2oC and 4.5oC is almost inevitable. Ominously, however, it also says that much higher increases, of 6oC or more, cannot be ruled out. IPCC?s latest report makes it clear that climate change may be far worse than previously thought because of potentially disastrous positive feedbacks, which could accelerate rising temperatures (IPCC, 2007).

Furthermore, a recent report from Britain?s Sir Nicholas Stern warned of the devastating economic effect global warming could have on the world in coming years (Stern, 2007). Stern, former chief economist at the World Bank, cautioned that if greenhouse gas emissions were not significantly reduced, by 2050 the global economy would shrink by up to 20%, millions of people would be permanently displaced and droughts would plague the earth.

So far, the main response both nationally and internationally has been to focus on initiatives aimed at reducing the potential size of these effects. Most industrial countries have sought to do this by committing themselves through signing the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol, to stabilize or reduce greenhouse gas emissions and enhance carbon sinks (Klaey, 2000; Baumert et al., 2005).

Climate change will potentially lead to such eventualities as drought and famine, which some of the CWANA countries have already experienced. The capacity of national governments and communities to mitigate disasters will be limited in the short to medium term, rendering them still vulnerable to the adversities of climate change. Climate change is a global issue with regional implications. Many multilateral environmental agreements address these issues, and some countries of the region have ratified some such agreements (WCED, 1987; UNEP, 2002).

Too much or too little rain can be a matter of life or death in some countries in the CWANA region (UNEP,

2002; WRI, 2005). At different times and in different places across the region, climate change poses the threat of both. Prolonged and severe climatic desiccation, coupled with intensive exploitation of soil, pasture, forest and other natural resources, as well as the huge increase in human and livestock populations will lead to extensive degradation and result in an inherently fragile environment in some parts of the region to the extent that conflicts caused or catalyzed by these compounding ecological factors are bound to take place (De Wall, 1989).

In fact, ecological degradation, caused mainly by climate change, has been so severe that traditional means for preventing and managing interethnic disputes have been rendered virtually unworkable. Indeed, many of the current disputes are being fought not along traditional political borders but along ecological borders that divide richer and poorer ecozones (Bachler and Spillmann, 1992).

To continue to treat the conflict in Darfur and many other parts of Africa as purely ethnic, tribal, political or religious and to ignore the growing impact of ecological degradation and depletion of the resource base will ultimately lead to a distorted understanding of the real situation. This will consequently limit the possibility for genuine conflict resolution (El-Nour, 1992; Suliman, 1993, 1996, 2000). Therefore, a new model of development is called for, in which strategies to increase human resilience in the face of climate change and the stability of ecosystems are central. Above all, the challenge calls for new flexibility and not a one-size-fits-all approach to development (De Wall, 1989; Suliman, 2000).

The aforementioned issues and other environmental factors precipitating climate change, like industrial pollution, can only be addressed through efficient technologies. Yet the available technology mix (AKST) can have both positive and negative effects on the climate, and at times may not be efficient or environmentally friendly. National governments will remain complacent with what already exists, at least in the short term. But this will compromise their attaining their environmental health agenda in that time frame.

Regionally, countries sharing borders or that are members of regional cooperation or custom unions could address cross-border environmental issues. The coping strategies proposed could at times be costly, and countries of the region might not be able to handle the issues on their own. At present, as issues of environmental goods and services are being negotiated in WTO, national governments and communities may not be able to engage in them proactively. Finally, considering the current weak AKST infrastructure and scarcity of human resources, countries will not be able to give the support needed to mitigate climate change.

In the absence of effective mitigation efforts, climate changes will potentially lead to major crises, which will encourage stronger alliances between selected countries to attempt to reduce the incidence and damage of further natural disasters. Development of AKST will counteract the adverse fallouts on the region (R?ing and Engel, 1991; Pardey and Beintema, 2001; Pingali and Traxler, 2002; Byerlee and Alex, 2003; Byerlee et al., 2005; NEPAD, 2005).

A key component of all the strategies is to link early warning and risk management systems to regional and local practitioners such as health-care providers and farmers