Foreword: Solving South Africa's interlinked energy, climate and water problems

Humans in permanent settlements have existed as part of this system for only around 10,000 years, arising during the Holocene, an extended warm and stable interglacial period. A massive fossil fuel based global economy, megacities, and a human population in the billions arose only in the last 100 years. During this period, human activities have begun having such a massive impact on the functioning of the earth system that it has been labeled a new geologic era: the Anthropocene (Crutzen and Stoermer 2000). Humans have always had a major influence on the ecosystems of which they were a part and which supported them. Pleistocene hunter/gathers used fire to radically modify their environment for their own advantage, and may have hunted several species of megafauna to extinction (Flannery 1994, 2006). Holocene farmers and city builders radically altered their local environments, with massive clearing, planting, and irrigation works. These civilizations also often collapsed by overextending themselves and losing resilience (Redman 1999, Diamond 2005, Costanza et al. 2007). But the scale of change and impact in the Anthropocene is unprecedented. Human civilization is now so interconnected globally that if a collapse comes it will have a global affect. During all of human history the primary drivers of development and change have been energy, water, and climate. In the Pleistocene current solar energy captured by natural ecosystems was simply gathered or hunted, while climate and water availability directed food availability and migration patterns. During the Holocene, ecosystems were domesticated, water was controlled to an extent, and climate could be moderated using the built environment. In the Anthropocene, current solar energy is being supplemented by aeons of past solar energy stored in fossil fuels. Water flow is highly manipulated and is being used to its limits, while climate is not only being adapted to, but also significantly changed by the massive burning of fossil fuels. This report looks at these critical, society-shaping linkages in South Africa over the next 15 years. It is unique in its integration of climate change, water quality deterioration, and dependence on coal-based electricity in projecting South Africa's water supply future to 2025. It looks at the effects of global warming on evaporation rates in water short South Africa and the effects of decreasing water quality. Adding these two elements gives a much bleaker scenario for future water availability. It then estimates the costs of water treatment and purification, including these effects and the "external" costs of the impacts on valuable ecosystem services. For example, the destruction of the ecological integrity of river catchments has led to the loss of ecosystem services of water supply and regulation, and created additional costs to replace these services. The report shows clearly that when these costs are included, coal-based electricity is not cheap and continued investment in coal-based energy supplies will bankrupt the country. Societies have collapsed before. Societies have also avoided collapse by adapting to changing conditions. Both South Africa and our global society are at a critical decision point. We require a transformation of our integrated worldviews, technologies, and institutions if we are to successfully adapt to the "full world" Anthropocene (Beddoe et al. 2009). This report lays out part of the path to a successful South African adaptation to the challenges it now faces. South Africa needs to move away from its current coal-based energy system and invest in renewable resources such as solar energy. For example, placement of solar collector "lids" on many of the open reservoirs in South Africa would help solve both the energy problem and reduce evaporation enough to help solve the water problem. These types of creative, integrated technical solutions are a key part of the transition. But South Africa (and the w