We've looked briefly at the historic drought that occurred in late 2015 and early 2016 over southern Africa. We look at some of the impacts on agriculture and food security. But the drought also had major impacts on river flows, some of the lowest on record and therefore big effects on water supply. So, for example, in Gaborone which is the capital city of Botswana, the reservoir that supplies the city ran dry, and there was basically no water coming out of the taps for for months on end. So, households had to buy bottled water. Shops and businesses had to close because of the water to run their businesses, and it had huge impacts on the local economy, as well as just a major inconvenience for people living in Gaborone. On Lake Kariba, which is the dam, the big dam, sitting on the Zambezi River, the flows into the dam were also at a historic low levels and there had to be rationing of the flow of water to the hydro power stations in the dam. This led to the ZAPSCO which is the Zambian power supply company implementing rolling blackouts across all of Zambia for several hours a day, which also then had big impacts on business, the economy, and even schools, just sort of everyday life. Zimbabwe was even worse there up to 17 hours of blackouts every day and so there the impacts are even more severe. So, we have to bear in mind that this was an historic drought the worst in 25 years, and so even the best adapted systems, whether it's water or agriculture, would struggle to cope with a drought of this magnitude. But if we if we look at at our best guess for the future over much of the region, it is the scenarios are full reduced rainfall. So, we should really have to plan for more frequent events like this in the future, these historic droughts. Quite likely, we get rare events of even greater magnitude. So, essentially, today's extremes would become closer to the normal of the future and we might well experience extremes in the future that we haven't experienced today. So, this drought we experienced a couple of years ago is really an example of the adaptation challenge. What do we do to minimize the impacts of events like this in the future? Then recognizing that there are unavoidable impacts, what do we do in terms of emergency responses and other responses that help us cope with the unavoidable impacts that we can't adapt to? I want to move next on to talking about water and its importance for development. The UN have recognized water as a fundamental human right, and that's defined as the right to sufficient and safe, acceptable, and physically accessible water that's affordable for personal and for domestic uses. So, given that sort of that the fact that water is a fundamental human right, it's not surprising that water is a key action point in both the millennium development goals and the new sustainable development goals. But you have to remember water is also important for wider aspects of human well-being and the economy, such important in food security and food production particularly through irrigated agriculture, it's important for energy security through hydro-power, which we've talked about briefly, as well as for cooling much of the existing fossil fuel and nuclear power stations that we depend on at the moment. Water is really important also in certain industrial processes that underpin the economy: mining, food processing, and the pulp and paper industry. Across these different areas, a lot of the water that is used is in agriculture, about 70 percent globally, followed then by water for industry and finally for domestic use which is actually the smallest demand on the available water. But we also have to remember that water is important for the environment in its own right. So, the rivers and lakes that we draw water from, are ecosystems of importance on their own, and they're also linked to other ecosystems, such as estuaries and wetlands. So, making sure that water is available in those ecosystems is important for ecosystem services, as we call them, which support wider aspects of society. Rivers and lakes are also important for human livelihoods. So many people make use of of lakes and rivers for instance for fishing but also for recreation and for spiritual use, so rivers and lakes have important cultural value that we need to be thinking about. So, climate change is a factor that has the potential to disrupt the current sort of balance of trade-offs between water use and water for the environment. It's for that reason that we need to really think about how to account for climate change in the way we plan for water use in the future.
