An Introduction!

Greeting my curious reader!

Today I shall introduce you to the wondrous world of climate change and water in Africa, the start of a journey that shall take us through many problems, solutions, case studies and more! Changing water supply in Africa with regards to environmental change is a hugely complex and varied issue, of paramount importance to the daily lives of many African citizens. Africa as a continent already experiences greater water variability in space and time than any other place on the planet, and this variability has already caused widespread human suffering and economic damage (Conway et al., 2009). In many cases, climate and land use change will be imposed onto already water-stressed catchments, hindering economic development objectives.

Why environmental and land use change?

My particular fascination of this topic stems from its position on the interface of two worlds (figuratively speaking!) – one being the physical, scientific analysis of future projections of climate change over Africa, and its impact on factors such as temperature, precipitation and ecosystem change. The other ‘world’ refers to the translation of these changes into the human impact, through factors such as food security, domestic water availability and perhaps even water-based conflict. All in all, this makes the task of writing a weekly blog on the matter fairly daunting, but also exciting!

Figure 1. A woman pumps groundwater supplies. Source: Wikimedia Commons.

Why is this a topic worth blogging about?

The mean annual temperature rise over Africa is likely to reach 2°C by the end of the 21^st century, in relation to the late 20^th century (Niang et al., 2014). To give a brief idea of the effects climate change would have on African water supplies, we can turn to Wit and Stankiewicz (2006). The non-linear response of surface water supply to rainfall is of particular importance when considering the effects of climate change on precipitation variability across Africa, especially seeing as a large proportion of the population rely on local rivers for water supply. 75% of African countries currently fall into an “unstable” climatic regime, whereby a small change in precipitation caused by climate change could cause considerable changes in the surface water supply.

Figure 2. The yellow areas refer to those currently in the “unstable” climatic regime, which will experience the most change in surface water drainage density with changes in regional annual rainfall. The regime makes up 25% of the total area. Source: Wit and Stankiewicz, 2006. 

A 10% decrease in precipitation over sub-Saharan Africa by 2050 would mean that those regions on the upper boundary of this climatic regime (i.e. receiving 1000 mm/year) would experience reduced surface water drainage of 17% - but the fate is even worse for those towards the lower end – regions receiving 500 mm/year would drop in drainage by half (Wit and Stankiewicz, 2006). Much of southern Africa already falls into this unstable regime, and much is projected to experience considerable losses of the surface water drainage it does possess, with IPCC projections (IPCC SRES, 2000). Imagine the impact this would have on a rural village that depends on local river water – their only water supply would drop to half its previous volume – that’s half the amount of water left for cooking, drinking, sanitation and agriculture!

Of course this is an extremely simplified overview of likely water changes over Africa, but I hope to explore these and other impacts in much more detail over the course of this blog. It’s important to remember that Africa is not one homogeneous unit; it possesses a host of communities both rural and urban, and the continent’s different regions will be impacted and respond to climate change in different ways. As well as future projections of physical climate parameters, I shall assess the human problems they will pose on both rural and urban communities, such as impacts on food security, spread of disease and potential for conflict. And, in a more positive light, I shall explore the strengths and weaknesses of the various strategies for adaptation and mitigation of these climate changes and impacts.