Groundwater and climate in Africa - a review

The paper "Groundwaterand climate in Africa - a review" by Richard Taylor et al. from 2009 reviews the major issues discussed in the 2008 "Groundwater and Climate in Africa"- Conference in Kampala (Uganda). There 23 African country representatives as well as scientists from UCL and people in charge from the Ministry of Water and Environment, UNESCO-IHP as well as 37 other nations met to discuss the issue of groundwater shortage in relation to climate change. This gave a unique opportunity to see both sides - the scientific and the political.  

One of these major concerns regarded the rising demand for renewable water sources due to rapid increasing population growth (largest in the world), boosting urbanization and their demand for food. Combined with a local warming 1.5 times higher than the global mean and from this mayor shifts in precipitation pattern Africa has a precarious situation to face in the future which already started. 
With the huge land mass of the country (~ 3x size of Europe) different climates are joined in this country. Land surfaces reaching extremes from tropical forests, deserts, glaciers, savannahs to normal cropland - many of these are subject to changes. Man-made adaptations to meet overpopulation related demands and early stages of climate adaptations are already changing these land covers - deforestation to gain cropland or new urban areas is only one example.   

There are two main types of basement rocks in Africa - almost impermeable mudstones and permeable sand- or limestones. The latter provides room for all major aquifers, many of them sadly located under national borders causing already some conflicts with its abstraction. Its total capacity is only broadly estimated due to leaking continent wide measurements of withdrawals and availability.
 The fact that these limestone reservoirs are locally restricted to certain semi-arid & arid regions makes it difficult to talk about this groundwater resource in term of future renewable water sources within Africa if the entire continent is taken to account. Nevertheless, areas having these reservoirs have a good water source during seasonal absent surface waters. 

Another drawback is caused by human contamination of these reservoirs. Even though the original water within the aquifer has mostly perfect drinking conditions not requiring any treatments, over-abstraction (on coastlines) can lead to saltwater intrusions or faecal discharge in large cities due to leaking sanitation can lower the water quality. 
A lowering groundwater table can also affect local river discharges. Ideas to trace recharge processes and rates were met with stable isotope ratios and noble gas inlets which still have not the ability to process all the necessary data for valid assumptions. Therefore, there are some major shifts in how to treat the problem of leaking data by changing the interpretation of the available data from precise future developments to a forecast which might process more valid estimations lessening the impact of given uncertainties (e.g. future land-use changes, seasonal precipitation shifts, changing albedo and flow). 

Concluding with an idea that it might be wiser to concentrate on population growth and its immediate impacts on the lands surface before predicting scarcities without looking at the actual water use in terms of worst-case scenarios. Even though groundwater is a possible renewable water source its recharge takes thousands of years in large scales and even then did not occur in recent history in all areas. Therefore, it is, in terms future continuous abstraction, a non-renewable resource - at least for within the lifetime of one generation.