Blog 2 : Climate Change impact on Water availability - part 1

The second of my blogs will focus on climate change and specifically the impact it has upon groundwater levels with extended focus on the accessibility for the people of African countries. This blog shall outline the effect climate change has on temperatures and thus rainfall before assessing the impact on groundwater supplies. Additionally, this blog shall assess the potential socio-economic impacts of increased variability in rainfall and groundwater levels as a result of climate change. In particular, this blog aims to highlight the political challenges that impacts of climate change bear in the future.

Climate Change:

It is estimated that temperatures in particularly sub-Saharan Africa will increase dramatically and well beyond 20th Century extents and projections. Indeed, by 2080 it is projected that there could be a 4% rise in temperature by 2080 compared to 1980 levels (Niang,2014). The increase in average temperature is likely to cause a depletion in air moisture which in turn is likely to increase the water holding capacity of air but also increase intensity of rainfall which tends to deplete air moisture (Kingston and Taylor,2010). The overarching result of said increase in average temperature is that there will likely be fewer low and medium intensity rainfall events (Allan and Soden,2008) but an increase in high intensity rainfall (Allan et al,2010) which increases the regularity of extreme weather events such as floods and droughts which could very possibly have devastating consequences for Sub-Saharan Africa.

Impact on Groundwater Levels:

The projected changes in rainfall may have potentially devastating effects upon groundwater levels (and subsequently crop yields). Indeed, Carter and Parker (2009) concur that medium intensity events are optimal for groundwater recharge. However, as discussed earlier, the extent of rainfall is likely to become more extreme and variable, which may impact on crop yields. That is to say, although not in Africa, Challinor et al. (2006) found that even with a minor drop in net rainfall (394mm to 389mm) there was a considerable drop in crop yields in Uttar Pradesh in India (1360kg/ha to 901kg/ha). 

On a larger scale, this may be a great cause for concern as shallow aquifers, which respond more quickly to seasonal and yearly changes in rainfall than deep aquifers (Barthel et al., 2009) e.g the Sahel. Due to shallow aquifers like the those in the Sahel or in Southern Africa which experience 200-500m rainfall per annum being responsive to variability in extent of rainfall there is a considerable chance that recharge will decline sufficiently to make droughts a more regular occurrence (Niang, 2014).

Socio-Economic impacts: 

The potential impact of climate change is not necessarily confined to physical factors either. That is to say, more than 50% of Sub-Saharan Africa relies on groundwater for food production and water supply (Carter and Parker, 2009) which means that those in poverty are increasingly vulnerable to climate change. Moreover, there is great concern for the future as population and thus demand for water will increase dramatically. It is estimated that the gross population of all of Sub-Saharan Africa will increase by at about 154% (UN,2008) and of that there is estimated to be a 326% rise in urban population by 2050 (45% increase in rural areas). Needless to say, there will be an increased burden on freshwater resources due to increased demand and as a result, we can expect to see a significant growth in water and food-related poverty and hunger in the first half of the 21st Century (Carter and Parker,2009). 

Furthermore, it is expected that climate change will impact food security considerably. Indeed Liu et.al (2018) suggests that climate change will cause strong regional variability in the degree of yield reduction. These yield losses will likely vary between the rest of Sub-Saharan Africa and Southern Africa.  Estimated yield losses at mid-century range from 18% for southern Africa (Zinyengere et al., 2013) to 22% aggregated across sub-Saharan Africa, with yield losses for South Africa and Zimbabwe in excess of 30% by 2050 (Schlenker and Lobell, 2010). While the obvious impact stated here is the potential for substantial increases in food insecurity, there is also potential for large scale economic issues. To that effect, any loss of productivity of high-value crops such as tea, coffee, and cocoa would have detrimental impacts on export earnings (Niang,2014). Exports of such products is key to employment of many in potentially affected countries and integral to the GDP of said countries also. Thus climate change and particularly attempting to mitigate the effects of it will become a key political challenge for the decades ahead in Africa.

Conclusion: 

This blog has covered the extent of climate change and its impact upon temperature and rainfall. In particular, it has exhibited that increases in temperature as a result of climate change will likely yield increase variability in rainfall and thus groundwater levels. In addition, the potential impact on groundwater levels are projected to present considerable political challenges in terms of both the availability and accessibility of fresh water resources and also the subsequent impact, in conjunction with rising population and demand, on food security in Sub-Saharan Africa. The next blog shall outline potential responses and mitigation to such challenges faced by Sub-Saharan Africa before giving a judgment on the best course of action.