The Environment, Water and Africa.

Lake Chad is a classic example of the impacts of environmental change on the hydrological system in Africa and therefore an excellent place for us to begin our exploration of this topic. Lake Chad is located in the centre of the semi-arid Sahel region of West Africa, spanning areas in Niger, Nigeria, Chad, and Cameroon.   In the 1960’s it was ranked as the world’s 6 th largest inland water body , covering an area of 25,000 km 2 . By 2004, its area was just 532 km 2 , a reduction of approximately 90%. The scale of the change can be visualised in Figure 1 . The lake has huge economic importance for the area, namely for the fishing industry but also for agriculture and pastoralism. Therefore measuring the changes to the lake and identifying the parameters that influence them is vital to adaptation. Figure 1 - A map of Lake Chad and its surrounding area, showing the character of the lake in 1960 and 2002. The rainfall patterns over the Lake Chad basin have a latitudinal gradient,

Climate change is an all too familiar phrase that is often accompanied by a profound, and yet distant, sense of dread. However the effects of climate change are already taking place, and it is widely agreed that Africa is experiencing temperature rises higher than any other continent . It’s important to understand the mechanisms behind climate change to understand it’s effects on the hydrological cycle and, ultimately, the African population. Climate Change. Earth’s climate has been widely variable throughout its history, from the humid ‘super greenhouse’ of the Eocene to a completely frozen planet known as ‘ Snowball Earth ’ . These changes have taken place over timescales that range from thousands to millions of years and have been influenced by numerous factors including the Milankovitch cycles (which describe cyclical variations in the Earth’s orbit) and factors influencing the Earth’s energy budget such as solar variations, volcanic activity and greenhouse gases (GHG’s). The