An evaluation of climate and run-off variability and associated livelihood risks

Climate change occurs over relatively long time scales, although some acceleration in changes can also be seen in data of the last twenty years. The reasons for the current changes in the climatological variables might be anthropogenic (e.g. greenhouse gas emission) or natural (e.g. solar variability etc.), or most likely a combination of both reasons. An increasing body of evidence shows that greenhouse gas emissions are changing our climate significantly. Climate change is projected to substantially reduce available water (as reflected by projected runoff from a catchment) in many of the water-scarce areas of the world A statistical analysis was carried out of over fifty years of precipitation, temperature and runoff data from several locations in the Mzingwane Catchment – the portion of the Limpopo Basin that falls within Zimbabwe. The trends show declines in precipitation and runoff and increases in maximum and minimum temperatures, across the catchment. The trends observed are comparable to those predicted from some of the global circulation models (GCMs) based on the Intergovernmental Panel on Climate Change Special Repor