| Overview : Located in subtropical southern Africa, Botswana is a semi-arid country with a highly variable climate. In particular, inter-annual variability in rainfall is substantial and influenced strongly by El Niño Southern Oscillation (ENSO) events. During devastating El Niño induced droughts in the 1980s and 1990s, Botswana lost a substantial portion of its livestock. Similarly, the super El Niño event of 2015/16 (the strongest El Niño event ever recorded) brought extensive drought to Botswana, and during both 2015 and 2016 the country’s livestock count was significantly reduced. It may be noted that such periods of drought are induced by the subtropical high-pressure systems strengthening and occurring over Botswana. These weather systems cause widespread subsidence, which not only suppress cloud formation and rainfall but also result in the occurrence of heat-waves. Against this background of high variability in rainfall, Botswana has been warming at an alarming rate over the last five decades, with recorded temperature increases in northern Botswana taking place at a rate of more than 3 ̊C per century. This rate of temperature increase is the highest recorded in southern Africa and about three times the global rate of temperature increase. It is critical to understand how continued anthropogenic forcing will result in further changes in the Botswana climate system during the course of the 21st century. The Intergovernmental Panel on Climate Change (IPCC) has in fact assessed in its Assessment Report Four (AR4) in 2007, Assessment Report Five (AR5) in 2013 and the Special Report on Global Warming of 1.5 °C (SR1.5) in 2018 that the larger southern African region, including Botswana, is likely to become generally drier under future climate change. Moreover, further drastic temperature increases are projected to occur over Botswana under low mitigation climate change futures, which may reach values as high as 6 °C towards the end of the 21st century. SR1.5 proceeded to point out that under 1.5 °C of global warming, reductions in livestock production and crop yield are likely to occur in subtropical southern Africa, with further reductions that may occur under 2 °C of warming. Should global warming continue further to reach values of say 3 °C, SR1.5 assessed that the collapse of the livestock industry and the maize crop may plausibly occur in subtropical southern Africa. Based on the foregoing, UNDP is looking for reputable and experienced consultancy firms to undertake consultancy on Tipping Points for climate change in Botswana. |
