Climate change scenarios for Angola: an analysis of precipitation and temperature projections using four RCMs

摘要

Climate change is expected to have a major impact on the world's environment, economy and society, especially in African countries such as Angola due to the dependence of many vital sectors on climate variability (e.g. agriculture) and their low adaptive capacity. With the advances in the availability of climate model data sets provided by programs such as the CORDEX, Angola can benefit from studies on future climate change using high-spatial-resolution data, which have previously been absent for this region. The purpose of this study is to analyse the projected changes in temperature and precipitation over Angola during the 21st century based on four regional climate models (RCMs). The spatial and temporal changeswere analysed using a high-and medium-low radiative forcing scenario to consider the uncertainty in greenhouse gas emissions. Changes in the average annual precipitation, average annual temperature and a drought index are studied for short-, mid-and long-term projections. Compared to the reference period, relevant changes are projected in temperature and precipitation indices for the different models under both emission scenarios. These changes include an increase in both the maximum and minimum temperature of up to 4.9 degrees C by the end of the century and an intensification of droughts. The precipitation projections are highly variable - increasing and decreasing - across the region and dependent on the RCMs. Despite these differences, the precipitation generally decreases over time (approximately -2 by 2100), with the southern region experiencing a stronger decrease in precipitation. Further investigation is needed to minimize projections uncertain, as the annual mean precipitation was overestimated by three of the RCMs (especially in the northern coastal units). Overall, these projected changes in climate can have important implications for the future of Angola, because they are expected tomagnify existing problems, thus creating new risks for human and natural systems.