Projected effects of 1.5 °C and 2 °C global warming levels on the intra-seasonal rainfall characteristics over the Greater Horn of Africa

Abstract

This study examines the effects of 1.5°C and 2°C global warming levels (GWLs) on intra-seasonal rainfall characteristics over the Greater Horn of Africa. The impacts are analysed based on the outputs of a 25-member regional multi-model ensemble from the Coordinated Regional Climate Downscaling Experiment project. The regional climate models were driven by Coupled Model Intercomparison Project Phase 5 Global Climate Models for historical and future (RCP8.5) periods. We analyse the three major seasons over the region, namely March-May, June-September, and October-December. Results indicate widespread robust changes in the mean intra-seasonal rainfall characteristics at 1.5°C and 2°C GWLs especially for the June-September and October-December seasons. The March-May season is projected to shift for both GWL scenarios with the season starting and ending early. During the June-September season, there is a robust indication of delayed onset, reduction in consecutive wet days and shortening of the length of rainy season over parts of the northern sector under 2°C GWL. During the October-December season, the region is projected to have late-onset, delayed cessation, reduced consecutive wet days and a longer season over most of the equatorial region under the 2°C GWL. These results indicate that it is crucial to limit the GWL to below 1.5°C as the differences between the 1.5°C and 2°C GWLs in some cases exacerbates changes in the intra-seasonal rainfall characteristics over the Greater Horn of Africa.

Impact of 1.5 oC and 2 oC global warming scenarios on malaria transmission in East Africa

“…Our results are consistent with findings from similar studies done over the study domain (e.g. Gudoshava et al ., 2020 ; Ogega et al ., 2020 ; Osima et al ., 2018 ).…”

“…Additionally, the RCP 8.5 has been widely used in Africa and beyond (e.g. Gudoshava et al ., 2020 ; Ogega et al ., 2020 ; Yan et al ., 2019 ). The four CORDEX-Africa RCM runs have been identified to be among the best in simulating precipitation characteristics over East Africa ( Ogega et al ., 2020 ).…”

“…Data on clinical malaria cases for East Africa were obtained from the Malaria Atlas Project ( Hay & Snow, 2006 ; Weiss et al ., 2019 ). The Malaria Atlas Project (MAP) obtains, curates, and shares a variety of malariometric data including malaria cases reported by surveillance systems, nationally representative cross-sectional surveys of parasite rate, and satellite imagery capturing global environmental conditions that influence malaria transmission.…”

“…Some work has been done towards understanding the potential impact of global warming in East Africa (e.g. Gudoshava et al ., 2020 ; Osima et al ., 2018 ). However, no conclusive literature exists on the potential impacts of 1.5 °C and 2 °C global warming levels (hereinafter GWL1.5 and GWL2.0) on health, among other sectors, in East Africa.…”

The Need for New Ways of Reference Evapotranspiration Assessment

“…Rainfed crop production is considered to be the most vulnerable area of the global economy in the initially dry regions of the Earth. Simulation models have testified about the necessity of the introduction of rational measures for resilience of climate change effects in one of the driest regions of the world (West Africa), taking into account three main scenario of further warming of the global climate: by 1.5, 2.0 and 3.0ºC [3]. Another study has proved a negative impact on sub-Saharan Africa agricultural productivity due to the environmental changes, which currently take place in the region [4].…”