Changes in extreme temperature events over Africa under 1.5 and 2.0°C global warming scenarios

Abstract

AbstractFollowing the December 2015 Paris Agreement, there is an international effort to limit global warming at 1.5 and 2.0°C relative to the pre‐industrial level. However, there is inadequate research quantifying the difference in extreme temperature between the two target levels, especially in Africa. This study used historical and future low‐warming projections of NCAR‐CESM to assess the differences in extreme temperature events under 1.5 and 2.0°C future scenarios relative to the recent climate taken from 1976 to 2005 over Africa. The results show that compared with the present day, the magnitude of the highest temperature (TXx) will increase by approximately 1.6/2.2°C in 1.5/2.0°C warming worlds, with more substantial warming in Sahara and Southern Africa. The lowest temperature (TNn) will increase by ∼1.9/2.5°C in 1.5/2.0°C future climates, where SAH and SAF will experience a higher intensity of warming followed by Eastern Africa and Western Africa regions. The frequency of hot days (TX90p) is projected to increase with global warming across the continent, with a high increase in SAF and SAH. The frequency of cold days (TN10p) is expected to decrease with global warming in many parts of Africa except in WAF. In most regions, there were no apparent changes revealed in the Warm Spell Duration Indicator relative to the recent climate across the continent except SAH in 1.5 and 2.0°C warming levels, while a decrease in Cold Spell Duration Indicator will be in SAH. Assessment of the avoided impacts in 1.5 relative to 2.0°C indicates that limiting global warming at 1.5 rather than 2.0°C could reduce the intensity, frequency and duration of extreme temperatures from 3 to 81%. However, the magnitude of avoided impacts differs among indices and sub‐regions. Hence, it is paramount for the African continent to limit global warming at 1.5 instead of 2.0°C.