Brief communication: Drought likelihood for East Africa

Abstract

Abstract. The East Africa drought in autumn of year 2016 caused malnutrition, illness and death. Close to 16 million people across Somalia, Ethiopia and Kenya needed food, water and medical assistance. Many factors influence drought stress and response. However, inevitably the following question is asked: are elevated greenhouse gas concentrations altering extreme rainfall deficit frequency? We investigate this with general circulation models (GCMs). After GCM bias correction to match the climatological mean of the CHIRPS data-based rainfall product, climate models project small decreases in probability of drought with the same (or worse) severity as 2016 ASO (August to October) East African event. This is by the end of the 21st century compared to the probabilities for present day. However, when further adjusting the climatological variability of GCMs to also match CHIRPS data, by additionally bias-correcting for variance, then the probability of drought occurrence will increase slightly over the same period.

The Impact of Human‐Induced Climate Change on Regional Drought in the Horn of Africa

“…Paleoclimatic data show that “century‐scale monsoon weakening events” have occurred in the past in East Africa (Kiage & Liu, ) and it is therefore possible that we are witnessing the early signs of such a climatic shift. However, most current model simulations predict the long rains to increase in response to anthropogenic greenhouse gas forcing—leading to the so‐called East African discrepancy (e.g., Tierney et al, ; Boulter et al, ; Rowell et al, ; Yang et al, ; see discussion in Yang & Huntingford, ). Yang et al () even suggested that the cause of this discrepancy was “systematic errors” in fully coupled models trying to simulate the East African precipitation climatology, concluding that “we are distressingly far from an adequate understanding or a usable ability to model climate variability and change in this socially critical region.”…”

“…The Horn of Africa is noted for combining complex topography with strong convection effects, resulting in a highly heterogeneous general precipitation climatology (Nicholson, ). Together with the challenges of a data‐poor part of the world and a high proportion of the population being dependent on rain‐fed agriculture (Yang & Huntingford, ), the importance of deriving strong and clear conclusions about drought occurrence in the subcontinent is very clear. The paradigm presented here, showing a simple, regional‐scale directional pattern that summarizes the changes that we may expect from anthropogenic climate change, should help local populations to become more aware of the importance of future climate trajectories and, therefore, to be more prepared for future drought in this part of Africa.…”

“…Simple regression statistics show that in the GHA evapotranspiration, a simple drought measure (Seneviratne et al, ; Teuling et al, ) was closely related to precipitation (Figures and ) during the 2014 Long Rains (Figure ). In the GHA, models that adequately characterize the long rains within the climate system are the key to greater understanding of the dynamics of major droughts (Yang & Huntingford, ). These models are additionally important because they form the basis of drought detection and early warning systems for the subcontinent.…”

Towards Climate Resilient Environmental and Natural Resources Management in the Lake Victoria Basin

“…Extreme rainfall is also expected to increase in the Basin (Akurut et al, 2014;Thiery et al, 2016;Ongoma et al, 2018). In relation to drought, current understanding of the impacts of climate change are highly uncertain (Yang and Huntingford, 2018). However, climate projections should be handled with care, when applied to decision making (Nissan et al, 2019).…”

Agro–ecosystem sensitivity to climate change over the Ethiopian highlands in a watershed of Lake Tana sub–basin

“…Change in climate and its adverse impacts are predicted to continue in East Africa [12], aggravating the existing challenges to satisfy the food demands of an ever-increasing population [13]. Climate change is evident in Ethiopia mainly through dramatic increment in surface temperature [14,15,16] that exacerbates recurrence of droughts [16,17] and change in precipitation patterns [18,19,20,21,22].…”