Southern Africa: challenge of the future

Representation of the Angolan low and Southern African Summer Precipitation in the CORDEX and CMIP5 models.

10.5194/egusphere-egu21-12531 ◽

2021 ◽

Author(s):

Sabina Abba-Omar ◽

Francesca Raffaele ◽

Erika Coppola ◽

Daniela Jacob ◽

Claas Teichmann ◽

...

Keyword(s):

Climate Change ◽

Regression Analysis ◽

Southern Africa ◽

Summer Precipitation ◽

Precipitation Variability ◽

Cmip5 Models ◽

Impact Of Climate Change ◽

The Future ◽

Rainfall Patterns ◽

The Impact

The impact of climate change on precipitation over Southern Africa is of particular interest due to its possible devastating societal impacts. To add to this, simulating precipitation is challenging and models tend to show strong biases over this region, especially during the Austral Summer (DJF) months. One of the reasons for this is the mis-representation of the Angolan Low (AL) and its influence on Southern Africa&#8217;s Summer precipitation in the models. Therefore, this study aims to explore and compare different models&#8217; ability to capture the AL and its link to precipitation variability as well as consider the impact climate change may have on this link. We also explore how the interaction between ENSO, another important mode of variability for precipitation, and the Angolan Low, impact precipitation, how the models simulate this and whether this could change in the future under climate change.&#160;We computed the position and strength of the AL in reanalysis data and compared these results to three different model ensembles with varying resolutions. Namely, the CORDEX-CORE ensemble (CCORE), a new phase of CORDEX simulations with higher resolutions (0.22 degrees), the lower resolution (0.44 degrees) CORDEX-phase 1 ensemble (C44) and the CMIP5 models that drive the two RCM ensembles. We also used Self Organizing Maps to group DJF yearly anomaly patterns and identify which combination of ENSO and AL strength scenarios are responsible for particularly wet or dry conditions. Regression analysis was performed to analyze the relationships between precipitation and the AL and ENSO. This analysis was repeated for near (2041-2060) and far (2080-2099) future climate and compared with the present to understand how the strength of the AL, and its connection to precipitation variability and ENSO, changes in the future.&#160;We found that, in line with previous studies, models with stronger AL tend to produce more rainfall. CCORE tends to simulate a stronger AL than C44 and therefore, higher precipitation biases. However, the regression analysis shows us that CCORE is able to capture the relationship between precipitation and the AL strength variability as well as ENSO better than the other ensembles. We found that generally dry rainfall patterns over Southern Africa are associated with a weak AL and El Nino event whereas wet rainfall patterns occur during a strong AL and La Nina year. While the models are able to capture this, they also tend to show more neutral ENSO conditions associated with these wet and dry patterns which possibly indicates less of a connection between AL strength and ENSO than seen in the observed results. Analysis of the future results indicates that the AL weakens, this is shown across all the ensembles and could be a contributing factor to some of the drying seen. These results have applications in understanding and improving model representation of precipitation over Southern Africa as well as providing some insight into the impact of climate change on precipitation and some of its associated dynamics over this region.

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Cotton in Southern Africa.

10.1079/9781800620216.0008 ◽

2022 ◽

pp. 129-155

Author(s):

Graham Matthews ◽

John Tunstall

Keyword(s):

Pest Management ◽

Southern Africa ◽

New Technology ◽

Crop Protection ◽

The Future

Abstract This chapter focuses on the crop protection and pest management of cotton crops in Southern Africa (Eswatini, Zimbabwe, Zambia, Malawi, Mozambique, and Angola). It discusses how new technology will bring major changes in how cotton is grown in the future.

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The potential value of seasonal forecasts in a changing climate in southern Africa

Hydrology and Earth System Sciences ◽

10.5194/hess-18-1525-2014 ◽

2014 ◽

Vol 18 (4) ◽

pp. 1525-1538 ◽

Cited By ~ 32

Author(s):

H. C. Winsemius ◽

E. Dutra ◽

F. A. Engelbrecht ◽

E. Archer Van Garderen ◽

F. Wetterhall ◽

...

Keyword(s):

Climate Change ◽

Heat Stress ◽

Southern Africa ◽

Weather Conditions ◽

Stress Conditions ◽

Mitigation Measures ◽

Seasonal Forecasts ◽

Weather Forecasts ◽

Dry Spells ◽

The Future

Abstract. Subsistence farming in southern Africa is vulnerable to extreme weather conditions. The yield of rain-fed agriculture depends largely on rainfall-related factors such as total seasonal rainfall, anomalous onsets and lengths of the rainy season and the frequency of occurrence of dry spells. Livestock, in turn, may be seriously impacted by climatic stress with, for example, exceptionally hot days, affecting condition, reproduction, vulnerability to pests and pathogens and, ultimately, morbidity and mortality. Climate change may affect the frequency and severity of extreme weather conditions, impacting on the success of subsistence farming. A potentially interesting adaptation measure comprises the timely forecasting and warning of such extreme events, combined with mitigation measures that allow farmers to prepare for the event occurring. This paper investigates how the frequency of extreme events may change in the future due to climate change over southern Africa and, in more detail, the Limpopo Basin using a set of climate change projections from several regional climate model downscalings based on an extreme climate scenario. Furthermore, the paper assesses the predictability of these indicators by seasonal meteorological forecasts of the European Centre for Medium-Range Weather Forecasts (ECMWF) seasonal forecasting system. The focus is on the frequency of dry spells as well as the frequency of heat stress conditions expressed in the temperature heat index. In areas where their frequency of occurrence increases in the future and predictability is found, seasonal forecasts will gain importance in the future, as they can more often lead to informed decision-making to implement mitigation measures. The multi-model climate projections suggest that the frequency of dry spells is not likely to increase substantially, whereas there is a clear and coherent signal among the models of an increase in the frequency of heat stress conditions by the end of the century. The skill analysis of the seasonal forecast system demonstrates that there is a potential to adapt to this change by utilizing the weather forecasts, given that both indicators can be skilfully predicted for the December–February season, at least 2 months ahead of the wet season. This is particularly the case for predicting above-normal and below-normal conditions. The frequency of heat stress conditions shows better predictability than the frequency of dry spells. Although results are promising for end users on the ground, forecasts alone are insufficient to ensure appropriate response. Sufficient support for appropriate measures must be in place, and forecasts must be communicated in a context-specific, accessible and understandable format.

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Suffer the Future. Policy Choices in Southern Africa

The International Journal of African Historical Studies ◽

10.2307/218160 ◽

1982 ◽

Vol 15 (3) ◽

pp. 506

Author(s):

Douglas L. Wheeler ◽

Robert I. Rotberg ◽

Ronald T. Libby

Keyword(s):

Southern Africa ◽

Policy Choices ◽

The Future ◽

Future Policy

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Challenges to cooperation on water utilisation in the Southern Africa region

Water Policy ◽

10.2166/wp.2013.116 ◽

2013 ◽

Vol 15 (4) ◽

pp. 554-569 ◽

Cited By ~ 1

Author(s):

Nola Redelinghuys ◽

André J. Pelser

Keyword(s):

Policy Implementation ◽

Water Relations ◽

Southern Africa ◽

Power Relations ◽

Policy Framework ◽

Transboundary Water ◽

National Sovereignty ◽

The Future ◽

Water Issues ◽

Regional Perspective

Transboundary water relations in Southern Africa are governed by an elaborate and intricate policy framework. In spite of this framework, the future of sustained cooperation on water utilisation in the region is still precarious and uncertain. Some subtle and unresolved dilemmas that may constrain future cooperation need to be dealt with. Two of these underlying dilemmas, namely the importance attached to national sovereignty and the strategic nature of water in the region, are explored in this article. These dilemmas form critical undercurrents that steer nations away from cooperation, cause stagnation in policy implementation and hamper progress in facilitating sustained solutions in transboundary water issues. Stemming from this background, this article argues for (a) the importance of a stronger regional perspective on water to steer countries away from the need to protect sovereign interests and (b) addressing the nature of current power relations in the region where water is concerned.

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