Crop response to climate change in southern Africa: A comprehensive review

In recent years, the rapid increase of CO2 emission in the atmosphere and the resulting issues such as global warming and climate change have now become significant barriers to environmental sustainability. Although fossil CO2 emissions have decreased in some of the world's largest emitters, including 11% in the EU, 12% in the US and 1.7% in China annually, the estimated global CO2 emission amount still reached 40 G tonnes in 2020. The purpose of studying biochar produced by pyrolysis is essential to develop the knowledge of carbon cycles and nutrient components in soil. Among all types of feedstocks, algae grow incredibly rapidly compared to other biological materials, about 500-1500 times higher, which will boot the carbon sequestration rate. Therefore, the study of algal biochar production through pyrolysis has great significance for migrating climate change and developing carbon capture and storage.This study focuses on a comprehensive review of previous literature on conventional and advanced macroalgae and microalgae pyrolysis for producing biochar and related valuable by-products like bio-oil and bio-syngas, aiming to establish a state-of-the-art of algal biochar for different soil-related applications and demonstrate the bottlenecks and opportunities. Specifically, a thorough comparison of algae species (20 microalgae and 20 macroalgae) is developed to benefit future researchers, involving chemical compositions, proximate analysis, solid-product fraction, physical properties and chemical properties. Redox conditions, surface functional groups and pH conditions are determined in lab-scale. Moreover, different algal biochar applications on soil and plant are analysed to optimise the commercial value of algal biochar, including soil conditioner, compositing additives, carrier for fertilisers, manure treatment and stable blending. Due to the abundant mineral contents (0.23-1.21% Na, 0.03-2.92% K, 0.75-7.17% Al, 0.19-1.24% Mg, 6.5-7% Ca and 0.04-0.69% Fe) of algal biochar, this study not only reviews the positive effects on soil improvement but also negative effects such as phytotoxic effect and heavy-metal pollution. A laboratory-based chemical oxidation approach (Edinburgh Stability Tool) is used to assess relatively long-term biochar stability and the influence of nutrient cycling. The optimal pyrolysis conditions (temperature, retention time and heating rate) and potential future commercial applications are obtained through the comprehensive review of algal biochar for soil improvement.&#160;&#160;&#160;&#160;

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Nature-based tourism operators’ perceptions and adaptation to climate change in Hwange National Park, Zimbabwe

Bulletin of Geography. Socio-economic Series ◽

10.2478/bog-2018-0034 ◽

2018 ◽

Vol 42 (42) ◽

pp. 115-127 ◽

Cited By ~ 7

Author(s):

William Mushawemhuka ◽

Jayne M. Rogerson ◽

Jarkko Saarinen

Keyword(s):

Climate Change ◽

Southern Africa ◽

National Park ◽

Empirical Studies ◽

Tourism Industry ◽

Adaptation To Climate Change ◽

Economic Role ◽

Change Perceptions ◽

Hwange National Park ◽

Adaptation Practices

Abstract Climate and weather are important resources for tourism. In particular, nature-based tourism activities and operations are largely dependent on and affected by environmental conditions and changes. Due to the significant socio-economic role of the nature-based tourism and the tourism industry, in general, in the region of southern Africa it is important to understand the dynamics between the industry and climate change. A key aspect of this understanding are perceptions and adaptation preparedness of tourism operators towards the estimated impact of climate change. There is a dearth of empirical studies on climate change perceptions and adaptation in nature-based tourism operations across southern Africa and specifically from Zimbabwe. This research gap is addressed in this article which provides an exploratory analysis of the nature of climate change adaptation practices occurring in southern Africa using evidence from Hwange National Park, Zimbabwe.

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Feed biomass production may not be sufficient to support emerging livestock demand: Model projections to 2050 in Southern Africa

10.31235/osf.io/qmdrt ◽

2021 ◽

Author(s):

Dolapo Enahoro ◽

Jason Sircely ◽

Randall B. Boone ◽

Stephen Oloo ◽

Adam M. Komarek ◽

...

Keyword(s):

Climate Change ◽

Biomass Production ◽

Southern Africa ◽

Simulated Data ◽

Biomass Productivity ◽

Livestock Production ◽

Human Populations ◽

Demand Model ◽

Livestock Feed ◽

By Products

The demand for livestock-derived foods has steadily grown over the past decades and rising incomes and human populations are expected to see demand further increase. It is unclear if current livestock feed resources are adequately prepared to meet future demand especially given the looming challenges of climate change. Many feeds such as grasses, crop by-products, and other biomass may not be widely grown commercially or sold in formal markets but are critical sources of livestock feed in many low-resource settings in which ruminant livestock production is important. The availability of these feed types can determine the extent to which the livestock sector can expand to meet growing, and sometimes critical, demand for animal-source foods. In this paper, we compare country-level projections of livestock demand from a global economic model to simulated data on feed biomass production. Our comparisons account separately for beef, lamb, and dairy demand. The data allow us to assess the future sufficiency of key sources of feed biomass, and hence aspects of the expansion capacity of livestock production in selected countries in Southern Africa. Our simulation results project that given the interacting effects of projected climate change and changes in income and population in the region, there will not be enough feed biomass produced domestically to meet growing demand for livestock products. For three types of feed biomass (feed crops including grains, grasses, and crop by-products) for which future livestock feed sufficiency was examined, our results showed feed sufficiency declines for all three feed types in Malawi and Mozambique, for two out of three in South Africa and for one of three in Zambia, under intermediate and extreme scenarios of climate change in 2050. Our results suggest an urgent need to improve feed biomass productivity to support future supply of animal protein in the study countries.

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Precipitation over southern Africa: Is there consensus among GCMs, RCMs and observational data?

10.5194/gmd-2021-54 ◽

2021 ◽

Author(s):

Maria Chara Karypidou ◽

Eleni Katragkou ◽

Stefan Pieter Sobolowski

Keyword(s):

Climate Change ◽

Southern Africa ◽

Regional Climate ◽

Coupled Model ◽

Added Value ◽

Rain Gauges ◽

Climate Simulations ◽

Observational Uncertainty ◽

Direct Contrast ◽

Improved Performance

Abstract. The region of southern Africa (SAF) is highly vulnerable to the impacts of climate change and is projected to experience severe precipitation shortages in the coming decades. Ensuring that our modelling tools are fit for the purpose of assessing these changes is critical. In this work we compare a range of satellite products along with gauge-based datasets. Additionally, we investigate the behaviour of regional climate simulations from the Coordinated Regional Climate Downscaling Experiment (CORDEX) – Africa domain, along with simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5) and Phase 6 (CMIP6). We identify considerable variability in the standard deviation of precipitation between satellite products that merge with rain gauges and satellite products that do not, during the rainy season (Oct–Mar), indicating high observational uncertainty for specific regions over SAF. Good agreement both in spatial pattern and the strength of the calculated trends is found between satellite and gauge-based products, however. Both CORDEX-Africa and CMIP5 ensembles underestimate the observed trends during the analysis period. The CMIP6 ensemble displayed persistent drying trends, in direct contrast to the observations. The regional ensemble exhibited improved performance compared to its forcing (CMIP5), when the annual cycle and the extreme precipitation indices were examined, confirming the added value of the higher resolution regional climate simulations. The CMIP6 ensemble displayed a similar behaviour to CMIP5, however reducing slightly the ensemble spread. However, we show that reproduction of some key SAF phenomena, like the Angolan Low (which exerts a strong influence on regional precipitation), still poses a challenge for the global and regional models. This is likely a result of the complex climatic process that take place. Improvements in observational networks (both in-situ and satellite), as well as continued advancements in high-resolution modelling will be critical, in order to develop a robust assessment of climate change for southern Africa.

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Climate Change: Briefings from Southern Africa

Transactions of the Royal Society of South Africa ◽

10.1080/0035919x.2016.1176082 ◽

2016 ◽

Vol 71 (2) ◽

pp. 205-206 ◽

Cited By ~ 1

Author(s):

Nicola van Wilgen

Keyword(s):

Climate Change ◽

Southern Africa

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Precipitation: The Thousand-Pound Gorilla in Crop Response to Climate Change

Handbook of Climate Change and Agroecosystems - Series on Climate Change Impacts, Adaptation, and Mitigation ◽

10.1142/9781848166561_0010 ◽

2010 ◽

pp. 179-190 ◽

Cited By ~ 5

Author(s):

Thomas R. Sinclair

Keyword(s):

Climate Change ◽

Crop Response

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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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