Search Results (7)

As urban areas expand rapidly, understanding the complex interactions between human migration, climate change impacts, and biodiversity loss is crucial for effective climate policy. However, comprehensive knowledge of the simultaneous interaction of these aspects is still scarce. Thus, this paper proposes the classification of ‘Climate Emergency Coastal Cities’, with the categorization of 43 cities into four levels according to their vulnerability (extreme, very high, high, and critical). Our study contributes to evidence-based climate policy and supports efficient resource allocation and interventions for the most vulnerable coastal cities. Highly anthropogenic megacities were ranked as the most sensitive to climate emergencies (Lagos, Nigeria; Jakarta, Indonesia; Los Angeles and Houston, USA; and Hong Kong and Shenzhen, China). It is noteworthy that in countries from both the Global North and South, the entry of new populations is a critical issue, and represents a threat to urban structures and biodiversity; however, in territories with fragile economies and numerous governance challenges, the required structure is still more challenging. The study concludes that integrated urban planning policies are crucial, considering various perspectives and coordinated actions. Policies should address marginalized urban groups and include migrants, and promote human well-being, ecosystem recovery, and climate mitigation, for effective adaptation. Full article

The complex and multidimensional effect of climate change, coupled with low socioeconomic development, in Sub-Saharan Africa (SSA) makes the region vulnerable to the changing climate and threatens its inhabitants’ survival, livelihood, and health. Subnational actions have been widely acclaimed as effective in combatting climate change. Local governments in SSA have been developing and implementing climate action plans to reduce greenhouse gas (GHG) emissions. In this article, we qualitatively assessed climate change mitigation technical pathways at the city level by studying four major African megacities’ climate plans and actions. The cities studied are Accra, Ghana; Addis Ababa, Ethiopia; Lagos, Nigeria; and Nairobi, Kenya. This study provides insight into the novel and innovative policy design and instrumentation options to sustainably address climate change mitigation in SSA. With the past literature focusing on climate adaptation for the Global South, this study shows leading context-specific efforts in climate change mitigation that simultaneously address local sustainable development needs. Our assessment identified the prioritized technical pathways for climate change mitigation in the selected cities, as well as innovative techniques and areas for improvement. Given that it also identifies emerging best practices, this study’s findings can be helpful to local governments and practitioners pursuing local deep decarbonization and international organizations supporting these programs. Full article

There have been increasing calls in gentrification studies to examine the geography of gentrification in slums, as little is known about the patterns and processes of slum gentrification, especially in sub-Saharan African cities where slums house over 50% of the urban population. This study explored the spatiotemporal changes in slums in Lagos, Nigeria, between 1984 and 20 on the pattern and drivers of gentrification. Data were collected from 42 slums in Lagos through remote sensing (1984–2020) and a field survey (2020–2021). The study integrated geospatial analysis with quantitative and qualitative analysis to investigate the patterns and drivers of gentrification in Lagos slums. The findings show that between 1984 and 2020, all the sampled slums had undergone gentrification processes, apart from those that were completely cleared. However, many slums continue to have deprived areas as they continue to gentrify. Almost all the slum communities have experienced slum clearance in the past. Additionally, the current and new housing developments in the study have favored middle- to high-income groups, which has led to the displacement of previous slum residents. The study identified slum clearance, fires and floodings, the presence of palaces in the community, the proportion of deprived areas in 1984, government interest in the slum, and the size of the church as drivers of slum gentrification processes in Lagos. Finally, the findings show that the vulnerability of slum dwellers increases with slum gentrification. Therefore, this study recommended developing policies and programs, such as sustainable relocation and low-cost housing, to mitigate the negative consequences of slum gentrification, especially in cities with significant shares of low-income groups. Full article

As one of the swiftly advancing megacities globally, Lagos faces significant challenges in managing its urban expansion. Mainly, this study focuses on monitoring and predicting urban growth using a comprehensive approach incorporating Global Land 30 (GL30), satellite-based nighttime light observations, and built-up and population density data. The application of remote sensing techniques, combined with utilizing the GL30 dataset, provides an effective means to monitor and predict urban growth trends and patterns. The major patterns occurred from 2000 to 2020, including increased cultivated land; reductions in grasslands, shrublands, and wetlands; and major urbanization. Predictive models indicate that urbanization will continue. Furthermore, employing the Cellular Automata (CA) Markov model in land-use and land-cover (LULC) change prediction. The findings revealed significant changes in LULC over the two decades. Particularly, the percentage of artificial terrain increased from 17.016% to 25.208%, and the area under cultivation increased significantly, rising from 46,771 km² (1.238%) in 2000 to 75,283 km² (1.993%) in 2020. Grasslands fell from 7.839% to 1.875%, while forest cover somewhat increased, climbing from 39.319% to 43.081%. Additionally, marshes fell from 9.788% to 5.646%, while shrublands decreased from 4.421% to 2.640%. Surprisingly, bare ground decreased sharply from 0.677% to 0.003%. To forecast future LULC changes, the study also used a Markov Chain Transition Matrix. According to the data, there is a 3.54% chance that agricultural land will become urban, converting it from being used for agriculture to urban development. On the other hand, just 1.05% of forested regions were likely to become municipal areas. This study offers foundations for the upcoming research to enhance urban growth models and sustainability strategies in the face of rising urbanization and environmental concerns in the region, as well as laying the groundwork for informed decision-making in the region. Full article

Rapid urbanization can lead to significant environmental contamination with potentially toxic elements (PTEs). This is of concern because PTEs are accumulative, persistent, and can have detrimental effects on human health. Urban soil samples were obtained from parks, ornamental gardens, roadsides, railway terminals and locations close to industrial estates and dumpsites within the Lagos metropolis. Chromium, Cu, Fe, Mn, Ni, Pb and Zn concentrations were determined using inductively coupled plasma mass spectrometry following sample digestion with aqua regia and application of the BCR sequential extraction procedure. A wide range of analyte concentrations was found—Cr, 19–1830 mg/kg; Cu, 8–11,700 mg/kg; Fe, 7460–166,000 mg/kg; Mn, 135–6100 mg/kg; Ni, 4–1050 mg/kg; Pb, 10–4340 mg/kg; and Zn, 61–5620 mg/kg—with high levels in areas close to industrial plants and dumpsites. The proportions of analytes released in the first three steps of the sequential extraction were Fe (16%) < Cr (30%) < Ni (46%) < Mn (63%) < Cu (78%) < Zn (80%) < Pb (84%), indicating that there is considerable scope for PTE (re)mobilization. Human health risk assessment indicated non-carcinogenic risk for children and carcinogenic risk for both children and adults. Further monitoring of PTE in the Lagos urban environment is therefore recommended. Full article

Polymer recycling is one of the major areas that need adequate intervention in any megacity’s effort toward sustainable development. However, megacities in Africa face various challenges in general waste management and also lag behind in developing efficient waste-to-wealth services. Therefore, this study examined the difficulties experienced by the actors involved in the value chain of polymer recycling in the Lagos megacity. Thirty in-depth interviews and four key informant interviews were conducted with value chain and supporting actors, while 400 questionnaires were administered among residents of Lagos metropolis. The study found that negative public perception, lack of adequate capital, poor health conditions, inefficient infrastructure, and technological difficulties are some of the problems in polymer recycling in the megacity. Therefore, social label redefinition, effective dissemination of recycling information, an efficient loan system, import duty relaxation, and stakeholder involvement are recommended. Full article

In this study, the hourly air temperature differences between City hall (urban) and Okoafo (rural) in Lagos, Nigeria, were calculated using one year of meteorological observations, from June 2014 to May 2015. The two sites considered for this work were carefully selected to represent their climate zones. The city core, City hall, is within the Local Climate Zone (LCZ 2) (Compact midrise) while the rural location, Okoafo, falls within LCZ B (Scattered Trees) in the south-western part on the outskirt of the city. This study is one of very few to investigate urban temperature conditions in Lagos, the largest city in Africa and one of the most rapidly urbanizing megacities in the world; findings show that maximum nocturnal UHI magnitudes in Lagos can exceed 7 °C during the dry season, and during the rainy season, wet soils in the rural environment supersede regional wind speed as the dominant control over UHI magnitude. Full article