The impacts of urbanization and climate change on the urban thermal environment in Africa

The impacts of urbanization

The impacts of urbanization and climate change on the urban thermal environment in Africa

The impacts of urbanization can be seen in the twenty-first century as the century has witnessed an unparalleled wave of urbanization, particularly on the African continent. Cities are developing at an incredible rate as populations grow and economies flourish, resulting in the rapid modification of landscapes and the built environment but this is without consequences.


This urban growth, however, doesn’t happen in isolation; it intersects with the global phenomenon of climate change, generating a complex web of difficulties and repercussions for metropolitan places. The modification of the urban thermal environment is one of the most important challenges coming from this nexus.


For a variety of reasons, the connection between urbanization and climate change is a significant source of concern. First, because of the concentration of heat-absorbing materials, restricted vegetation, and increased energy usage, the consequences of rising temperatures are felt more acutely in metropolitan areas. Second, when cities grow, natural landscapes are replaced by impermeable surfaces, affecting natural cooling mechanisms and worsening heat-related problems. Third, the cumulative effects disproportionately affect vulnerable people, aggravating already existing social and environmental inequities.


Growing urbanization in Africa


Africa’s population is rapidly increasing, particularly in the East and West. According to Statista, Africa’s urbanization rate was expected to be approximately 44 percent by 2021. Since 2000, when urbanization accounted for 35% of the total population, the continent’s urbanization has gradually expanded. This percentage is anticipated to rise more in the following years. However, the proportion of the population living in rural and urban areas varies across the continent.


Gabon and Libya were the most urbanized countries in Africa in 2019, with each reaching 80%. In comparison, roughly the same proportion of the population lived in rural areas in Burundi and Niger, which had urbanization rates of only 13 and 17 percent, correspondingly. Between 1990 and 2015, roughly 4500 new cities were established in Africa, according to the OECD. Between 1990 and 2020, urban populations increased by nearly 500 million people.


Urban areas in these countries are experiencing severe spatial, social, economic, and environmental transformations. This is because of a variety of factors such as access to resources, technological innovation, global capital circulation, and the impact of climate change on main industry activities. As individuals migrated from rural to urban regions, many African cities grew unplanned, with a combination of commercial centers, industrial sectors, residential neighborhoods, informal settlements, and agricultural grounds.


Notwithstanding the economic advantages gained by many who relocated to cities, millions of Africans lack access to resources and facilities to meet their basic requirements, such as housing, water, food, health, and education. Over 59% of Sub-Saharan Africa’s urban population is projected to live in informal settlements. The perception that cities provide better economic prospects still draws numerous individuals to reside in cities. However, doing so exposes them to the effects of climate change.


Urbanization, climate change, and the thermal environment in Africa


The urban thermal environment of African cities is changing dramatically because of the combined effects of climate change and growing urbanization, as we are currently witnessing. Warmer temperatures and a rise in the incidence of extreme events attributed to climate change worsen how human activities affect the urban thermal environment. Furthermore, rising impermeable surfaces and shrinking blue and green spaces in and around urban regions limit atmospheric moisture played a role by evaporation and transpiration of urban areas’ latent heat flux.


The dynamics and consequences of the urban thermal environment can vary dramatically due to complicated interactions between biophysical variables such as air circulation, vapor pressure, and soil qualities. In addition, urban environments alter albedo and nocturnal radiation, and urban mobility increases greenhouse gas emissions, which are likely to raise local temperatures.


Over 300 million African metropolitan inhabitants are expected to be exposed to 15-day heat waves exceeding 42 degrees Celsius by 2100. Higher temperatures can have direct and acute consequences on the health of those most susceptible like children, the sick, and older people, as well as exacerbate indirect effects such as reductions in productivity, disease spread, water shortages, and interruptions of power supply.


Furthermore, as in Port Harcourt, Nigeria, high temperatures exacerbated by UHI would hasten the establishment of urban pollution islands with smog and dirty air, increasing respiratory problems. Overall, African countries are susceptible to rising temperatures. These climatic impacts have an economic cost and reduce GDP.


The complex interplay between urbanization and climate change has had far-reaching consequences for Africa’s urban thermal environment. With more people relocating to cities in search of greener pastures, the continent’s fast urbanization has resulted in the expansion of urban infrastructure and increasing energy consumption, which has contributed to the urban heat island effect (UHI). This phenomenon, exacerbated by climate change, has resulted in higher temperatures, deteriorating air quality, and general alterations to the urban thermal landscape.


These changes have far-reaching and varied consequences. Heat stress and health concerns connected with rising temperatures particularly impact vulnerable people, such as the elderly and low-income communities. Furthermore, the changing thermal environment has the potential to damage ecosystems, strain energy supplies for cooling, and reduce overall urban livability.


To address these issues, a comprehensive solution combining sustainable urban design, green infrastructure development, and climate adaptation measures is required. African cities can reduce the negative effects of urbanization and climate change on the thermal environment by implementing initiatives such as enhancing green spaces, promoting energy-efficient building designs, and incorporating climate-resilient technologies. International collaboration and knowledge-sharing will also be critical in identifying contextually appropriate solutions.

Related Post