In recent years, the growing toll of extreme heat in urban environments has captured global attention, especially in the Global South. This alarming trend is backed by a new investigation highlighting the significant disparities in “cooling capacity” between urban areas in the Global North versus those in the Global South. While cities in affluent nations boast more greenery that effectively mitigates heat, many cities in developing countries suffer from a dearth of urban green spaces. This imbalance is concerning as extreme temperatures lead to an increase in heat-related illnesses and fatalities among vulnerable populations.
As urban environments continue to absorb the impacts of climate change, the phenomenon known as the “urban heat island” effect—with urban areas remaining considerably warmer than their rural counterparts—exacerbates this public health issue. The absence of adequate green spaces in cities in the Global South means that they are not only inadequately equipped to handle heat stress but are also failing to provide vital sanctuary areas for individuals seeking relief from soaring temperatures.
Recent research published in the journal Nature Communications assesses the effectiveness of urban greenery in cooling cities around the world. The findings indicate that cities in the Global South have only about 70% of the cooling benefits enjoyed by their counterparts in the Global North. This disparity highlights an urgent need for strategic investments in urban green infrastructure to mitigate the effects of heat and improve overall urban resilience.
The study utilized satellite data focusing on the 500 largest cities, revealing that the top cities for cooling capacity are predominantly located within the United States. Cities such as Charlotte and Raleigh-Durham stand out due to favorable demographics and urban planning practices that prioritize green spaces. Conversely, cities like Mogadishu in Somalia and Sana’a in Yemen rank among the lowest in cooling capacity, underlining the severe impact of limited green infrastructure on the health of urban populations in these regions.
The consequences of failing to address the lack of urban green space in the Global South are dire. The intersection of rising temperatures and urbanization poses significant challenges, especially in less economically developed regions where populations are dense and resources scarce. These cities are particularly vulnerable to extreme heat, with scientists predicting that without proactive intervention, substantial portions of the world’s population will experience dangerously high temperatures by the end of this century.
Regions like India and Nigeria already face significant heat risks. Vulnerable groups, particularly those living in slums with little-to-no access to cooling facilities, will be hit hardest unless communities see a shift towards strengthened urban planning that includes extensive greenery.
To combat this growing crisis, experts emphasize the necessity of investing in and promoting urban green infrastructure across the Global South. Strategies may include creating more parks, enhancing existing green spaces, and planting tree canopies in densely populated areas.
Enhancing urban greenery is not merely an aesthetic ambition; it serves a critical function in reducing urban temperatures, as highlighted by Professor Tim Lenton from the Global Systems Institute at the University of Exeter. Green spaces can contribute to cooling urban areas by an average of 3°C during warm seasons, a seemingly small number that can make a tremendous difference during periods of extreme heat.
However, the task will not be simple. Initial costs can be substantial, and ensuring sufficient maintenance once green spaces are established is vital for long-term effectiveness. Collaboration among governments, non-governmental organizations, and local communities will be crucial to executing these initiatives.
Sustained investment in urban greening is not just an environmental or engineering challenge—it’s a matter of public health equity. Addressing the cooling capacity deficit in cities of the Global South is of utmost importance for safeguarding millions of lives. Policymakers must prioritize these initiatives, as the health and well-being of urban populations in developing regions depend heavily on our response to climate change and its myriad effects. Global efforts to enhance urban infrastructure, particularly through the lens of ecological design, will play a pivotal role in fostering more resilient, livable cities capable of withstanding the challenges posed by extreme heat in the coming decades.