A recent study has revealed a troubling disparity in the “cooling capacity” provided by urban greenery between cities in the Global South and those in the Global North, making the former significantly more vulnerable to extreme heat. Conducted by an international team, including researchers from the University of Exeter, UK, the study analysed satellite data from 500 of the world’s largest cities, uncovering that cities in the Global South are equipped with only about 70 per cent of the cooling capacity found in their Global North counterparts.
As global temperatures continue to rise, exacerbated by the ‘urban heat island’ effect, cities are becoming much hotter than rural areas, leading to a surge in heat-related illnesses and deaths. The study, published in Nature Communications, highlighted that urban green spaces play a crucial role in cooling surface temperatures, reducing them by approximately 3 degrees Celsius during warm seasons. However, this benefit is unequally distributed. On average, Global South cities possess only two-thirds of the cooling capacity compared to those in the Global North.
This disparity stems from differences in both the quantity and quality of urban green infrastructure. Tropical and subtropical cities, located closer to the equator, tend to have weaker cooling capacities due to their geographical and climatic conditions. Consequently, cities in the Global South, which are often hotter and lower-income, are less equipped to combat rising temperatures with green infrastructure, despite their greater need for it.
The researchers identified vast potential for enhancing urban cooling in these regions, particularly in cities like Mogadishu, Somalia, which was found to have the lowest cooling capacity, followed by Sana’a in Yemen and Rosario in Argentina. The study underscores the urgent need for increased investment in urban green spaces in the Global South to mitigate the growing threat of extreme heat.
As global warming continues to intensify, addressing this disparity is crucial for reducing heat-related inequalities and protecting vulnerable populations, especially in densely populated and rapidly urbanising regions such as India and Nigeria. Without significant intervention, these cities will continue to face the brunt of climate change, with dire consequences for public health and wellbeing.