Handbook for urban heat management in the global south

The year 2024 was the warmest on record, coming on the back of a record-breaking decade of escalating
global average temperatures (WMO 2025). Global temperatures have risen by nearly 1.5 degrees Celsius
(°C) above pre-industrial levels causing more extreme temperature peaks making heatwaves more common, more intense, and longer-lasting (Lee et al. 2023). On average, globally, a heatwave that would have occurred once in 10 years in the pre-industrial climate will now occur around every three years, and that heatwave will likely be 1.2°C warmer (WMA 2024). Meanwhile, if the world hits 2°C of global warming, heatwaves would, nominally, occur every two years and be 2.6°C hotter. Even small increases in mean temperature have detrimental effects on people’s health and livelihoods especially of vulnerable groups, local economies, urban infrastructures, and the environment (Lee et al. 2023).
Extreme heat is a silent killer and one of the deadliest climate risks. Estimates show that, between 2000 and 2019, approximately half a million heat-related deaths occurred globally each year, with many remaining unreported in official statistics (Ballester et al. 2021). High temperatures reduce productivity, resulting in increased economic costs and a slowdown in sustainable development. Economic losses range from 8 percent of gross domestic product (GDP) per capita per year in the poorest regions
to 3.5 percent in the wealthiest regions (Callahan & Markin 2022). Everyone is at risk, but impacts are unevenly distributed across the population with respect to physical and socioeconomic factors. Low-income families, very young and old people, people living with chronic health conditions, pregnant women, and outdoor workers are some of the groups that are particularly vulnerable to extreme heat.
Cities are at the heart of the issue. Cities tend to be hotter than their surroundings; this phenomenon is measured and described as the urban heat island (UHI). Cities can be up to 10°C hotter than their surroundings (Alonzo et al. 2021). These pockets of higher temperatures develop when built-up areas, like tarmacked roads and buildings, store heat while narrow streets with high buildings trap heat.

source:

https://openknowledge.worldbank.org/entities/publication/92e9d108-0c0a-4369-b22a-fba4ba850d1c