Inside the race to prepare cities for extreme heat

In an effort to combat extreme heat, researchers at Stanford University are testing a simple and cost-effective solution: painting roofs white. In a settlement in Makassar, Indonesia, where nearly 40% of the population lives in informal communities with limited municipal services and air conditioning, temperatures often exceed 90 degrees Fahrenheit.

By applying bright white paint to just a few of these corrugated metal roofs, Stanford's Makassar project led by Rishee Jain aims to lower indoor temperatures by up to 5 degrees Fahrenheit, which can be crucial during heat waves.

Heat waves pose significant health risks, exacerbating conditions like cardiovascular disease, diabetes, and asthma, and increasing susceptibility to illnesses such as dengue fever. As global warming continues, the frequency and intensity of heat waves are expected to rise worldwide, with some regions experiencing an additional 50 heat-stress days annually.

Researchers at Stanford are not only focusing on individual buildings but also on entire cities. John Openshaw, leading the white-roofs project, emphasizes the need for quick interventions due to the limited time available. Climate scientist Noah Diffenbaugh notes that many human and natural systems will struggle under the increasing frequency of extreme events, even if global warming is eventually curbed.

The researchers are also considering the challenges faced by cities historically with mild climates, such as San Francisco, London, and Paris, where air conditioning is scarce and buildings were designed to retain heat. Gregory Deierlein, an engineer at Stanford, is exploring ways to help cities prepare for multiple hazards, including heat waves, earthquakes, and wildfires.

By assessing building vulnerabilities and developing comprehensive solutions, the team aims to improve public health and safety in the face of increasingly common and extreme natural disasters.