Hong Kong faces extreme heat as reliance on air conditioning grows amid global warming

In an era of extreme summers, it’s time to look beyond air conditioning

In Hong Kong, air conditioning is ubiquitous but conventional models harm the environment. More responsible solutions are needed

The Labour Department recently upgraded its Heat Stress at Work Warning system, making it easier for higher-tier alerts to be sent out, so that employers and workers, especially those who have to work outdoors, can react quickly during very hot weather.

Unfortunately, the most we seem to be able to do is issue warnings and recommend passive mitigation measures such as relaxing the work schedule, resting in the shade and staying hydrated. We are sitting ducks as temperatures peak year after year.

This has been a testing summer with multiple record-breaking hot days across the globe. In 2024, Hong Kong’s hottest year on record since 1884 saw 52 very hot days (33 degrees Celsius or higher) and just two extremely hot days (35 degrees or higher); the highest temperature hit that year was 35.7 degrees in September. This year, we have already seen three extremely hot days in August alone and a record high of 36.9 degrees – according to the Observatory in Tsim Sha Tsui; at the Sheung Shui weather station, the mercury hit 39.8 degrees. This is a terrifying rate of increase.

How much human action has contributed to the extreme weather we are experiencing is up for debate. Are the heatwaves, super typhoons and storms, torrential rains and floods, and severe droughts around the world the result of irresponsible climate crimes we have committed? While it is easy to point fingers, empirical science demands solid evidence and data analysis.

What we do know, for certain, is that the heatwaves in Asia are linked to a strong El Nino pattern developed in the Pacific Ocean when waters became warmer, affecting trade winds. No country in Asia was entirely spared from the extreme weather and all have developed some form of advisory system and national processes to battle the heat.

Hong Kong was able to handle the heat a bit better but only because we are spoiled by the convenience of air conditioning. From high-end homes in wealthy neighbourhoods to deteriorating tenement houses in dilapidated districts, condensation units are a familiar sight and strolling in the city’s overly air-conditioned shopping malls has become a sport for common folk during the summer.

In contrast, European countries, for instance, were not so lucky. Many had no air conditioning but this was not only because of regulatory restrictions, historic preservation mandates or environmental concerns. The continent historically enjoyed mild and short summers, so buildings tended to adopt passive cooling measures, which used to be able to handle the warmest days; it would be a technical challenge to retrofit many of these structures. Also, given that energy costs in Europe are significantly higher than in North America or Asia, air conditioning is a luxury few can afford.