Scorching summers set to become the norm, warns expert

August 05, 2016 17:32
Hong Kong could see summer temperatures of 40°C in future, says Prof. Gabriel Lau. Photo: HKEJ

It is getting common nowadays to see news reports warning us that temperatures in Hong Kong will keep hitting new highs during the summer months and also more frequently than ever before.

For instance, the city recently experienced its hottest July day in 48 years, with several districts recording temperatures of 37 degrees Celsius and higher.

Gabriel Lau Ngar-cheung, AXA Professor of Geography and Resource Management and director of the Institute of Environment, Energy and Sustainability at the Chinese University of Hong Kong, says that despite the record temperatures most Hong Kong people still seem unconcerned about climate change and appear to have low environmental awareness.

With worsening global warming, Hong Kong could see summer temperatures of 40°C in future, while also facing the prospect of more fierce rainstorms and stronger typhoons, Lau warned.

"Though it is highly related to people's livelihood, the public doesn't seem to grasp the impact of climate change when they are told that global temperature has increased by two or three degrees Celsius," he says. "However, it will be much easier to conceptualize if we warn that the number of hot nights in the city will surge in the near future."

Hot nights, by definition, refer to days with a minimum temperature of 28°C or above.

"Forty or fifty years ago, there were only three or four hot nights in summer on average, but now such nights are up more than 10-fold, with 30 to 40 such nights annually in recent years," the professor says.

When the Hong Kong Observatory was first established in 1883, the set record of a severe rainstorm yielded only a few dozen millimeters in an hour. But now, we often hear something like 150 millimeters within an hour, Lau added.

It is necessary to reduce emissions to alleviate climate change, he said, arguing that such initiative works like insurance.

The 2015 United Nations Climate Change Conference was regarded as a historic turning point, as the participating 195 countries agreed by consensus to reduce their carbon output "as soon as possible".

Lau says it can serve as a good start, but warned that even if every participant delivers on their promise, it is unlikely to keep global warming "to well below 2 degrees Centigrade".

What also worries him is that Hong Kong is rather unprepared for coping with climate change.

Outlining a series of potential problems associated with global warming, Lau warned that senior citizens and those with respiratory illnesses will suffer most amid rising temperatures.

Also, there is the prospect of electricity black-outs as households and offices use air-conditioning for long hours, putting a huge strain on energy resources.

In terms of public health, the city's healthcare system could come under stress due to epidemics caused by tropically active insects as they thrive in Hong Kong due to increased temperatures.

Among other potential problems, Hong Kong may also need to brace for potential floods in the city's underground railway system and places in low-lying coastal areas.

Lau says there is a lot that Hong Kong can do to safeguard its environment, an aspect that hasn't received enough care over the years.

Citing an example, he pointed out that waste-sorting efforts have been too slow in the city and that many items that can be recycled are instead ending up at landfills.

The society as a whole must develop greater environmental awareness, with each citizen making a conscious effort to go green in their daily lives, Lau said.

Only through a concerted drive can we ensure a more sustainable future for our city, he said.

This article appeared in the Hong Kong Economic Journal on Aug. 2.

Translation by Darlie Yiu

[Chinese version 中文版]

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Writer of the Hong Kong Economic Journal