Environment & Health Hong Kong

Why are cotton tree flowers not blooming? Ex-Hong Kong Observatory chief warns of climate change

Former director of the Hong Kong Observatory Lam Chiu-ying has warned of climate change by detailing his observations of a cotton tree in his neighbourhood.

Lam, a meteorologist, served as the head of the Observatory between 2003 and 2009. After stepping down, he remains vocal about environmental issues and has criticised the government over development plans.

tiandiyouqing

Photo: tiandiyouqing.blogspot.hk screenshot.

In a blog post on Wednesday, Lam said that the flowers of the cotton tree near his home had started to blossom. But comparing the number of old leaves that experienced the winter, and the new leaves that had sprung, the flowers appeared to be recoiling, he observed.

This, he said, stands in contrast to the situation in previous years when the tree branches would be bare and the flowers would bloom furiously: “This is a sign of global warming.”

Lam explained that, according to the life cycle of trees, the leaves are supposed to wither and fall onto the ground so as to allow the tree to store more energy and encourage the blooming of red flowers as spring arrives.

However, if the winter was not cold enough and the leaves do not wither and fall, it will continue sapping energy from the tree and there will not be sufficient energy left for flowers to fully bloom.

cotton tree

Photo: Stand News.

Lam said that some HongKongers may question why the weather is cold if there is indeed global warming – as there were days with low temperatures in January and February. However, he said they fail to understand that global warming is a worldwide phenomenon and reflects an overall trend of over a century.

“[T]his is mistakenly believing that a couple of days in Hong Kong is representative of a hundred years on Earth,” he added.

“The cotton tree objectively reacts to the world and would not lie like human beings; its recoiling flowers tell us that the climate has changed…”

Lam also wrote about the topic in 2016.


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Why are cotton tree flowers not blooming? Ex-Hong Kong Observatory chief warns of climate change