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Climate change

No way Hong Kong is about to enter a mini ice age, never mind the global warming deniers

    PUBLISHED : Monday, 17 December, 2018, 11:02am
    UPDATED : Monday, 17 December, 2018, 11:01am

    I refer to the letter from Wyss Yim (“Cold days each winter hold the key to climate”, December 7). It is almost a predictable pattern that climate change deniers will pop up and exaggerate the effect of solar activity on the Earth’s temperature whenever there are reports of anticipated decrease in solar activity. The climate myth of “low sun spots may result in a mini ice age” or the like has long been debunked.

    Your readers are referred to our blog titled “Can a quiet sun halt warming on Earth?” for more details. In essence, the contribution of solar activity to the variation in the Earth’s temperature is rather insignificant, as compared to the fast-growing influence of human-caused increase in greenhouse gases (“UN weather group: Greenhouse gases in air rose again in 2017”, November 22).

    In the meteorological community, winter in the northern hemisphere is usually defined as December-January-February. Temperature records taken at the Hong Kong Observatory and the Pak Tam Chung weather station both show an obvious decreasing trend in the number of cold days, be it measured in terms of calendar years or meteorological winters.

    To set the record straight, there were 21 and 46 cold days logged at the Observatory and Pak Tam Chung, respectively, in the winter of 2017-18.

    It should be noted that, in a warming climate, the chance of breaking high temperature records is higher compared to a stationary climate. The odds could be enhanced further when favourable weather conditions set in, for example, the persistence of a ridge of high pressure, bringing prolonged fine weather to the affected region.

    Lee Sai Ming, senior scientific officer, Hong Kong Observatory