Has global warming hit Hong Kong? Count cold days, not hot ones, to decide

I refer to the report (“Record May heat just the start, Observatory says”, November 30). The temperature records broken in May are best explained by the sun’s heating capacity in combination with the poor dispersion of heat generated by human activities under the abnormally dry, calm and cloudless conditions.

A better indication of local warming trends, if any, is to look for a declining number of cold days (defined as equal to or below 12 degrees Celsius) each winter, typically during the months from December to March.

Time to break out the winter coats, there’s a cold snap coming

During the 2017 winter there were 54 cold days at the rural Pak Tam Chung station but only 22 cold days at the Observatory’s headquarters station. Rural stations less influenced by urban heat are obviously better than urban stations in indicating natural variability.

The Observatory should consider doing a reanalysis of temperature records based on the number of cold days each winter instead of the number of cold days each year. Contrary to the Observatory’s alarmist claim on global warming, Nasa has already indicated that the sun is currently entering a new phase of low sun spots which may result in a mini ice age.

Wyss Yim, Pok Fu Lam