Past and Future Changes in the Climate of Hong Kong

Over the years,the Hong Kong Observatory has carried out scientific studies to evaluate the observed climate trends and project the future climate in Hong Kong.Analysis of the meteorological observations at the observatory's headquarters in Tsim Sha Tsui since 1885 reveals that the temperature rise in Hong Kong during the past 124 years is in accord with the global rising trend. The accelerated rising trend in the mean temperature in last few decades may be attributed to the anthropogenic influences, especially urbanization.A similar increasing trend is also observed for rainfall.Other observations such as increasing cloud amount and decreasing total global solar radiation are all consistent with the global trend.Studies of past occurrences of extreme temperature and rainfall have also been carried out.The results indicate that cold episodes have become rarer while very hot days and heavy rain events are becoming more frequent.The observatory also makes use of the data from the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) and employs statistical downscaling techniques to carry out projections of temperature and precipitation in the 21st century.It is found that the rise in temperature in Hong Kong will be slightly higher than the global mean in the 21st century.The annual rainfall in Hong Kong is also expected to rise by the end of the 21st century,so is its year-to-year variability.