Trends: socio-economic, climate changeHong Kong’s high wealth comes with a high demand for water and energy, for which Hong Kong is almost completely reliant on import. This makes the coastal city susceptible to climate stressors in the surrounding regions, particularly in the Pearl River Delta.
Records dating back to 1885 show that the annual mean temperature of Hong Kong exhibits a long-term increasing trend. During 1982-2011, the annual mean temperature increased by about 0.2°C per decade. The temperature rising trend is a result of global warming and local urbanization. Compared with 1980-1999, a temperature rise of around 4 to 5°C is projected for 2090-2099. Furthermore, cold days will decrease but hot nights and very hot days are projected to increase for the rest of this century.
As climate change will cause an increase in the sea level and the amount of rainfall, the need for improving drainage infrastructure to protect lives and properties against flooding is pressing. Exacerbated flooding in its turn would affect the economy, public works and promote the growth of disease.
Sea level rise is likely to cause saline water intrusion. In Hong Kong this is however not an issue as most of the fresh water supply is imported. Agriculture and industries have almost been phased out throughout Hong Kong and there will thus be little damage in these sectors.
On average, Hong Kong is affected by about six tropical cyclones each year. With climate change, while the frequency of tropical cyclones affecting Hong Kong is not expected to increase significantly, there will be more days with heavy rain by the end of the century. During these rainstorms, the rural low-lying areas and natural flood-plains in the northern part of the territory and some locations in the older urban areas would be subject to flooding.