Hong Kong getting hotter as a result of global warming

Research conducted by the Hong Kong Observatory indicates that Hong Kong is getting warmer in line with the global warming trend.

In rural areas, the rate of warming is about 0.2 degree Celsius per decade, while at the Observatory's headquarters in the heart of urban Hong Kong the corresponding rise is about 0.6 degree. The difference of 0.4 of a degree can be attributed to the effects of urbanisation.

In recent years, global warming and the associated climate change have become the focus of scientific research. The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 to provide governments and the international community with authoritative scientific assessments on climate change, its potential impact and the possible response strategies.

According to the IPCC's latest assessment report, the global average surface temperature rose by approximately 0.6 degree in the 20th century due to increases in the concentration of greenhouse gases in the atmosphere.

The Hong Kong Observatory has been accumulating temperature reading for the past 118 years. Analysis of the temperature data indicates that there was an average rise of 1.2 degrees per 100 years.

The annual mean temperature rose from 22.0 degrees Celsius in the late 19th century to a mean of 23.5 degrees in the most recent decade. The warming has become significantly faster in the past 10 years or so, reaching 6 degrees per 100 years.

As global warming and the associated changes in the global climate system will have a significant impact on eco-systems, human health, and social and economic activities, the issue of climate change has caused great concern among governments and the public.

"According to the IPCC's assessment, there is a global warming trend," the Assistant Director of the Hong Kong Observatory, Mr Yeung Kai-hing, said today (August 1).

"For the Northern Hemisphere, the 1990s was the warmest decade since instrumental records began in 1861, and 1998 was believed to be the warmest year during the past millennium. Something similar occurred in Hong Kong," he said.

"The 1990s was the warmest decade since records at the Observatory began in 1885; and 1998 was the warmest year with a mean temperature of 24.0 degrees. Among the seven hottest years, six occurred after 1990."

Mr Yeung said that to evaluate the potential impact of global warming, it was possible to compare the temperature trend at the Hong Kong Observatory Headquarters with the global trend.

This shows that the temperature at the Observatory followed more or less the same trend as the global temperature during the pre-World War II period.

In the post-war years, there were two periods with notable temperature rises at the Observatory. The first was from the mid-1950s to the mid-1960s. The second begins in the 1980s, and ties in with the global trend of significant warming in the past two decades.

Mr Yeung said this faster rate of warming could be attributed to the effects of high density urban development. However, at Cheung Chau, there had been no significant rise in temperatures since the 1970s, indicating that changes in temperatures over the seas around Hong Kong were small.

"The Hong Kong Observatory attaches great importance to climate change. It is not only a scientific issue, but is also closely related to the environment, energy use and economic activities," he said.

Various computer climate models forecast a continuing rise in the global average temperature, of 1.4 to 5.8 degrees from 1990 to 2100. This would result in further changes in the global climate system.

"The Observatory will strengthen its research on climate change and promote public understanding of this subject. We will also actively co-operate with other government departments and the World Meteorological Organisation in the field of climate change, contributing towards the greater goal of sustainable development," Mr Yeung said.

End/Friday, August 1, 2003