HK, Guangzhou get warning on warming

PUBLISHED : Tuesday, 21 August, 2007, 12:00am
UPDATED : Tuesday, 21 August, 2007, 12:00am

The climates of Hong Kong and Guangzhou have warmed twice as fast as the global average in the past century and the situation is worsening, a mainland research institute warned yesterday.

Peng Shaolin, the former vice-president of the Chinese Academy of Science's Guangzhou branch, said temperatures in the two cities rose by an average of 1.2 degrees Celsius over the past 100 years, compared with the global average of 0.6 degrees.

Professor Peng, who heads Sun Yat-sen University's ecology institute, said southern China was one of the areas that had been experiencing the effects of global warming more deeply than other parts of the world.

'And we believe the temperature rise [in Hong Kong and Guangzhou] will still be faster than the global average in the future,' he said.

He said the temperature in Hong Kong and Guangzhou had risen more quickly mainly because of the 'heat island effect'.

Hong Kong should be in a perfect place to be cooled by offshore winds, but 'the skyscrapers and the increasing population density have made it difficult for the island to get rid of heat', Professor Peng said.

He added that heavy use of air conditioners and cars in the two cities had destroyed the natural weather system and that urbanisation had created severe air pollution that acted like a layer of thin film to restrict heat release.

'Hong Kong and Guangzhou must pay close attention to the heat island effect because the situation in Guangzhou is serious and getting worse,' he said.

Professor Peng said his research found that Guangzhou's biggest forest, on Baiyun Mountain, generated 2,100 tonnes of oxygen for nearly 3 million people every day but about 10 per cent of it was threatened by vines growing rapidly in hot weather. 'The vines kill other plants by covering them and stop their photosynthesis.'

Other researchers find that the vines have already killed off dozens of hectares of the mountain's forest.

Previous studies indicated that the mainland was warming at an average 0.4 degrees every 100 years, but that in some parts of the country, such as Tibet , the process was much faster.

Mainland media reported last month that Tibet was warming by 0.3 degrees every 10 years, faster than any other part of the world.

'Tibet is extremely sensitive to temperature changes because of its altitude,' Professor Peng said.

'A German meteorologist has warned that the biosystem in some parts of the world will collapse after global temperatures increase by an average of 3 degrees Celsius,' he added.