Abnormal weather fronts that have battered China of late mostly stem from national particular geographic climate conditions, according to Gu Wanlong, director assistant of the China Meteorological Administration Climate Center.
Some experts have sought to point the finger at global warming for the recent extreme weather conditions, claiming that the unbalanced distribution of rainstorms, sky-high temperatures, prolonged periods of drought and powerful typhoons are proof of the realities of climate change.
However, according to Gu, China's rainy seasons are dictated by the movements of monsoons and these can cause either massive flooding or crippling drought.
"The strength of the summer monsoon determines the location of main rainbelt," said Gu. "This year, the summer monsoon hit China later than in previous years, leading the rain to slowly drift northwards along the Yangtze River and Huaihe River. Therefore, most of the rainstorms were centered on the Huaihe River instead of the middle and lower reaches of Yangtze River."
Similarly, Sichuan's rainstorms and drought can also be blamed on sub-tropical weather front movements, leisurely shifting north from the southern oceans. "Therefore, once warm and moist air encounters cold air, precipitations will occur," explained Gu.
This reason also caused the widespread droughts throughout Sichuan and Chongqing in 2006.
Gu explained that agents for climate change interact in five distinct five spheres of the earth, namely the atmosphere, hydrosphere, cryosphere, lithosphere and biosphere, although sun radiation and planetary movements play a part. Although human activities such as industrial production play a part, no solid evidence exists to chart their exact influence on climate change outside the greenhouse effect.
In this conundrum lies the debate as to the real effect of the greenhouse effect on climate change and on whether it will continue to have an impact.
Certain Chinese experts have stated that an accumulation of greenhouse gases caused floods in the south amidst increased precipitation while leaving the north afflicted by drought. On the other hand, the decrease of greenhouse gases would shift the rain belt to the north and trigger an opposite reaction.
Floods and drought have been a permanent fixture in Chinese headlines since June, with over 700 people killed in floods, landslides, mudslides and storms across 24 provinces and 82.05 million affected.
More than 533,000 houses collapsed and close 26.18 million hectares of farmland were affected, resulting in 73.58 billion yuan (US$9.68 billion) in direct losses, according to a report from the Ministry of Civil Affairs.
(China.org.cn by Huang Shan, August 1, 2007)