A methane leak from a natural gas field outside Chongqing in southwest China was partly the cause of the area's worst drought on record, claimed an atmospheric scientist yesterday.
But despite support from another academic, other scientists believe the severe drought, which has affected both Chongqing and next-door Sichuan Province, has a simpler explanation abnormal weather conditions.
Kuang Yaoqiu, a researcher with the Guangzhou Institute of Geochemistry under the Chinese Academy of Sciences, said: "Methane contributes to the greenhouse gas effect, which is regarded as a major factor behind the heat wave and drought."
Kuang started studying the relationship between the methane leak and the drought when he returned to Guangzhou, capital of south China's Guangdong Province, from a weather seminar in Russia a week ago.
He was asked by a reporter from the Guangzhou-based Nanfang Daily to comment on a view that the drought was related to the Three Gorges Project.
"The Three Gorges Project has had little impact," Kuang told China Daily yesterday.
But afterwards he began looking at the methane leak five months ago in Kaixian County in Chongqing.
The leak triggered a massive explosion at a gas well on March 25. There were no injuries, but more than 5,000 local residents had to be evacuated.
"I noticed that the drought and heat wave in Chongqing actually began in May, shortly after the leak," Kuang said.
Drought and hot weather have also hit most areas of inland China since May.
"But it is only in Chongqing, where the methane leak occurred, that the drought has been severe and persistent," Kuang added.
Chongqing had no rain for more than 80 days until earlier this week, and two-thirds of its rivers have dried up.
"When the methane was emitted into the air it raised air temperatures which, as a result, intensified the greenhouse gas effect there," Kuang claimed.
The scientist's opinion was backed up by Peng Taoyong, a researcher with Guangdong Meteorological Bureau.
"The methane leak has intensified the greenhouse gas effect around Chongqing, partly leading to the high temperatures," Peng told China Daily yesterday.
He has been studying tropical disasters, including typhoons, storms and droughts, for many years.
"The increasing greenhouse gas effect in inland China has been blamed for continuous drought and heat waves," he added.
But sources with the Chongqing Meteorological Bureau said abnormal airflows were one of the main causes of the region's heat wave.
"Subtropical high pressure from the western Pacific Ocean hanging over southwest China has been stronger than ever before," Cheng Bingyan, an official with the bureau was quoted by Xinhua as saying.
Cheng added that recent coastal typhoons had also pinned down pressure and prevented it from moving on.
"Besides that, cold air from north was weaker than before, which has not helped cool down the pressure," Cheng said.
(China Daily August 24, 2006)