최근 저명한 과학자들이 이끈 연구의 결과에 따르면 소형 댐에 저류된 물에서 나오는 메탄이 이전 예상 수치에 비해 상당히 높은 것으로 드러났다.

안드레아스 맥(Andreas Maeck)과 그의 동료들이 진행한 이번 연구는 ACS가 출판한 환경 과학과 기술(Environmental Science & Technology)저널에 게재되었다. 이 연구는 유럽 강에 위치한 6개의 소형 댐에 저류되어 있는 물에서 배출되는 메탄의 분석에 초점을 두며 이루어졌다. "우리가 연구한 결과는 주요한 강의 댐에서 발생하는 퇴적물이 배출하는 메탄이 전세계 깨끗한 물의 생산을 약 7% 가까이 방해할 수 있다는 것을 보여주고 있다."라고 보고서는 말하고 있다. 더 나아가, 보고서는 위와 같은 배출이 새로운 에너지 개발과 물 부족에 따른 댐 건설 유행으로 인해 계속 증가하고 있다고 말한다.

August 1, 2013 -- There are recent reports from leading scientists that indicate more methane than previously believed is emerging out of the water behind small dams.

A study by Andreas Maeck and colleagues, published in ACS Publications' journal Environmental Science & Technology, describes analysis of methane release from water impounded behind six small dams on a European river. "Our results suggest that sedimentation-driven methane emissions from dammed river hot spot sites can potentially increase global freshwater emissions by up to 7 percent," said the report. It noted that such emissions are likely to increase due to a boom in dam construction fostered by the quest for new energy sources and water shortages.

The report points out that the large reservoirs of water behind the world's 50,000 large dams are already a known source of methane. Like carbon dioxide, methane is one of the greenhouse gases, which trap heat near Earth's surface and contribute to global warming. Methane, however, has a warming effect 25 times more powerful than carbon dioxide. This methane comes from organic matter in the sediments that accumulate behind dams.

That knowledge led to questions about hydroelectric power's image as a green and nonpolluting energy source. Maeck's team decided to take a look at methane releases from the water impoundments behind smaller dams that store water less than 50 feet deep.

With the "green" reputation of large hydroelectric dams already in question, scientists are finding that millions of smaller dams on rivers around the world make an important contribution to the greenhouse gases linked to global climate change.

[출처: Waterworld / 2013년 8월 1일]