Reservoirs found to emit more methane than was previously thought
Researchers at Washington State University have found that the world’s reservoirs are producing the equivalent of all the greenhouse gases produced in Canada.
As reported in the journal BioScience and by phys.org, the work by the U.S. academics has found that reservoirs emit roughly 1 gigaton of carbon dioxide per year, which is about 1.3% of all the greenhouse gases produced by humans.
They say that reservoirs are a particularly important source of methane, which is 34 times more potent than carbon dioxide over a century.
The authors found that the total rates of methane emissions from reservoirs are higher per area than reported previously -— by about 25%. The analysis drew on “scores” of other studies and is the most comprehensive study to date of the links between reservoirs and greenhouse gases.
They acknowledge that reservoirs have an important function in power generation, flood control, navigation and water. But these man-made lakes alter the ecosystem because they tend to flood large amounts of organic matter that produce carbon dioxide, methane and nitrous oxide as the vegetation dies and breaks down. They say reservoirs also receive a lot of organic matter from upstream rivers, “which can further stimulate greenhouse gas production.”
The WSU researchers are the first to consider methane bubbling in models of reservoir greenhouse gas emissions.
The publication of the report in phys.org triggered a long trail of 37 comments debating the issue.
To read the article in phys.org, click here.