Actual real numbers are here:
The university press release that your link cites says:
It's an important source, but it's not what should be attacked first. Coal, oil, gas production, rice cultivation, etc., are much, much more important sources.
Cheers,
Scott.
3. Anthropogenic Sources
3.1 Rice Cultivation
What we know:
Rice production may account for 10% (~30-60 Tg) of the total annual methane emission.
Since 1980, rice production has risen by over 40% through the combined effects of increased harvest areas and higher yields.
Over 90% of the harvested area is confined to Asia.
The university press release that your link cites says:
VANCOUVER, Wash. – Washington State University researchers say the world’s reservoirs are an underappreciated source of greenhouse gases, producing the equivalent of roughly 1 gigaton of carbon dioxide a year, or 1.3 percent of all greenhouse gases produced by humans.
It's an important source, but it's not what should be attacked first. Coal, oil, gas production, rice cultivation, etc., are much, much more important sources.
Cheers,
Scott.