Lakes emit greenhouse gases

Greenhouse gas emissions from inland waters are greater than previously thought, a Swedish-led study has found. As a result, nature's ability to absorb human emissions may be overstated, according to a study published in the journal Science. "In the debate, one often hears that the natural sinks can offset human fossil fuel emissions. Our results show that one cannot rely on it fully," said Professor David Bastviken of Linköping University, who led the study. Inland waters, including lakes, reservoirs, streams and rivers, are often substantial methane sources in the terrestrial landscape. However, they are not yet well integrated in global greenhouse gas budgets, wrote Bastviken. Data from 474 freshwater ecosystems and the most recent global water area estimates indicate that methane emissions from freshwaters correspond to 25 percent of all carbon dioxide, the study found...more