UCL in the News: Streams bounce back from decades of acid rain, study finds

Streams in central and eastern Canada, the northeastern U.

S., Scandinavia and Britain are returning to a natural brown after years of running clear because there's less acid rain polluting them, a new study has found.

The colour, similar to that of weak tea, comes from dissolved organic matter and is "indicative of a return to a more natural, pre-industrial state," the study's British, Canadian and American authors say in the science journal Nature. …

"A huge amount of carbon is stored in the form of organic deposits in soils, and particularly in the peatlands that surround many of our remote surface waters," said Don Monteith [UCL Environmental Change Research Centre].

"In the past two decades, an increasing amount of this carbon has been dissolving into our rivers and lakes, turning the water brown." …

Tom Spears, 'Ottawa Citizen'