Oregon Public Broadcasting

Soot from cars and power plants causes snow to melt faster. That’s the conclusion of a new study from the Pacific Northwest National Laboratory in Richland, Washington. Correspondent Anna King reports.

Soot gets deposited on snow. It’s hard to see. In fact, without clean snow to compare it to, you probably wouldn’t even notice. But that soot builds up and the particles absorb the sun’s energy instead of reflecting it like clean snow does.

One of the scientists who worked on the study is William Gustafson. He says soot can warm up the snow and air around it by more than one degree.

That may not sound like much, but Gustafson says dirty snow can melt weeks earlier than pristine snow.

William Gustafson: “Depending on where you are, to which mountain range you are looking at and things like that, you can get an earlier melt of a couple of weeks or a month earlier in the snowy regions.”

And that leaves less water for the middle of the summer. Bad news for fish, farmers and power generators.

The study will be published in the Journal of Geophysical Research-Atmospheres.