B.C. flood shows how climate change could fuel atmospheric river storms

Atmospheric rivers of the kind that flooded British Columbia will become larger and possibly more destructive because of climate change, scientists say.

Columns in the atmosphere hundreds of miles long carry water vapour over oceans from the tropics to more temperate regions in amounts more than double the flow of the Amazon River, according to the American Meteorological Society.

These "rivers in the sky" are relatively common, with about 11 present on Earth at any time, according to NASA.

But warming air and seas around the globe causes conditions that scientists said will make them hold more moisture, causing extreme precipitation when they make landfall, often on the west coasts of North America, South America and Western Europe.

Because of climate change, atmospheric rivers are projected to become slightly less frequent, but more intense, according to a 2018 study led by researchers from NASA's Jet Propulsion Laboratory.