Scientists say aerosols -- which encourage the formation of clouds, which in turn cool the earth -- may be changing ocean currents in ways that promote climate change.

"The Atlantic Ocean, especially the North Atlantic, is peculiar: Every few decades, the average temperature of surface water there changes dramatically.

Scientists want to know why that is, especially because these temperature shifts affect the weather. New research suggests that human activity is part of the cause.

Scientists originally thought that maybe some mysterious pattern in deep-ocean currents, such as an invisible hand stirring a giant bathtub, created this temperature see-saw.

And that may be part of it. But there's a new idea: The cause isn't in the water; it's above it — a kind of air pollution called aerosols."

Christopher Joyce reports for NPR's All Things Considered April 4, 2012. [2]