Gulf Stream weakening now 99% certain, and ramifications will be global

A new analysis has concluded that the Gulf Stream is definitely slowing, but whether it's due to climate change is hard to tell.

The Gulf Stream is almost certainly weakening, a new study has confirmed.

The flow of warm water through the Florida Straits has slowed by 4% over the past four decades, with grave implications for the world's climate.

The ocean current starts near Florida and threads a belt of warm water along the U.S. East Coast and Canada before crossing the Atlantic to Europe. The heat it transports is essential for maintaining temperate conditions and regulating sea levels.

But this stream is slowing down, researchers wrote in a study published Sept. 25 in the journal Geophysical Research Letters.

"This is the strongest, most definitive evidence we have of the weakening of this climatically-relevant ocean current," lead-author Christopher Piecuch, a physical oceanographer at the Woods Hole Oceanographic Institution in Massachusetts, said in a statement.

The Gulf Stream is just a small component of the thermohaline circulation — a global conveyor belt of ocean currents that moves oxygen, nutrients, carbon and heat around the planet, while also helping to control sea levels and hurricane activity.