North Atlantic overturning circulation

From the Gulf Stream off the coast of Florida, the wind drives the water northward and eastward toward Europe in the Atlantic Current, before steering it into the Nordic Seas and the Norwegian Current. In these northern regions the water cools, sinks and flows back south as a deep ocean current. Both the wind and the sinking contribute to driving the large-scale circulation in the North Atlantic.
Animation: Eli Muriaas / Bjerknes Centre for Climate Research

[@ulmasbekrakhmatullaev8808]

What would happen if there was no circulation?

[@Ian-nl9yd]

well, there always will be some circulation, because the equator is hotter than the poles, and because the earth spins. but there has indeed been some concern that climate change may weaken the northeastward currents in the north atlantic, the result of which would be europe getting colder.