The Gulf Stream is a current of warm water in the North Atlantic Ocean that travels up the Eastern coast of North America. Media reports have raised concerns that it may collapse as the climate warms due to human activities like burning fossil fuels. But this concern is the result of confusion. The Gulf Stream is part of a wind-driven, clockwise circulation in the upper layers of the North Atlantic. It depends on basic wind patterns and Earth’s rotation, which won’t cease in a warming world.
The confusion arises because the Gulf Stream plays a role in a broader system of North Atlantic currents driven by changes in saltiness and temperature of seawater. As warm water moves northward in what is called the ‘Atlantic Meridional Overturning Circulation’, it cools, sinks, and flows back southward in the ocean’s deeper layers. As polar ice sheets and glaciers melt in the warming climate, less-dense fresh water is released into the North Atlantic. Climate scientists worry that less dense waters won’t sink for their southward journey, causing this circulation to slow or stop, triggering major shifts in regional climate.
Though the Gulf Stream will continue flowing, it is not immune to climate change. One study, using tens of thousands of temperature and salinity measurements collected by robotic platforms, showed that it has absorbed excess heat and shifted towards the Atlantic coast. Another study, based on forty years of measurements across the Gulf Stream between Florida and the Bahamas, found the current has slowed in recent decades. These studies highlight ways a critical part of the planet’s climate system is being impacted by climate change.
