Climate change will impact the Gulf Stream more than we thought

Discovery of new evidence regarding the behavior of the Gulf Stream during the last Ice Age could mean that it is more sensitive to future climate change than we previously thought. 

The study, published in the journal Nature and led by researchers at University College London (UCL), found that around 20,000 years ago an extraordinarily strong Gulf Stream was related to more intense winds over the subtropical North Atlantic. 

This finding suggests that a slowdown of such winds, as some studies have speculated could occur with ongoing climate change, would in fact take power away from the Gulf Stream and carry potential consequences for heat distribution, sea level.

Gulf Stream sensitivity to changing wind patterns

A surface oceanic current known as the Gulf Stream was responsible for carrying warm tropical water from the US east coast to Europe, releasing heat in the atmosphere and causing the European continent to warm up. 

The Earth, even with a record high Gulf Stream during the last ice age, was still substantially colder than it is today due to large northern hemisphere ice sheets.

“We found that during the last ice age, the Gulf Stream was much stronger because of stronger winds across the subtropical North Atlantic. As a result, the Gulf Stream was still moving lots of heat northwards, despite the rest of the planet being far colder,” explained lead author Jack Wharton, a professor in UCL’s department of geography.

“Our work also highlights the Gulf Stream’s potential sensitivity to future changes in wind patterns.”

Disrupting deep water formation 

The Gulf Stream is part of the Atlantic Meridional Overturning Circulation (AMOC), which is influenced by deep water formation and winds. 

Climate change could weaken the AMOC by disrupting deep water formation, primarily due to melting glacial water from Greenland, and reducing wind strength. 

If the AMOC collapses, European temperatures could drop by 10 to 15 degrees Celsius, severely impacting agriculture and weather patterns. The wind-driven decrease in the Gulf Stream would exacerbate this cooling effect.

Ocean currents move heat around the planet

“It’s not always recognized how much ocean currents are responsible for transferring heat around the planet and shaping our climate,” said co-author Mark Maslin, a professor in the same department. 

“Paradoxically, the warming of the climate could cool down much of Europe by disrupting the AMOC. Our new research adds to this understanding, and shows that the weakening of the winds which drive the Gulf Stream could reduce the circulation of heat, further affecting the continent.”

The study challenges the simplified “conveyor belt” metaphor of the AMOC, suggesting a more complex system of interconnected loops, with each part reacting uniquely to climate change. 

“Rather than the established conveyor belt metaphor, perhaps it is better to think of the AMOC as a series of interconnected loops. There is the subtropical loop – that the Gulf Stream is part of – and a subpolar loop, which carries heat further northwards into the Arctic,” explained senior author David Thornalley, an ocean and climate scientist at UCL.

Past strength of the Gulf Stream 

The researchers analyzed fossil remains of foraminifera from sediment cores off North Carolina and Florida to gauge the prehistoric Gulf Stream’s strength. 

The findings indicated that during the last ice age, the Gulf Stream was twice as deep and fast as it is today. This historical perspective helps understand potential future changes in oceanic currents and their global climate impacts.

This research underscores the importance of considering multiple factors and complex interactions within ocean currents when predicting climate change impacts. 

As the climate continues to warm, the sensitivity of the Gulf Stream and other components of the AMOC will play crucial roles in shaping future climate conditions, particularly in Europe.

Broader implications of the study

The findings from this research not only deepen our understanding of the Gulf Stream’s dynamics but also highlight the urgent need for policies that address climate change.

Governments and organizations worldwide must consider the potential impacts of a weakened Gulf Stream when developing climate action plans.

Future research should focus on creating more detailed climate models to predict how wind patterns and ocean currents will evolve.

Collaboration between scientists, policymakers, and the public is essential in creating sustainable solutions that mitigate the effects of climate change and protect our interconnected global ecosystem.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–