Led by Oregon State University professor Christo Buizert, recent research demonstrates the potential for world-altering shifts in climate, driven by changes in the current, known as the Gulf Stream or Atlantic Meridional Overturning Circulation. 

Through research using ice cores from Greenland, Buizert and other researchers were able to unearth evidence of the incredible effects the weakening of the AMOC could have on worldwide climate, especially in northern Europe. 

Buizert has been working at Oregon State University, focusing on climate science and specializing in changes to atmospheric gasses and their relationship to global climate. “My work is on reconstructing past climate change,” Buizert said. 

Buizert was recently in Greenland, gathering samples of ice. Using the information his lab gathered, Buizert is attempting to predict future climate trends, focusing on the potential weakening or collapse of the AMOC current, which would “be catastrophic,” according to Buizert.

Ice cores hold the secret to finding information about our climate in the past, freezing information about past atmospheric conditions in ancient ice. 

“It sort of works like a tree ring. Every year has a fresh layer of snow, but it’s so cold that the snow never melts. So, it piles up and piles up. … The snow has been piling up for hundreds of thousands, even millions of years in Antarctica, and it preserves some memory of what the climate was like at that time,” Buizert said. 

Using these ancient layers of snow can be vital for understanding climate change and, in particular, what is in our atmosphere. Buizert uses ice core data for “reconstructing the atmospheric history of greenhouse gasses,” which are the main drivers of modern and prehistoric climate change.  

This data Buizert gathered has been trapped inside of ice for millions of years. 

“These ice cores trap inside of them little bubbles of air, ancient air. … The snow slowly gets compacted by new snow that falls on top, but not all that air is squeezed out … and as the ice gets denser, … those bubbles are trapped permanently in the ice.”

Using this trapped air, Buizert can understand what the air in our atmosphere was like long ago and, therefore, connect greenhouse gasses to changes in global climate. 

“We can extract the air from those bubbles and we can measure the concentration of (greenhouse gasses), and we can use that to reconstruct how they have changed,” Buizert said.

Buizert’s work focuses on identifying what he calls “tipping points,” which can be warning signs of irreversible damage from climate change. 

“Our climate has potentially what we call these ‘tipping point’ situations. You can think of it as a threshold in the climate system. Imagine it’s warming very gradually, but the response doesn’t always have to be gradual,” Buizert said.

With Buizert’s recent work, which is focused on the AMOC current in northern Europe, going over one of these tipping points would create irreversible damage to the climate in northern Europe and have major consequences worldwide. 

You go over one of those tipping points, you cross one of the thresholds, and within a decade or so, this current collapses irreversibly, which would mean even if we stopped warming the earth, this current wouldn’t recover. The moment the AMOC shuts down, in the winter the whole north Atlantic will be covered in sea ice, according to Buizert’s research.

Europe would experience the most direct change if the AMOC were to collapse, but the effects would be worldwide. Buizert said, “The moment this AMOC current collapses, you get cooling in Europe. At the same time, we see the monsoons around the world change.” 

When the AMOC collapses, Buizert’s research suggests that the annual monsoons will fail in Asia, India and Africa. That would mean catastrophic droughts and famine, according to Buizert.

Drought usually comes in tandem with heat, which would also kick up globally, despite a localized “little ice age” in Europe and Greenland.  

“The rest of the ocean would actually start to warm even faster. It’s not global cooling or global warming, it’s just redistribution of heat,” Buizert said. “So, if the AMOC were to collapse, … you’d cool northern Europe, but you’d warm much of the rest of the world.” 

Fortunately — or unfortunately if you want sunny, warm winters in Oregon — Oregon’s climate would likely be relatively unchanged by the AMOC collapsing. 

“Oregon would not really be affected as much, it would mostly be northern Europe,” Buizert said.

However, these effects on climate in Europe would be felt worldwide in other ways.

“You have to distinguish between climate impacts and … social impacts, and so the global and economic social disruptions would be so large that Oregon would be impacted,” Buizert said. 

However, less-developed research suggests that Oregon would potentially experience drastic changes to climate in the event of the AMOC collapsing. 

Buizert stressed this is not well-understood, but explains ice cores in Alaska have evidence that “abrupt warming in the Gulf of Alaska” could occur if the AMOC were to collapse, which would impact Oregon’s climate. “That’s also supported by some (marine) sediment cores,” Buizert said.

Regardless of the potential for warming in Alaska, Buizert says the impact would be felt locally. “So, maybe there would be actually an impact. It’s hard to imagine there wouldn’t be, … just smaller, an order of magnitude smaller than what you would see in the Atlantic,” Buizert said.

The impact of the AMOC collapsing would be massive and felt worldwide, as global climate and commerce would be impacted. 

“It would be very catastrophic if the AMOC were to collapse,” Buizert said. 

As for the future of the AMOC current, Buizert said, “Whether (the AMOC) will weaken in the future, it seems almost inevitable to some degree.”