TED Climate Summit – Is climate change slowing down the ocean?

Ocean waters are constantly on the move, traveling far distances in complex currents that regulate Earth’s climate and weather patterns. How might climate change impact this critical system? Oceanographer Susan Lozier dives into the data, which suggests that ocean overturning may slow as our climate warms — and takes us on board the international effort to track these changes and set us on the right course while we still have time.

Susan Lozier speaks at Session 2 of TED Countdown Summit

Oceanographer Susan Lozier dives into the importance of the ocean’s natural circulation, which overturns water in a way that naturally captures carbon and regulates global temperatures. She shares the incredible research being done internationally to track changes in this overturn, as warming global temperatures could slow the circulation, lessen carbon uptake and increase the rate of climate-related disasters. While a collapse in this age-old system isn’t likely until 2100, Lozier warns of the dangers faced by future generations if we don’t change course now, calling for climate action to lower temperatures within the next 10 years.

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Susan Lozier Appointed to Climate Security Roundtable

By Jess Hunt-Ralston

At the direction of Congress, the National Academies of Sciences, Engineering, and Medicine is establishing a Climate Security Roundtable convening experts from academia, the private sector, and civil society to provide support to the Climate Security Advisory Council (CSAC).

CSAC is a joint partnership between the U.S. Intelligence Community and the Federal Science Community and seeks to better understand and anticipate the ways climate change affects U.S. national security interests.

The new Climate Security Roundtable will support CSAC in anticipating, preparing, and ultimately preventing climate security crises from escalating into national security challenges and threats.

Susan Lozier, dean and Betsy Middleton and John Clark Sutherland Chair of the College of Sciences at Georgia Tech, will serve a three-year term on the Roundtable.

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2021 brought a wave of extreme weather disasters. Scientists say worse lies ahead.

By Sarah Kaplan and Brady Dennis

There are millions of tips out there on “The weather of the past will not be the weather of the future,” says a NOAA scientist. “As long as we are emitting greenhouse gases at a historically unprecedented rate, we should expect this change to continue.”

Scores of studies presented this week at the world’s largest climate science conference offered an unequivocal and unsettling message: Climate change is fundamentally altering what kind of weather is possible, and its fingerprint can be found in the rising number of disasters that have claimed lives and upended livelihoods around the world.

Record-shattering heat waves, devastating floods, scorching wildfires and persistent droughts are among the litany of catastrophes scientists say they can definitively link to human activities — primarily the burning of fossil fuels.

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The Atlantic’s vital currents could collapse. Scientists are racing to understand the dangers.

BJames Temple

On a Saturday morning in December of 2020, the RRS Discovery floated in calm waters just east of the Mid-Atlantic Ridge, the massive undersea mountain range that runs from the Arctic nearly to the Antarctic.

The team onboard the research vessel, mostly from the UK’s National Oceanography Centre, used an acoustic signaling system to trigger the release of a cable more than three miles long from its 4,000-pound anchor on the seabed.

The expedition’s chief scientist, Ben Moat, and others walked up to the bridge to spot the first floats as they popped up. The technicians on deck, clad in hard hats and clipped into harnesses, reeled the cable in. They halted the winch every few minutes to disconnect the floats as well as sensors that measure salinity and temperature at various depths, data used to calculate the pressure, current speed, and volume of water flowing past.

The scientists and technicians are part of an international research collaboration, known as RAPID, that’s collecting readings from hundreds of sensors at more than a dozen moorings dotting the Atlantic roughly along 26.5° North, the line of latitude that runs from the western Sahara to southern Florida.

They are searching for clues about one of the most important forces in the planet’s climate system: a network of ocean currents known as the Atlantic Meridional Overturning Circulation (AMOC). Critically, they want to better understand how global warming is changing it, and how much more it could shift in the coming decades—even whether it could collapse.

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How the climate crisis played a role in fueling Hurricane Ida

Louise Boyle

Hurricane Ida made landfall last weekend near New Orleans as a Category-4 storm, lashing the region with winds of up to 150mph (240kph), heavy rains and several feet of storm surge on the 16th anniversary of Hurricane Katrina.


Several factors linked to the climate crisis are helping to fuel more powerful, destructive storms like Ida, scientists say.

The latest report from the Intergovernmental Panel on Climate Change, the world’s leading authority on climate science, found that storms with sustained higher wind speeds – in the Category 3-5 range – have likely increased in the past 40 years.

The ocean absorbs over 90 percent of excess heat caused by greenhouse gas emissions from the burning of fossil fuels and that warm water feeds hurricanes.

“There is more energy available, so intensification of these hurricanes is expected,” Dr. Susan Lozier, president of the American Geophysical Union and an expert on the interaction of oceans, hurricanes and climate change, told The Independent. “And intensification brings more winds.”

More than a million people lost power when Ida toppled thousands of transmission lines and knocked 216 substations offline. Utility companies warned that thousands could remain in the dark and without air conditioning or running water for several weeks amid stifling heat and humidity.

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A Crucial System of Ocean Currents Is Faltering, Research Suggests

By Heather Murphy

The water in the Atlantic is constantly circulating in a complex pattern that influences weather on several continents. And climate scientists have been asking a crucial question: Whether this vast system, which includes the Gulf Stream, is slowing down because of climate change.


Now, scientists have detected the early warning signs that this critical ocean system is at risk, according to a new analysis published Thursday in the scientific journal Nature Climate Change.

“I showed that this gradual slowing down of the circulation system is associated with a loss of stability,” said Niklas Boers, a researcher at the Potsdam Institute for Climate Impact Research in Germany, “and the approaching of a tipping point at which it would abruptly transition to a much slower state.”


[Susan Lozier] called Dr. Boers’ study “interesting,” but said she wasn’t convinced that the findings showed that circulation in that ocean system is slowing. “There are lots of things to worry about with the ocean,” she said, such as the more definitive concerns involving sea-level rise.

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OSNAP and Earth’s Heat Pump: The Ocean Conveyor Belt

By Allison Shirreffs

The ocean covers more than 70% of the Earth and operates in a state of equilibrium with the atmosphere to regulate climate and CO2 levels. As a result, dynamics that affect the uptake of CO2 across the ocean surface affect global atmospheric temperatures.

Lozier, who ( in addition to her duties as dean and AGU president ) studies ocean circulation and the impact of ocean physics on marine ecosystems, is currently leading the NSF-funded project OSNAP, the Overturning in the Subpolar North Atlantic Program. OSNAP is an international observing network with a necklace of ocean instruments — strung from Canada to Greenland to Scotland — measuring what’s commonly known as “the ocean conveyor belt,” explains Lozier. “The overturning circulation is a huge current system that drives regional and global climate.

“What happens if the overturning circulation slows down because the waters of the surface warm — or if they get fresher because there’s more glacial melt?” Lozier asks. “If the ocean doesn’t take up as much CO2, that’s a good news, bad news story.” Good news because less CO2 in the water means fewer adverse effects, such as ocean acidification, but bad news because more CO2 stays in the atmosphere.

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In the Atlantic Ocean, Subtle Shifts Hint at Dramatic Dangers


The warming atmosphere is causing an arm of the powerful Gulf Stream to weaken, some scientists fear.


It’s one of the mightiest rivers you will never see, carrying some 30 times more water than all the world’s freshwater rivers combined. In the North Atlantic, one arm of the Gulf Stream breaks toward Iceland, transporting vast amounts of warmth far northward, by one estimate supplying Scandinavia with heat equivalent to 78,000 times its current energy use. Without this current — a heat pump on a planetary scale — scientists believe that great swaths of the world might look quite different.

Now, a spate of studies, including one published last week, suggests this northern portion of the Gulf Stream and the deep ocean currents it’s connected to may be slowing. Pushing the bounds of oceanography, scientists have slung necklace-like sensor arrays across the Atlantic to better understand the complex network of currents that the Gulf Stream belongs to, not only at the surface, but hundreds of feet deep.

“We’re all wishing it’s not true,” Peter de Menocal, a paleoceanographer and president and director of the Woods Hole Oceanographic Institution, said of the changing ocean currents. “Because if that happens, it’s just a monstrous change.”

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Lozier Elected to American Academy of Arts and Sciences

College of Sciences Dean Susan Lozier has been elected a member of the American Academy of Arts and Sciences.

Susan Lozier, dean and the Betsy Middleton and John Clark Sutherland Chair in the College of Sciences, has been elected a member of the American Academy of Arts and Sciences. She is among 276 artists, scholars, scientists, and leaders in the public, non-profit, and private sectors who will be inducted Oct. 9-11.

The Academy was founded in 1780 by John Adams, John Hancock, and others to honor exceptionally accomplished individuals and engage them in advancing the public good. Lozier, an expert in physical oceanography with an interest in large-scale ocean circulation, is being recognized for decades of extraordinary work.

“It’s incredibly humbling to be recognized by members of this arts and sciences community, given its rich history,” Lozier said. “I have always balked at the myth that science is the journey of a lone individual as I have enjoyed working with students, postdocs, and colleagues over the years and have gained immeasurably from those interactions. Since I view science as a community effort, building on the work that others have done and laying the foundation for the future, being recognized by the community is particularly gratifying.”

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