“There’s no coming back from this:” Why the global ocean crisis threatens us all

Ten years after the release of her seminal book Sea Sick, Alanna Mitchell again plumbs the depths of the latest research on the health of the world’s oceans — and comes up gasping

  • Published Sep 26, 2019
  • Updated Jun 01, 2022
  • 4,426 words
  • 18 minutes
Ten years after the release of her seminal book Sea Sick, Alanna Mitchell again plumbs the depths of the latest research on the health of the world’s oceans — and comes up gasping Expand Image

WE ARE HUNTING WHALES in Antarctica and time is running out. Unlike the harpooners of old, our goal is not to butcher them for blubber. Instead, it’s to get close enough to slap satellite-linked tracking tags on them. And rather than kill them, the point is to figure out how to make sure they survive.

It’s humpbacks, among the biggest mammals on Earth, we’re looking for. After three days, the team I’m following, led by Ari Friedlaender, an ecologist who is director of research at the California Ocean Alliance, hasn’t succeeded in tagging one yet. Bundled up in heavy-duty snow pants and fire-engine-red coats, we have seen scores of them. And we’ve gotten near enough to several to shoot hollow-tipped crossbow arrows into them to retrieve worm-sized samples of black skin and pink fat that will tell us whether they’re pregnant or stressed or contaminated with pollutants.  

But no luck so far with the tags. And we know that we have only a few more days before storms will force us back to the ship that brought us to Antarctica — One Ocean Expeditions’ adventure expedition vessel RCGS Resolute — and back to Argentina. This is the last scientific expedition of the season. And it’s almost over. 

So, this morning we’re riding low to the water in three inflatable Zodiacs, bumping through chunks of brilliant white ice in Wilhelmina Bay near the top of the Antarctic peninsula. It’s one of the whales’ favourite feeding spots. The air is crisp. The sea is the colour of a storm cloud. We are alert for any sign of action: the spurt of a blowhole, the fishy smell of their breath, a fin, a tail fluke, the sleepy top of a humped back suspended in the water.

Left: A map showing accelerating carbon uptake in the Southern Ocean. Right: A humpback whale breaches in Antarctica’s Wilhelmina Bay, a hot spot for ocean health researchers. (Map: Chris Brackley/CanGeo; Photo: Bruce Patterson)
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Again and again, the boat carrying Friedlaender and the taggers tries to sneak up on a whale. Again and again, the humpbacks sense the approach and, with seconds to spare, dive beyond reach. 

They know something is up. All of a sudden, a huge male, maybe 15 metres long and likely weighing 40 tonnes or so, swims up to our Zodiac. We try to remain still, knowing that if we are plunged into the icy water we risk death. Away he goes. 

And then he heads back. Penguins are standing at attention on an iceberg nearby, motionless. He comes closer, and then closer, the dark mass of his body suddenly appearing alongside the boat, dwarfing it. A mere metre away from where I’m sitting, he stops, raising part of his head above the water. I see the bumps covering his skin like shiny black knobs, close enough to touch. He looks straight at me, eye to eye, mammal to mammal. He appraises me for a moment, pauses, then dives back down and vanishes. 

Researchers from the California Ocean Alliance. (Photo: Adeline Heymann)
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I AM IN ANTARCTICA to mark an anniversary. My book Sea Sick: The Global Ocean in Crisis, came out 10 years ago. It’s had quite a life. It became an international bestseller, won the Grantham Prize for Excellence in Environmental Reporting and then, weirdly, five years ago morphed into a one-woman play (with the help of two artistic directors) that I’m still performing around the world.  

When Sea Sick came out, it was one of the few books to piece together the story of how humans are hurting the ocean. Not just bits of it — like fish populations — but the whole thing as a system. And since the ocean controls several key chemical systems on the planet, including carbon and oxygen, we’re damaging not just the ocean’s ability to support creatures that live in the ocean, but its ability to support life on land, too.

The short story: The ocean’s chemistry is changing in lockstep with climate change. That’s because the ocean is a global sponge. It absorbs about a third of the extra carbon dioxide we put into the atmosphere from burning fossil fuels, as well as most of the extra heat that carbon has trapped against the body of the planet. 

But instead of examining the effects of all that carbon and heat on the ocean, most scientists were breathing a sigh of relief a decade ago. Better in the ocean than the air, they would say. The ocean was saving us from even more rapid climate disaster. Which was true. Except that carbon is awful for the ocean too, turning it warm, breathless and sour, or acidic.

Worse, both ocean and climate are changing faster than ever as we pump ever more carbon dioxide into the atmosphere. Today, its concentration in the atmosphere is 415 parts per million by volume. When Sea Sick went to press it was 387. 

A lot more than that has changed in 10 years. The ocean’s role in climate is finally widely understood — it is its most prominent component. Research on ocean acidification — how carbon dioxide reacts chemically with water to make carbonic acid, changing its pH — has exploded. It’s now coordinated, widespread and financed, says Carol Turley, senior scientist at Plymouth Marine Laboratory in the United Kingdom and known as the “acid queen of the world” for her efforts on the topic. 

And while 10 years ago, scientists understood the process of ocean acidification, they didn’t know much about how it affected species and their marine communities and the people who depend on them, says Jean-Pierre Gattuso, research scientist at Sorbonne University and the Institute for Sustainable Development and Inter­national Relations in Paris, France. 

Nor did they understand how a more acidic sea interacts with other carbon-based changes like warmer waters and rising sea levels. Now, instead of looking at the shock effects of acidification on a single species in a beaker in a lab, they’re looking only at systems in the ocean over larger areas and longer time frames to figure out whether species will be able to adapt, he says. 

The ocean may not yet have a proper seat at the climate table, but it was mentioned in the 2015 Paris Agreement, a victory for scientists and campaigners on the ocean, Turley says. And in September 2019, the Intergovernmental Panel on Climate Change published a special report on the ocean and cryosphere, another first.

So, I’m on a quest to figure out what’s new after these 10 years. That means chatting again with some of the scientists, such as Turley, who talked to me before, and to others, such as Friedlaender, who have done bold new research in the years since. Is there more hope? Or less? 

The answers, to my surprise, are in Antarctica.

Researchers and other expedition-goers aboard One Ocean Expeditions’ RCGS Resolute often encounter huge chunks of melting ice (Photo: Adeline Heymann)
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ANTARCTICA IS NOT whales and penguins and ice. To Joellen Russell, an oceanographer at the University of Arizona, it’s also, most critically, about wind.

Russell is one of the people whose findings over the past decade have transformed our understanding of the ocean. She uses climate models. Her work is focused on the Southern Ocean, the great expanse of water surrounding Antarctica. In fact, she calls herself a Southern Ocean evangelist. Why there? 

“It’s the same answer as, ‘Why do you rob banks?’ Because that’s where the money is,” she says, laughing. “Why do I go to the Southern Ocean? Because that’s where the carbon uptake is. That’s where the heat uptake is.” 

In other words, the ocean is the biggest part of the climate system, and the Southern Ocean is the biggest part of the ocean system. 

The Southern Ocean has been one of the key controllers of the planet’s climate for millions of years. That’s due to the winds, the ferocious westerlies that drive a massive current around its ice-covered, stand-alone land mass. Called the Antarctic Circumpolar Current, it is the planet’s biggest current — by far — connecting its waters to those of the other ocean basins in a dynamic swirl.

Flash to the past: That current gained strength 34 million years ago after Antarctica broke apart from the last of the continents that, hundreds of millions of years earlier, had been mashed together in the supercontinent Pangaea. But once Antarctica was untethered and the current could move around it unimpeded, everything changed. Global temperatures dropped, and the Antarctic ice sheets formed. It was a tipping point that helped fashion the modern climate. 

What about today, as the rising concentration of carbon dioxide in the atmosphere forces rapid change in the climate?

Finally, scientists have the tools to work it out. Ten years ago, climate models didn’t take the interactions of chemistry, geology and biology in the Southern Ocean into account, Russell says. And, restricted by sea ice, weather and episodic ship voyages, scientists didn’t have the numbers to feed into the models, either. Today, they do. That’s thanks to what Russell calls a technological revolution: a new armada of floating probes measuring everything from acidity to oxygen to temperature — continuously, year-round, even under the sea ice. 

The probes are showing that, once again, the Southern Ocean will be a major player in the planet’s future climate, and in ways scientists didn’t predict. 

It goes like this: Since the 1970s, the Earth’s ocean has soaked up 93 per cent of the extra heat that carbon dioxide has trapped in the atmosphere. But it’s not evenly distributed. Most of that heat — between two-thirds and all of it — has gone into the Southern Ocean. 

“The doorstop that’s keeping the Antarctic ice sheet from sliding into the ocean is being melted because there’s extraordinary warming right at the feet,” says Russell. 

Penguins are one of many species impacted by warmer waters, melting sea and landfast ice, and rising sea levels. (Photo: Daisy Gilardini)
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A study by Eric Rignot of the University of California, Irvine, and others published in January 2019 found that the melting is speeding up. Ice across the frozen continent is melting six times as fast now as it was in the 1980s, satellite imagery shows. If all the ice covering Antarctica were to go into the sea — melted or not — the study calculated it would raise sea levels by nearly 60 metres. That would redraw the world’s maps.

As well, because westerly winds churn up the water so fiercely, half the carbon that the global ocean has absorbed has gone into the Southern Ocean, accelerating acidification there.  

Across the ocean, pH has dropped from 8.20 to 8.05 since we began burning fossil fuels at the start of the Industrial Revolution. Because pH is measured on an exponential scale, that means it’s 30 per cent more acidic now than it was just 250 years ago. The ocean has not been this acidic in 65 million years, when the last mass extinction caused non-avian dinosaurs to go extinct. 

Today, shells of sea snails are already starting to dissolve in the Southern Ocean’s more acidic waters. But now, the acidic assault on the Southern Ocean is coming from below as well. To the surprise of researchers, a great gush of old water with a pH of 7.8 — meaning greatly more acidified — is finding its way to the surface from deep below. 

“This is old Pacific deep water, the rottingest, oldest water ever,” says Russell, adding: “It’s supposed to stay down there.” 
Those deep waters are not just more acidic, they’re also starved of oxygen. So much of it is rising up that the floating sensors are telling flabbergasted researchers that about a fifth of the Southern Ocean surface waters are now consistently running short of oxygen. 

“I don’t know if you know how shocking that is,” says Russell, explaining that winds whip that water around so much that it ought to be saturated with oxygen from the atmosphere all the time. Instead, it’s breathless. 

That’s bad enough. But the winds have begun driving even bigger change. Those westerlies chasing the Antarctic Circumpolar Current are also unexpectedly getting stronger. And that’s from the interaction of a one-two atmospheric punch from our species. 

We ripped a hole in the ozone layer through the use of chlorofluorocarbons in aerosol sprays. That hole makes the stratosphere, or upper atmosphere, cooler. At the same time, the troposphere, or lower atmosphere, is warming up because of the carbon we’ve put there. So now there’s a bigger temperature difference than ever between upper and lower atmospheres. In Antarctica, that comes to 8 C, says Russell. The bigger the difference, the stronger the westerlies.

But we’ve stopped using CFCs, and the ozone hole is getting smaller. Will the temperature difference last?

“Forever. For our forever,” she says. “That’s it. There’s no coming back from this.” 

That means the winds will stir up the ocean around Antarctica even more, forcing it to eat carbon and heat.  

“We’ve got all this old, cold water that’s never seen our human atmosphere before, and it comes to the surface and it takes a big gasp of both heat and carbon and it goes back down,” says Russell. 

And while you could applaud the fact that the heat and carbon are leaving the atmosphere, the downside is that the ocean’s chemistry is going to change even faster.

Worse still, once the carbon has done its damage there, will it stay buried in the abyss? Alas, no. Now that scientists have winter probes, they’re finding that some of it is escaping back into the air. Terrifyingly, the leak could add back into the atmosphere half the carbon the Southern Ocean currently soaks up, says Russell.

Which means the climate will deteriorate even faster, too. Another unexpected twist. 

“We’re trying to use our models to look forward to find out if that leak of carbon in the winter is going to get worse. It’s very scary,” says Russell, adding that she’s racing to refine the models. “I want to do that yesterday.” 

She believes that once the information is clear, we’ll avert catastrophe. I ask her why. 

“That is faith and hope. Because when we couldn’t see it and we didn’t know about it, it was all mush and we couldn’t make plans. But now we can see it and it’s obvious,” she says. “And that makes all the difference.”

Researchers from the University of California, Santa Cruz attempt to tag whales with transmitting devices to study the health of the species. (Photo: Madeline Cottingham)
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HERE IN A ZODIAC in Wilhelmina Bay, it’s hard to imagine the planet-altering chemical changes going on beneath us. Now that our curious male humpback has gone away, I take a moment to look around. 

The sea seems timeless. Even immutable. And so does the massive icy continent behind us. We humans, by contrast, seem so tiny, so powerless, so vulnerable. In this moment, it is impossible to understand that our single species is capable of changing the speed of the winds, the architecture of the water column, the very chemistry of the water and air all creatures depend on.

Even Friedlaender, who is standing in the rear of another boat as he steers, evokes images of old. He’s in his element. From a distance, he looks like an ancient sea god — a Greek Poseidon maybe, or Ægir of the old Norse faith. 

But he and his team are doing state-of-the-art work here in Antarctica. His tag, should he ever get one on a humpback, is like a smartphone on suction cups that will transmit to satellites orbiting the planet. It will take video that will make it seem as if viewers are riding the whale’s back on a deep dive into the ocean. The tag plots the whale’s trajectory and depth, offers a glimpse of how it navigates. It tells us not just what the whale is doing, but also whom it is with. Maybe even how it reacts to different conditions in its environments, and why. 

Brandon Southall, senior scientist of Southall Environmental Associates in California, an acoustics expert, is on tap to record how whales communicate with each other — and their prey. A couple of other researchers holding joysticks are set to send up a pair of videocamera-equipped drones to get overhead footage of the whales as they sleep, feed and evade the tags. 

In effect, the scientists are building a four-dimensional story of how whales behave in Antarctica, like a sophisticated video game. It’s the most detailed picture ever of how these creatures live. 

At the front of the Zodiac, Southall is poised, one foot up on the side, long pole in front of him with a tag at the ready, sneaking up on the whale. It’s the iconic image of the harpooner in a rowboat from two hundred years ago, the eternal battle of human and beast.  

Ecologist Ari Friedlaender (left) and acoustics expert Brandon Southall (right) are studying whales to better understand global ocean health. (Photos: Madeline Cottingham)
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Except more than ever now, the whales need humans to protect them. Once, it was from hunting. In the Southern Hemisphere in the 20th century alone, commercial hunters killed two million whales for their blubber, pushing many species to the edge of extinction. 

Humpbacks were favourites. They were easy to kill because they hung out in bays like this one and — bonus — floated when dead. Commercial hunting of humpbacks stopped in 1966 after the International Whaling Commission banned it. By the 1970s, protests against the commercial hunt of any whales were a rallying cry of the modern environmental movement. 

Today, humpbacks are in the throes of a baby boom. But it may be short-lived. They still need us to take action. But this time on carbon. This precise part of the planet is changing faster than anywhere else. It’s 7 C warmer here than it was in the 1950s. Ice sheets are collapsing. Polar animals, such as the Adélie penguins that used to live on this part of the Western Antarctic Peninsula, are being forced to move further south, refugees from the heat. 

The big question mark is krill. These tiny, see-through, shrimp-like creatures are the main food of humpbacks and other filter-feeding whales. The baleen whales scoop them up in their giant maws, along with masses of sea water, then press the water out and swallow the krill. When they’re really hungry, they eat a tonne or more a day. 

But as the water becomes warm, breathless and sour, it loses its ice and some of its phytoplankton and prospects for krill are poor. I’ve been scanning scientific papers and International Panel on Climate Change reports only to discover, to my horror, that climate models predict krill will vanish from this very bay by 2100 if we don’t rein in our use of fossil fuels. And not just here, but also from a raft of other time-honoured whale-feeding spots along the peninsula north of Marguerite Bay. No krill, no whales. So much for the baby boom. 

That’s part of the reason Friedlaender and his team spend so much time here listening to the story the whales can tell. They’re trying to help others hear it before it’s too late. 

“We are still exploring everything for the first time,” says Friedlaender.

In fact, 10 years ago, he was in this same bay, Wilhelmina, tagging his very first Antarctic humpback. That proved you could do more than just count whales in this part of the world — you could also try to understand them. Then, there was no information on such critical details as their behaviour underwater or how they relate to their prey. Now, Friedlaender is able to look at the Southern Ocean starting from the perspective of the whale. 

For example, he knows now that humpbacks sleep in the day and feed at night at this time of year. They’re fat, loaded up for the big swim to tropical breeding grounds thousands of kilo­metres away, reluctant to dive. Three weeks ago, Friedlaender was just putting this part of the picture together. 

He and his team have been here for months, hitching rides on One Ocean Expeditions’ tourist expeditions, going to the same bays over and over, tagging and getting pieces of skin and fat. The way he puts it, he’s getting the chance to ask questions he didn’t even know he couldn’t answer before.

Again, his Zodiac gets close to a group of humpbacks. Southall is poised with the tag. Again, the whales dive before he can attach it. We are deflated for a moment until, off to the right, we see four whales rising out of the water on their sides in an elegant formation. Their mouths are agape, filling with ocean and krill, expanding like giant water balloons. And then I hear them vocalizing. Loudly. It brings to mind horses whinnying. There is a joy to it that flows across the water. I realize my mouth is open too. In wonder. 

I am marvelling at the many different scales this story is playing out on: It’s not just the planet, the stratosphere, the troposphere and the depths of the ocean. It’s also about a single continent, its sheets of ice and currents. Zooming in, it’s down to this bay, those whales and krill. From there, the tiny pieces of whale flesh we’ll take back to the lab, where we will focus in even more closely, looking for a glimpse into the animals’ very genes. And all of it, every bit, affected by human action. 

One more try this morning for a tag. We’re holding our breath. Success! Finally! Whoops of joy from all three Zodiacs. The whale dives, swims around for a while, then sheds the tag. When it floats to the surface, Friedlaender and his team snatch it out of the water. It hasn’t stuck for long, but long enough to provide a few more critical bits of information. 

Triumphant, we race back to the ship, feeling absurdly like heroes, hoping for even more luck this afternoon. 

A video-recording, motion-sensing tag affixed to a whale in Wilhelmina Bay (Photo: Steve Rose)
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IT’S NOT TO BE. By the time we get back to the ship and out of our polar gear, we are already headed back to Argentina. Fast. Terrible storms are brewing in the Drake Passage, the savage body of water between us and South America. We can’t wait out this one because more are on the way. If we don’t leave right now, we’ll be stuck. It’s cut our time in Antarctica in half. 

Even the crew is looking thoughtful, discreetly putting out seasickness bags — lots of them — in every corridor. It’s going to take us a couple of days to get back across the Drake, and word is the waves are expected to hit 18 metres high. 

By the second night, it feels like we’re in a blender. At midnight, I open the drape covering my cabin window. I’m on the fourth deck, and the waves are a lot higher than me. It’s terrifying to be face to face with the fury of the ocean, whipped up, I suppose, by the winds Russell is studying. Carbon plus ozone hole equals temperature difference and more ferocious westerlies. Rarely in my life have I felt this vulnerable. 

I can’t sleep, or even stay in my bed, so I start to think. 

Over these past 10 years, all the trends I wrote about have intensified. The picture has become both sharper and bleaker. We always knew the stakes were high, but that, too, has come into clearer focus. In June 2019, biologists told us that a million species are in danger of extinction from our actions. Now, the geologists are weighing in, comparing today’s warm, breathless and sour ocean with oceans of the past. Life as we know it is in danger.

“Every time there was a mass extinction … you have this cocktail of higher acidification and higher temperature and lower oxygen,” says Gattuso, adding: “This cocktail was very deadly in the geological past. And it is this cocktail we are preparing ourselves for the ocean today.” 

There’s no quick fix. For all our power, Homo sapiens cannot heal the ocean. We can only stop harming it. John Fyfe, senior scientist with Environment and Climate Change Canada in Victoria, calculates that it could take millennia for the ocean to go back to normal once we stop putting carbon into the atmosphere. “The ocean,” he says, “has a very long memory.” 

But stopping carbon emissions is not a technological problem any more. During the last decade, renewable energy has become cheaper than many fossil fuels. We have the knowledge we need to stop putting carbon into the atmosphere — and therefore the ocean — and we have roadmaps that will get us there without disrupting the economy. 

“It’s not like disaster is coming and you are at a loss, you don’t know what to do,” says Gattuso. “We know what to do. We just need to implement it.”

Again and again, I throw open the drape, peer into the black waves. I feel as though the demons of the deeps are swallowing me up. Suddenly, I think of Joanie Kleypas, a marine ecologist at the National Center for Atmospheric Research in Boulder, Colorado. I met her in Puerto Rico when I was writing Sea Sick, and she explained ocean acidification to me for the first time.

She’s turned her attention to corals. They are even more endangered now than they were 10 years ago, the result of acidification, hot water, overfishing, disease, bleaching. Along with a team of young ecologists, she’s raising baby corals on the Pacific side of Costa Rica, the first major reef restoration project in Central America. They’re cinnamon brown and tough as nails. She calls them “corals of the hood.” 

It’s become clear to her that corals, long known to be symbiotic with the phytoplankton that live inside them and feed them, have now become symbiotic with humans.

“We have to be part of their survival,” she says. 

I wonder if it’s even bigger than that. Have we become symbiotic with life as we know it, no matter where it is on the planet? We certainly need some creatures for our own survival, for oxygen, climate control, pollination, food, to name a few.

But how many species can be lost before we die off, too? What if we are dependent on whales and penguins and krill and phytoplankton and the thousands of other creatures we evolved with in ways we are only beginning to glimpse? Mass extinction, I fear, fails to discriminate. 

At the end of Sea Sick, I asked a question: What story do you tell yourself about why you are here? Looking out the window of my cabin into the frenzied Drake, I ask it again. We have run out of time. Now we have to choose whether we will hurtle further into destruction or pull back and restore what we’ve lost. It’s life or death. 

Firmly, I close the drape. I shut out the demons. I will not give in. I am here to press on. I am here to find hope, wherever it is. 


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