Episode 2: Carbon Suckers

Chapter 1

Laurie:
Here’s something obvious. The world has to phase out fossil fuels to have a chance of avoiding climate catastrophe.We all know this. But that doesn’t seem to be the plan for some people…

Amy Westervelt:
I think it was Occidental Petroleum last year that put out a press release claiming they had produced the world’s first zero-carbon barrel of oil.

Laurie:
That’s Amy Westervelt, a journalist who’s been investigating what fossil-fuel companies are up to. And yeah — you heard right. A zero-carbon barrel of… carbon. This approach to tackling climate change isn’t really about stopping fossil fuels. Because apparently, we’re going to keep burning more and more of them.

Archival voice (Oxy advert):
…lead with solutions to help our world reach net zero…

Laurie:
But it’s not just fossil-fuel companies. Many governments, in promising to tackle climate change, have set net-zero targets. And again, you might think that means simply stopping burning fossil fuels. But you’d be wrong.

Archival voice (Rishi Sunak):
Even in 2050, when we are at net zero, it is forecast that around a quarter of our energy needs will still come from oil and gas.

Laurie:
And it gets weirder. Recently, a former head of the Intergovernmental Panel on Climate Change — the IPCC, whose reports helped make “net zero” the central concept in climate policy — called net zero a “dangerous trap.”

Bob Watson:
It lulls us into a false sense of complacency. It’s taken our eye off the ball…

Laurie:
Let’s take a minute to understand what’s going on. Think of a big bucket. It’s how the atmosphere works. Every country has a tap that gushes planet-heating emissions.
It’s the cumulative amount that matters. Imagine a set of lines drawn inside the bucket. Deepest in the bucket is the 1.5 °C line — when the cumulative emissions reach it, a 1.5 °C global temperature rise follows. Decades of climate science have helped us identify roughly where those lines are marked — though others, like the one that could trigger the breakdown of the Atlantic circulation, remain uncertain. So rapidly turning off the taps is critical to limiting the danger. Luckily, nature helps — plants, soils, and oceans act like a small outlet valve draining the bucket. If the taps were turned down enough, the bucket could reach a balance between what’s coming in and what’s going out. That balance is what “net zero” means: the level in the bucket stops rising. But because nature’s drain is so small, reaching net zero requires the world to almost completely turn off the taps — to slash planet-heating pollution nearly to zero. And yet… that’s not how many governments and companies seem to be thinking about it.

Archival montage:
The U.S. is pumping more oil than any country ever has in the history of the world. BP’s turning away from the energy transition. It’s very profitable right now to drill.

Laurie:
But how can that add up? How can the world reach net zero while still burning vast amounts of fossil fuel — still filling up the bucket? The answer exposes one huge assumption now underpinning all climate plans — a get-out-of-jail card many are relying on to make their numbers work. It’s an idea barely anyone’s talking about. We didn’t vote for it. It might not even work. Because, with little fanfare, governments and companies are betting the future on inventing technologies that drain the atmospheric bucket. That’s a big bet — and one that helped get us into this mess in the first place. I’m Laurie Laybourn. You’re listening to Overshoot. And this is Episode Two: Carbon Suckers.

Chapter 2

Laurie:
It all started in Swedish paper mills. Back in the year 2000, an engineer named Kenneth Möllersten was starting a PhD in Sweden. Since then, Kenneth’s had a glittering career — and it all began with an idea.

Kenneth Möllersten:
We decided that the topic of my dissertation should be on what can be done in Swedish pulp and paper mills to mitigate greenhouse gases.

Laurie:
Kenneth realised there was something special about paper mills — and it’s all to do with trees. The mills used trees grown specifically for paper production — trees that wouldn’t have been planted otherwise. And before they were cut down, those trees spent their lifetimes sucking carbon from the atmosphere. So before the trees were fed into the paper mills, they’d already helped drain a little bit from the atmospheric bucket. That was one benefit. The mills also burned leftover waste from the pulped trees to produce electricity. That process released emissions — but Kenneth realised they could be captured before they escaped, using a device in the smokestack that trapped the pollution. The captured carbon could then be stored underground. Installing such a device would mean no new emissions from the mill — and because the trees had already absorbed carbon, the overall contribution to the bucket could even be negative.

Kenneth Möllersten:
And in that way, you have created, yeah, a negative emission — a stream of CO₂ that goes from the atmosphere into the underground.

Laurie:
At the time, no one was really talking about “negative emissions” — about actively draining the bucket beyond what nature already provided. All the focus was on turning off the taps. It was Swedish paper mills that led Kenneth to this idea. By early 2001, he was ready to present it to the world.

Kenneth Möllersten:
I went to Cambridge to present this paper at a conference, and after I had done my presentation, this gentleman came up to me looking excited.

Laurie:
That was Michael Obersteiner, another researcher. While governments were taking climate change more seriously, Michael was worried about a future where it became even more dangerous — where something like the Atlantic circulation could collapse. He was looking for…

Michael Obersteiner:
A backup option or a risk-mitigation option — so that, in a kind of Manhattan-Project-type effort, we could deploy negative emissions on a large scale and avoid such abrupt climate changes.

Laurie:
Michael thought Kenneth had found that backup plan. Because he saw it was bigger than paper mills — it could be scaled up globally. Together they came up with a plan. Large forests could be grown to suck carbon from the atmosphere. The wood could then be burned to make electricity — in power plants fitted with carbon-capture devices. No new emissions would enter the bucket. That meant not just zero-carbon electricity — but negative emissions on a global scale. It quickly came to be known as Bioenergy with Carbon Capture and Storage — or BECCS for short.

Michael Obersteiner:
You never want to have this competition between BECCS and decarbonisation. It can only be complementary for managing additional risks. You restrict yourself to a decarbonisation pathway, and if you get bad news, you switch it on.

Laurie:
This wasn’t meant as a backup for if the world failed to cut emissions. It would be impossible to deploy such systems at the scale and speed needed if that happened.

Kenneth Möllersten:
This option should not be seen as an argument in favour of doing nothing about climate change now and then switching on this technology later. It’s not likely BECCS can be initiated rapidly enough, at sufficient scale, to follow that path.

Laurie:
While others had toyed with similar ideas, Kenneth and Michael were the first to publish theirs in a major academic journal — and people noticed. Among them were climate scientists who built computer models of how to decarbonise the global energy system. And they had a problem. Their models showed that staying well below 2 °C required massive social and economic changes — reductions in energy use in wealthy countries, lifestyle shifts — changes that looked politically unpalatable. So some modellers turned to Kenneth and Michael’s backup plan. They built scenarios that included large-scale bucket-draining.

It helped resolve a tension: Between, on one hand, the need for huge societal change, and on the other, a world demanding ever-greater energy and fossil fuels. The modellers did include warnings that there were huge questions about what large-scale draining could actually deliver. But those caveats were often missed — buried deep in technical reports handed to policymakers who didn’t grasp the details. Then two things happened. First, emissions weren’t falling fast enough — some countries were actually increasing them. The bucket was filling faster than ever. Second, science showed that going above 1.5 °C was even more dangerous than previously thought. So not only was the bucket filling, but the line we needed to stay below had moved downwards. And so the modellers assumed more bucket-draining to make the math work.

Michael Obersteiner:
Then there was a race — who produces the deeper scenarios?

Laurie:
The more that happened, the less attention was paid to how big an assumption this really was — to think we could rely on large-scale negative emissions later. Bit by bit, the gap widened between how people talked about net zero and how we were actually supposed to get there. By 2018, it became clear there was no longer a choice. When the IPCC published its 1.5 °C report, nearly all the scenarios relied on large-scale carbon removal in the future. And as it’s become clear that the world is overshooting 1.5, those assumptions have gone into overdrive. That’s how the contradiction can exist: Countries and companies are burning fossil fuels, the world is overshooting 1.5, and at the same time, they say they’re committed to staying below 1.5. How can that add up? Answer: more bucket-draining — more assumed future carbon removal.

Kenneth Möllersten:
I’ve heard many scientists say, “We didn’t think what we were doing was realistic, but we were asked to do it.” They’re presenting scenarios compatible with 1.5 degrees that include massive amounts of negative emissions — and we really don’t know how to get all this into the world to be deployed.

​​Chapter 3

Laurie:
The biggest problem of all is that the promise of draining the bucket in the future may have obscured the failure of governments and companies to turn down the taps now. If you think the bucket can be drained later, you might pay less attention to how it’s filling up today — to the failure to rapidly reduce emissions. And if you’re a politician under pressure to set a net zero target, you know reaching it could be hugely disruptive to the status quo. So if someone tells you that you can go slower on emissions today but still hit net zero later, you might take that option. Or you might not even realise the complexities — and instead simply interpret what you hear as “yes, it’s all possible.” The promise of carbon sucking gives a seductive excuse to carry on — it makes it seem like there’s an easier way to get to net zero. And that’s why Sir Bob Watson, the former head of the IPCC, calls net zero a “trap.”

Bob Watson:
The target of net zero is excellent. However, the political trap is that it lulls us into a false sense of complacency. Any politician can guarantee we’ll have net zero by 2050 — they’re not going to be around to be held accountable. It’s taken our eye off the ball, and the ball is near-term reductions — fifty percent by 2030.

Laurie:
But this complacency doesn’t just result from well-meaning experts or confused politicians. Here’s Ketan Joshi, an expert on how companies talk about negative emissions.

Ketan Joshi:
The IPCC say carbon removal is not an excuse, it’s not a replacement for reducing emissions. But the funny thing is — it is, in the way it’s talked about in the corporate world. They talk about carbon removal as a way of undoing their emissions — almost exclusively. They present it as a tool for dealing with what they’ve done.

Laurie:
For fossil-fuel companies, turning off the tap means cutting profits. But the promise of future carbon sucking offers an excuse to carry on. So it’s been used to cultivate the impression that there’s an easy way out — part of a vast mechanism of reassurance that delays real decarbonisation. Just think of that “zero-carbon” barrel of oil. To justify the claim, the company says it will suck carbon from the air later and store it underground — someday.

Amy Westervelt:
You know, it’s not a hard sell to tell people, “Don’t worry, nothing has to change. We can just slap some technology on it.”

Laurie:
And so, bit by bit, the world has become reliant on sucking vast amounts of carbon from the atmosphere. Whether governments realise it or not — whether you realise it or not — this is what the world’s climate plans now assume. In less than two decades, an idea to help Swedish paper mills reduce their emissions has gone global. Kenneth and Michael’s backup plan became the plan.

Chapter 4

Laurie:
So what scale of bucket-draining are we now talking about? There’s no single answer — it depends on what the world does over the coming years. If the taps stay open, more carbon sucking will be needed. Modellers like Detlef, whose work appears in the State of Carbon Dioxide Removal report, have some estimates. In a scenario of “limited overshoot” — where global temperature rise hits 1.6 °C for a few decades and then falls back below 1.5 by the end of the century — the report finds that worldwide bucket-draining efforts must more than triple in the next decade, and increase nearly six-fold by 2050. That’s going from removing around two billion tonnes of carbon a year now to up to seven billion by 2035. It’s a planetary-scale engineering challenge — another one, alongside phasing out fossil fuels. At the moment, almost all carbon removal — 99.9% — is done by nature: plants, soils, and oceans. Here’s David Ho, a professor of oceanography at the University of Hawai‘i.

David Ho:
There are what people call nature-based solutions — say, afforestation, reforestation, or doing something with soil carbon, or restoring wetlands.

Laurie:
The remaining 0.1% comes from techniques that aren’t primarily about supporting nature — they’re technological.

David Ho:
One that’s very popular these days is direct air capture. Imagine giant fans sucking in air, using a sorbent to remove the CO₂, and then storing the carbon somewhere.

Laurie:
We can think of this as creating a new outlet valve in the bucket — and right now, it’s a tiny one.

David Ho:
Let’s say a direct air capture plant removes 4,000 tons of CO₂. If we look at it as a time machine, it takes us back to an atmosphere we had three seconds ago — and it takes a year to get there. So 4,000 tons of removal right now is very ineffectual.

Laurie:
But according to the State of CDR report, that will have to change — fast. By 2035, these technologies will have to increase their carbon-sucking capacity a thousandfold. By 2050, nearly four thousandfold. And then, they’ll have to sustain that removal for generations. Can the world do this? It’s not impossible — humanity has achieved extraordinary feats before. But there are huge challenges. First — it’s unfair.

Michael Obersteiner:
Not only do we transfer a huge risk to future generations in terms of climate impacts, but we also burden them with environmental guilt — to take CO₂ out of the atmosphere when we don’t really know today how to do it at a large scale.

Laurie:
Barely anyone realises this. It rarely makes the news. No one voted for it. Many people did vote for net zero — probably thinking it meant reducing emissions, not signing up for another planetary engineering project. So what happens, politically, when people start to notice? Who’s supposed to do it? Who pays? Who’s accountable? For example — is Uganda expected to help? Uganda is responsible for just 0.007% of all historical carbon emissions. The U.S. has contributed 3,500 times more. Uganda is already struggling with deadly climate impacts — should it now help invent and deploy vast carbon-sucking technologies too. These are huge, unanswered questions. And even if such removals were possible, they come with risks and trade-offs. Here’s Professor Diána Ürge-Vorsatz, from the Central European University in Vienna, and vice-chair of the IPCC.

Diána Ürge-Vorsatz:
Just to capture three gigatons, we’re talking about as much land as twice the size of India. And about twice today’s total agricultural water use.

Laurie:
And who decides how that land is used?

Ketan Joshi:
What you often end up with are situations where corporations seize land or take control of it — often harming Indigenous communities.

Laurie:
To make matters worse, all carbon that’s taken from the atmosphere must be stored indefinitely — for generations — whether captured by machines or by nature.

But what happens…

Diána Ürge-Vorsatz:
What if that forest burns down? What if we decide to convert that land again — for parking lots, or for a port, or anything else we need?

Laurie:
The storing is expensive too — and the energy costs are huge.

Michael Obersteiner:
If the countries that contributed the most were to clean up their own mess, it would basically eat up their entire governmental budgets.

Ketan Joshi:
You end up with carbon-removal facilities incentivising growth in fossil-fuel power output, because of the new energy demand. Alternatively, they might consume renewable power that should’ve been displacing fossil fuels.

Laurie:
Let’s stop there — you get the picture. There are three things to understand about it. First — these challenges must be overcome. The world does need to develop carbon-removal capabilities if we want a liveable climate. That’s the reality of overshooting 1.5. We’re in the storm, and we need every tool available to steer away from catastrophe. Whether we like it or not, carbon removals are one of those tools. And there are upsides — expanding nature’s capacity to absorb carbon can also restore ecosystems, helping to tackle other environmental crises. That’s a win-win. But it won’t be enough. Here’s Kenneth Möllersten again.

Kenneth Möllersten:
I don’t think negative emissions are the problem. The problem is that we are not decarbonising — the world hasn’t collaborated in the way necessary to deal with climate change. That’s the problem.

Laurie:
While large-scale carbon removals are now inevitable, they can’t help us avoid catastrophe without a massive acceleration in decarbonisation. The scale of emissions pouring into the bucket is simply too great — no matter how heroic the future assumptions become. So the need to scale up carbon removals cannot be used as an excuse to go slow on cutting emissions. No more promises of “zero-carbon oil.” No more carbon-sucking fantasies — whether born of optimism or manipulation. These fantasies must end. They’re part of why we’re in this storm — and they still threaten to distract us from navigating it. One idea to help: change how we talk about net zero. Right now, most targets don’t specify how much of the effort will come from reducing emissions versus removing them later — and that causes confusion. As Bob Watson says, this must change.

Bob Watson:
I would argue that whether you’re a government or in the private sector, you should tell us what those actions are — what’s direct emission reduction and what’s reliance on negative emissions.

Chapter 5

Laurie:
The need for more carbon removal — and the risks and trade-offs that come with it — should push us to rethink how we approach decarbonisation, and what’s politically possible. Often, the conversation is about swapping fossil-fuel technologies for zero-carbon ones — like replacing petrol cars with electric. But there’s much more to it.

Diána Ürge-Vorsatz:
The more we allow our energy and material use to increase — and the slower we implement zero-carbon technologies — all of these increase the amount of carbon removal we’ll have to do.

Laurie:
Decarbonisation can be sped up if the world also slows down its demand for energy and materials — which keeps rising every year. That’s a particular responsibility of wealthy countries that consume far beyond their needs. But so far, that’s not a major part of their strategy. And it requires more than replacing dirty tech with clean — it means redesigning the carbon-spewing systems of society. Buildings show this clearly. Solar panels and zero-carbon heating help — but so does better design. Buildings that naturally stay cool or warm, that use passive techniques and insulation, need far less energy. We’ve known how to build like this for millennia. It’s not glamorous — not like electric cars or carbon-sucking machines — but often the boring, proven solutions work fastest.

Diána Ürge-Vorsatz:
We can make buildings that need extremely little energy for heating or cooling — while residents are healthier, the air quality is better, comfort improves, and we can do it cost-effectively. We even reduce energy poverty.

Laurie:
That’s another win-win — and there are many more. Take planned obsolescence — companies designing products that break after a few years. Stamping down on that — demanding durable, repairable goods — reduces energy use, saves money, and eases the carbon burden. Some argue that high-emission activities should simply be banned — like private jets. Others say consumerism itself, especially in wealthy societies, must be dialled back. Whatever the solution, the key is to compare it with the alternative — which is an even bigger, riskier carbon-sucking challenge in the future, with all its unfairness and costs. That’s the central reality of overshoot. But not enough governments and companies are exploring creative ideas for how to do this — or how to make them politically possible. Sure, it might not be easy. But it’s far more realistic than becoming a bunch of carbon suckers.

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