Imagine a world where we not only stop adding carbon to the atmosphere but also start taking it out.
In this episode, we'll talk about the fascinating topic of carbon removal technology, from machines that act like giant air filters to innovative uses of rocks and bio-waste.
[00:00:05] Hello, hello, hello, and welcome to English Learning for Curious Minds, by Leonardo English, the show where you can listen to fascinating stories and learn weird and wonderful things about the world at the same time as improving your English.
[00:00:21] I'm Alastair Budge, and today we are going to be talking about carbon removal.
[00:00:27] It’s a story about climate change, technology, chemistry, economics and market dynamics, and the future of the planet.
[00:00:36] It is also, although you might not know it, about you.
[00:00:40] A tiny proportion of the world’s population has contributed to global carbon removal, but you, if you are listening to this episode, are in that special category.
[00:00:51] Don’t worry, I will explain it all in a few minutes, so let’s get right into it and talk about carbon removal.
[00:01:00] Spending too much time reading articles in the newspaper about climate change can quickly make you pretty depressed.
[00:01:08] Week after week, month after month, year after year, there are scientists warning us that the planet is heading for a climate catastrophe, and despite every congress, conference, or global agreement promising to do everything to reduce carbon emissions, overall, we as a planet, as a species, keep on missing our goals.
[00:01:34] Most recently, in the 2016 Paris Agreement, 195 countries pledged to make sure that the global temperature is no more than 2°C higher than pre-industrial levels, and “preferably”, it should be kept below 1.5°C higher.
[00:01:55] Last year, in 2024, the average temperature was more than 1.5°C above pre-industrial levels, meaning that just 8 years after this supposedly landmark global agreement was signed, we have already missed one of the targets.
[00:02:14] And, at the risk of sounding even more glum and gloomy, scientists are almost unanimous in their conclusion that it is getting worse.
[00:02:25] According to one article last year, a rise of 1.6°C is the absolute best we can hope for, and this would still require vast behavioural and structural changes in our society.
[00:02:41] And while many developed countries have done a pretty good job at reducing their emissions, many developing countries are still at the very early stages of their “carbon journey”.
[00:02:54] China produces more CO2 than all of Europe and the USA combined, and its rate of CO2 emissions shows no sign of slowing.
[00:03:06] Even on a per capita basis, the average person in China emits 90% more CO2 than someone in the UK.
[00:03:16] And yes, there is the perfectly reasonable comeback to this that this isn’t personal consumption, but taking into account CO2 production from manufacturing and so on.
[00:03:27] So, for every person feeling smug about their “zero emission” electric car in London or Paris or Madrid, there might not be black smoke coming out of your exhaust pipe, but producing that car did result in lots of CO2 emissions, they just happened on the other side of the world.
[00:03:47] But without getting into the intricacies of who is responsible for carbon emissions or trying to point fingers at individuals or countries, climate change is a fundamentally global problem.
[00:04:03] It knows no borders; it affects everyone, albeit in different ways.
[00:04:09] And while, at least in most of the media, the attention has been focussed on reducing carbon emissions–of flying less, of eating less meat, of living as sustainably as possible–there is a flip side, another important part of reducing the amount of carbon in the atmosphere and therefore reducing the rise of global temperatures.
[00:04:33] And that is to remove the carbon that has already been released into the atmosphere.
[00:04:40] At the risk of sounding like a school geography teacher, I want to pause briefly to address a few basic but important points.
[00:04:50] The planet has a natural carbon cycle. Carbon moves through the land, the oceans, the air, and every living thing on Earth, and it has done so for millions of years.
[00:05:04] Plants and trees absorb carbon dioxide from the air and store it in their leaves, roots, and the soil. Tiny marine organisms, like plankton, also take in carbon dioxide from the water.
[00:05:19] Some carbon is also released naturally. For example, when a volcano erupts, it sends carbon dioxide into the atmosphere. Burning wood does the same.
[00:05:31] And animals, including us, good old humans, we emit carbon dioxide when we breathe out. When we die, the carbon in our bodies is also returned to the environment.
[00:05:44] And for a long time, this carbon cycle was in balance. The amount of carbon dioxide released into the atmosphere was more or less equal to the amount that was absorbed by plants, oceans, and soil.
[00:06:00] But starting around the time of the Industrial Revolution, we began burning fossil fuels — coal, oil, and natural gas — and we did so and still do so on a massive scale. This, as you know, releases huge amounts of extra carbon dioxide into the atmosphere.
[00:06:21] We began emitting more CO2 than the Earth could absorb. And almost every year since then, the amount has increased.
[00:06:31] So now, almost 200 years later, there are more than 3,000 gigatons of carbon dioxide in the atmosphere.
[00:06:41] A gigaton is a billion metric tonnes.
[00:06:45] And if 3,000 billion tonnes of an invisible gas is hard to imagine, the key point is this: it’s an increase of 50% compared to the start of the Industrial Revolution.
[00:07:01] And this carbon dioxide in the atmosphere acts like a kind of blanket around the Earth. It traps heat from the sun, which causes global temperatures to rise.
[00:07:13] Clearly, that is a gross simplification, but it helps bring us to the next point, which is this.
[00:07:21] Given that there is all of this carbon dioxide in the atmosphere, and carbon dioxide causes global heating, and global heating is bad, what would happen if we could “remove” the carbon dioxide?
[00:07:37] This is the principle behind carbon removal: to work on removing carbon dioxide from the planet.
[00:07:45] So, what's happening?
[00:07:47] What does carbon removal actually involve? And how does one go about removing carbon dioxide from the atmosphere?
[00:07:55] Well, the good news is that we know how to do it. The bad news is that it’s hard, expensive, and still in its very early stages.
[00:08:07] Broadly speaking, carbon removal technologies aim to do exactly what trees and oceans do naturally: take in carbon dioxide and store it somewhere safe and out of the atmosphere.
[00:08:22] Some approaches aim to speed up natural processes like mineral weathering, where rocks slowly react with carbon dioxide and trap it in solid form.
[00:08:34] Others are more technological; machines that literally suck carbon dioxide directly out of the air and store it underground. Some store carbon in soil or plants, others inject it into rock formations, and a few even store it in the ocean.
[00:08:54] One of the most talked-about is something called direct air capture, where large machines act like giant air filters, pulling in huge volumes of air and using chemical processes to extract the CO2.
[00:09:11] Once it’s captured, the carbon is compressed and injected deep underground, where it can stay for thousands of years.
[00:09:20] Then there’s this thing called enhanced weathering, where crushed rocks are spread onto farmland or coastlines. These rocks naturally react with carbon dioxide in the air or water, forming stable compounds that are eventually washed into the ocean and stored as bicarbonate.
[00:09:43] Another promising method is something called biomass carbon removal and storage.
[00:09:49] This includes things like burning plant waste to generate energy, capturing the carbon that’s released, and storing it underground, essentially closing the loop.
[00:10:01] There are other approaches too: turning biomass into bio-oil and injecting it underground, using chemical processes in the ocean to increase its carbon absorption, or even sinking agricultural waste to the bottom of oxygen-poor seas, where it breaks down very slowly and locks away carbon in sediment.
[00:10:24] It all sounds promising in theory, and even in practice, most of these technologies work pretty well.
[00:10:33] But there is a problem. They are still expensive, and as of now, they haven’t been deployed anywhere close to the scale that is required.
[00:10:45] To remove just 1% of global annual emissions, we’d need to capture around 400 million tonnes of CO₂ per year.
[00:10:56] Today, the total removed by these carbon removal technologies is only about 2 million tonnes — that’s just 0.005% of global emissions.
[00:11:09] In other words, we’re only half a percent of the way to just 1%.
[00:11:16] And carbon removal is a classic victim of the chicken and egg problem.
[00:11:23] Because there aren’t many customers, the cost of carbon removal is still very high, often many hundreds of dollars per tonne of CO2.
[00:11:33] And because the cost is high, there aren’t many customers.
[00:11:37] In other words, it’s hard to lower the cost without customers, but hard to get customers when the cost is so high.
[00:11:47] But history is full of examples where this cycle was broken.
[00:11:53] The first computers were massive and cost millions.
[00:11:57] The first hard drives could store a few megabytes but cost a fortune. Vaccines, solar panels, smartphones–they all started out very expensive, slow, and niche.
[00:12:12] But as technology improved and demand grew, prices fell dramatically.
[00:12:21] In the case of solar panels, the cost has fallen by 99.6% since they were first developed.
[00:12:30] A similar thing could happen with carbon removal, but it needs investment. These technologies and companies need customers to buy from them, so they can invest and improve their technology and methods, so they can bring costs down and be more efficient, so there are more customers, and so on.
[00:12:51] And that’s where you come in.
[00:12:54] You might not have noticed this, but we have a little thing on our website and on receipts which says, “Leonardo English contributes 1% of your purchase to remove CO2 from the atmosphere”.
[00:13:10] This doesn’t pay for me to buy a train ticket to scatter crushed rocks on a beach or to go and plant trees in a forest. The payment processor that we use is called Stripe. It’s one of the biggest payment processors in the world, and it has quite a cool non-profit initiative called Stripe Climate.
[00:13:33] You can literally just switch on a setting and divert a percentage of all payments towards this initiative. Yes, it’s small, and this is a tiny business in the grand scheme of things, but it's better than nothing.
[00:13:49] So I wanted to tell you a little bit about this initiative, firstly because I think it's very cool and potentially important, and secondly because as a member, you have supported it, even if you might not have known it.
[00:14:05] Stripe Climate operates under an umbrella called Frontier, which is something called an “Advance Market Commitment” and is a big project between Stripe, Alphabet [which is the company behind Google], Meta [which is the company behind Facebook] and a few other large technology companies.
[00:14:28] The idea behind this initiative is to solve this “chicken and egg” problem.
[00:14:35] It brings together large companies that can guarantee that they will buy carbon removal technologies from promising companies so that they can invest in building and scaling their technologies now, rather than waiting for other customers to arrive, which might never happen.
[00:14:54] And they are backing some pretty cool projects, so I wanted to tell you about a few of them that your support has helped make possible.
[00:15:04] Firstly, there’s one called Eion, which is a company that works with farmers to mix a specially developed silicate rock into soil. This rock reacts with carbon dioxide in the air and eventually turns it into a stable form of carbon that ends up in the ocean. It’s a natural process, but Eion is speeding it up, and they’re also helping improve soil quality at the same time.
[00:15:35] Another one is called Phlair, which uses a process called electrochemical pH-swing.
[00:15:42] It might sound technical, but essentially, it captures carbon dioxide from the air using a chemical solvent, then permanently stores the carbon in construction materials, like bricks or concrete, so it never returns to the atmosphere.
[00:16:00] Then there’s one with the ominous name of Vaulted Deep. Maybe it sounds like a horror film, or someone’s gaming name, but it's a company that basically buries food underground.
[00:16:15] Obviously, it’s a little more complicated than this. It takes organic waste, things like food scraps and agricultural leftovers, and injects it deep underground in specially built wells.
[00:16:29] As it decomposes, the carbon stays locked away. Not only does this stop carbon from entering the atmosphere, but it solves the problem of environmental waste, and it doesn’t require fancy new infrastructure.
[00:16:46] And finally, there’s a project close to home, at least where I am.
[00:16:51] There’s a Swedish company called Exergi, and it’s another nice example of how this technology sometimes seems obvious.
[00:17:01] What it is doing is retrofitting a biomass power plant in Stockholm.
[00:17:07] This biomass power plant already takes waste products from the timber industry, such as sawdust, branches, and wood, then burns them to generate electricity for people living in Stockholm.
[00:17:21] But what this company is doing is adapting the power plant so that the CO2 generated during this process is captured before it’s released into the atmosphere, then transporting it away and burying it deep underground.
[00:17:39] It’s a nice example because it is a mixture between carbon removal and emission reduction, and also shows how these technologies aren’t always rocket science; they just need enough people to believe in them so they can be scaled and deployed on a global basis.
[00:17:58] And these are just a few of the dozens of companies working on this challenge.
[00:18:04] I’ll put a link in the description to the Stripe Climate website, so you can go and check out some of these companies if you are interested; there are some really cool ideas and projects in there.
[00:18:16] Some will fail, some will succeed, and there’s a real challenge in verifying and monitoring how much carbon is truly removed.
[00:18:27] But all of them are helping build the foundations for what might one day be a massive global industry.
[00:18:36] So, can carbon removal save the planet?
[00:18:40] No, not by itself.
[00:18:42] But alongside reducing emissions, switching to clean energy, protecting forests, and changing how we live and work, it’s one of the tools we’ll need to have a fighting chance.
[00:18:55] And thanks to you, one of the relatively few people on this planet who has helped fund real carbon removal, that future perhaps looks just a tiny bit brighter.
[00:19:08] OK then, that is it for carbon removal, this fascinating and vastly important technology.
[00:19:14] I hope it's been an interesting one and that you've learnt something new.
[00:19:18] As always, I would love to know what you thought of this episode.
[00:19:22] Firstly, did you notice that little piece of text about “removing CO2” when you became a member? I imagine most people don’t notice it, or if they do, they are a bit confused about what it means, but I’d be curious to know.
[00:19:36] And secondly, how does knowing about these kinds of technologies make you feel? Excited, nervous for the future, or perhaps that it’s a distraction from the bigger problem of reducing our emissions in the first place?
[00:19:50] I would love to know, so let’s get this discussion started. You can head right into our community forum, which is at community.leonardoenglish.com and get chatting away to other curious minds.
[00:20:02] You've been listening to English Learning for Curious Minds by Leonardo English.
[00:20:07] I'm Alastair Budge, you stay safe, and I'll catch you in the next episode.
[00:00:05] Hello, hello, hello, and welcome to English Learning for Curious Minds, by Leonardo English, the show where you can listen to fascinating stories and learn weird and wonderful things about the world at the same time as improving your English.
[00:00:21] I'm Alastair Budge, and today we are going to be talking about carbon removal.
[00:00:27] It’s a story about climate change, technology, chemistry, economics and market dynamics, and the future of the planet.
[00:00:36] It is also, although you might not know it, about you.
[00:00:40] A tiny proportion of the world’s population has contributed to global carbon removal, but you, if you are listening to this episode, are in that special category.
[00:00:51] Don’t worry, I will explain it all in a few minutes, so let’s get right into it and talk about carbon removal.
[00:01:00] Spending too much time reading articles in the newspaper about climate change can quickly make you pretty depressed.
[00:01:08] Week after week, month after month, year after year, there are scientists warning us that the planet is heading for a climate catastrophe, and despite every congress, conference, or global agreement promising to do everything to reduce carbon emissions, overall, we as a planet, as a species, keep on missing our goals.
[00:01:34] Most recently, in the 2016 Paris Agreement, 195 countries pledged to make sure that the global temperature is no more than 2°C higher than pre-industrial levels, and “preferably”, it should be kept below 1.5°C higher.
[00:01:55] Last year, in 2024, the average temperature was more than 1.5°C above pre-industrial levels, meaning that just 8 years after this supposedly landmark global agreement was signed, we have already missed one of the targets.
[00:02:14] And, at the risk of sounding even more glum and gloomy, scientists are almost unanimous in their conclusion that it is getting worse.
[00:02:25] According to one article last year, a rise of 1.6°C is the absolute best we can hope for, and this would still require vast behavioural and structural changes in our society.
[00:02:41] And while many developed countries have done a pretty good job at reducing their emissions, many developing countries are still at the very early stages of their “carbon journey”.
[00:02:54] China produces more CO2 than all of Europe and the USA combined, and its rate of CO2 emissions shows no sign of slowing.
[00:03:06] Even on a per capita basis, the average person in China emits 90% more CO2 than someone in the UK.
[00:03:16] And yes, there is the perfectly reasonable comeback to this that this isn’t personal consumption, but taking into account CO2 production from manufacturing and so on.
[00:03:27] So, for every person feeling smug about their “zero emission” electric car in London or Paris or Madrid, there might not be black smoke coming out of your exhaust pipe, but producing that car did result in lots of CO2 emissions, they just happened on the other side of the world.
[00:03:47] But without getting into the intricacies of who is responsible for carbon emissions or trying to point fingers at individuals or countries, climate change is a fundamentally global problem.
[00:04:03] It knows no borders; it affects everyone, albeit in different ways.
[00:04:09] And while, at least in most of the media, the attention has been focussed on reducing carbon emissions–of flying less, of eating less meat, of living as sustainably as possible–there is a flip side, another important part of reducing the amount of carbon in the atmosphere and therefore reducing the rise of global temperatures.
[00:04:33] And that is to remove the carbon that has already been released into the atmosphere.
[00:04:40] At the risk of sounding like a school geography teacher, I want to pause briefly to address a few basic but important points.
[00:04:50] The planet has a natural carbon cycle. Carbon moves through the land, the oceans, the air, and every living thing on Earth, and it has done so for millions of years.
[00:05:04] Plants and trees absorb carbon dioxide from the air and store it in their leaves, roots, and the soil. Tiny marine organisms, like plankton, also take in carbon dioxide from the water.
[00:05:19] Some carbon is also released naturally. For example, when a volcano erupts, it sends carbon dioxide into the atmosphere. Burning wood does the same.
[00:05:31] And animals, including us, good old humans, we emit carbon dioxide when we breathe out. When we die, the carbon in our bodies is also returned to the environment.
[00:05:44] And for a long time, this carbon cycle was in balance. The amount of carbon dioxide released into the atmosphere was more or less equal to the amount that was absorbed by plants, oceans, and soil.
[00:06:00] But starting around the time of the Industrial Revolution, we began burning fossil fuels — coal, oil, and natural gas — and we did so and still do so on a massive scale. This, as you know, releases huge amounts of extra carbon dioxide into the atmosphere.
[00:06:21] We began emitting more CO2 than the Earth could absorb. And almost every year since then, the amount has increased.
[00:06:31] So now, almost 200 years later, there are more than 3,000 gigatons of carbon dioxide in the atmosphere.
[00:06:41] A gigaton is a billion metric tonnes.
[00:06:45] And if 3,000 billion tonnes of an invisible gas is hard to imagine, the key point is this: it’s an increase of 50% compared to the start of the Industrial Revolution.
[00:07:01] And this carbon dioxide in the atmosphere acts like a kind of blanket around the Earth. It traps heat from the sun, which causes global temperatures to rise.
[00:07:13] Clearly, that is a gross simplification, but it helps bring us to the next point, which is this.
[00:07:21] Given that there is all of this carbon dioxide in the atmosphere, and carbon dioxide causes global heating, and global heating is bad, what would happen if we could “remove” the carbon dioxide?
[00:07:37] This is the principle behind carbon removal: to work on removing carbon dioxide from the planet.
[00:07:45] So, what's happening?
[00:07:47] What does carbon removal actually involve? And how does one go about removing carbon dioxide from the atmosphere?
[00:07:55] Well, the good news is that we know how to do it. The bad news is that it’s hard, expensive, and still in its very early stages.
[00:08:07] Broadly speaking, carbon removal technologies aim to do exactly what trees and oceans do naturally: take in carbon dioxide and store it somewhere safe and out of the atmosphere.
[00:08:22] Some approaches aim to speed up natural processes like mineral weathering, where rocks slowly react with carbon dioxide and trap it in solid form.
[00:08:34] Others are more technological; machines that literally suck carbon dioxide directly out of the air and store it underground. Some store carbon in soil or plants, others inject it into rock formations, and a few even store it in the ocean.
[00:08:54] One of the most talked-about is something called direct air capture, where large machines act like giant air filters, pulling in huge volumes of air and using chemical processes to extract the CO2.
[00:09:11] Once it’s captured, the carbon is compressed and injected deep underground, where it can stay for thousands of years.
[00:09:20] Then there’s this thing called enhanced weathering, where crushed rocks are spread onto farmland or coastlines. These rocks naturally react with carbon dioxide in the air or water, forming stable compounds that are eventually washed into the ocean and stored as bicarbonate.
[00:09:43] Another promising method is something called biomass carbon removal and storage.
[00:09:49] This includes things like burning plant waste to generate energy, capturing the carbon that’s released, and storing it underground, essentially closing the loop.
[00:10:01] There are other approaches too: turning biomass into bio-oil and injecting it underground, using chemical processes in the ocean to increase its carbon absorption, or even sinking agricultural waste to the bottom of oxygen-poor seas, where it breaks down very slowly and locks away carbon in sediment.
[00:10:24] It all sounds promising in theory, and even in practice, most of these technologies work pretty well.
[00:10:33] But there is a problem. They are still expensive, and as of now, they haven’t been deployed anywhere close to the scale that is required.
[00:10:45] To remove just 1% of global annual emissions, we’d need to capture around 400 million tonnes of CO₂ per year.
[00:10:56] Today, the total removed by these carbon removal technologies is only about 2 million tonnes — that’s just 0.005% of global emissions.
[00:11:09] In other words, we’re only half a percent of the way to just 1%.
[00:11:16] And carbon removal is a classic victim of the chicken and egg problem.
[00:11:23] Because there aren’t many customers, the cost of carbon removal is still very high, often many hundreds of dollars per tonne of CO2.
[00:11:33] And because the cost is high, there aren’t many customers.
[00:11:37] In other words, it’s hard to lower the cost without customers, but hard to get customers when the cost is so high.
[00:11:47] But history is full of examples where this cycle was broken.
[00:11:53] The first computers were massive and cost millions.
[00:11:57] The first hard drives could store a few megabytes but cost a fortune. Vaccines, solar panels, smartphones–they all started out very expensive, slow, and niche.
[00:12:12] But as technology improved and demand grew, prices fell dramatically.
[00:12:21] In the case of solar panels, the cost has fallen by 99.6% since they were first developed.
[00:12:30] A similar thing could happen with carbon removal, but it needs investment. These technologies and companies need customers to buy from them, so they can invest and improve their technology and methods, so they can bring costs down and be more efficient, so there are more customers, and so on.
[00:12:51] And that’s where you come in.
[00:12:54] You might not have noticed this, but we have a little thing on our website and on receipts which says, “Leonardo English contributes 1% of your purchase to remove CO2 from the atmosphere”.
[00:13:10] This doesn’t pay for me to buy a train ticket to scatter crushed rocks on a beach or to go and plant trees in a forest. The payment processor that we use is called Stripe. It’s one of the biggest payment processors in the world, and it has quite a cool non-profit initiative called Stripe Climate.
[00:13:33] You can literally just switch on a setting and divert a percentage of all payments towards this initiative. Yes, it’s small, and this is a tiny business in the grand scheme of things, but it's better than nothing.
[00:13:49] So I wanted to tell you a little bit about this initiative, firstly because I think it's very cool and potentially important, and secondly because as a member, you have supported it, even if you might not have known it.
[00:14:05] Stripe Climate operates under an umbrella called Frontier, which is something called an “Advance Market Commitment” and is a big project between Stripe, Alphabet [which is the company behind Google], Meta [which is the company behind Facebook] and a few other large technology companies.
[00:14:28] The idea behind this initiative is to solve this “chicken and egg” problem.
[00:14:35] It brings together large companies that can guarantee that they will buy carbon removal technologies from promising companies so that they can invest in building and scaling their technologies now, rather than waiting for other customers to arrive, which might never happen.
[00:14:54] And they are backing some pretty cool projects, so I wanted to tell you about a few of them that your support has helped make possible.
[00:15:04] Firstly, there’s one called Eion, which is a company that works with farmers to mix a specially developed silicate rock into soil. This rock reacts with carbon dioxide in the air and eventually turns it into a stable form of carbon that ends up in the ocean. It’s a natural process, but Eion is speeding it up, and they’re also helping improve soil quality at the same time.
[00:15:35] Another one is called Phlair, which uses a process called electrochemical pH-swing.
[00:15:42] It might sound technical, but essentially, it captures carbon dioxide from the air using a chemical solvent, then permanently stores the carbon in construction materials, like bricks or concrete, so it never returns to the atmosphere.
[00:16:00] Then there’s one with the ominous name of Vaulted Deep. Maybe it sounds like a horror film, or someone’s gaming name, but it's a company that basically buries food underground.
[00:16:15] Obviously, it’s a little more complicated than this. It takes organic waste, things like food scraps and agricultural leftovers, and injects it deep underground in specially built wells.
[00:16:29] As it decomposes, the carbon stays locked away. Not only does this stop carbon from entering the atmosphere, but it solves the problem of environmental waste, and it doesn’t require fancy new infrastructure.
[00:16:46] And finally, there’s a project close to home, at least where I am.
[00:16:51] There’s a Swedish company called Exergi, and it’s another nice example of how this technology sometimes seems obvious.
[00:17:01] What it is doing is retrofitting a biomass power plant in Stockholm.
[00:17:07] This biomass power plant already takes waste products from the timber industry, such as sawdust, branches, and wood, then burns them to generate electricity for people living in Stockholm.
[00:17:21] But what this company is doing is adapting the power plant so that the CO2 generated during this process is captured before it’s released into the atmosphere, then transporting it away and burying it deep underground.
[00:17:39] It’s a nice example because it is a mixture between carbon removal and emission reduction, and also shows how these technologies aren’t always rocket science; they just need enough people to believe in them so they can be scaled and deployed on a global basis.
[00:17:58] And these are just a few of the dozens of companies working on this challenge.
[00:18:04] I’ll put a link in the description to the Stripe Climate website, so you can go and check out some of these companies if you are interested; there are some really cool ideas and projects in there.
[00:18:16] Some will fail, some will succeed, and there’s a real challenge in verifying and monitoring how much carbon is truly removed.
[00:18:27] But all of them are helping build the foundations for what might one day be a massive global industry.
[00:18:36] So, can carbon removal save the planet?
[00:18:40] No, not by itself.
[00:18:42] But alongside reducing emissions, switching to clean energy, protecting forests, and changing how we live and work, it’s one of the tools we’ll need to have a fighting chance.
[00:18:55] And thanks to you, one of the relatively few people on this planet who has helped fund real carbon removal, that future perhaps looks just a tiny bit brighter.
[00:19:08] OK then, that is it for carbon removal, this fascinating and vastly important technology.
[00:19:14] I hope it's been an interesting one and that you've learnt something new.
[00:19:18] As always, I would love to know what you thought of this episode.
[00:19:22] Firstly, did you notice that little piece of text about “removing CO2” when you became a member? I imagine most people don’t notice it, or if they do, they are a bit confused about what it means, but I’d be curious to know.
[00:19:36] And secondly, how does knowing about these kinds of technologies make you feel? Excited, nervous for the future, or perhaps that it’s a distraction from the bigger problem of reducing our emissions in the first place?
[00:19:50] I would love to know, so let’s get this discussion started. You can head right into our community forum, which is at community.leonardoenglish.com and get chatting away to other curious minds.
[00:20:02] You've been listening to English Learning for Curious Minds by Leonardo English.
[00:20:07] I'm Alastair Budge, you stay safe, and I'll catch you in the next episode.
[00:00:05] Hello, hello, hello, and welcome to English Learning for Curious Minds, by Leonardo English, the show where you can listen to fascinating stories and learn weird and wonderful things about the world at the same time as improving your English.
[00:00:21] I'm Alastair Budge, and today we are going to be talking about carbon removal.
[00:00:27] It’s a story about climate change, technology, chemistry, economics and market dynamics, and the future of the planet.
[00:00:36] It is also, although you might not know it, about you.
[00:00:40] A tiny proportion of the world’s population has contributed to global carbon removal, but you, if you are listening to this episode, are in that special category.
[00:00:51] Don’t worry, I will explain it all in a few minutes, so let’s get right into it and talk about carbon removal.
[00:01:00] Spending too much time reading articles in the newspaper about climate change can quickly make you pretty depressed.
[00:01:08] Week after week, month after month, year after year, there are scientists warning us that the planet is heading for a climate catastrophe, and despite every congress, conference, or global agreement promising to do everything to reduce carbon emissions, overall, we as a planet, as a species, keep on missing our goals.
[00:01:34] Most recently, in the 2016 Paris Agreement, 195 countries pledged to make sure that the global temperature is no more than 2°C higher than pre-industrial levels, and “preferably”, it should be kept below 1.5°C higher.
[00:01:55] Last year, in 2024, the average temperature was more than 1.5°C above pre-industrial levels, meaning that just 8 years after this supposedly landmark global agreement was signed, we have already missed one of the targets.
[00:02:14] And, at the risk of sounding even more glum and gloomy, scientists are almost unanimous in their conclusion that it is getting worse.
[00:02:25] According to one article last year, a rise of 1.6°C is the absolute best we can hope for, and this would still require vast behavioural and structural changes in our society.
[00:02:41] And while many developed countries have done a pretty good job at reducing their emissions, many developing countries are still at the very early stages of their “carbon journey”.
[00:02:54] China produces more CO2 than all of Europe and the USA combined, and its rate of CO2 emissions shows no sign of slowing.
[00:03:06] Even on a per capita basis, the average person in China emits 90% more CO2 than someone in the UK.
[00:03:16] And yes, there is the perfectly reasonable comeback to this that this isn’t personal consumption, but taking into account CO2 production from manufacturing and so on.
[00:03:27] So, for every person feeling smug about their “zero emission” electric car in London or Paris or Madrid, there might not be black smoke coming out of your exhaust pipe, but producing that car did result in lots of CO2 emissions, they just happened on the other side of the world.
[00:03:47] But without getting into the intricacies of who is responsible for carbon emissions or trying to point fingers at individuals or countries, climate change is a fundamentally global problem.
[00:04:03] It knows no borders; it affects everyone, albeit in different ways.
[00:04:09] And while, at least in most of the media, the attention has been focussed on reducing carbon emissions–of flying less, of eating less meat, of living as sustainably as possible–there is a flip side, another important part of reducing the amount of carbon in the atmosphere and therefore reducing the rise of global temperatures.
[00:04:33] And that is to remove the carbon that has already been released into the atmosphere.
[00:04:40] At the risk of sounding like a school geography teacher, I want to pause briefly to address a few basic but important points.
[00:04:50] The planet has a natural carbon cycle. Carbon moves through the land, the oceans, the air, and every living thing on Earth, and it has done so for millions of years.
[00:05:04] Plants and trees absorb carbon dioxide from the air and store it in their leaves, roots, and the soil. Tiny marine organisms, like plankton, also take in carbon dioxide from the water.
[00:05:19] Some carbon is also released naturally. For example, when a volcano erupts, it sends carbon dioxide into the atmosphere. Burning wood does the same.
[00:05:31] And animals, including us, good old humans, we emit carbon dioxide when we breathe out. When we die, the carbon in our bodies is also returned to the environment.
[00:05:44] And for a long time, this carbon cycle was in balance. The amount of carbon dioxide released into the atmosphere was more or less equal to the amount that was absorbed by plants, oceans, and soil.
[00:06:00] But starting around the time of the Industrial Revolution, we began burning fossil fuels — coal, oil, and natural gas — and we did so and still do so on a massive scale. This, as you know, releases huge amounts of extra carbon dioxide into the atmosphere.
[00:06:21] We began emitting more CO2 than the Earth could absorb. And almost every year since then, the amount has increased.
[00:06:31] So now, almost 200 years later, there are more than 3,000 gigatons of carbon dioxide in the atmosphere.
[00:06:41] A gigaton is a billion metric tonnes.
[00:06:45] And if 3,000 billion tonnes of an invisible gas is hard to imagine, the key point is this: it’s an increase of 50% compared to the start of the Industrial Revolution.
[00:07:01] And this carbon dioxide in the atmosphere acts like a kind of blanket around the Earth. It traps heat from the sun, which causes global temperatures to rise.
[00:07:13] Clearly, that is a gross simplification, but it helps bring us to the next point, which is this.
[00:07:21] Given that there is all of this carbon dioxide in the atmosphere, and carbon dioxide causes global heating, and global heating is bad, what would happen if we could “remove” the carbon dioxide?
[00:07:37] This is the principle behind carbon removal: to work on removing carbon dioxide from the planet.
[00:07:45] So, what's happening?
[00:07:47] What does carbon removal actually involve? And how does one go about removing carbon dioxide from the atmosphere?
[00:07:55] Well, the good news is that we know how to do it. The bad news is that it’s hard, expensive, and still in its very early stages.
[00:08:07] Broadly speaking, carbon removal technologies aim to do exactly what trees and oceans do naturally: take in carbon dioxide and store it somewhere safe and out of the atmosphere.
[00:08:22] Some approaches aim to speed up natural processes like mineral weathering, where rocks slowly react with carbon dioxide and trap it in solid form.
[00:08:34] Others are more technological; machines that literally suck carbon dioxide directly out of the air and store it underground. Some store carbon in soil or plants, others inject it into rock formations, and a few even store it in the ocean.
[00:08:54] One of the most talked-about is something called direct air capture, where large machines act like giant air filters, pulling in huge volumes of air and using chemical processes to extract the CO2.
[00:09:11] Once it’s captured, the carbon is compressed and injected deep underground, where it can stay for thousands of years.
[00:09:20] Then there’s this thing called enhanced weathering, where crushed rocks are spread onto farmland or coastlines. These rocks naturally react with carbon dioxide in the air or water, forming stable compounds that are eventually washed into the ocean and stored as bicarbonate.
[00:09:43] Another promising method is something called biomass carbon removal and storage.
[00:09:49] This includes things like burning plant waste to generate energy, capturing the carbon that’s released, and storing it underground, essentially closing the loop.
[00:10:01] There are other approaches too: turning biomass into bio-oil and injecting it underground, using chemical processes in the ocean to increase its carbon absorption, or even sinking agricultural waste to the bottom of oxygen-poor seas, where it breaks down very slowly and locks away carbon in sediment.
[00:10:24] It all sounds promising in theory, and even in practice, most of these technologies work pretty well.
[00:10:33] But there is a problem. They are still expensive, and as of now, they haven’t been deployed anywhere close to the scale that is required.
[00:10:45] To remove just 1% of global annual emissions, we’d need to capture around 400 million tonnes of CO₂ per year.
[00:10:56] Today, the total removed by these carbon removal technologies is only about 2 million tonnes — that’s just 0.005% of global emissions.
[00:11:09] In other words, we’re only half a percent of the way to just 1%.
[00:11:16] And carbon removal is a classic victim of the chicken and egg problem.
[00:11:23] Because there aren’t many customers, the cost of carbon removal is still very high, often many hundreds of dollars per tonne of CO2.
[00:11:33] And because the cost is high, there aren’t many customers.
[00:11:37] In other words, it’s hard to lower the cost without customers, but hard to get customers when the cost is so high.
[00:11:47] But history is full of examples where this cycle was broken.
[00:11:53] The first computers were massive and cost millions.
[00:11:57] The first hard drives could store a few megabytes but cost a fortune. Vaccines, solar panels, smartphones–they all started out very expensive, slow, and niche.
[00:12:12] But as technology improved and demand grew, prices fell dramatically.
[00:12:21] In the case of solar panels, the cost has fallen by 99.6% since they were first developed.
[00:12:30] A similar thing could happen with carbon removal, but it needs investment. These technologies and companies need customers to buy from them, so they can invest and improve their technology and methods, so they can bring costs down and be more efficient, so there are more customers, and so on.
[00:12:51] And that’s where you come in.
[00:12:54] You might not have noticed this, but we have a little thing on our website and on receipts which says, “Leonardo English contributes 1% of your purchase to remove CO2 from the atmosphere”.
[00:13:10] This doesn’t pay for me to buy a train ticket to scatter crushed rocks on a beach or to go and plant trees in a forest. The payment processor that we use is called Stripe. It’s one of the biggest payment processors in the world, and it has quite a cool non-profit initiative called Stripe Climate.
[00:13:33] You can literally just switch on a setting and divert a percentage of all payments towards this initiative. Yes, it’s small, and this is a tiny business in the grand scheme of things, but it's better than nothing.
[00:13:49] So I wanted to tell you a little bit about this initiative, firstly because I think it's very cool and potentially important, and secondly because as a member, you have supported it, even if you might not have known it.
[00:14:05] Stripe Climate operates under an umbrella called Frontier, which is something called an “Advance Market Commitment” and is a big project between Stripe, Alphabet [which is the company behind Google], Meta [which is the company behind Facebook] and a few other large technology companies.
[00:14:28] The idea behind this initiative is to solve this “chicken and egg” problem.
[00:14:35] It brings together large companies that can guarantee that they will buy carbon removal technologies from promising companies so that they can invest in building and scaling their technologies now, rather than waiting for other customers to arrive, which might never happen.
[00:14:54] And they are backing some pretty cool projects, so I wanted to tell you about a few of them that your support has helped make possible.
[00:15:04] Firstly, there’s one called Eion, which is a company that works with farmers to mix a specially developed silicate rock into soil. This rock reacts with carbon dioxide in the air and eventually turns it into a stable form of carbon that ends up in the ocean. It’s a natural process, but Eion is speeding it up, and they’re also helping improve soil quality at the same time.
[00:15:35] Another one is called Phlair, which uses a process called electrochemical pH-swing.
[00:15:42] It might sound technical, but essentially, it captures carbon dioxide from the air using a chemical solvent, then permanently stores the carbon in construction materials, like bricks or concrete, so it never returns to the atmosphere.
[00:16:00] Then there’s one with the ominous name of Vaulted Deep. Maybe it sounds like a horror film, or someone’s gaming name, but it's a company that basically buries food underground.
[00:16:15] Obviously, it’s a little more complicated than this. It takes organic waste, things like food scraps and agricultural leftovers, and injects it deep underground in specially built wells.
[00:16:29] As it decomposes, the carbon stays locked away. Not only does this stop carbon from entering the atmosphere, but it solves the problem of environmental waste, and it doesn’t require fancy new infrastructure.
[00:16:46] And finally, there’s a project close to home, at least where I am.
[00:16:51] There’s a Swedish company called Exergi, and it’s another nice example of how this technology sometimes seems obvious.
[00:17:01] What it is doing is retrofitting a biomass power plant in Stockholm.
[00:17:07] This biomass power plant already takes waste products from the timber industry, such as sawdust, branches, and wood, then burns them to generate electricity for people living in Stockholm.
[00:17:21] But what this company is doing is adapting the power plant so that the CO2 generated during this process is captured before it’s released into the atmosphere, then transporting it away and burying it deep underground.
[00:17:39] It’s a nice example because it is a mixture between carbon removal and emission reduction, and also shows how these technologies aren’t always rocket science; they just need enough people to believe in them so they can be scaled and deployed on a global basis.
[00:17:58] And these are just a few of the dozens of companies working on this challenge.
[00:18:04] I’ll put a link in the description to the Stripe Climate website, so you can go and check out some of these companies if you are interested; there are some really cool ideas and projects in there.
[00:18:16] Some will fail, some will succeed, and there’s a real challenge in verifying and monitoring how much carbon is truly removed.
[00:18:27] But all of them are helping build the foundations for what might one day be a massive global industry.
[00:18:36] So, can carbon removal save the planet?
[00:18:40] No, not by itself.
[00:18:42] But alongside reducing emissions, switching to clean energy, protecting forests, and changing how we live and work, it’s one of the tools we’ll need to have a fighting chance.
[00:18:55] And thanks to you, one of the relatively few people on this planet who has helped fund real carbon removal, that future perhaps looks just a tiny bit brighter.
[00:19:08] OK then, that is it for carbon removal, this fascinating and vastly important technology.
[00:19:14] I hope it's been an interesting one and that you've learnt something new.
[00:19:18] As always, I would love to know what you thought of this episode.
[00:19:22] Firstly, did you notice that little piece of text about “removing CO2” when you became a member? I imagine most people don’t notice it, or if they do, they are a bit confused about what it means, but I’d be curious to know.
[00:19:36] And secondly, how does knowing about these kinds of technologies make you feel? Excited, nervous for the future, or perhaps that it’s a distraction from the bigger problem of reducing our emissions in the first place?
[00:19:50] I would love to know, so let’s get this discussion started. You can head right into our community forum, which is at community.leonardoenglish.com and get chatting away to other curious minds.
[00:20:02] You've been listening to English Learning for Curious Minds by Leonardo English.
[00:20:07] I'm Alastair Budge, you stay safe, and I'll catch you in the next episode.
