Well, hello, and a very warm welcome to week five of Oxford net zero climate in the balance,
which is our series of conversations throughout the term in which we're exploring what we know and importantly,
what we need to know to achieve net zero emissions and stabilise the climate.
I'm Steve Smith, executive director of the Oxford Net Zero Initiative,
and this week it's my privilege to be joined by Tim Kruger of the Oxford Martin School to talk about the role of negative emissions.
If the concepts of negative emissions stands out to you, then stay tuned to find out more.
That's what we're here for, and some of you who did see the schedule a little while ago might have noticed that.
Michael Oubre Steiner is a director of the Environmental Change Institute here.
Had planned to be with us. He sends his apologies.
Unfortunately, he got called just in the last week to advise the European Commission that another meeting at the same time.
So he's very sad not to be here, but nevertheless we're in superb hands with him.
He, too is involved in Oxford net zero and has really been a leading lights over the last decade or so in
putting negative emissions on the agenda here in the UK and not just researching specific measured methods,
but also pioneering work really on policies to govern them and wider engagement across society
about how we approach these and other novel climate technologies in a responsible way.
So Tim is an Oxford Martin fellow, and he manages the geoengineering programme.
He's co-author of the Oxford Principles to guide the conduct of geoengineering research,
and these have been widely influential on researchers and policy makers in the field.
He's also founder of a negative emissions start up company, and no doubt he will give you a little bit more information about that soon.
So he really understands not only the research landscape, but also the very practical issues and trying to scale up negative emissions.
So as ever, we're very keen to hear from you, the audience, for you to send us your questions and we're going to do our best to answer them as we go.
Tim will explain to us what negative emissions means, and some of the issues around them set out the key issues for the first 30 minutes or so.
And at any time during this talk, please do drop in your question. You need to be viewing on crowd cost rather than the YouTube channel,
and you should be able to see on crowd carson crab cost and ask a question button at the bottom right of your screen so you can click on that.
You can write in your question. And importantly, you can vote on other questions you like to just so you know, we are recording this event,
and it will be available to watch on YouTube later on via the Oxford Martin School channel,
along with all the other conversations in this box with net zero series. So I think that said four housekeeping announcements.
So, Tim, welcome over to you. Thank you very much, Steve.
I appreciate that. So as Steve says, I work at the University of Oxford and I run the programme that looks at the whole
range of proposed techniques of removing carbon dioxide from the atmosphere.
And also, I'm the founder and CEO of a company called Origin Power, which is developing a technology to remove CO2 from the air as well.
And I won't be talking about origin. That's that's separate what we're going to be talking about the broader issues here.
But I can certainly bring the experience of being involved in a start-up in this space to the discussion that follows.
So in this series so far, you have heard a lot about need to get to net zero.
And there's been a lot of focus I need to get to net zero in order to stabilise the climate.
And there's been a lot of focus on what we need to do to reduce emissions, and that is absolutely crucial that we do that.
But mitigation alone is not enough. We can't get that.
We can't get to zero just by cutting emissions. We're also going to have to remove CO2 from the atmosphere as well.
So in order to avoid dangerous climate change, and obviously there are different definitions of where dangerous climate change starts.
But if you want to achieve the 1.5 degree goal, we really need to get to net zero by 2050, and that means very radical reductions in emissions.
And then the application of what's known as negative emissions,
the actual removal of CO2 from the atmosphere to counteract any remaining emissions that there are.
We've made a mess. We have used the atmosphere as a dump for our CO2 and for a long time since the industrial
revolution that we've been adding large amounts of fossil carbon to the atmosphere.
We thought that we could do this without having consequences,
but we now understand that it does have consequences, that it does raise the temperature, acidification as well.
And we need to stop adding to that problem.
And the scale of the problem is enormous.
So this this plot here shows a report from the unit emission cut proposal that the United Nations Environment Programme
every year they publish a report saying What we're doing in cutting emissions and what we need to do going forward.
And this was from 2017, and this was a plot showing what would need to happen to emissions in order to have a good chance of keeping below 2°C.
Bear in mind, at the time, the target was 1.5 to two degrees after the Paris Agreement,
and a lot of people were saying, Well, what would we need to do to get to two degrees the the yellow line?
I'm not sure if you can see biomass, but if you can the yellow line, the business as usual is kind of the trajectory we're on at the moment.
The Red Line, this hard right term here is tree that we would need to follow to get two degrees.
And that shows that we need to have very, very steep cuts in emissions.
And then we need to at some point in about the 2030s, we need to get to net zero.
That is, we need to get our emissions down to zero.
That's so we need to get our emissions down and then counter any remaining emissions with
negative emissions so that this brown line here shows what's happening to emissions.
And then this blue is negative emissions. This is removing CO2 from the atmosphere.
And really, at this stage, we don't know whether we can actually do these negative emissions.
I don't think this is a projection, a kind of trajectory of what needs to happen.
It doesn't mean that it will happen. We don't know exactly how we are going to cut emissions as aggressively as this,
and we certainly don't know whether we can deploy proposed negative emission techniques at the scale that is implied here.
And the other thing to note about this is that this is for two degrees.
If you want to get to 1.5 degrees, you have to cut even quicker. You need to get to net zero by 2050.
So that means steeper cuts in emission and more rapid build up of technologies that can remove CO2 from the atmosphere.
So it really is a massive challenge that we face.
The size of the challenge, we had about 40 billion tons of carbon dioxide into the atmosphere each year.
And if we want to stabilise temperatures, we have to reduce that to net zero.
So we might be able to do a new 75 percent reduction in emissions.
That's 10 billion tons. And then you need to remove that equivalent 10 billion tons.
It's important in the context of the pandemic, we've seen emissions falling, and last year it's expected they'll have fallen by about seven percent.
But in order to be on track for one and a half degrees, we would need to reduce emissions by about 7.6 percent every year.
So we need to have a contraction of industry of about that amount or completely reconfigure industry to achieve that.
And it's going to be extremely hard to actually achieve, and we will need to remove multiple billions of tons of carbon dioxide per year.
And quite soon we'll have to do that. And ultimately, you will probably need to remove trillions of tonnes of carbon dioxide.
So the kind of central projections are that if we can reduce emissions very aggressively and to be honest,
I think a lot of those scenarios where we reduce emissions very aggressively are really quite optimistic.
But if we were to do that, we're talking hundreds of billions of tons of CO2.
I think a more realistic view is we're going to need to remove trillions of
tonnes of carbon dioxide from the atmosphere over the course of this century.
So what did these proposed techniques look like and always use were proposed because none of them have really been deployed,
anything like a material scale? This this chart.
This picture here gives a quick overview of a large number of proposed techniques,
and there are a large number of techniques that potentially could be used.
I'm not going to go through this particular image in detail, except to point out that you've got the top, you've got CO2 in the air.
In the middle, you have a variety of different ways in which CO2 could be removed from the air and then to the bottom,
you have different ways in which the CO2 is stored away from the atmosphere.
We need to take the CO2 out of the air through a process and then stored away from the atmosphere for a long period of time for it to be effective.
And over on the left side of the the image, you have techniques that harness photosynthesis.
Nature's power to take CO2 out of the Earth through photosynthesis.
On the right hand side, you have what's known as engineered carbon dioxide removal methods,
which use various chemical processes that you can industrialise in the middle.
There are some techniques that use a combination of biomass and engineered approaches.
So I'm going to go through a few of these.
I'm not going to go through all of them, but I'll go through a few of them and just give kind of headlines about what they are and what they can do.
But before I do that, I want to talk about the criteria that we should look at in order to assess these proposed techniques.
And there are dozens of criteria that you could use. And but I'm going to just focus on three of them.
And the first of those is safety. So is it safe now?
What do I mean by safe? It's not just about the kind of health impacts, but it's also is it safe from a societal point of view?
Can we do this in a way that doesn't create countervailing side effects to society, to the environment, biodiversity, all sorts of things.
And as we go through it, you will see what I mean by some of these side effects.
But it's important that just as with a treatment for a disease, pretty much every treatment has side effects.
The question is, does it have countervailing side effects?
All these side effects so severe that they mean that you can't effectively use those techniques?
So the very simple level, if you had something that could cure diabetes and resulted in dandruff, you go, Okay,
that's not a countervailing side effect you've you've managed to address this big problem of diabetes,
and it's giving you the small problem of dandruff. If, however, it was the other way around, then obviously that isn't something that you would want.
It's the safety is the first of the criteria. The second one is, is it robust?
And this comes in two parts. First of all, does it actually work?
So there are all sorts of proposed techniques out there, but you need to be very careful when you do the sums.
When you add it all up, how much energy is spent and how much carbon is captured, et cetera.
Some of the proposed techniques don't actually look very good once you've done what's known as a life cycle assessment.
So that's really important. But the other part is, is it permanent?
It might fix the problem in the short term, but if it doesn't fix the problem in the long term,
then it's just a temporary fix and you go back to where you started and it's not robust.
The third criteria is scalable. Are we talking about something that is a mouse or an elephant?
Is it small scale? Is it going to have a tiny impact? Or is it going to have a massive impact?
And it's likely that there isn't any one of these proposed techniques that can be scaled to the extent of solving the whole problem.
So it's going to be a portfolio approach that's going to be needed in order to address this matter of principles that we need.
But it's really important to understand how big these different techniques are when you're trying to remove trillions of tons from the atmosphere.
If you're only removing 100 million tons, it's really not very much.
It doesn't move the scale very much.
You need things that can really be deployed a billion tons of gear scale, and some techniques can achieve that and some can't.
So let's start talking about some of the proposed techniques. One of them is trees.
Forestry. So if you take a piece of land that doesn't have trees on it and you grow trees as they grow, they take CO2 out of the atmosphere.
And this is probably at first sight, everyone's favourite idea.
Because who doesn't like trees and the great trees? I love them.
I'm all in favour of them. But there are certain questions about them.
So the first is, are they safe now planting trees?
Seems like a really good idea, but the scale at which you would have to plant trees in order to have a material impact on the amount
of CO2 in the atmosphere would potentially cause harm in terms of things like the supply of food.
You need land that can photosynthesise that can grow things. If you're replacing crop plants with trees, that can be a problem.
There are also issues of who owns the land.
Often, people in models will say, Oh, we're going to put this on marginal land, but marginal land is where marginalised people often live,
and you've got to be very careful about the the amount who actually owns that land and that the land rights that go with it.
You just have to be careful about what kind of trees you plant. It's about planting the right tree in the right place.
It's not about blanketing a piece of land with with a monoculture that wouldn't be good for biodiversity.
So there is potential. There are lots of co-benefits that can come from planting trees, watershed management, livelihoods, all sorts of good things.
We have to understand what's the the scalability of it.
How much land could you actually plant with? Trees kind of have a material impact.
And really, one of the most important aspects is the permanence of the storage.
So when a tree is growing, it's taking CO2 out of the air.
The issue comes is will that land remain forested if there's a fire or if someone
chopped down the tree or there's an invasion of pests that kill the trees?
When those trees die, they release CO2 back into the atmosphere.
So we need to be sure that when we lock the carbon off in the in the trees that didn't remain there permanently,
because if it doesn't, it's not going to have a long term impact on the problem that we face, which is climate change.
Biochar is another way of using photosynthesis, so by China is taking plant matter and charring it,
heating it up so it turns into this black material,
which you can put into the soil that can have benefits for the soil and including improving
productivity of the soil and the carbon will stay in the soil for a period of time.
The question is how long does it stay in the soil? In some places, it can stay for a very long time.
But how long it stays is a function of where you put it, how deep it is, how you put it in,
how you produce the biochar, the temperature and humidity, many different factors.
And if the carbon doesn't stay locked up for a long time, it's not a permanent fix.
It's just a temporary fix. And again, the question is the scalability. We only have so much land on which to plant trees or to undertake biochar.
If we do this at a bigger scale, can we do it hard in order to have a permanent effect?
Another technique is called Banks, which stands for biomass energy with carbon capture and storage.
And this is obviously a very simplified diagram.
But the idea is that you grow biomass that takes CO2 out of the air and then you burn that biomass in a power station that generates energy,
which can be used for electricity, for example.
But you capture the CO2 and you bury it deep underground, where it stays permanently and stable geological formations said.
The idea here is the CO2 is travelling from the air to underground, and you're getting another useful product out of it.
But the questions again, all about the scalability and the impact of this.
So there is a power station in the UK called Drax,
and Drax is buying biomass from around the world and transporting it to their power station in Yorkshire, burning it there.
And at the moment, they emit the CO2 back into the atmosphere, and that's broadly carbon neutral, according to this accounting.
But if you were to capture that CO2 and put it on the ground and that's what Drax plans to do, then it would be carbon negative.
The question is, how scalable can you do that? What are the impacts?
How much strain are we putting on our ecological systems by doing that?
Now we come to direct our caption, I hasten to add, this is an artist's impression.
This kind of flies what kind of images to the left of the image.
There are a version, a nice impression of a machine that can suck CO2 out of the atmosphere.
And this is something that could probably be done at a large scale, but it would have very large implications in terms of energy.
Trying to capture CO2 from the air is likely to be energy intensive, and it's going to cost a lot of money.
So there are many factors that we need to look at when we are trying to decide what may be the best way to approach this.
There's another series of techniques called enhanced weathering.
This is where you grind up certain kinds of rocks and in grinding them up, you increase the surface area.
These these kinds of rocks are ones that whether they're whether naturally and thing,
whether they take CO2 out of the atmosphere and by grinding them up, you make them weather more quickly.
And this could have potential to draw down a large amount of CO2.
But there are all sorts of impacts associated with grinding up the material to that size.
So again, none of these things are slam dunks. Is it going to work straight away?
We have to understand what the trade offs are to understand if they can work.
And then there's the ocean. So this is an image just off the coast of France and the UK.
And it shows an algal bloom. And what happens is that the ocean's in being host to these algal blooms.
As the algae blooms, it takes CO2 out of the atmosphere. And when those organisms, they sink to the bottom.
And that that draws down some carbon dioxide. There are some proposed techniques which involve adding iron to the ocean.
So parts of the ocean are deficient in iron.
And the thought is, well, if you add iron to those parts of the ocean, you allow more algal blooms, more drought, more drawdown of CO2.
But this again has lots of potential side effects, and there are very serious questions about the scalability of this approach as well.
So what I'm pointing out here is not saying any one of these is the solution or this one's good.
That one's bad. I'm not in that game.
What I'm doing is, I'm saying there are lots of proposed techniques, but we need to understand what the trade-offs about them are.
One issue that comes up across all of these techniques is a concern about the social acceptability,
not just of individual techniques, but of the whole field, and this is encapsulated in a phrase that's known as moral hazard.
So moral hazard is the concern that if we talk about these techniques or if we implement these techniques,
that they will undermine the will to cut emissions.
And this is something that has been put out by people who are opposed to looking at these techniques.
And I totally understand the concern.
At the same time, I think we need to actually look at how we deal with it and put it in the context of the pandemic that we have.
If we want to stop the pandemic, we need to not only reduce transmission, but we also need to research vaccines as well.
And I don't think many people would say we shouldn't research vaccines because it
might reduce the ability of people or the will of people not to keep socially distant.
There is likely to be an effect there. But at the same time, you need both.
It's not one or the other, it's both. And I would say that again about this whole ambition to achieve net zero.
It's about reducing emissions and it's about removing CO2 as well.
So one one scenario I might look at here is imagine some people chatting and one of them says, What do you mean you work on a cure for diabetes?
That's a terrible shame on you. You wouldn't hear that the argument could be well, if we're if we know about the problem of diabetes,
the best thing to do would be to stop people from eating so much and having the health problems associated with that.
If we got rid of obesity, we wouldn't need a cure for diabetes.
And actually, I, if you're researching a cure for diabetes, you're just undermining the will of people to stick to a healthy diet.
I don't agree with that, but I'm putting that out as a kind of counterargument.
And so prevention is better than a cure. And just to give you a, you know, his his what's happened to obesity in the US over the last few decades?
And here's what's been happening with CO2 emissions, and there are some kind of similarities.
It is a matter to some degree of self-control, but it's also broader cultural issues which people individuals don't have so much control over.
So what we want to do is, yes, we want to prevent it, but if we can't prevent it, we also need to have a cure.
We can't rely on emissions falling at the rate that they have in this last year for the next three decades that it's unrealistic to do so.
And if you can't prevent it, you sure need a cure. So this is a plot that shows what happens to.
The level of CO2 in the atmosphere, if at the same time shown by those green, blue and orange curves, you cut all emissions completely.
So this is a kind of hypothetical scenario where all industry shuts down instantaneously and everybody on the planet dies immediately,
which, by the way, I'm not advocating as a policy option. But if that were to happen, you would see the level of CO2 in the atmosphere go down.
But it would go down very gradually. So we are currently at about 410 parts per million of CO2 in the atmosphere.
We don't know what a safe level of CO2 in the atmosphere is.
It depends on a lot of different factors which we don't fully have the answer to.
But say you wanted to get to 350 parts per million?
There's an organisation called 350.org, and they think that's the right level.
If everybody, if ever all emissions stop now, it will be several centuries before you actually go back to 350 parts per million.
So. If we overshoot and we may well overshoot, we will need these techniques to remove CO2 from the atmosphere.
But these things aren't going to happen for free. I talked to the beginning about this being a waste management problem.
And when we have waste management problems, we expect to have to pay to clear them up.
So we do not expect people to sweep the streets, to sweep the streets for nothing.
They are paid to do so. We have to pay to treat wastewater and nuclear waste.
This is not tidy itself. Well, we have to pay people to tidy it away.
So we have to create incentive structures that actually ensure that people do clean up this waste.
And we need to be very careful how we create this incentive structures so that we don't create perverse incentives.
So I'm going to leave it there. Oh, just one more thing Anderson's law.
This is a complicated area, and there's a science fiction writer called Paul Anderson, and he had a law and the law was.
I have yet to see any problem, however complicated when you look at it in the right way did not become still more complicated.
This is a complicated area, and the more you look into it, the more complicated it becomes.
But we do need to look into it because without making admissions, we're not going to be able to achieve net zero.
We're not going to be able to cut prices at 1.5 degrees. Thank you very much.
Thank you, Tim, for that overview.
It was really nice that you explain the landscape of the different approaches out there and actually there's a nice link.
For those of you interested on that, on the natural and biological methods too weak to where I was discussing with
Nathalie Seddon and Cecil Girardin the role of nature and reaching net zero.
And there's quite a bit of information there about the limitations too,
but also the opportunities for enhanced carbon capture and storage in nature as part of a nature based solutions.
Tim, I'm going to throw to you first. A question which wasn't at the top of the list wasn't isn't currently voted.
The most popular, but I think is a good scene setter, one for for what you've just said and the discussion we'll have next.
So you mentioned that you're the founder of a for profit venture and greenhouse gas removal carbon dioxide removal.
So can you talk a bit about the ethical issues you face in the fall through and in being in that role and also at the same time,
an advocate for CO2 removal? Yeah, certainly.
So I've been involved in this space for about 12 years, and I joined Oxford 10 years ago, and when I joined,
I was very clear that I was going to be working part time on this attempt to remove CO2 from the atmosphere in a commercial sense.
So I've always attempted to be as transparent as possible about that and make it clear.
And I, when I'm having conversations with people, I'd bring it up as it's something that's important to me to be clear about that.
And when I talked to policymakers, I say that I think one of the things that I have tried to do in the programme at the
Oxford Martin School is to ensure that when people are looking at these techniques,
they are looking at them in a technology agnostic way that they don't come into these discussions in a way that says,
Well, this is the right answer and everything else is wrong. We need to or assume that certain techniques are going to work at the moment.
You have the disintegration assessment models where it assumes that backs is going to be deployed at a massive scale, but we don't know if it will.
And so I think it's really important to go into those conversations and say, we don't know which of these techniques can work.
We need to look at all of them and understand their issues.
I think another point about this, it is that I recognise that it's very difficult for policy makers to make policy about incentivising the removal.
I said in the absence of technologies that can actually show that they need a machine that goes ping.
And this creates a chicken and egg problem because if there aren't any technologies and there's no policy,
but there's no policy, there's no incentive to develop the technologies.
And so part of what I'm doing in trying to develop these technologies is to actually have the machine that goes ping to say that we can do this,
but it can only be done if there is a mechanism, but actually fairly incentivises it.
And so that actually creates a kind of fact on the ground that policymakers have to respond to.
And I think that's an important thing to do. So I'm going to buy the work that I do at Oxford in order to inform the work that I do in my company,
but also bring the work that I do in my company to actually usefully inform the work that I do at Oxford.
So people have to make up their own minds as to whether what I'm doing is right or appropriate.
I thought about it a lot. I think it is.
I've communicated that clearly to other people, and I certainly don't seek to advance my technology over other technology.
I think that would be. Thanks, Tim.
That leads us nicely on to several questions we've received actually about the policy side of things.
So how do we get this going? I'll just pull out a few themes that the divorced from different angles, about different routes.
And I know certainly I think we first met when I was working in policy on this stuff,
and you've always been quite quite good at taking the view across the range of different approaches and not just your technology.
So for instance, we've got Stuart Clark asking about airline passengers paying a carbon tax on their ticket price to pay for removals.
He asks about the cost, and we'll come back to the cost question, actually, but that's one way in which removals could be incentivised.
Miles Allan is in the conversation and says to stir things up,
why should the taxpayer pay for CO2 removal to compensate for the impact of a still profitable industry?
So if oil and gas is the use of oil, coal and gas is the major source of emissions, and they're still turning a profit if they are.
Then why should the taxpayer pay in place of them?
A third angle just on this point, as is the idea of carbon removal offsets more generally as a as a viable route to financing that.
So most Dan Brown asks this and asks, given that some of these are capital intensive projects,
maybe green bonds or other vehicles are more appropriate. So I know you've done quite a bit of thinking about the different ways in which
you might scale these things up from a policy and consensus point of view. What's your thinking on what the right vehicle should be?
Okay, so I think we can use to take a lead from the the successful roll out of wind and solar.
So if you go back three decades, there was some early stage technologies in wind and solar very expensive.
But there was a recognition that we needed to have a lower carbon footprint in the emissions that we had from the power generation.
And so I there was a programme, certainly in the UK and in other countries, similar as well.
Which incentivised the development and deployment of these techniques.
And so in the UK, we had something called contracts for difference,
which was basically a guaranteed price for delivering electricity from wind and solar.
And what that did is that it did several things, but it really just kick started that industry.
It said, this is what we need to develop, and it actually got people to deploy the techniques.
And once you start deploying these techniques, you have learning curve effects, so the costs come down.
You also de-risk the technology. So initially,
people who are lending money to develop these techniques will charge a very high interest rate on
the money that the lending because the technologies are risky from a technology point of view,
they're also risky from a regulatory point of view.
If you don't know how much you're getting paid, then it's going to mean that people are going to go well.
I'm not sure we want to back you because we don't know if you're going to make any money out.
But with a fixed price fairly high at the beginning, then what that means is you get money coming in.
And that has been enormously successful in driving down the cost of wind and solar so that they're now cheaper than many fossil fuels in many,
many locations around the world. So I think we can take that as an example of how to move.
It's a we call pre-commercial procurement.
It's a recognition that there is a market failure, that there isn't an incentive to move in that space unless someone moves in there and says,
right, we're going to give you effectively a fixed price for us at the beginning.
So I think that's how we should start. I think that subsequently,
once there has been kind deployed and we can see a pathway get a better understanding cost
because at the moment that isn't clear on the standard COS there's all sorts of things model.
That's a very big difference between what's modelled and what actually happens.
But once we've got those costs beginning to come down, then we can move to something similar to what we do with how we treat recycling waste.
So paper and packaging and electronic equipment in the U.K., we have something called the producer responsibility obligation.
And this is something that relies on a very good approach, which is that the polluter pays.
If you pollute, then you are the person the pace.
And what we need to do is we need to ensure that the costs are transferred to the polluters, said Miles Allan's point.
We need to make sure that the people who are producing the pollution are the ones who pay.
And yes, ultimately that will be the consumers, because if the consumers are benefiting from the use of technologies,
of course pollution, then they're the ones who should be paying for it.
Hopefully, that answers some of the questions that were three there, and I wasn't quite sure if I've got enough of them anyway.
No. Thanks, Tim. I think that underlines the fact that we're talking about.
We're talking about a wide range of different methods here, aren't we actually?
So it sounds like that the contrasts for difference approach, presumably it is actually the taxpayer who provides that money, even if indirectly.
But then you're saying what you want is a is a set of policies which might
help early stage deployment and de-risk those things which might cost money.
And then in the long run, when you've got these things deployed at scale,
you are actually you're arguing that you put you put the cost on the on the polluter pays principle.
And I think just just to add that to that abusing chairman's privilege, of course, thinking about the range of different removal methods,
we do have quite a lot of policies in place and approaches that we've tried with varying degrees of success with tree planting.
And in the U.K. we have we've had a system of grants for a long time, but also now we have the Woodland Carbon Guarantee,
which is effectively a contract for difference, a guaranteed carbon price for the sequestration that trees provide.
So as a tree planted, you then get an income stream, which is guaranteed at a at a carbon price.
So there is that precedent for tree planting.
I just want to pick up on that question of cost, though you touched on you made the point that the costs are actually quite uncertain.
And in Stuart's question about if if airline passengers had to pay a carbon removal tax, let's say for that flight, how much would it be?
So Stewart flying to New York return, for instance, I think the carbon footprint of that is about a tonne, just under a tonne of carbon.
So if you think of the cost of removal being x pounds per ton,
then you can just simply multiply that by one to get the cost that you would add to a flight ticket.
But Tim, what do we know? What do we know about the costs of these different approaches?
So yeah, it's it's an extremely good question.
So you can go and buy an offset for a very low amount of money.
People will say I will plants and trees for you and that will remove CO2 from the atmosphere and indeed it will.
Those trees will remove CO2 during the lifetime of those trees.
But the question is how long is that lifetime and how permanent is that removal?
And will the person who sells you that carbon removal guarantee it for a thousand years?
Can they guarantee that those trees will remain standing?
And if not, then what mechanism do you need to put in place to ensure that the carbon is removed permanently?
And there are other techniques. So there's a company in Switzerland called Climeworks.
They have machines to take CO2 out of the air and they inject it into the ground.
They have an operation in Iceland where they inject the CO2 in it, the CO2 they inject into the ground,
reacts deep underground and forms another kind of mineral that it will stay that from there.
And that is a more expensive technique, but it is more permanent.
And so you have this trade-off between.
You can get something that will store the CO2 for some decades, maybe a century, and you have other techniques that will basically store CO2 for tens,
hundreds of thousands of years, and you need to have a way of comparing those those two, because otherwise the temptation is to go for the cheap oil.
But it isn't permanent and it will then come back out.
And I think one of the things is it's not just about how well it manages the forest, but how robust is the forest to future climate change.
So in California, California has allowed these offsets for forestry,
one plot of land that Californians are using to help to balance their carbon budget is a piece of land in Oregon,
and recently there was a forest father and a lot of the carbon was released.
Now the scheme has got like a buffer.
They say we we have a buffer of land that we use to account for the fact there will be forest fires.
But there are a number of projections that say if you project where the climate is likely to go,
we're going to see an increase in the amount of forest fires and says very difficult to actually know at the moment
whether the offsets that are related to forestry will actually result in long term removal of CO2 from the atmosphere.
And I think it's really important there's been a lot of work that's been done on the greenhouse gas protocol,
understanding exactly how we measure emissions of CO2.
We need a similar sort of standard that looks at the removal of CO2 from the atmosphere as well to understand how
we treat the different levels of permanence that there are between different ways of removing CO2 from the air.
So I'm going to ask a few questions on the theme of.
The overall role of removal in these in these mitigation pathways,
so you made it you advocated a pretty strong case that we're going to need this stuff,
but you also touched on the fact that there's quite a lot of discussion about moral hazards,
the idea that in talking about this stuff, you might actually suppress the much needed action on emissions reductions.
So Troy asks the question Is there any actual evidence to suggest that talk of GHG removal limits a person's willingness?
Or we might even expand this out to an organisations or governments willingness to enact mitigation methods?
What's the actual evidence on that front? I think it's it's difficult to point to clear evidence that it does,
but there is certainly an understanding that policymakers who are not inclined
to reduce emissions might wish to use this as a crock to excuse their inaction.
And I so it is a, I think, a strong potential issue.
I think one way of dealing with this,
and that's something that they've done in Sweden and the recommendations that are there about them achieving that.
So I said Sweden has set a net zero target for 2045, which is more ambitious in the UK.
And what they've said is that they wish to achieve that target 85 percent through emission reduction and 15 percent through removals.
And I think that is a sensible approach because what it does is it recognises that there is a need for removals,
but it doesn't talk about removals at a massive scale that allows industry to carry on as normal.
And I think that's where a lot of campaigners get anxious about discussion about removals is that they think that it will allow industry off the hook.
And they look at how in the past certain elements to the fossil fuel industry have
talked about using carbon capture and storage on emissions from their operations.
And they've talked about it, but haven't actually done anything about it.
So they think a they recognise that there is a gap between what people say they might do to address the problem and what they're actually.
So what we need to do is we need to hold companies and governments to account and say,
Well, if you're going to achieve this net zero target, how are you going to do it?
What is it that you need to do to actually get there and hold them accountable to do that?
I think another thing that I would say about the moral hazard argument is that in a situation where you have a company polluting
and there are missing CO2 in the atmosphere and there is no feasible way in which you can remove CO2 from the atmosphere,
you can campaign against that organisation and tell them they're being bad and that they need to clean up the mess that they can just shrug and say,
Well, there's no way we can clean up the mess. So what can we do?
There's nothing that we can do. But if you get to a situation where that is a way in which they can clean up the mess,
then if a company says we can't clean up the mess, they're not actually being correct.
What they're saying is we don't want to clean up the mess.
And this is a very real moral difference between a company saying We can't clean up the mess and we don't want to clean up the mess.
And I would say that once you've got ways in which you can safely,
robustly and scalable and remove CO2 from the atmosphere, you actually create an obligation to do so.
Before it was impossible to clean up the mess.
Now it is so violent, so I think actually the argument is is not so much about the moral hazard of if we develop these technologies,
people won't deploy them. I think actually, if you develop the technologies and they are safe and they are robust and they all scalable,
then people will have a moral obligation to do so. So the morality cuts both ways, yes.
Just to add to that,
I think quite a few people in the academic community are quite life to this moral hazard issue and have written fairly extensively about it.
Now I know Duncan McLaren at Lancaster University has done quite a lot of work on this,
and he is one of the main people proposing precisely what you say that the Swedish model is a good one.
You should have separate targets for emissions reductions on the one hand and scaling up of removals on the other hand,
and don't join them together into net zero targets have emissions targets and removal targets.
And if I may, I'll just touch on what one person asked specifically about a paper I've written on this topic,
which is called the case for transparent net zero targets.
So I was kind of arguing maybe slightly differently to attend that, but we don't need separate targets.
I think just to briefly summarise it, my perspective on it.
Certainly, it's not to argue that there isn't any form of moral hazard.
So I think that there's lots of discussion. Conceptually, the moral hazard mitigation deterrents may happen.
I think one one of the clearest examples Duncan McLaren gives is,
I think that's a case of someone who works for a carbon removal company in the states arguing in
a in an evidence session and said that to the U.S. federal government that if you scale this up,
you can preserve the life of coal-fired power plants.
But but I'd say that broadly, it's mainly a conceptual argument, and the evidence is very hard to unpick as to whether it really is happening.
Part of this carbon removal is just at a very early stage. And so I say not not that you should never in any circumstances separate out targets,
but I say a lot of issues that are raised about carbon removal in the House document actually link two aspects of emissions reduction as well.
And so it's so, so that conjoined issues that need teasing out not necessarily solved by naively separating targets.
So I say, you know, one of the arguments is you can delay action because you can actually reverse the climate.
And we know that, as you said, if you go net negative, you can bring down global temperature.
But actually, that doesn't mean that the climate is purely reversible. There are a lot of irreversibility in ice sheet melts and so on.
So you really want to set targets on a time scale where you're not banking on overshooting and then coming back.
You are trying to get as low as possible, and that means near-term action is critical.
The second aspect is around that the uncertainties around some of these technologies and can they
deliver and that's both the carbon that's argument that pertains to some high tech carbon removal.
It also pertains to some high tech emissions reductions,
like battery powered planes and other forms of carbon capture and storage of cement works, for instance.
So. So the argument there is to have a plan to actively innovate, but not bank on all these magic bullets actually materialising.
And the third point is is it's some of the questions about carbon storage and subsequently.
So if you promise trees and then they burn or get riddled with pests, as you say, or even if you put the CO2 in geological stores, they can leak.
And we'll be discussing that with Mike Kandel and Roderick Abbey in a future talk in a couple weeks time.
So but again, you can you can reduce emissions by capturing them and storing them.
So it's not a carbon removal problem per say, it's a it's a carbon storage.
Where are you going to put this carbon question? So just to say I'm not necessarily arguing that target separation is something you'd never do?
Let's say, though,
those three factors are the more important and deeper things to think about if you do those and then consider target separation useful.
That's fine. But I guess the point I was making was if you think that target separation social based problems.
I disagree. You need to think about those actively engaged with what you're saying about you have targets,
but then there's a whole bunch of other stuff you need to do under that. So that's enough for me.
I want to go back to the questions you were all asking. One of them is linked, actually, and it is.
It's it's about this question of risk, actually. So PIP Wheaton says there are some pretty big assumptions in all of this.
What makes you think that will be more likely to scale up unproven negative emissions technologies and cut emissions more aggressively?
So is there any more you want to add Tim on this? This balance of risk question?
So I think the question of that gets entirely right.
You know, we don't know. And I think it's really important to say that, you know,
and I talk about these proposed techniques and I said that we really don't know if we can achieve them or not.
I think I'd probably go back to the beginning of the pandemic and people are saying, right, well, we need to develop a vaccine.
And there was a lot of uncertainty as to whether it would be actually possible to do and whether it would be possible to achieve a vaccine within.
It would take three five years and it seemed how long it's taken with other diseases.
And in fact, that's been an extraordinary story about how quickly we have.
Let's say we haven't been involved in it myself, but the people working on this have achieved these vaccines,
but there was no guarantee at the outset that a vaccine would be deliverable.
And I think that there's no guarantee whatsoever that any of these proposed techniques can deliver at anything like the scale that's required.
But I think that we shouldn't it's not an either or it's not saying we need to focus more on removal techniques and less on reductions in emissions.
We need to focus very hard on both, but we're not going to be able to achieve the one and a half degree or the two degree or frankly,
two and a half degrees without doing everything we can on both reducing emissions and proposed techniques to remove CO2 from the atmosphere.
So I think it's a false dichotomy to say we need to focus more on this and not on that.
I think we need to do both. So yeah, that's how I would respond to that.
That question, just the needle you a bit more on that one.
I mean, I agree with your point, Tim. And the way I would phrase it, I think, is that exploring these options is part of a sensible.
Sensible risk management of a portfolio of all your options to try and get to net zero and stabilise climate.
But in the reality of governments and companies making investment decisions, they don't have infinite pots of money.
So it could be argued that whenever you're making a decision to to to invest in scaling up removals, that's money.
There's an opportunity cost. That's money that could have been spent on emissions reductions.
So do you have any practical thoughts on how how that decision could be made in practise?
Does it come down to, you know, looking at technology readiness,
levels of technologies and costs of capital and kind of standard financial management?
Or would you approach it slightly differently? I'd approach it slightly differently.
I think first of all, I would say, you know, back in the early 2000s, there was a similar sort of debate about mitigation and adaptation,
and there were people who were vociferously opposed to putting resources into adaptation because it was defeatist.
We really needed to mitigate. If we mitigated enough, we wouldn't need an application.
And there was a recognition that actually people are suffering now and would continue to suffer unless we did more on adaptation.
And it wasn't a matter of mitigation or adaptation. It's both.
But I take your point about allocation of resources, and I think that the efficient way to allocate resources is not actually say,
OK, what's the technology readiness level of this technique or that technique?
Because we really do not know. I've been working in this field for 10 years, and I've tried to get a very broad view of the proposed techniques.
And what I'm constantly aware of is how much I don't know about these techniques.
Yes, there are positive aspects of them, but then there are all sorts of side effects which could be countervailing to these proposed techniques.
And so what I think is is actually needed is not to pick winners, but instead to create an environment from which winners can emerge.
And I think that is not done by saying, well, these techniques are capital intensive, so we need to have some sort of model that supports them.
And this technique is has this particular, he said.
We need to create a mechanism for that.
What we need to do is we need to create a mechanism similar, as I say, to how we did with wind and solar, where with that it was,
we're going to pay you this much per kilowatt hour of electricity, a megawatt hour of electricity that you generate.
That's that's the unit for electricity,
for carbon removal techniques that metric should be and a certain amount of money per tonne of CO2 removed from the atmosphere.
And then you apply that across all the techniques.
And then what you get is you get people investing because they can see that there is a way of actually making these things real.
Making a business out of it, you got people investing and developing these techniques, but you're not favouring one technique over another.
You set the success parameter in the parallel case of of the pandemic.
You're not saying how the vaccine should work.
You are saying that the vaccine should prevent people getting ill, prevent transmission or whatever your goal is.
And so I think it isn't actually about when is at this point it is about.
Providing the incentives to allow the whole field to grow, and I think it's really important to do that because otherwise you will get
people who are incumbent industry players who will be pushing their technique,
building the regulation in their favour.
And actually, what you want is you want to have a diversity of ideas out there competing for what the its right to left thinking.
You need to decide where it is you want to get to and then you need to bring people on to actually deliver on that.
OK, so another question here, we're starting to come to the end, so if you if you're good and brief on this one,
Tim, even though it's a very complex question, I reward you with one final one.
So Ollie Stedman asks a great question who is the way in this discussion?
So are we talking about actions that a single country can take and actually other
countries that might need to go negative in order to achieve global net zero?
So I'm going to break that into two parts. Actually, there's both the country question and you might have to go to net zero or beyond net zero.
So it's a net negative, but also where it where are the exciting developments?
Which countries or which organisations do you think will be the ones that that can that can be the front runners in this space?
Okay. So the way I'm immediately thinking of policymakers in the UK, sensible is situated.
And this needs to be done in many different countries.
Going back to the example of solar, you saw the impact of one country, Germany, providing subsidies for solar,
which led to a massive increase in solar panels being produced in a driving down of price.
And then that lower price was able to break into markets around the world.
So it's very possible for one country to have an impact which then can be rolled out everywhere.
At the moment, the people who are leading in this space in the United States are incentives from California
and also federal incentives that incentivise removal of CO2 from the atmosphere.
And if other countries don't respond with similar sorts of mechanisms regulations,
they're going to run away with this industry as a whole to come to the the point about historic emissions.
Yes, I think that the UK, as a pioneer in the industrial revolution, has got a long legacy of CO2.
So it's not just about getting to net zero emissions in 2050.
We also have to examine the historic emissions that we have, so I think it's very possible for it to be equitable.
The UK may actually have to go carbon negative to a large extent in the latter half of this century in order to counteract the emissions,
and they previously tried to replace it with it, right?
That leaves me with a tough choice as to which question I'm going to give you because there are so many very good ones.
I think we've got strong support for you approach to the idea that the polluter should pay.
That's definitely the ethical answer in several people's views.
We have a brief question, which I'll tackle from Daniel Schorr asking Is there a reliable estimate of
concentration of CO2 equivalent in 2050 and when will we be approaching 300?
I can tell you, Daniel, that in terms of carbon dioxide in the atmosphere, we're already at about 410 parts per million now, I think.
And when you add on the other planet warming greenhouse gases you get,
if you measure it in carbon dioxide equivalent to something like 500 people at the moment, parts per million.
That's some offsetting from the poor air quality we have. So the other athletes and some CO2,
that underlines the fact that we have probably a long way past what's the widely accepted view about the long term level we should be at.
And that's partly why carbon removal is a hot topic these days.
I'm going to ask you very briefly about this.
There are a few other questions about this distinction between sort of natural carbon removal, restoring natural sinks and more engineered methods.
Do you have a preference, Tim? How would you go about thinking about distinguishing between those tubes?
Is that a helpful distinction and where where would you put your emphasis if you had to put it on one?
So I'm, as I mentioned earlier, I'm the advocate of right to that thinking, which is where we want to end up.
And okay, what is going to allow us to actually get to where we want to end up?
And I think that there are many benefits of nature based solutions beyond the removal of CO2 from the atmosphere so done in the right way,
we can restore ecosystems,
increase biodiversity, livelihoods, amenity value, watershed catchment, all sorts of different things that we can do if we do it in the right way.
We've said that you could do it in the wrong way as well. There are some very large plantations of Sitka Spruce in in in Ireland,
which certainly the locals are not very happy about producing dark forests, which are a very non biodiverse.
And so it's about planting the right trees in the right place.
I think one of the advantages of nature based solutions is that they have broad appeal and public supports, and nobody's nobody's down on the trees.
You know, the trees are good, and that's great because we are going to need public support.
It's going to cost money. People are going to need to pay for it.
And I think at the 2019 election in the UK, every every large party was campaigning that we needed to plant more trees.
And there was almost the kind of planting trees, arms race. And I think it got up to about two billion trees with the highest bid, which,
by the way, would have been an area of the size of Wales to plant with trees.
And we don't actually have that large an area to play with at the moment.
And so I think there is some sense in saying, OK, let's use nature based solutions,
but we have to recognise that if we don't sort everything else out along the way,
then what you're doing with putting carbon into trees and into soil is you're basically creating a pile of kindling that if
the temperatures should rise because other things in our political system don't deliver the reductions in emissions required,
then that carbon is going to go up in smoke, quite literally, and it's just going to return the CO2 into the atmosphere.
So I think it's a good start, but I don't think we should rely on it exclusively.
We can't hope to balance the carbon based budget on the backs of nature.
We have pumped trillions of tonnes of CO2 into the atmosphere through the extraction of fossil fuels over the last few centuries.
And yes, some of that can be taken up by by plants, but not all of it by any means.
We are over time, I'm afraid, Tim, so I'm going to have to leave it there and just say thank you very much for that
fascinating talk and thank you to all of you in the audience for joining us too.
If you're interested in thinking about this further, as I mentioned,
you can find on the Oxford Martin School YouTube channel the previous talks, including one focussing on nature based solutions.
So you may find some of the answers to your questions there. And also in a couple of weeks time, we'll be talking about geological carbon storage.
But join us again next Monday, when I'll be discussing climate justice, ethics and governance in the context of net zero.
And that will be me with Lavanya Raj Yamani, Henry Q, Tom Vatsa and Harvey Alisan.
So proper conversations be happier if you're interested in that to join us,
and you can register by clicking on the green button under the video screen.
Right now, all that remains for me to do is wish you all a very good week.
So goodbye and see. See.