Well, hello, everybody, and welcome to last, but by no means least of the Oxford net zero seven.
I'm sitting in for Steve Smith, who is busy recruiting today, so it's all happening with Oxford net zero.
But this is not the last event we're running. So the next major event actually is the formal launch of the programme on May the 7th,
so that the afternoon of May the 7th, where we not only launch the Oxford Net Zero initiative,
but we also launch the university's Oxford University's own sustainability strategy,
and we've got a number of exciting panels and lectures and so forth to mark that event on May the 7th.
So do job by will open. It's going to be virtual, of course, but it's all open to the public.
So do take down in your diary.
But today we have Professor Ross, Abby and Roxana Shafi and Sniffy Gill all talking to us about the role of the oceans in achieving net zero.
This is a really important topic.
The reason I said at the beginning this it's announced in the series only because of diary constraints, not for any other reason.
And so it's clearly going to play an important role in the discussions in COP26 in Glasgow,
as people are starting to weigh up how much of the carbon dioxide generated by our use of fossil fuels.
Can we count on the oceans to mop up? And how can we encourage them to more?
So I think it's going to kick off with just some quick introductions to our speakers.
Ross Rigby is one of the true investigators on the Oxford Zero initiative.
She's a professor of physics of geology in the sciences departments in the university, and she's been working on carbon sequestration,
primarily in the oceans and also the carbon cycle in the oceans on all sorts
of timescales ranging from years to millennia to millions of years for for,
for some quite a while. Actually, I'm not quite sure how long you've been.
I won't say I realise I failed to do my homework on that one. Sorry about that post, but you can tell people how long you been working on this.
And Sophie Gill is a patient in this group, the Ocean Bug Group, and has worked but worked previously for time.
It works and a consulting.
And Roxana Shafi is also a Ph.D. student in the Ocean Bulks Group that is currently seconded to the Scottish Parliament Information Centre.
The ocean is being an important topic for Scotland in the Glasgow cop.
So over to you, Ross. Can I just sorry before we say I'm don't forget, you can ask questions and you can even more importantly,
vote on other people's questions to promote questions that you think are particularly interesting in the course of the talks.
And we'll be picking up on those questions and I'll be sort of feeding them through to the speakers as we go along.
OK. O'Bagy Ross. And I can see your screen now finals.
OK, great. OK, that's fantastic.
Well, thank you, Miles, and thank you, everybody for the opportunity to speak here.
And Miles sort of highlighted, I guess, my my my proclivity, which is that in the end, I'm a geologist by training.
And I guess what I what I want to show you is how we can use the past to perhaps give us hints as to how to make solutions in the future.
And so I'm just showing you here, this is something I guess that inspired the Oxford Net-Zero logo,
and it's a series of different pathways that we may take in terms of emissions to try and hit that net zero at around 2050.
And I guess the key the key point to note, of course, is that all pathways that limit our global warming to 1.5 degrees C predict the use of carbon
dioxide removal on the order of 100 to 1000 billion tons of CO2 over the 21st century.
So that requires some kind of rate of CO2 draw down of one to 10 billion tons of CO2 per year.
Now I'm going to try, and in all of our talks, we we've tried to be consistent with units,
but this is a sort of horrible fit for geochemists is a horrible world.
People talk about gigatons of carbon. Billion tons of carbon masses of CO2.
And I guess the thing to realise is that where you in to convert between tons of carbon and tons of CO2, it's kind of a factor of four.
You're just accounting for the carbon in that CO2 molecule.
But just the numbers to keep in mind are 100 to a thousand gigatons of CO2.
So what's happened already, and I guess the the the key thing about the Asians is that they are already being a major
part of limiting the amount of CO2 that is accumulating in the atmosphere was shown on.
This figure is going from 1750 to around 2010.
A little bit later is the emissions of CO2 from fossil fuel and the cement industry, as well as from land use change.
And you can see those rising up to about 10 a pentagram so gigatons of carbon per year.
When you look beneath that, those kind of horizontal line,
you can see that there is uptake of CO2 in the green zone is what being what's being taken up into
the terrestrial biosphere into some regrowth of the terrestrial biosphere on land in the light blue?
That's the amount of CO2 that is accumulating in the atmosphere. And indeed, is it leading to this global warming?
But in the dark blue, you can see the ocean sink.
So this is how much CO2 is already being taken up into the ocean, and this is occurring because of equilibrium.
The oceans are at equilibrium with the atmosphere, so the more we put into the atmosphere, the more we put into the oceans.
And I guess what we're trying to examine in these next few talks is can we can we manipulate the oceans?
Almost such they take CO2 out of the atmosphere that goes beyond equilibrium, where they are actually actively sequestering that CO2.
Part of the reason that the oceans are so good at sequestering CO2 is because when CO2 dissolves in the ocean,
it reacts and it equilibrate to form the carbonate species in the carbonate species.
And that's shown in this lower panel to the bottom right of the slide here and at a pace of about eight, which is what the oceans are.
The majority of the carbon is existing is by carbonate and carbonate time,
and it's only the sort of small reservoir in the green here of CO2 aqueous that is actually exchanging with the atmosphere.
In terms of quantities, the oceans are already taking up about two gigatons of carbon per year,
and we think that since the start of the industrial revolution, they've taken up about 500 gigatons of CO2 from the atmosphere.
So they're already a good sinkers of CO2. And the question is, can we manipulate that into the future?
And as I've hinted, part of what I want to talk about is the fact that we can take lessons from the past.
And indeed, I started out as a geologist fascinated by glacial interglacial cycles of temperature and atmospheric carbon dioxide and really wanted
to try and get to the bottom of why carbon dioxide seems to breathe in and out of the ocean on these glacial interglacial timescales.
So I'm just showing you in this panel a time scale from 800000 years in the past to the modern day.
And you can see these cycles in temperature in the orange curve here,
where we're changing temperatures by the order of about 10 degrees C and these
are recorded in the ice and in ice cores from Antarctica in the upper curve.
What I'm showing you is is the fluctuations in carbon dioxide in blue here,
and you can see that carbon dioxide this is captured in air bubbles that are being shown in the in the left hand side of this slide.
And they vary on the order of about 100 p.m. between glacial and interglacial time scales.
And you can see that that magnitude of change is almost exactly the same as the amount of CO2 that we put into the atmosphere.
In terms of gigatons of carbon, one ppm is about to gigatons of carbon or eight gigatons of CO2.
And so just from looking at this, we can assume that the glacial ocean is storing about 200 gigatons of carbon from the atmosphere,
purely from the diminishing CO2 in the atmosphere. We point to the ocean as the mechanism behind this because it contains a large
reservoir of carbon that is quite easily interchangeable with the atmosphere.
And so it's able to to therefore breathe out the CO2 and absorb the CO2 on these quite rapid timescales.
And many other reservoirs have have much slower rates of change and are unable to account for these CO2 fluctuations in the same way.
So it's sort of there's been a big community effort. Oh, I should say sorry.
So the glacier world, of course, look very different to the modern day.
And it turns out that we have to account also for the fact that the terrestrial biosphere in a glacier world was very much smaller.
We know at this time about 20000 years ago that ice sheets expanded and covered that large part of northern Europe.
And you can see on this sort of projection looking down on the North Pole of the globe,
you can see England peeking out from the bottom of the ice sheet there in the lower part of that panel.
And of course, this is a time when England couldn't argue whether it was part of Europe or not.
There was. A land connexion between us, so this large ice sheet was covering major parts of the terrestrial biosphere,
and as a result there was there was less carbon being stored there,
and the estimates are that actually this smaller terrestrial biosphere in terms of peat vegetation,
in terms of the soil carbon that was stored was probably around 300 to 700 gigatons of carbon smaller at the glacial times.
So not only did the oceans have to sequester that atmospheric CO2, they also had to store this extra carbon from the terrestrial biosphere.
So that gives us a total glacial ocean storage of about 900 gigatons of carbon, or 30 600 gigatons of CO2.
So this is three to four times more than we need to sequester in the coming century to to hit our 1.5 degrees C target.
Much of what I've worked on, and this is kind of an interesting little message for perhaps for thinking about the
future is that we are all trying to saw what was it explaining this glacial CO2 change,
looking at individual mechanisms and really whether the field has got to now,
is that probably in order to account for that large change in carbon requires a multitude of different mechanisms to do that.
And these rely on the biology, the chemistry and the physics of the glacial ocean.
So just to sort of think about it, how would we draw CO2 down into the ocean?
Well, firstly, I've mentioned that the surface ocean is at equilibrium with the atmosphere,
and so we would need to somehow shift that equilibrium more towards CO2 being dissolved in the surface ocean.
We can do that by raising the edge of the ocean, by lowering the temperature or by lowering the salinity.
And those those effects have the impact of drawing CO2 down via changing the equilibrium,
the additional parts that could be manipulated as the power of the biological pump.
So we have a whole ton of organisms photosynthesising in the surface waters.
They remove carbon dioxide into their organic matter and they drop down into the deep ocean and they take that carbon dioxide with them.
So if they remove more CO2 from the surface ocean, that has also has the impact of sequestering carbon in the deep ocean.
These are all set against the physics that ocean overturning.
So how rapidly perhaps CO2 water's being taken down into the deep ocean via this mixing that occurs in the
ocean versus the rate of upwelling of CO2 in the ocean or sorry of carbon rich waters from from beneath.
So these are the sorts of dials that we could think about changing in the glacial ocean,
and there are proxies, various ways of indirect ways of trying to tease apart these different mechanisms.
And what I'm just showing here is is a is a model which tries to piece together how each of these different mechanisms contributed to changing CO2.
So I'll control run has about two hundred and eight tpmf of CO2.
If we then allow the ocean to cool and increase the solubility of CO2,
as well as having that cooling impact change the circulation pattern of the ocean
that takes down about half of the glacial CO2 if we then allow nutrient addition.
And this is something that Sophie will talk about in some detail. The kind of impacts of the fact that we know the glacial world was dustier.
There was more iron which fertilised that biological pump of carbon that can remove almost the other half of the glacial CO2.
But then if we if we take the land carbon reduction and put that back into the ocean, that makes the CO2 go back up.
So we're now at 2:15 p.m. We then lower the sea level, which raises the salinity of the ocean.
And that again adds to the CO2 in the atmosphere.
And the final part that needs to occur to sort of reach our glacial target almost is the fact that the lowering
of that sea level eliminates all the shelf area with things like calcium carbonate or accumulating in corals,
and that calcium carbonate then builds up in the ocean as sort of alkaline et al.
Colonisation of the ocean. And that allows us to then reach a sort of final glacial CO2 target.
So these are the sorts of dials that have contributed to explaining this total CO2 drawdown.
So and indeed, we've had we've got proxies which can both tell us about the quantity of CO2 that was was taken into the ocean,
as well as the impacts of it. And so what I'm showing here is is a reconstruction that we've made using a new proxy for deep ocean oxygen.
Now the great thing about being able to reconstruct deep ocean oxygen is it allows us to quantify
how much CO2 is has been taken into the ocean via the process at the biological pump and via.
Ratification, both of which remove oxygen from the seawater, so any biological mechanism which lowers CO2.
The fact that we're making more organic matter means that it has to be respected and it demands and takes out oxygen from the water column.
And so we've been able to show that the response and carbon concentrations are much higher in the glacial ocean.
And indeed, that biological pump mechanism accounts for about a third of the glacial CO2 storage,
but also gives us much lower oxygen concentrations across the Atlantic and in the deep Pacific.
So that's the additional impact that we can see of these mechanisms is that we know that
the glass relation had a higher rate again because of that addition of the calcium
carbonate from the loss of the corals and the impact of that on the remaining calcify as
the pelagic calcified of the forum and from the calligraphers is that they calcify more.
We have records where the mass of these their calcite shells increases as you go into glacial periods.
So this gives us some insight into the impact of these different sequestration processes on the biota that's living there.
And just a final slide, a sort of alarming component, perhaps of the lower oxygen,
which would undoubtedly impact the microbes that are living in the ocean in terms
of the larger organisms and the diversity of organisms living in the deep ocean.
We don't have good diversity measures across the global ocean,
but our general understanding is that the diversity of benthic fauna correlates
with bottom water temperatures where a colder ocean leads to lower diversity.
But it also correlates with productivity in the surface ocean and the rain of organic carbon, essentially providing food to the deep ocean.
And so, of course, in the glaciation, these things are working in different directions. Colder temperatures give us lower diversity,
but we certainly have evidence that the biological pump was stronger and that could have fuelled higher diversity.
But it would seem that that generally that the diversity is less controlled by oxygen availability and more so by this rain of organic carbon.
So I guess what I wanted to show you was that the glacial ocean gives us more than
the capacity required to account for to try and sequester CO2 going into the future.
And it gives us these hints at potential impacts of differing mechanisms on the fauna that is already living there.
And I'll leave you there and let Sophie take over. Thank you very much, Ross.
And some some really intriguing hints there about the potential here.
We're going to hear from all three speakers and then go to questions, but do keep the questions coming.
Apologies for my question, but I'm still intrigued by it. So when we're getting on to.
So whenever he's finished speaking. But if you've got if you've got a specific technical question for the speakers, do you highlight it?
And I'll try and answer that as we go along. Just give it up. Okay, so over to you.
Sophie, next. Oh, great.
I can hear you now. Right? And you're just going to share your screen, and it seems to be sharing.
Okay, well then Sophia. Fantastic. Thank you.
So I'm going to introduce the proposed methods to you artificially enhance a magnitude or accelerate the rate of carbon
storage in today's oceans to actually draw down the carbon dioxide that's already in the atmosphere from prior emissions.
And many of these take their inspiration from the kind of oceans physical,
chemical and biological systems that have operated differently in the geological past, as Ross has outlined.
And so here is a kind of family tree, if you like,
as proposed ocean based carbon dioxide removal techniques often referred to as Ocean CD-RW techniques.
And these CD-RW techniques can be broadly split into those which aim to increase the carbon removal capacity of the oceans abiotic pumps.
So the physical and chemical aspects of how the ocean works or the ocean's biological pumps,
so influencing the biology of the oceans store more carbon.
And I think Roxana is going to dive into blue carbon management in more detail, but just to briefly touch on it here.
In many cases, it's not technically considered to be a carbon removal scheme as a blue carbon.
Habitats like mangroves, grasses, etc., a large source of CO2.
But unless these habitats are specifically being expanded, so drawing down more carbon than they currently are.
This doesn't really count as carbon dioxide removal. So let's outline each of the techniques for this family tree now.
What are they and what's their cedar potential? So artificial dwelling means to stimulate enhanced downward transport of cold CO2,
saturated downward transport surface waters down to the deep ocean for storage of up to hundreds, or potentially even thousands of years.
And this technique is really still in its infancy in terms of peer reviewed research.
So there's no real good estimates of its potential yet.
But moving on to community enhancement, and this is a scheme that aims to add alkaline materials to the surface ocean,
either directly or through enhanced weathering or electrochemical production to
increase the CO2 solubility in seawater through the Surface Oceans buffer system,
which rules kind of outlined previously. And this technique has the potential to store up to one gigatons of carbon per year,
or the equivalent of about three point six seven gigatons of carbon dioxide per year.
And moving on to deep storage, this aims to make use of the department store carbon rich material,
either by injecting CO2 directly into the deep water layers of the ocean or by injecting liquid CO2 into marine geological reservoirs.
And this is a difficult one to quantify because it varies a bit depending on location.
But it's been estimated that for basaltic rocks offshore Iceland and we could store a wide range really hit for the estimate,
but between 60 to seven thousand gigatons of carbon dioxide total.
So ocean fertilisation means addition of nutrients to stimulate primary production,
whether that be using the micronutrient iron or the macronutrients, nitrogen and or phosphorus.
And the CDC estimates vary slightly depending on which method of nutrient addition
is used and iron addition is by far the most research pathway of the two.
Iron Edition makes up the vast majority of literature on ocean CDR techniques because there were actually 10 to 15
mesoscale iron enrichment experiments that were carried out in different areas of the global ocean since the early 1990s.
And the consensus, I think nowadays is that this technique doesn't really have the potential to be deployed due to the myriad of disruptive
effects on ecosystems and issues with production of climate relevant gases like nitrous oxide or dimethyl sulphide.
And these effects were established relatively early on in the timeline of these experiments being wrong.
So I would argue we can learn how to more quickly produce relevant data for Ocean CD-RW using iron fertilisation as a kind of case
study and artificial upwelling works in a similar way to ocean fertilisation and supplying nutrients to simulate primary production.
But instead of adding nutrients to the surface ocean directly, we do it by enhancing oakwood transport of nutrient rich waters.
And this has potential to store between nought point two to eight point nine gigatons of carbon per year.
And finally, microbial cultivation makes use of macroalgae to remove carbon dioxide from
surface waters through organic carbon export and through the sinking of biomass.
And and there's a slightly lower carbon at sorry carbon storage estimate for this technique than the others.
But arguably, macro algal cultivation comes with less technological barriers and kind of fewer potential ecosystem impacts.
And I think something we see often with these CD-RW techniques is the higher the risk of unintended or should I probably
say as yet unknown impacts for many of the techniques and potentially the high the reward in terms of carbon removal.
And so there's that kind of risk reward trade-off there.
And for the combined sea, the potential of all of these techniques,
taken together is around six point four gigatons per year based on the available data,
plus the geological storage potential of deep storage and geological reservoirs, which as we saw, was potentially pretty sizeable.
But the estimates vary dependent on location and we're also it's somewhere
between one to 10 gigatons of carbon per year is what we need to be aiming for.
So this looks pretty good in terms of the potential for the ocean. But actually, this includes the figure for iron fertilisation here, which,
as I said, I think he's incredibly unlikely to be ruled out as a seed scheme.
So it's evident that no single one of these techniques will be enough kind of on its own.
We'll probably need a full portfolio of these techniques operating together to meet international carbon removal targets.
And aside from ocean iron fertilisation, we don't have enough data about any of the other schemes, even our C enhancement,
which is by far the next most researched technique to be able to make informed decisions about their deployment.
So we need to get moving on, generating the most relevant data for these schemes quickly and efficiently and to progress research in this area.
We really need to learn from the case of the iron fertilisation so we can identify that for any seed scheme.
There are kind of three priority research questions which everyone researching these schemes should be trying to answer.
So I've listed them here, and I think number three can also be extended beyond science to kind of include governance, economics and social science.
And even after the huge, amazing scientific effort that we saw with iron fertilisation research,
we're still not sure where the iron fertilisation really answers the second point
here whether it resulted in increased carbon export and storage in the deep ocean.
And that's a key barrier to decisions concerning its deployment.
So just touching briefly on my personal research, I'm trying to establish where the calcifying plankton, so those which make their peaceful,
intricate shells out of calcium carbonate pictured here we have a chocolate for under foreign minister.
Outside, as a by-product of increasing their calcium carbonate production,
if we add extra alkalinity to the ocean and also whether there are any potential damaging
impacts on these calcified in their role as a major component in the Ocean's ecosystem.
And so my research is kind of currently a work in progress.
It's unpublished at the moment. I'm still working on it, I still doing my Ph.D.,
but I've been able to show that there's a potential increase in calcification as
a result of alkalinity enhancement via a couple of different chemical pathways.
And it but it may be that this increase is no greater than the decrease in calcium carbonate
production we've seen as a result of ocean acidification over the last few years,
as we've we've had the impacts of anthropogenic climate change actually on the ocean.
And this is something I'm currently trying to unpick.
But just to kind of round off what are the things that we need to move forward and achieve an ocean that looks something a little bit like this,
even if not completely fulfilling all of these kind of check points of different carbon removal strategies.
But how do we move towards achieving some enhanced carbon sinks? So I think there's two major things.
First one is that we need a coordinated, prioritised research strategy framework within which to operate.
And secondly, we need coordination between sectors which will enable these decisions about
deployment of these schemes to be assessed in a kind of safe and responsible way.
And also, like I said, generate the data in the most efficient way possible to answer the questions that that we need to know the answer to.
And so, yeah, over the rocks on it to tell us a little bit more about kind of blue carbon stores, I think.
Thank you very much, Sophie. Yes, and if we didn't see any very specific questions for Sophie, so I'll sort of keep logging the questions,
keep them coming, keep voting for other people's questions and overdue Roxana.
All right, well, thank you, Roz and Sophie, for that. I think you've set the stage really well, that's what I'm about to say.
Just to reiterate, as Miles said, My name is Roxana Shafi.
I'm a DPhil researcher at the University of Oxford and currently on the research to comment to the Scottish Parliament Research Centre,
where I'm working on a policy briefing on blue carbon. So I've put my email and Twitter there.
Please feel free to ask me any questions if I don't get around to answering them today for you,
and I'm always keen to chat more about the science, of course.
So the term blue carbon really came into existence in 2009 and following on from this key report compiled by a number of institutions and experts and
the central aim of this piece of work was to draw policymakers attention to the vast quantities of carbon which is stored in the marine environment.
And this is against the backdrop of the policy landscape that was primarily focussed on land based ecosystems.
So in order to do this, the authors coined the metaphor blue carbon to describe carbon stored in marine and coastal ecosystems,
and green currents describe carbon in land based habitats such as forests.
So some of the main definitions will perhaps focus more on coastal habitats and species.
And this is the carbon which is stored in the living biomass and the underlying soils and sediments of coastal habitats like mangroves,
salt marshes, sea grasses and kelp. And the reason that they typically tend to be at the forefront of this blue carbon definition is because
they're the things that can be managed on a policy scan a national scale a bit more easily than perhaps,
for instance, carbon stored in the oceans globally.
But as a as has been mentioned that the carbon which is stored across the oceans
on seafloor sediments has also been incorporated into this definition of carbon.
So when we're talking about blue carbon, how significant are these stores?
So there's an emerging evidence base to show that blue carbon actually exceeds what we call trading carbon.
And this is predominantly because of the vast quantities of carbon which is stored on sea seafloor sediments,
so they store a whopping three thousand one hundred seventeen billion tonnes.
So billion tonnes is equivalent to gigatons and that we've been kind of switching between
the two and coastal habitats contribute quite a lot less around forty five billion tonnes,
but still very important in terms of the ecosystem benefits.
So given that kind of quick whistle stop tour of what sort of quantities are we talking about here?
How can we start thinking about blue carbon in terms of policy frameworks for climate change mitigation?
And there's really two ways that we can do this. The first of all,
we can think about this is the imperative to preserve blue carbon habitats so they don't release more
carbon and make climate change a big issue and so that they can continue sequestering carbon in the future.
And the second way of thinking about blue carbon habitats in this kind of chimes more into what
Sophie was speaking about earlier is in terms of restoring and creating more of these environments.
They actually enhance and increase carbon sequestration and storage.
So in terms of the preservation of these environments?
There is now a significant body of knowledge to show that human activities are causing damage to known carbon stores.
For instance,
now it's predicted that around 1.3 percent of the ocean floor is trawled annually and trawling is a type of bottom towed fishing practise,
which involves tracking a net or a heavy steel frame along the ocean floor in order to catch fish.
And as you can kind of see here, this physically disturbs the sediment and can release the carbon into the overlying water column.
And the second way that this kind of mostly affects coastal areas is coastal land developments, where they're physically clearing these regions.
So it's not predicted that half of the world's mangrove habitats have been lost because of coastal
land developments and the scale of carbon release from these activities is not insignificant.
And trawling and coastal habitat loss actually has recently been discovered to release more carbon dioxide emissions than the aviation industry.
And on the same order of magnitude as deforestation. So the second way that we can think about blue carbon, as I alluded to,
is how can we use these ecosystems in order to increase carbon sequestration and storage?
And it's estimated that if we were to restore wetlands globally,
we could potentially have 40 percent of the needed mitigation mitigation potential to maintain global temperature rise
within two degrees C above pre-industrial levels and blue carbon environments are often thought of as a really attractive,
nature based solution, and nature based solutions was the focus of one of the previous net zero series.
So I would really recommend go back and look at that.
If you're if you're interested in nature based solutions and these are solutions refers to the sustainable management
and use of nature for tackling socio environmental challenges and particularly focussed on climate change.
And the reason that blue carbon is often seen as an attractive solution is because if you were
to take a metre squared of blue carbon environment like seagrass or something like that,
and then compare it with its equivalent green carbon environment, oftentimes the blue carbon environments sequester more,
so they capture more carbon dioxide out of the atmosphere permanent metre squared yet.
So this is some of the data that we've been looking at the Scottish Parliament showing that Scotland's blue
carbon environments are often able to sequester more carbon dioxide than the equivalent land based ecosystems.
And while we can kind of think back to the carbon storage of these ecosystems and perhaps the restoration and enhancement of coastal habitats,
it's not going to be the panacea for being able to sequester all the carbon dioxide that
we need to and some of the figures that have emerged earlier from some of the talks.
And it's one piece of the puzzle, and it can't be understated how important restoring some of these ecosystems are,
and especially from a climate change adaptation perspective,
because coastal ecosystems are hugely important in increasing the resilience to climate change effects which are already being observed.
So a decade on from the first kind of initial coining of the blue carbon term, this metaphor,
where have we gotten from a policy perspective, what's being done about them considering these ecosystems and climate change mitigation?
So 28 countries include blue carbon in their mitigation actions in their nationally determined contributions.
And these are the specific efforts that are being made by countries to reduce national emissions
and adapt to the impacts of climate change in response to the Paris Climate Agreement.
And 59 countries include blue carbon in their adaptation strategies.
And this has largely been mediated by the IPCC frameworks, including wetlands, into policy into greenhouse gas emissions inventories.
But this does only relate to salt marshes, mangroves and seagrasses.
So lots of other habitats which could potentially sequester high amounts of carbon are not being included.
COP26 Climate Convention and biodiversity themed convention opportunities to
raise the profile of blue carbon and increase momentum and keep it going on.
But I've kind of just want to throw out to you at the end of some food for thought,
given the emerging evidence based I presented here is this blue carbon policy world moving quickly enough,
especially in contrast to what we know about terrestrial environments and how it developed
the policies for terrestrial based ecosystems in terms of climate change mitigation.
So I'd be happy to discuss this more. And yeah, thank you very much for listening.
Well, thank you again and thank you all. That was a great series of talks and lots of questions coming in, so hopefully we'll back up on screen.
Good to see you all. And I there was the sort of those one question which is, which is come through is everybody's excited to hear about this.
I mean, this this fundamental question about, you know, if we start using the oceans in this way,
any activity in the oceans which come that comes into Robert,
Chris, by the way, any active in the oceans at climatically significant scale will have undesirable ecosystem consequences.
And do we have know enough about the oceans to be confident about this?
And can we get that knowledge fast enough in order to be able to use it?
So so what what are the implications of sort of as it were using the oceans to mop up fossil carbon?
He wants to take that one to start with. I guess we should have known this for me warming?
Yes. I mean, I think the one thing I'd say this thinking from an ocean alkalinity enhancement perspective is that we
have already detrimentally impacted the ocean and its chemistry by emitting the CO2 that we have so far.
We know that the edge of the ocean has declined and there is alarm about ocean acidification.
And so I think in terms of, in a way, part of the manipulation of ocean chemistry.
If we think just of P.H. and raising alkalinity, part of that could be considered in the sense that we're restoring it to where it was.
And if we can do it in such a way that we're not adding a whole ton of other impurities
that I think that the the ecosystem impacts of that could only be a good thing.
Whether we can do that in a in a in scale, in a way that is acceptable, that's that's another question.
So I guess I guess I feel that part is is OK.
I agree that. But I think there are many possibilities within SoFi's schemes.
Things like putting liquid CO2 down into the bottom of the ocean and I suspect, would probably not have major impacts on the biota.
But maybe, Sophie, do you want to say a bit more about which which of the techniques you thinking?
And I guess what we what we learnt from the glacial ocean again, I suppose that's what I was really trying to figure out is that yes,
there may be impacts on calcify as associated with alkalinity enhancement.
And but in terms of biodiversity of the fauna in the deep ocean,
I'm not sure we could see big impacts of that from this much larger than a three fold greater CO2 sequestration in the glaciation.
I guess that's what I want to say. So if you do have more to add on that, yeah,
I just I think you've kind of said most of the things that I would want to highlight and the main one being that particularly so iron fertilisation,
we do know that there are potentially a myriad of kind of unintended consequences.
But. Like I said, I think that is very unlikely to be rolled out was a feeder scheme for those reasons,
and actually the hope is that we would do the research to make sure that that won't happen.
We will never roll anything out where we think there will be significant disruption of ecosystems.
However, the ecosystems are being disrupted because of ocean acidification at the moment.
So if we don't do anything, then they're not going to, then they're not going to kind of survive the pressure that we're putting on them.
So especially with ocean alkalinity enhancement, which is the scheme that I work on, yeah,
I think there's enormous potential to reverse the damaging effects of ocean acidification as well as drawing down extra carbon dioxide.
And there are natural analogues in the present day as well, not just in the kind of past oceans.
For example, the Black Sea is actually a naturally high alkalinity ocean,
and that ecosystem functions pretty normally compared to other ecosystems in the ocean, just a much higher alkalinity.
And there is a kind of a much higher calcification budget in that ocean.
So there is some evidence that more calcium carbonate production happens there.
However, the ecosystem isn't completely thrown out of whack by just being a naturally hierarchical and sea.
So I think there's a lot of potential for that technique, and to be honest, the other techniques.
I can't massively speak to the unintended impacts yet because there's just not been the research done.
But like I said, hopefully in the coming years, we will we will know a bit more.
Just look solid. Can I just ask you because you're dealing directly with politicians and moment at the moment?
Do you do you find that politicians are sort of there are certain kinds of interventions that are just a no-no for people?
I mean, people open to the idea of being carbon storage or is it just a mystery to people?
And what are you finding? And most definitely.
And I think that's because blue carbon is especially with the restoration of some of these environments,
which have been damaged in the past, is seen as a almost a low risk strategy.
And perhaps the sequestration potential isn't as high as some of these geoengineering techniques.
But given the multitude of benefits in terms of biodiversity, which has implications for water quality tourism, all these different things,
it's a kind of a win win solutions for policymakers, the kind of, I guess,
when it comes to the big quantities of carbon and we are discussing just a bit earlier,
some of that seems to be a kind of a higher risk reward sort of scenario in terms of sequestration,
whereas these big carbon environments perhaps not going to be the the thing that the
solution to these problems that have a lot of other benefits in terms of climate change,
adaptation and resilience. And how does the Scottish Government react to the suggestion we should ban trawling?
I think you have to say with this, perhaps not so much the government, but the fishing industry.
Yeah, it's the balance is a tension of balance. It's a tension between different industries.
You you use the ocean and make their living from it. And also, we want to protect the biodiversity.
And of course, it's in it's in everybody's interest to protect the Biodiversity Fund from an economic perspective, sustainability perspective.
But now it's moving forward. But perhaps at the paces, the terrestrial terrestrial sphere has moved forward in the past.
Right, thanks, yes.
So we've got a question specifically about seagrass, which I'm intrigued by as well, because I've sort of heard about who wants to take that one up.
It's basically how cost effective is seagrass for carbon sequestration for the UK.
And I don't see I'd like to extend it to Charlie Fraser.
Was this and he put cost in brackets. And I'd like to take the cost out there because I'd like seagrass is quite a lot is discussed,
I think, quite a bit around the UK as a carbon sequestration idea.
So what is the potential and could it be cost effective?
Who wants to take that one up? And I'll just say something quickly and I'll open the floor.
But I think from a carbon perspective for Scotland, at least metre squared per year,
seagrass is sequester around 500 grams of carbon dioxide, whereas healthy forestry is around 190 to 700, so it's a big range.
So I actually I would challenge the the the the the notion that they're not as
efficient as forestry because we're talking about efficiency in terms of carbon.
We're not, not kind of just money. And I think potentially you're restoring areas which have been degraded,
so you're not necessarily planting over regions which are being used for the land and uses.
He will say that for the UK, Sophie.
Well, I was I was just going to kind of jump in as well just on the kind of co-benefits side, especially for the economics.
And this is something that affects kind of macro cultivation as an idea as well.
So there's not been a huge number of studies that focus purely on macro with cultivation as a carbon dioxide sequestration technique.
However, there is plenty of evidence that growing microalgae kind of offshore in areas that we currently
don't use for cultivation of crops could be a really efficient way of producing kind of biofuels.
So that would be a great alternative to having to use large swathes of land.
So, yeah, there are potentially some kind of big economic co-benefits to some of these schemes growing biomass just offshore.
And that was. Your muted.
Yeah. You're not anymore. No, no, no. I think Sophia and Roxana have done a good job.
I've got a follow up on seagrass because when you put a forest,
the sort of time scales at which it takes up CO2 is sort of the order of 50 years or so as it's growing.
If you plan a forest on degraded land,
it'll be taking up carbon for a good sort of 50 to 100 years before it reaches full maturity and the rate of carbon uptake slows.
What about seagrass? I mean, what are the timescales here?
If you take an area which used to be sea grass and thought it was seagrass, it might take up a whole lot of carbon.
Right away, but how long does it keep taking carbon up and when does that carbon go?
Yes, that's a good question to seagrass form and these meadows and beds, which have great underlying soils and sediments.
So most of the storage and seagrass is not actually associated with the living green stuff that you see,
but more so in the underlying soils and sediments. And that would be wrong that considered long term carbon sequestration.
So for long timescales, hundreds of years, so they are comparable stores,
whereas something like kelp help only stores carbon in the living kelp seaweed biomass.
So you actually need to get that kelp into long term carbon sediment stores, for instance, on the seafloor sediments.
In order for it to be kind of considered to be locking down that carbon, that's why when it comes to the aquaculture stuff,
you either need to harvest it and then take all out the sea or do something else with it,
rather than just letting it rot and then releasing that carbon back up to the user.
Yes, the issue of Times Square is something important to consider.
We got several questions about timescales that we've already been touching on,
but there's one really interesting question from Felicia Lou on governance mechanisms.
I mean, this is obviously a big priority for Oxford. Net zero is how do we how do we manage all this, all these different policies and technologies?
I mean, I don't know who wants, you know,
obviously Law of the Sea as a big governance criterion or sort of framework in which all of these discussions are taking place.
But does anybody want to talk to the the way in which we're setting about or we could set
about governing large scale implementation of some of these carbon storage solutions?
He wants to take that one up. I'm happy to jump in quickly, but I think Roxana is definitely the expert on blue carbon here,
but just specifically in terms of some of the other techniques.
I think there's a real difference that comes up between whether schemes are considered kind of coastal,
whether they can be considered into the kind of national jurisdiction of a particular country,
for example, or whether they are an international scheme.
So just speaking to iron fertilisation, which is one of probably the major most researched schemes out of the kind of artificial manipulation side,
one of the major things that kept coming up was, well,
there isn't currently any piece of legislation that would properly account for the governance of such a scheme where
it kind of large scale intervention in the ocean and depending on why you do it completely international waters.
So I think for these kind of offshore international schemes, we will probably need to see some specific legislation drawn up.
For example, I think it's the London protocol. It just doesn't cover the right, the right basis.
So yeah, we need we need. We need lawyers working on this. But yes, for kind of more coastal schemes like, for example,
mackerel cultivate Asian blue carbon management, that side of things, it does become a lot easier.
So yeah, depending on whether it's kind of international or national. Roxana, did you want to entertain?
Yes, I kind of a regional like national level,
the and there are opportunities for protecting and using blue carbon ecosystems for climate change mitigation.
And it's, as I mentioned, it's moving at a much slower pace in this restaurant environment.
The impression I get is that this the big geoengineering strategies will require a coordinated strategic framework internationally,
whereas there are ready opportunities for countries to be using blue carbon, blue carbon and policy to make those changes.
Now, whereas the I don't know, Sophie, correct me if I'm wrong,
that the big kind of do engineering techniques are perhaps not there yet in terms of the framework that is needed in order to to move it,
to move forward at pace. And.
To Georgia Tech, yeah. No, but it's just as a final point, I guess not all ocean chemistry manipulation has to occur out at sea.
I guess again, we sort of go back to my comfort zone of ocean alkalinity enhancement,
but there are certainly ideas and projects that are about to be deployed at a field scale that use the process of accelerated weathering,
of spreading rocks onto to crops to accelerate the weathering components of carbon drawdown.
And that would lead, we think, to alkalinity runoff into two streams and rivers and then ultimately into the sea.
So I guess just I mean, it's I think in a way,
we've got three scientists here you can who can speak best to the science of these
these processes more perhaps than the intricacies of the policies and the economies.
But it is an incredibly interconnected problem in the sense that some of these deployment schemes can occur on land, I guess, is my point.
And then the question is how long governs? No, I don't think at the moment the the the the law controls how much alkalinity comes out of rivers.
I don't think that's something that's currently legislated against or before.
Yeah, of course, all these corrections are exactly why we need Oxford zero.
So shameless plug. But so can I just ask a specific question, which we just been asked about some CFC 11 and that sink reversal.
But rather than just focussing on just specifically that?
Can I broaden that a bit to? Well, one of the big concerns we've got with nature based solutions on land is the possibility that as the world warms,
some of the carbon stores that were just as a result of global warming itself,
some of the carbon stores that we're relying on to mop up fossil carbon emissions may become
less reliable or even reverse and start rereleasing that carbon back into the atmosphere.
So I mean, is that something which we worry we should be worrying about in terms of ocean carbon storage as well?
That the success of ocean carbon storage almost depends on our success in actually stopping global warming in the first place?
So I can speak a little bit if if you want, yes, there.
I think that's that's very true, and there is an element by which let's say we were to to accelerate terrestrial based systems for sequester.
Strings, the carbon that it has been storing well, we've been going through this anthropogenic perturbation, but that's it.
That's the sort of mass balance problem, I guess.
I guess what I what I wanted to say is that certainly it would seem if I if I take my geologists household and and look at the glacial termination,
then as that started to be released, it was clear they were positive feedbacks in the system,
which allowed the CO2 to keep on going up in the atmosphere.
And, you know, just just taking that very simply thinking about, say, stratification in the ocean.
For example, as you as you warm the ocean,
you'll get a change of density contrasts across the ocean and potentially help the mixing and the rerelease of CO2, potentially from the deep waters.
We would have exactly the same impacts we certainly thought about and the impacts of
temperature on re mineralisation of organic carbon rates and as you increase temperature.
So make sure that all the organic carbon you make in the in the biological pump will release much faster and therefore shallower,
and therefore have more potential to go back up into the atmosphere.
So I think, yes, there are a very clear temperature impacts on carbon feedbacks within the ocean.
I guess again, you know, safe you. I probably always go back to work Lindsay enhancement.
But that's one that I think is less sensitive to CO2 naturally raising the age.
It's it's kind of that is manipulating the chemistry back to where it should be.
Yeah, I think the same applies for blue carbon environment. I mean, the kind of biological species as well.
There's already evidence that the phytoplankton, which are these main kind of sequesters of carbon dioxide around the coast,
that this species distribution has changed over the last in response to warming and different species sequester carbon at a different rate.
So there will be effects. I don't think this is a problem that's necessarily unique to terrestrial environments,
but definitely one that needs to be considered in the oceans as well.
Thanks. Did you want to specify what? Great, so, so so there's a more general, by the way, I've learnt what's microalgae are seaweed for me.
I can't I learn something every week, but that's the great thing about these seminars.
But there's a more just that sort of wrap up on a much more general question from Martin Gibson.
Pollution control has been moving away from end of pipe solutions. And in a sense,
what we're talking about here is beyond the end of the pipe in the sense that it's
sort of dealing with the carbon dioxide after it's been released into the atmosphere.
And the question is, are we suggesting reversing this and promoting the ocean as the solution to high carbon emissions?
And if I might, so just please pass this over to two or three speakers as well.
But just to stress that the emphasis of Oxford net zero almost inevitably is on thinking beyond the kind of,
you know, the ocean alternate, your initiative is about the sort of final twenty five percent of emissions.
It's about the hard to abate sectors, the economic activities that are so valuable that it's very hard to imagine
any conceivable carbon progress discouraging people from doing them at all.
So in a sense, just by the question, by the exam question we've set ourselves in in the Oxford That Zero initiative,
we are thinking more in terms of what people consider end of pipe solutions.
Of course, that doesn't take away from the importance of reducing emissions in the short term and curtailing the total amount of carbon we
have to deal with in the first place because there's obvious limits as we've heard more speakers on these and the pipe solutions.
But you know, that's that's the easiest question we set ourselves in.
In a sense, we need to know how these things could work just in case we need them, even if we hope that we never will.
Certainly for some of the more sort of extreme scenarios of having to mop up very large volumes of carbon,
but just actually over to Sophie Sophie on this,
because you've been sort of thinking in the in the big picture on this sort of picture of how do you when you're talking to people about this,
how do you balance out these interventions with the challenge of reducing emissions in the first place?
Sort of at what point if if a tech company comes to you and says, Look, we want to get to net zero tomorrow,
but we've heard we're going to do what you can do this with just some blue carbon solutions.
You know, what's the answer? Good question. To be honest, I don't think there is a simple answer to this at all.
And one of the major problems I found with both kind of looking at this on a bigger picture scale
and a more kind of consulting capacity and also working on this specifically as a Ph.D. student,
one of these schemes in particular, I think one of the major challenges is this kind of moral hazard that I think has been
brought up at multiple times in these these talks and they are supporting schools,
being having kind of a you kicking the can down the road,
telling people that they don't have to reduce their emissions because at some point along the line,
there's going to be a technological innovation that's going to save the world and we're not going to have to worry about CO2 emissions.
We just will have something that cleans up a bit like you have your rubbish taken out every day,
which I think is unrealistic to assume that we will be able to offset all of our emissions using schemes like this.
However, my personal kind of opinion on this is that it's very clear that we need to
actively remove carbon from the atmosphere as well as reduce our emissions.
Otherwise,
we are not going to meet the kind of 1.5 degree or two degree target that we really need to hit to avoid some of the worst impacts on ecosystems,
biodiversity and human life as well.
So I think ideally, we wouldn't be in a situation where we need these schemes.
However, we are. So we need we need to do the research now to make sure that we are able to implement these in a safe way if we do require them.
But yeah, in an ideal world, like I said, we would not need these,
but I think it is becoming apparent that we will need things to actively remove carbon as well as reducing emissions.
Well, thank you. Thank you. That's couldn't really.
I couldn't really top that as a way of ending these, this series of seminars from the Oxford Net Zero initiative.
So since we're on the hour, it remains just me to thank all three speakers today very much for some,
some really great presentations and also particularly to thank the Oxford Martin School and
Clara Barria for hosting all of these behind the scenes making this series of events possible.
Don't forget, we have the formal launch of the oxybenzone initiative in a month or so's time,
the 7th of May that afternoon, and you can hear from a number of.
Both academics associated with initiatives and politicians and business people who are working with us,
as well as the Mongkok down in your diary and all of these folks have been recorded,
so you can find them all on the Oxford Martin School website and to get in touch with the Oxford Net Zero initiative.
If you want to stay on our mailing list and keep abreast of what we're doing because the initiatives that are just starting,
we've had a lot to do in the next few years. Thank you all very much for joining these seven of both the participants, the questioners, the speakers.
It's been a great series. We've had a fantastic turnout of people.
We've made the most of being online and will, but we are nevertheless as as the as the world turns,
we are hoping we'll be seeing some of you in person before too long. So thank you all very much.
Thanks to you and Clara for hosting everything thanks to our speakers today and have a good afternoon.