June 19, 2025 • 21 mins
Can climate catastrophe be stymied by tweaking seawater chemistry?
In this episode of C&EN Uncovered, host Craig Bettenhausen speaks with C&EN reporter Fionna Samuels about her recent C&EN cover story concerning Ocean Alkalinity Enhancement (OAE) as a method to combat climate change by increasing ocean alkalinity to absorb more CO2. Uncovered offers a deeper look at subjects from recent stories pulled from the pages of Chemical & Engineering News. Check out Fionna’s story on engineering our oceans to mitigate the effects of Climate Change.
Subscribe to Stereo Chemistry now on Apple Podcasts, Spotify, or wherever you listen to podcasts.
Credits
Executive Producer: David Anderson
Host: Craig Bettenhausen
Reporter: Fionna Samuels
Video + Audio Producer: Jeremy Barr
Episode artwork: Michael Sswat
Music: Commercial Flow, Shutterstock
Contact Stereo Chemistry: Contact us on social media at @cenmag or email cenfeedback@acs.org.
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Craig Bettenhausen (00:00):
Craig, welcome to CNN uncovered. I'm
(00:02):
Craig Bettenhausen. CNNuncovered is a podcast series
from Stereo Chemistry. In eachepisode, we'll take another look
at a recent cover story inchemical and Engineering News,
and hear from CNN reportersabout striking moments from
their reporting, their biggesttakeaways, and what got left on
the cutting room floor. Thisepisode, we're looking at a
recent cover story about a COtwo abatement method called
Ocean alkalinity enhancementthat aims to use the world's
oceans to remove more carbonfrom the atmosphere. Are Earth's
(00:25):
vast oceans our biggest alliesin the fight against greenhouse
gasses. Can we augment the powerof nature to keep our planet
alive longer? We'll put a linkto the story in today's show
notes. I'm here with CNNassistant editor Fiona Samuels,
who wrote the article. Hi Fiona.
Fionna Samuels (00:37):
Hi Craig. It's so nice to be here.
Craig Bettenhausen (00:39):
Yeah, good to have you.
for
So for anyone that hasn't had achance to read the story yet,
can you give a brief recap ofwhat's in the article? Yeah, so
basically, I reported on a fewdifferent experiments, field
trials, specifically, that arehappening around the world to
look at how we can add alkalinesubstances to ocean water in
(01:02):
order to help it draw down morecarbon dioxide from the
atmosphere. And all of this isin an effort to sort of stymie
the worst effects of climatechange. And how did you get
interested in this topic? Itactually started out looking at
solar radiation modification, orsolar geoengineering, which is
putting stuff into theatmosphere to reflect sunlight
(01:22):
back into space. But it turnsout that there are almost no
field trials happening in thatspace right now because it's so
controversial, and the method isvery questionable. But there is
quite a few different thingshappening in the marine carbon
dioxide removal space. Soinstead of reflecting sunlight
(01:42):
to cool the planet, removingcarbon dioxide to help cool the
planet, interesting. So one ofthe things I had noticed in your
story is this experiment calledLoch Ness. Tell me about Loch
Ness. The experiment not theCeltic sea monster or both. I'm
flexible.
Fionna Samuels (01:56):
So unlike the monster, I guess this experiment
is real and it's officiallyhappening. They just got the
permit, finally approved withthe EPA. It's being led by a
researcher at Woods HoleOceanographic Institute. His
name is Dr Adam Subhas, and whatthey're doing is they are
releasing a solution of sodiumhydroxide into the water and
(02:19):
looking at where that alkalinewater goes, and measuring a
whole bunch of different thingsto try to see if they can
quantify how much carbon dioxideis absorbed by the water because
of that increased alkalinity.Seems too simple to be
intuitive. Can you explain howwould dumping a bunch of lye
into the water do anything aboutcarbon dioxide in the
(02:40):
atmosphere. Well, so carbondioxide dissolves in water
naturally. This is an ongoinggeochemical process, and when
the gas dissolves into thewater, it quickly reacts to form
carbonic acid, which thendissolves into different
carbonate ions. And because it'san acid protons, so that's why
we get ocean acidification. Andit was really interesting
(03:01):
because many of the researchersthat I spoke to for this story
started off as researchers ofocean acidification. So the pH
plays a big role in how muchcarbon dioxide can be absorbed
and then sequestered in oceanwater. And by raising the pH or
making it more alkaline, notonly are you sort of combating
(03:22):
that acidification that happenswith carbon dioxide dissolution,
but you're also making it somore carbon dioxide can be
absorbed and then sequestered ascarbonate ions and bicarbonate
ions. It's a little bit likemagic, to be honest.
Craig Bettenhausen (03:37):
And what kind of scales would this need
to operate on to make an impact?
Fionna Samuels (03:41):
Well, that's a great question. So right now,
humanity is releasing carbondioxide on gigaton orders of
magnitude. So that's 1 billionmetric tons, and it's our annual
emissions are close to 40billion metric tons. Obviously
we need to reduce emissions.That's number one. But there are
certain sectors that can't beeasily decarbonized. So
(04:03):
aviation, agriculture, thosecows are going to keep farting.
So we need to do more than justradically decrease emissions.
Scientists think we need to alsostart removing carbon dioxide
from the atmosphere, but ifwe're thinking on gigaton scale
of emissions, we want toprobably remove gigatons of
(04:24):
carbon dioxide. That would begreat. We can't do that right
now. We're not even to millionsof metric tons. So one of the
researchers, David Ho, had areally good analogy. He thinks
of carbon removal like a timemachine. So if you're thinking
we're emitting 40 billion metrictons of carbon dioxide annually
around the globe. And if wecould remove 1 million metric
(04:47):
tons with these carbon dioxideremoval techniques, you would
have had gone back 13 minutes intime. That's equivalent to 13
minutes of carbon emissions. Sothe scale is huge, and.
It's impossible to do it withcarbon dioxide removal
techniques alone. Emissionreduction is absolutely vital.
Craig Bettenhausen (05:06):
So I can imagine getting sodium hydroxide
on a laboratory scale. You canget it at the hardware store,
but on that kind of scale, we'renot just talking about that kind
of material. Where are we goingto get that much base
equivalence, that muchalkalinity? Yeah,
Fionna Samuels (05:20):
so now you're talking about sort of the life
cycle of these sort oftechniques. And there's actually
a few different techniques. It'snot just putting sodium
hydroxide in the water. So withsodium hydroxide, the Loch Ness
team is truly only interested infiguring out if ocean alkalinity
enhancement is a viablesolution, and so they're
basically using the cleanestform of alkalinity in the sense
(05:44):
that sodium hydroxide, they canbe incredibly confident of what
they're putting in the water.They can be very confident about
the kinds of reactions that arehappening. Sodium ions already
exist in seawater. Hydroxideions also exist in seawater, but
obviously at a far lowerabundance and the pH, they very
well constrained how the pH willfluctuate after their release
(06:06):
and at different timescalesafter the release. That's why
they're using sodium hydroxidein the real world. You're right.
Sodium hydroxide is notnecessarily a viable way to
increase the alkalinity of thesebodies of water, because you
would need vast amounts of it.And right now, a lot of sodium
hydroxide is actually producedin chlorine chemical reactions,
(06:26):
but we produce chlorine forother chemistry is happening
anyway. Other researchers arelooking at alkaline minerals. So
like olivine is a big one, andthat would come from mining
minerals around the world. Wehumanity, different people are
already sort of spreading thesemined minerals on agricultural
fields and elsewhere. So thosesources of mineral alkalinity
(06:51):
exist already, which is whythese folks who are using
minerals argue that that mightbe a better option. A third
technique actually useselectrolysis to separate
alkaline seawater from acidicseawater. But the problem with
that is then you have a bunch ofacid, and there's not a huge
market for acid to change the pHof things. So you're right when
(07:12):
it comes to scalability, thelife cycle of these chemicals is
very important to consider,where they're coming from, where
the byproducts are going. Ifwe're thinking about mining
alkaline minerals, you need tothink about if those mines are
emitting more carbon than can betaken up by the ocean or other
carbon dioxide removaltechniques where the energy is
(07:33):
coming from. All of this stuffis a big question mark. The
field trials right now arereally focused on whether or not
the chemistry is workable from astandpoint of like we
theoretically know that thisshould work, but does it in the
real world.
Craig Bettenhausen (07:49):
So that suggests the question, how are
they going to tell what are theymeasuring to see if this
Fionna Samuels (07:54):
works? They're measuring a bunch of different
things. So the Woods Hole folksare. They're throwing the whole
instrument laboratory at theproblem. They're going to be
taking water in through the shipthat they're driving and
releasing the alkaline solutionbehind to sample for the
pressures of oxygen and carbondioxide dissolved in the water.
They're also going to be lookingat how the pH changes. They're
(08:17):
going to be looking at totaldissolved inorganic carbon,
which is all those carbonateions. They're going to be
looking at changes in the marinelife in the area. Of course,
they're going to make sure thatthey're not, or they plan to
make sure that they're not goingto be dumping anything on a
whale's head, right? But as longas there's not any big animals
(08:40):
around the they're gonna dumpthis solution, and then they
will be taking a plankton netand dragging the plankton net
behind the boat to look at howthese little, tiny marine plant,
like creatures, plankton, ishard to find. Sorry,
Craig Bettenhausen (08:56):
yeah, things at the bottom of the food web,
how the bottom of the food web?Yes, yes, they're
Fionna Samuels (09:01):
looking at how plankton, which is the bottom of
the food web, will be affectedby this experiment in the real
world, because other researchershave already looked at how
plankton are affected inmicrocosms and mesocosms, which
are basically containers filledwith seawater.
Craig Bettenhausen (09:15):
Yes, I liked in your story, you had this
vocabulary where the mesocosms,and started right off with that,
I immediately, I was like, Ineed to I'm in just so I can
find out what that word means.
Fionna Samuels (09:24):
Yeah. So mesocosm is basically like a
giant test tube, like 1000s ofliters of water in a test in an
enclosed container. And then themicrocosms are smaller volumes
of water, so more on the literscale. And the nice thing about
microcosms is that, becausethey're so small, you can
standardize a bunch ofexperiments across the world,
you can have a bunch ofdifferent labs doing a very
(09:44):
similar experiment withdifferent samples of water. So
like you can go out and scoopocean water off the coast of
Maine or off the coast ofAustralia or off the coast of
England, right? Like any ofthese places
Craig Bettenhausen (09:57):
and the mesocosms, these are in the
water. But not the water can'tpass from one side of this
mesocosm out into the generalcorrect
Fionna Samuels (10:04):
so the 1000 liter containers, the mesocosms,
they are just containers in theocean. The researchers flood the
container, collect all thiswater and then make sure that if
there are any fish or anythingelse accidentally get caught up,
to remove the fish. Becausethat's too complex, they're
really only interested in theplankton, the bottom of the food
web at this point. Historically,the research so far has really
(10:26):
only been interested at thatlevel. Future research, though,
might look at some fish larva,but yeah, and then that water is
totally isolated from thesurrounding water, so anything
that's added to the mesocosm iscontained within the mesocosm,
and you don't worry aboutputting anything into the
surrounding open water system.
Craig Bettenhausen (10:44):
Yeah. I wanted to ask about that because
you encountered some critics,some people that aren't happy
about this. Were they worriedabout the Loch Ness project
specifically? Were theyskeptical about ocean alkalinity
enhancement, or were theyagainst climate change
mitigation as a whole effort?
Fionna Samuels (10:58):
Yeah, so I think, I think you're talking
about James Carey, one of thesources in my story, yes, he was
skeptical about Loch Nessspecifically, but also about
ocean alkalinity enhancement,more generally, Loch Ness, he's
not totally convinced that theywill be able to measure all the
things that they want tomeasure, because it's just open
water systems are incrediblycomplex, and so measuring
(11:19):
anything in the open ocean isgoing to be very difficult. The
Signal to Noise is very hard totease out. So he was skeptical
about that. But more broadly, Ithink he has concerns about
scalability. And scalability isa big question in all of these
things, because we are emittingso much carbon dioxide that it
(11:40):
almost doesn't pay to do any ofthis before seriously figuring
out ways to cut emissions. Thescientists, of course, argue
that we need to have a solidresearch based foundation to
even have discussions aboutcarbon dioxide removal on a
grand scale. But others, ofcourse, worry that focusing on
(12:00):
research for futureapplications, sort of moves the
goal post for the current needsof just emission reductions.
Yeah, I run
Craig Bettenhausen (12:09):
into that debate a lot like I should be
redoing this at all, and it's alot of the same dynamics of a
lot of people think we will needthese carbon removal
technologies a little bit downthe line. But yeah, there's
lower hanging fruit that weshould be picking but it won't
be ready then, if we don't startworking on it. Now, it's a
difficult balance.
Fionna Samuels (12:25):
Yeah, definitely. And again, all the
researchers that I talked towere not interested in selling
carbon credits and they weren'tinterested in trying to make
this a commercial sort ofopportunity. They're really just
wondering, Will this work, andthe models that climate
scientists have run suggest thatocean alkalinity enhancement and
(12:46):
other carbon dioxide removaltechniques could be incredibly
valuable, worthwhile pursuits inthe fight against climate
change. But without doing theseexperiments in the real world,
in field trials, there's just abig question mark about whether
the real world is toocomplicated for this to work.
Craig Bettenhausen (13:05):
I'm gonna reveal my chemist background and
say I'm curious about at the labscale, though. I mean, is there
solid proof at the liter scalethat making the solution more
basic will cause carbon dioxideto dissolve into it? Do we have
that basis? Really solid?
Fionna Samuels (13:17):
Yeah, they figured that out. They are
confident that carbon dioxidewill dissolve into water more
readily if the water is morebasic, which is actually part of
the reason why the oceans are sopowerful already. So the oceans
are absorbing vast amounts ofcarbon dioxide every year, and
that's because their sort ofinherent pH is around 8.3 which
(13:40):
is quite basic compared to otherbodies of water. In fact, tap
water is often more acidic thanthat, and sodium hydroxide is
often used in municipal watertreatment plants in order to
change the pH which helpsprevent corrosion from pipes. So
you know, humans are alreadydoing pH modification on our
(14:00):
drinking water and the ocean isalready super basic. It's just a
question of whether or not wecan see these effects in the
real world, because the ocean isso huge.
Craig Bettenhausen (14:11):
Yeah. Are there any other characters from
your interviews that you wantedto bring in but didn't quite
Fionna Samuels (14:15):
fit? That's a good question. Yeah, the section
that ended up not going into thepiece was really about how the
researchers are communicatingwith the public about their
work, which was more of like asocial sciences kind of
discussion. And those folks wereall great, and there are some
really fabulous social scienceresearch happening in this
space, and really importanttakeaways, like you need to talk
(14:37):
to stakeholders before startingyour experiment, which seems
really obvious, but sometimesscientists are so excited to,
you know, go out and startcollecting data that it might
not occur to them that thepeople living in these areas
will feel very betrayed, almost,if this kind of science happens
(14:57):
without any of their input. Andso it's incredible. Incredibly
important to have the localcommunities involved in the
whole scientific process fromeven before applications for
permits are submitted. And
Craig Bettenhausen (15:09):
so, I mean, how was the community responding
to the Loch Ness experiment? Imean, they had your person that
was opposed to it because theydidn't think it was going
Fionna Samuels (15:16):
to work, yeah. So there have been some vocal
opponents in the localcommunity, but it also seems
like there was potentially lessI mean, there was some reporting
that there are local communitymembers who are still not
convinced that it's a good ideato put stuff into the water. But
there were also the Loch Nessresearchers did take lots of
(15:37):
conversations into account andchange some of their
experimental design based onwhat the local fishing community
said and other stakeholderswanted from the experiment.
Craig Bettenhausen (15:49):
Yes, I guess this is happening out of Cape
Cod, and that is not an areaknown for a lot of community
activism. It's not a quiet sitback and let everything happen
to them, kind of a place, yeah,
Fionna Samuels (15:57):
the most important thing with all of
these environmental field trialsis to engage community members
early and for the entire timethat you're doing the
experiment, and do more than itgoes beyond just educating
people. It actually requiresthat they are involved in the
decision making process. So CapeCod is not the
Craig Bettenhausen (16:17):
only place that they're looking at this
kind of thing. There are someother experiments probing this
idea of ocean alkalinityenhancement.
Fionna Samuels (16:24):
Yeah. So the other experiment that I talked
about in the piece was really,really small scale, tiny scale
off the coast of Australia.They're putting minerals down in
the sediment in the water tojust see how worms and other
creatures that live down therewill respond their results this
really recent. It was ourwinter, their summer, but they
just recently finished thatproject, and they told me that
(16:47):
their results are promising. Theworms don't seem to care. But
the scale at which they weredoing it is so small compared to
what will need to happen. There
Craig Bettenhausen (16:56):
are scale where they're like swimming down
there with a single vial.They're
Fionna Samuels (16:59):
swimming down with a single vial, opening it
up, pouring it and then watchingfor a few weeks, taking samples
every few weeks, and then takingup sediment samples. Obviously,
that's such a small scale thatthat's not what any sort of real
world application will looklike. We do actually have
examples of real world mineralapplications. So there's a
(17:21):
company called Vesta that hasdone some olivine trials where
they've put huge amounts ofcrushed olivine sand along, I
think it was the coast of NewJersey, and off the coast as
well, obviously, tons and tonsof crushed rock is a lot
different than a tiny little bioof crushed rock. And they're
interested in figuring out somekind of carbon credit, some way
(17:44):
of making this techniqueprofitable. If there's any
future in these sorts oftechniques, there should be
small scale, very safe fieldtrials before actually
approaching anything that lookslike what we would need to
combat climate change in a realway, which is unfortunate. It's
like such a bummer, right? Like,the best solution is for
(18:06):
everyone to bike to work and gofrom there,
Craig Bettenhausen (18:10):
stop eating so much meat. Compost. Yeah, oh
God.
Fionna Samuels (18:13):
There's this carbon dioxide removal technique
where you use electricity totake carbon dioxide out of
seawater and pretty much, andthen you put that carbon dioxide
into the ground, you inject itinto some sort of geologic
formation, pretty much everyonethought that that was a very
silly approach, because theocean is one of the most stable
(18:36):
places for carbon dioxide toLive. Carbon dioxide is
sequestered into carbonate,which is all of those sorts of
ions that are in the ocean willstay in the ocean as carbonate
for 10,000 years. So it's sillyto take stable carbon dioxide
out of the ocean to putsomewhere else, because the
ocean is a really good home forit. So
Craig Bettenhausen (19:00):
in June, actually, I'm going to visit a
pilot rig in New York City,where a startup is testing a
system like the enhanced oceanalkalinity that you're
describing. They're going to addreactive alkaline minerals to
remove CO two this time from theEast River in New York, instead
of the ocean. What should I askthem? What should I be looking
for? What
Fionna Samuels (19:16):
you should ask them, how they're measuring how
much carbon dioxide is beingremoved from the air, how
they're measuring carbon dioxideuptake. All
Craig Bettenhausen (19:23):
right, so is there anything else to me
reporting that you wish youcould have fit in somehow?
Fionna Samuels (19:27):
The one thing that I didn't emphasize, and I
would like to have emphasized,is that a big piece of all this
research is what the researcherscalled monitoring, reporting and
verification, and that goes intosort of figuring out if this is
a usable technology forsomething like carbon credits.
And what that means is that youneed to be able to monitor how
(19:48):
much carbon dioxide is removed.You need to be able to report
it, which is a whole differentsort of infrastructure that's
separate from the science. Andthen you need to verify it so
other people need to be able tocome in. And measure the same
thing that you measured. And alot of this research right now
depends on modeling. There arevery few field trials, although
(20:08):
it's a growing field so therewill likely be more field trials
in the near future, butmonitoring carbon dioxide
removal on a global scale isgoing to be incredibly
challenging, which is why thesesort of open field trials are so
important, because if you canmonitor it on the small scale,
and you can prove that you areable to monitor how much carbon
dioxide is removed on the smallscale, and then other people are
(20:32):
able to verify that you aremeasuring what you think you're
measuring, then that basicallyopens the door to realistic
sorts of deployments in thefuture.
Craig Bettenhausen (20:42):
Okay, well, Fiona, thanks for diving deep on
this with us.
Fionna Samuels (20:44):
Thanks for having me. Thank you so much.
Craig Bettenhausen (20:46):
And I usually use that line. It's not
always literal, but this time itwas,
Fionna Samuels (20:49):
I was gonna say, that's a great pun you caught me
off guard with that one.
Craig Bettenhausen (20:55):
You can find Fionna Samuels story about
oceans as climate change allieson CNN website, or in the April
14, 2025, print issue of CNN, weput a link in the show notes
along with the episode credits.We'd love to know what you think
of CNN uncovered. You can shareyour feedback with us by
emailing C E N feedback at ACS,dot, O, R, G, you can find me on
social media as at Craig ofwaffles, Fiona. How can
(21:15):
listeners get in touch with you?
Fionna Samuels (21:16):
I'm at F Morningstar on blue sky.
Craig Bettenhausen (21:19):
All right, this has been C&EN uncovered a
series from C&EN StereoChemistry. Stereo Chemistry is
the official podcast of chemicaland Engineering News. Chemical
and Engineering News is anindependent news outlet
published by the AmericanChemical Society. Thanks for
listening.
Craig, welcome to CNN uncovered. I'm
(00:02):
Craig Bettenhausen. CNNuncovered is a podcast series
from Stereo Chemistry. In eachepisode, we'll take another look
at a recent cover story inchemical and Engineering News,
and hear from CNN reportersabout striking moments from
their reporting, their biggesttakeaways, and what got left on
the cutting room floor. Thisepisode, we're looking at a
recent cover story about a COtwo abatement method called
Ocean alkalinity enhancementthat aims to use the world's
oceans to remove more carbonfrom the atmosphere. Are Earth's
(00:25):
vast oceans our biggest alliesin the fight against greenhouse
gasses. Can we augment the powerof nature to keep our planet
alive longer? We'll put a linkto the story in today's show
notes. I'm here with CNNassistant editor Fiona Samuels,
who wrote the article. Hi Fiona.
Fionna Samuels (00:37):
Hi Craig. It's so nice to be here.
Craig Bettenhausen (00:39):
Yeah, good to have you.
for
So for anyone that hasn't had achance to read the story yet,
can you give a brief recap ofwhat's in the article? Yeah, so
basically, I reported on a fewdifferent experiments, field
trials, specifically, that arehappening around the world to
look at how we can add alkalinesubstances to ocean water in
(01:02):
order to help it draw down morecarbon dioxide from the
atmosphere. And all of this isin an effort to sort of stymie
the worst effects of climatechange. And how did you get
interested in this topic? Itactually started out looking at
solar radiation modification, orsolar geoengineering, which is
putting stuff into theatmosphere to reflect sunlight
(01:22):
back into space. But it turnsout that there are almost no
field trials happening in thatspace right now because it's so
controversial, and the method isvery questionable. But there is
quite a few different thingshappening in the marine carbon
dioxide removal space. Soinstead of reflecting sunlight
(01:42):
to cool the planet, removingcarbon dioxide to help cool the
planet, interesting. So one ofthe things I had noticed in your
story is this experiment calledLoch Ness. Tell me about Loch
Ness. The experiment not theCeltic sea monster or both. I'm
flexible.
Fionna Samuels (01:56):
So unlike the monster, I guess this experiment
is real and it's officiallyhappening. They just got the
permit, finally approved withthe EPA. It's being led by a
researcher at Woods HoleOceanographic Institute. His
name is Dr Adam Subhas, and whatthey're doing is they are
releasing a solution of sodiumhydroxide into the water and
(02:19):
looking at where that alkalinewater goes, and measuring a
whole bunch of different thingsto try to see if they can
quantify how much carbon dioxideis absorbed by the water because
of that increased alkalinity.Seems too simple to be
intuitive. Can you explain howwould dumping a bunch of lye
into the water do anything aboutcarbon dioxide in the
(02:40):
atmosphere. Well, so carbondioxide dissolves in water
naturally. This is an ongoinggeochemical process, and when
the gas dissolves into thewater, it quickly reacts to form
carbonic acid, which thendissolves into different
carbonate ions. And because it'san acid protons, so that's why
we get ocean acidification. Andit was really interesting
(03:01):
because many of the researchersthat I spoke to for this story
started off as researchers ofocean acidification. So the pH
plays a big role in how muchcarbon dioxide can be absorbed
and then sequestered in oceanwater. And by raising the pH or
making it more alkaline, notonly are you sort of combating
(03:22):
that acidification that happenswith carbon dioxide dissolution,
but you're also making it somore carbon dioxide can be
absorbed and then sequestered ascarbonate ions and bicarbonate
ions. It's a little bit likemagic, to be honest.
Craig Bettenhausen (03:37):
And what kind of scales would this need
to operate on to make an impact?
Fionna Samuels (03:41):
Well, that's a great question. So right now,
humanity is releasing carbondioxide on gigaton orders of
magnitude. So that's 1 billionmetric tons, and it's our annual
emissions are close to 40billion metric tons. Obviously
we need to reduce emissions.That's number one. But there are
certain sectors that can't beeasily decarbonized. So
(04:03):
aviation, agriculture, thosecows are going to keep farting.
So we need to do more than justradically decrease emissions.
Scientists think we need to alsostart removing carbon dioxide
from the atmosphere, but ifwe're thinking on gigaton scale
of emissions, we want toprobably remove gigatons of
(04:24):
carbon dioxide. That would begreat. We can't do that right
now. We're not even to millionsof metric tons. So one of the
researchers, David Ho, had areally good analogy. He thinks
of carbon removal like a timemachine. So if you're thinking
we're emitting 40 billion metrictons of carbon dioxide annually
around the globe. And if wecould remove 1 million metric
(04:47):
tons with these carbon dioxideremoval techniques, you would
have had gone back 13 minutes intime. That's equivalent to 13
minutes of carbon emissions. Sothe scale is huge, and.
It's impossible to do it withcarbon dioxide removal
techniques alone. Emissionreduction is absolutely vital.
Craig Bettenhausen (05:06):
So I can imagine getting sodium hydroxide
on a laboratory scale. You canget it at the hardware store,
but on that kind of scale, we'renot just talking about that kind
of material. Where are we goingto get that much base
equivalence, that muchalkalinity? Yeah,
Fionna Samuels (05:20):
so now you're talking about sort of the life
cycle of these sort oftechniques. And there's actually
a few different techniques. It'snot just putting sodium
hydroxide in the water. So withsodium hydroxide, the Loch Ness
team is truly only interested infiguring out if ocean alkalinity
enhancement is a viablesolution, and so they're
basically using the cleanestform of alkalinity in the sense
(05:44):
that sodium hydroxide, they canbe incredibly confident of what
they're putting in the water.They can be very confident about
the kinds of reactions that arehappening. Sodium ions already
exist in seawater. Hydroxideions also exist in seawater, but
obviously at a far lowerabundance and the pH, they very
well constrained how the pH willfluctuate after their release
(06:06):
and at different timescalesafter the release. That's why
they're using sodium hydroxidein the real world. You're right.
Sodium hydroxide is notnecessarily a viable way to
increase the alkalinity of thesebodies of water, because you
would need vast amounts of it.And right now, a lot of sodium
hydroxide is actually producedin chlorine chemical reactions,
(06:26):
but we produce chlorine forother chemistry is happening
anyway. Other researchers arelooking at alkaline minerals. So
like olivine is a big one, andthat would come from mining
minerals around the world. Wehumanity, different people are
already sort of spreading thesemined minerals on agricultural
fields and elsewhere. So thosesources of mineral alkalinity
(06:51):
exist already, which is whythese folks who are using
minerals argue that that mightbe a better option. A third
technique actually useselectrolysis to separate
alkaline seawater from acidicseawater. But the problem with
that is then you have a bunch ofacid, and there's not a huge
market for acid to change the pHof things. So you're right when
(07:12):
it comes to scalability, thelife cycle of these chemicals is
very important to consider,where they're coming from, where
the byproducts are going. Ifwe're thinking about mining
alkaline minerals, you need tothink about if those mines are
emitting more carbon than can betaken up by the ocean or other
carbon dioxide removaltechniques where the energy is
(07:33):
coming from. All of this stuffis a big question mark. The
field trials right now arereally focused on whether or not
the chemistry is workable from astandpoint of like we
theoretically know that thisshould work, but does it in the
real world.
Craig Bettenhausen (07:49):
So that suggests the question, how are
they going to tell what are theymeasuring to see if this
Fionna Samuels (07:54):
works? They're measuring a bunch of different
things. So the Woods Hole folksare. They're throwing the whole
instrument laboratory at theproblem. They're going to be
taking water in through the shipthat they're driving and
releasing the alkaline solutionbehind to sample for the
pressures of oxygen and carbondioxide dissolved in the water.
They're also going to be lookingat how the pH changes. They're
(08:17):
going to be looking at totaldissolved inorganic carbon,
which is all those carbonateions. They're going to be
looking at changes in the marinelife in the area. Of course,
they're going to make sure thatthey're not, or they plan to
make sure that they're not goingto be dumping anything on a
whale's head, right? But as longas there's not any big animals
(08:40):
around the they're gonna dumpthis solution, and then they
will be taking a plankton netand dragging the plankton net
behind the boat to look at howthese little, tiny marine plant,
like creatures, plankton, ishard to find. Sorry,
Craig Bettenhausen (08:56):
yeah, things at the bottom of the food web,
how the bottom of the food web?Yes, yes, they're
Fionna Samuels (09:01):
looking at how plankton, which is the bottom of
the food web, will be affectedby this experiment in the real
world, because other researchershave already looked at how
plankton are affected inmicrocosms and mesocosms, which
are basically containers filledwith seawater.
Craig Bettenhausen (09:15):
Yes, I liked in your story, you had this
vocabulary where the mesocosms,and started right off with that,
I immediately, I was like, Ineed to I'm in just so I can
find out what that word means.
Fionna Samuels (09:24):
Yeah. So mesocosm is basically like a
giant test tube, like 1000s ofliters of water in a test in an
enclosed container. And then themicrocosms are smaller volumes
of water, so more on the literscale. And the nice thing about
microcosms is that, becausethey're so small, you can
standardize a bunch ofexperiments across the world,
you can have a bunch ofdifferent labs doing a very
(09:44):
similar experiment withdifferent samples of water. So
like you can go out and scoopocean water off the coast of
Maine or off the coast ofAustralia or off the coast of
England, right? Like any ofthese places
Craig Bettenhausen (09:57):
and the mesocosms, these are in the
water. But not the water can'tpass from one side of this
mesocosm out into the generalcorrect
Fionna Samuels (10:04):
so the 1000 liter containers, the mesocosms,
they are just containers in theocean. The researchers flood the
container, collect all thiswater and then make sure that if
there are any fish or anythingelse accidentally get caught up,
to remove the fish. Becausethat's too complex, they're
really only interested in theplankton, the bottom of the food
web at this point. Historically,the research so far has really
(10:26):
only been interested at thatlevel. Future research, though,
might look at some fish larva,but yeah, and then that water is
totally isolated from thesurrounding water, so anything
that's added to the mesocosm iscontained within the mesocosm,
and you don't worry aboutputting anything into the
surrounding open water system.
Craig Bettenhausen (10:44):
Yeah. I wanted to ask about that because
you encountered some critics,some people that aren't happy
about this. Were they worriedabout the Loch Ness project
specifically? Were theyskeptical about ocean alkalinity
enhancement, or were theyagainst climate change
mitigation as a whole effort?
Fionna Samuels (10:58):
Yeah, so I think, I think you're talking
about James Carey, one of thesources in my story, yes, he was
skeptical about Loch Nessspecifically, but also about
ocean alkalinity enhancement,more generally, Loch Ness, he's
not totally convinced that theywill be able to measure all the
things that they want tomeasure, because it's just open
water systems are incrediblycomplex, and so measuring
(11:19):
anything in the open ocean isgoing to be very difficult. The
Signal to Noise is very hard totease out. So he was skeptical
about that. But more broadly, Ithink he has concerns about
scalability. And scalability isa big question in all of these
things, because we are emittingso much carbon dioxide that it
(11:40):
almost doesn't pay to do any ofthis before seriously figuring
out ways to cut emissions. Thescientists, of course, argue
that we need to have a solidresearch based foundation to
even have discussions aboutcarbon dioxide removal on a
grand scale. But others, ofcourse, worry that focusing on
(12:00):
research for futureapplications, sort of moves the
goal post for the current needsof just emission reductions.
Yeah, I run
Craig Bettenhausen (12:09):
into that debate a lot like I should be
redoing this at all, and it's alot of the same dynamics of a
lot of people think we will needthese carbon removal
technologies a little bit downthe line. But yeah, there's
lower hanging fruit that weshould be picking but it won't
be ready then, if we don't startworking on it. Now, it's a
difficult balance.
Fionna Samuels (12:25):
Yeah, definitely. And again, all the
researchers that I talked towere not interested in selling
carbon credits and they weren'tinterested in trying to make
this a commercial sort ofopportunity. They're really just
wondering, Will this work, andthe models that climate
scientists have run suggest thatocean alkalinity enhancement and
(12:46):
other carbon dioxide removaltechniques could be incredibly
valuable, worthwhile pursuits inthe fight against climate
change. But without doing theseexperiments in the real world,
in field trials, there's just abig question mark about whether
the real world is toocomplicated for this to work.
Craig Bettenhausen (13:05):
I'm gonna reveal my chemist background and
say I'm curious about at the labscale, though. I mean, is there
solid proof at the liter scalethat making the solution more
basic will cause carbon dioxideto dissolve into it? Do we have
that basis? Really solid?
Fionna Samuels (13:17):
Yeah, they figured that out. They are
confident that carbon dioxidewill dissolve into water more
readily if the water is morebasic, which is actually part of
the reason why the oceans are sopowerful already. So the oceans
are absorbing vast amounts ofcarbon dioxide every year, and
that's because their sort ofinherent pH is around 8.3 which
(13:40):
is quite basic compared to otherbodies of water. In fact, tap
water is often more acidic thanthat, and sodium hydroxide is
often used in municipal watertreatment plants in order to
change the pH which helpsprevent corrosion from pipes. So
you know, humans are alreadydoing pH modification on our
(14:00):
drinking water and the ocean isalready super basic. It's just a
question of whether or not wecan see these effects in the
real world, because the ocean isso huge.
Craig Bettenhausen (14:11):
Yeah. Are there any other characters from
your interviews that you wantedto bring in but didn't quite
Fionna Samuels (14:15):
fit? That's a good question. Yeah, the section
that ended up not going into thepiece was really about how the
researchers are communicatingwith the public about their
work, which was more of like asocial sciences kind of
discussion. And those folks wereall great, and there are some
really fabulous social scienceresearch happening in this
space, and really importanttakeaways, like you need to talk
(14:37):
to stakeholders before startingyour experiment, which seems
really obvious, but sometimesscientists are so excited to,
you know, go out and startcollecting data that it might
not occur to them that thepeople living in these areas
will feel very betrayed, almost,if this kind of science happens
(14:57):
without any of their input. Andso it's incredible. Incredibly
important to have the localcommunities involved in the
whole scientific process fromeven before applications for
permits are submitted. And
Craig Bettenhausen (15:09):
so, I mean, how was the community responding
to the Loch Ness experiment? Imean, they had your person that
was opposed to it because theydidn't think it was going
Fionna Samuels (15:16):
to work, yeah. So there have been some vocal
opponents in the localcommunity, but it also seems
like there was potentially lessI mean, there was some reporting
that there are local communitymembers who are still not
convinced that it's a good ideato put stuff into the water. But
there were also the Loch Nessresearchers did take lots of
(15:37):
conversations into account andchange some of their
experimental design based onwhat the local fishing community
said and other stakeholderswanted from the experiment.
Craig Bettenhausen (15:49):
Yes, I guess this is happening out of Cape
Cod, and that is not an areaknown for a lot of community
activism. It's not a quiet sitback and let everything happen
to them, kind of a place, yeah,
Fionna Samuels (15:57):
the most important thing with all of
these environmental field trialsis to engage community members
early and for the entire timethat you're doing the
experiment, and do more than itgoes beyond just educating
people. It actually requiresthat they are involved in the
decision making process. So CapeCod is not the
Craig Bettenhausen (16:17):
only place that they're looking at this
kind of thing. There are someother experiments probing this
idea of ocean alkalinityenhancement.
Fionna Samuels (16:24):
Yeah. So the other experiment that I talked
about in the piece was really,really small scale, tiny scale
off the coast of Australia.They're putting minerals down in
the sediment in the water tojust see how worms and other
creatures that live down therewill respond their results this
really recent. It was ourwinter, their summer, but they
just recently finished thatproject, and they told me that
(16:47):
their results are promising. Theworms don't seem to care. But
the scale at which they weredoing it is so small compared to
what will need to happen. There
Craig Bettenhausen (16:56):
are scale where they're like swimming down
there with a single vial.They're
Fionna Samuels (16:59):
swimming down with a single vial, opening it
up, pouring it and then watchingfor a few weeks, taking samples
every few weeks, and then takingup sediment samples. Obviously,
that's such a small scale thatthat's not what any sort of real
world application will looklike. We do actually have
examples of real world mineralapplications. So there's a
(17:21):
company called Vesta that hasdone some olivine trials where
they've put huge amounts ofcrushed olivine sand along, I
think it was the coast of NewJersey, and off the coast as
well, obviously, tons and tonsof crushed rock is a lot
different than a tiny little bioof crushed rock. And they're
interested in figuring out somekind of carbon credit, some way
(17:44):
of making this techniqueprofitable. If there's any
future in these sorts oftechniques, there should be
small scale, very safe fieldtrials before actually
approaching anything that lookslike what we would need to
combat climate change in a realway, which is unfortunate. It's
like such a bummer, right? Like,the best solution is for
(18:06):
everyone to bike to work and gofrom there,
Craig Bettenhausen (18:10):
stop eating so much meat. Compost. Yeah, oh
God.
Fionna Samuels (18:13):
There's this carbon dioxide removal technique
where you use electricity totake carbon dioxide out of
seawater and pretty much, andthen you put that carbon dioxide
into the ground, you inject itinto some sort of geologic
formation, pretty much everyonethought that that was a very
silly approach, because theocean is one of the most stable
(18:36):
places for carbon dioxide toLive. Carbon dioxide is
sequestered into carbonate,which is all of those sorts of
ions that are in the ocean willstay in the ocean as carbonate
for 10,000 years. So it's sillyto take stable carbon dioxide
out of the ocean to putsomewhere else, because the
ocean is a really good home forit. So
Craig Bettenhausen (19:00):
in June, actually, I'm going to visit a
pilot rig in New York City,where a startup is testing a
system like the enhanced oceanalkalinity that you're
describing. They're going to addreactive alkaline minerals to
remove CO two this time from theEast River in New York, instead
of the ocean. What should I askthem? What should I be looking
for? What
Fionna Samuels (19:16):
you should ask them, how they're measuring how
much carbon dioxide is beingremoved from the air, how
they're measuring carbon dioxideuptake. All
Craig Bettenhausen (19:23):
right, so is there anything else to me
reporting that you wish youcould have fit in somehow?
Fionna Samuels (19:27):
The one thing that I didn't emphasize, and I
would like to have emphasized,is that a big piece of all this
research is what the researcherscalled monitoring, reporting and
verification, and that goes intosort of figuring out if this is
a usable technology forsomething like carbon credits.
And what that means is that youneed to be able to monitor how
(19:48):
much carbon dioxide is removed.You need to be able to report
it, which is a whole differentsort of infrastructure that's
separate from the science. Andthen you need to verify it so
other people need to be able tocome in. And measure the same
thing that you measured. And alot of this research right now
depends on modeling. There arevery few field trials, although
(20:08):
it's a growing field so therewill likely be more field trials
in the near future, butmonitoring carbon dioxide
removal on a global scale isgoing to be incredibly
challenging, which is why thesesort of open field trials are so
important, because if you canmonitor it on the small scale,
and you can prove that you areable to monitor how much carbon
dioxide is removed on the smallscale, and then other people are
(20:32):
able to verify that you aremeasuring what you think you're
measuring, then that basicallyopens the door to realistic
sorts of deployments in thefuture.
Craig Bettenhausen (20:42):
Okay, well, Fiona, thanks for diving deep on
this with us.
Fionna Samuels (20:44):
Thanks for having me. Thank you so much.
Craig Bettenhausen (20:46):
And I usually use that line. It's not
always literal, but this time itwas,
Fionna Samuels (20:49):
I was gonna say, that's a great pun you caught me
off guard with that one.
Craig Bettenhausen (20:55):
You can find Fionna Samuels story about
oceans as climate change allieson CNN website, or in the April
14, 2025, print issue of CNN, weput a link in the show notes
along with the episode credits.We'd love to know what you think
of CNN uncovered. You can shareyour feedback with us by
emailing C E N feedback at ACS,dot, O, R, G, you can find me on
social media as at Craig ofwaffles, Fiona. How can
(21:15):
listeners get in touch with you?
Fionna Samuels (21:16):
I'm at F Morningstar on blue sky.
Craig Bettenhausen (21:19):
All right, this has been C&EN uncovered a
series from C&EN StereoChemistry. Stereo Chemistry is
the official podcast of chemicaland Engineering News. Chemical
and Engineering News is anindependent news outlet
published by the AmericanChemical Society. Thanks for
listening.
Popular Podcasts
Crime Junkie
Does hearing about a true crime case always leave you scouring the internet for the truth behind the story? Dive into your next mystery with Crime Junkie. Every Monday, join your host Ashley Flowers as she unravels all the details of infamous and underreported true crime cases with her best friend Brit Prawat. From cold cases to missing persons and heroes in our community who seek justice, Crime Junkie is your destination for theories and stories you won’t hear anywhere else. Whether you're a seasoned true crime enthusiast or new to the genre, you'll find yourself on the edge of your seat awaiting a new episode every Monday. If you can never get enough true crime... Congratulations, you’ve found your people. Follow to join a community of Crime Junkies! Crime Junkie is presented by audiochuck Media Company.
24/7 News: The Latest
The latest news in 4 minutes updated every hour, every day.
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.