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Not Cool Ep 21: Libby Jewett on ocean acidification

7 November, 2019

The increase of CO2 in the atmosphere is doing more than just warming the planet and threatening the lives of many terrestrial species. A large percentage of that carbon is actually reabsorbed by the oceans, causing a phenomenon known as ocean acidification — that is, our carbon emissions are literally changing the chemistry of ocean water and threatening ocean ecosystems worldwide. On Not Cool episode 21, Ariel is joined by Libby Jewett, founding Director of the Ocean Acidification Program at the National Oceanic and Atmospheric Administration (NOAA), who explains the chemistry behind ocean acidification, its impact on animals and plant life, and the strategies for helping organisms adapt to its effects. She also discusses the vulnerability of human communities that depend on marine resources, the implications for people who don't live near the ocean, and the relationship between ocean acidification and climate change.

Topics discussed include:

  • Chemistry of ocean acidification
  • Impact on animals and plant life
  • Coral reefs
  • Variation in acidification between oceans
  • Economic repercussions
  • Vulnerability of resources and human communities
  • Global effects of ocean acidification
  • Adaptation and management
  • Mitigation
  • Acidification of freshwater bodies
  • Geoengineering

References discussed include:

The oceans actually now, just in general, hold 70 times more carbon dioxide than the atmosphere.The modeling studies that have been done have projected out that the oceans actually could continue to absorb, even as the last fossil fuels are being burned. That's a lot of carbon dioxide.

~ Libby Jewett


Ariel Conn: Hi Everyone. Ariel Conn here with episode 21 of Not Cool, a climate podcast. We’ve been talking a lot about the climate impact of carbon and other greenhouse gases in the atmosphere. But not only will carbon increase global temperatures, leading to rising sea levels and warmer oceans in general, but a significant percentage of the carbon emitted into the atmosphere ends up in the oceans, leading to major problems like ocean acidification. To talk about these issues today, we’ll be joined by Libby Jewett, who is the founding Director of the Ocean Acidification Program at the National Oceanic and Atmospheric Administration, also known as NOAA. 

Libby co-led NOAA-wide meetings of scientists and policymakers to conceive and develop NOAA's first comprehensive ocean acidification research plan. She chairs the Ocean Acidification Interagency Working Group (under the Subcommittee on Ocean Science and Technology) where she helped develop an ocean acidification strategic research plan for the nation. And she is co-chair of the Executive Council of the Global Ocean Acidification Observing Network. She earned a Ph.D. in Biology with a focus on Marine Ecology at the University of Maryland, a Master of Public Policy at Harvard University's Kennedy School of Government, and a B.A. at Yale University.

Libby, thank you so much for joining us today.

Libby Jewett: Thank you for having me.

Ariel Conn: The very first question I have for you, since this is an episode about ocean acidification, is how do you define ocean acidification? What is it?

Libby Jewett: Very simply, ocean acidification is the changing chemistry of the oceans that's happening as a result of increasing levels of carbon dioxide in the atmosphere. The more we look, the more we realize that chemistry is actually very complicated. We think of changes in chemistry in the global ocean as version 1.0; that was our initial understanding of what was happening. And then as we began to look more closely at the coastal ocean, we realized that the variability is actually very high there. But that's the basic idea, is that the ocean is taking up the carbon dioxide in the atmosphere that humans are putting there through the burning of fossil fuels, and that causes ocean acidification.

Ariel Conn: Maybe this is in my own head, but I sort of lump ocean acidification and climate change all into the same earth problems. And so I was wondering if you could just quickly explain what the distinction between the two is.

Libby Jewett: We explain ocean acidification and climate change by explaining that these are two phenomena that are happening as a result of increasing levels of carbon dioxide in the atmosphere. So the 20, 25% that's going into the atmosphere is actually causing climate change, and that's temperature changes and sea level rise, changes in weather patterns. All of those things are derived from increasing levels of CO2 being in the atmosphere. And then about 25% or so, up to 30%, is going into the ocean, and that is what's driving ocean acidification. And then about 40% is actually taken up by trees and grass and other things on land. So we look at climate change and ocean acidification as actually distinct processes; however, they do interact because temperature change combined with ocean acidification will have impacts on marine ecosystems.

Ariel Conn: The breakdown of how much is going into the atmosphere, versus land, versus the ocean, is sort of interesting to me. Right now my understanding is one of the ways we're saying that we're trying to address climate change is we can plant more trees, or improve our agriculture, so that more carbon is absorbed into plants and back into the land. But we don't want that happening in the ocean. So why is it bad in the ocean?

Libby Jewett: So, because of the chemistry of the interaction of carbon dioxide with water molecules, we actually have the increase in acidity that results by the oceans taking up CO2. However, there are plants in the ocean which are, and will be, benefited by carbon dioxide. They don't live very long, the way you have long-lived trees, or forests, or jungle, that are actually sequestering carbon. In the ocean, the greatest amount of primary productivity or the generation of oxygen through photosynthesis is happening by micro organisms, algae and stuff. And the algae doesn't live very long, and some of it sinks to the bottom and some of it sort of recirculates there. So you don't have the sinks, at least, in the surface ocean. So therefore more of the carbon dioxide is actually interacting with the water molecules and thus causing this acidifying effect of the water.

But it's actually a great question. I don't think anyone's actually asked me that exact question before.

Ariel Conn: Yay.

Libby Jewett: I'm thinking on the fly.

Ariel Conn: So actually I've heard that about algal blooms, that they absorb carbon initially, but then as they die off they're very damaging.

Libby Jewett: Most, not all, because there are large phytoplankton blooms that happened in the big deep open ocean — and this was my work before I started working on ocean acidification. When they happen in more shallow systems — like Chesapeake Bay for instance, or Puget Sound, or even the Gulf of Mexico — the algae blooms get very prolific, and then they sink to the bottom where there's less oxygen, and they decay down there. They use up actually even more oxygen, so you have these areas that are actually considered dead zones now. And in that process, they actually put out CO2 as well. So they've sucked up the CO2 in the surface, but then they die and go to the bottom, and then they emit the CO2. So now you have low oxygen and high CO2 in the coastal ocean.

And so when I talked about version 2.0 of OA, that's where we've made a lot of headway I think. Although we still have more distance to go in terms of understanding that chemistry of the coastal ocean.

Ariel Conn: When we talk about the oceans absorbing carbon, is it more the plants within the ocean that are absorbing the carbon, or is it actually changing the chemistry of the water itself?

Libby Jewett: The latter.

Ariel Conn: Okay.

Libby Jewett: I'd say the majority of the carbon dioxide that goes into the water is just basically diffusing into the ocean. And as it does that, some of it will remain in the CO2 form, but most of it actually combines with the water molecules to create carbonic acid; that's the favored direction of the chemistry. So carbon dioxide combines with water and creates something called carbonic acid. And it's called carbonic acid because it almost immediately disassociates and releases a hydrogen ion. The increase in the hydrogen ions is what's causing the increase in acidity, or decrease in pH. And pH is a measure of hydrogen activity.

Ariel Conn: Also, another quick chemistry review: can you remind us what acidic water is versus basic, and why the pH balance is relevant?

Libby Jewett: One thing we want to make clear when we talk about ocean acidification is that we're not heading anytime soon, and probably ever, to the water being actually acidic. We're right now in the global open ocean at about 8.1 on the pH scale. So basic, which is where we are now, is anything on the pH scale above seven; and then anything below is considered acidic. And when we talk about ocean acidification, we're actually talking about a directional process. We're acidifying the oceans, but we would be incorrect if we said that the oceans were acidic. I hope that's clear. And it is something we struggle with in terms of communication of the phenomenon.

Ariel Conn: It seems easier to say ocean acidification than oceans, I guess, becoming less basic?

Libby Jewett: Right. So it's not quite as catchy.

Ariel Conn: Right. So what is the impact of acidification on the animals and plant life in the oceans?

Libby Jewett: Our program in NOAA started up in 2011, but actually scientists at NOAA had been studying the phenomena for many, many years. The harbinger of dismay started occurring in the middle of the 2000s — about 2005 or '06 — when shellfish industries along the Pacific Northwest coast started experiencing mass mortality in their hatcheries. And the oyster industry out there is very reliant on hatcheries for seed in order to grow up oysters for market. And when the hatcheries started experiencing this, originally they thought it was probably one of the many other stressors that they knew about — diseases and viruses, bacteria, maybe low oxygen. It was only when scientists at one of the hatcheries actually attended a lecture by one of our NOAA scientists, in which the NOAA scientist — Richard Feely — was talking about ocean acidification and what its implications might be, that he actually connected that what was happening might actually be a real life example of impacts of ocean acidification.

And they started from that point on measuring the carbonate chemistry in the hatchery water that was coming in — they just use natural water and phytoplankton that comes with it to feed their baby oysters — that they realized that the water was now, at certain times of the year, very corrosive and was having an impact, and causing mortality as a result. And over the past 10 years or so, we've actually been able to help them develop technology so they can monitor that and actually figure out how to approach it — which is, for them, putting buffer in the water in those times of year so that the oyster spat can grow. So that's an actual specific example where impacts have been seen.

Beyond that, we've actually done quite a bit of experimental work on a whole range of species from phytoplankton to fish, and trying to see are there direct effects, are there indirect effects because of the food that they eat, on a whole range of species. And it's not only us in the US but scientists from around the globe who are doing this work. And we've begun to piece together a story which says on the whole, we're seeing the potential for a lot of negative effects. There will be winners and losers, and as I said before, there are going to be some phytoplankton that are benefited by carbon dioxide in the water, and then whatever eats them obviously would be benefited as well. But then there are going to be others that maybe won't be so affected, and then there are going to be a whole range of species that will be negatively affected over time.

Ariel Conn: The one that we hear the most about, or at least the one that I've heard the most about, is the reefs. How long have we been tracking that?

Libby Jewett: Well, through the NOAA program, we've actually been monitoring through something called the National Coral Reef Monitoring Program for probably 10 years, maybe a little bit less. As we became aware of the importance of monitoring the carbonate chemistry for any shell-building organisms, we've been trying to monitor that on reefs. I will say that OA is only one of the problems that reefs are encountering, and temperature and bleaching is a much larger effect — and of course that's being caused by climate change, our related twin stressor.

Ariel Conn: I guess I didn't realize that. I thought the bleaching was an effect of the acidification. But that's not the case, it's the temperature?

Libby Jewett: Yes.

Ariel Conn: Okay.

Libby Jewett: Now, the extent to which ocean acidification may be an underlying stressor that makes reefs more vulnerable to bleaching — that's a hypothesis that's been thrown around, but it's not really one that's been proven yet. The research has focused on looking at corals’ ability to keep up with sea level rise, and keep the structure intact that they are — the complexity of coral reef structure, keep building that up. Because all the time, just through natural processes, coral reefs are eaten by fish, and dying, and regrowing, and I mean they're very vibrant, dynamic ecosystems. And one of the things that has been shown in laboratories is that the dissolution of the carbonic structure of reefs, which is the core component, is likely increasing over time as a result of ocean acidification. So it’s just that much harder for them to keep themselves whole, I guess.

And as a result of that, we actually have an increase in bioerosion, which is other organisms coming in and being able to drill down into the coral skeletons, because they're less strong than they were before. But it's all very hard to tease out, because it's of course happening simultaneously. And you have the bleaching on top of that.

Ariel Conn: And sorry, were you saying that rising sea level also is negatively impacting that, or did I misunderstand?

Libby Jewett: Well, because the seas are rising, in order for corals to keep within the photic zone, which is where they need to be — part is their reason for existence is they have those zooxanthellae in their tissues that are photosynthesizing. So those are little micro algae that photosynthesize and support the growth of the coral, on top of the coral also eating zooplankton out of the water column. They're so interesting, fascinating. But in order for those zooxanthellae to work, they have to be within a certain distance of the water surface, and solar radiation that reaches them through the water. And if the sea levels rise and they're not able to keep within a certain distance of that, then they could be negatively affected over time. There's a lot of different forces at play.

One of the areas of study right now — or a couple of areas of study — are, one, identifying areas around the globe, coral reefs out in the Western Pacific, or perhaps in the Caribbean, who seem to be actually thriving, and otherwise seem to be resilient to ocean acidification, because perhaps they've grown up in a little embayment where either temperature or pH has been stressful for eons. Just naturally, because of those conditions that I was talking about before where local conditions can affect the local waters.

And so, identify those groups of corals that are resilient — and there are resilient corals out there. So that's actually very helpful. And in the Caribbean, which has actually been hit even harder by bleaching than even the Western Pacific, we've been looking at areas that are pretty stressed close in coastal region — some even in the port of Miami, where you would think no coral could live; and there are corals there — and looking at them and trying to think about could we use these to restore other reefs that have been otherwise damaged either by bleaching, or ship strikes, or something. And because these seem to be a resistant breed of coral, using them as restoration target. So there are pockets of hope.

Ariel Conn: Yeah. You've mentioned a couple of times now some solutions that people are looking at, and I'm going to want to come back to that; that's definitely one of the big questions that I have. But first, where you're talking about some corals are more resistant than others: how are we seeing variations in the impact of ocean acidification, and I guess temperature increases, around the world? Are there places that are less affected? More affected? Or is it pretty evenly spread around the globe, and it's just regions where the animals were already stressed that they're able to adapt?

Libby Jewett: The entire ocean is in contact with the atmosphere. And so there's the global phenomenon of ocean acidification because of that. The atmosphere is pretty well mixed. As CO2 goes up in the atmosphere, it's taken up by the ocean. However, that rate of uptake is variable because for one, cold water can hold more gas than warm water. So we're obviously more worried about our polar regions for that reason. They actually just naturally have higher CO2, and they're sort of reaching some threshold, perhaps, because of the increased level of CO2. And on top of that, in the Arctic we're losing ice. And ice was a barrier between the atmosphere and the ocean — and now there's more of the Arctic that's open, which makes it more permeable to that CO2 going in.

So one, we have lower pH in our polar oceans — but again, that's somewhat variable. We have upwelling regions; so when I talk about the Pacific Northwest, if you get to understand more of the oceanography of the global ocean, there are regions around the ocean where deep water — which has actually been out of touch from the atmosphere for, could be 50 years, could be a thousand years — is actually upwelling to the surface. And this happens in a few distinct regions, and the Pacific Northwest happens to be one of those. And because that water was in touch with the atmosphere, in the case of the Pacific Northwest, around 50 to 75 years ago, it actually was taking up CO2 levels that were in the atmosphere 50 to 72 years ago and is now upwelling along our coast.

So it's actually an upwelling of CO2 levels that are greater than what you would see in the surface ocean, and also enhanced by what it saw when it subducted. And I won't go into a whole lot of detail, but suffice it to say the oceans aren't all uniform. So you have these upwelling regions, you have polar regions. And then you have the tropics, which, from our modeling exercises — unlike the poles, they're actually very saturated in what we call calcium carbonate. And I haven't even gone into all of that chemistry, but that's what basically disappears as the pH changes. And that's what shell-building organisms need to build their shells. That's kind of a simplified way of approaching it. But the tropical oceans are very saturated, but they're also changing the fastest in terms of the changing carbonate chemistry, because they're warmer and they take up more CO2. So that's worrisome.

And then we have what's going on in the global ocean. They're more or less acidifying in the global ocean, because there's less complicated biology there, at a fairly steady rate. And then you have, very close to shore, estuaries where the carbonate chemistry is even more complicated. I would say we're still trying to get a handle on exactly how atmospheric CO2 is affecting estuaries, because they actually are, in many cases — like at the mouth of a marsh — will be sources of CO2 to the atmosphere, because there's so much decomposition happening within those regions. I mean, just think of that marshes, and there's a lot of material in the water. That CO2 — because the atmosphere now has relatively, to that water, less CO2 — the CO2 actually off-gases. So it's very complicated, but that differential will change over time as there’s more CO2 in the atmosphere. So that will actually over time affect that system as well.

Ariel Conn: Okay. Is there a maximum amount of CO2 the oceans can absorb?

Libby Jewett: Actually, no. The modeling studies that have been done have projected out that the oceans actually could continue to absorb, even as the last fossil fuels are being burned. That's a lot of carbon dioxide. And the oceans actually now, just in general, hold 70 times more carbon dioxide than the atmosphere. So they've actually provided a service to the planet, because they've taken up the carbon dioxide that maybe would have stayed in the atmosphere. But the people who study this — and I'm actually not a carbon chemist, I just pretend I'm one — as they take up more carbon dioxide over time, the rate of uptake will decrease, because they just become full of carbon dioxide. There's a bunch of different processes that happen, but they'll keep taking it up. The rate will diminish over time.

Ariel Conn: So you've mentioned stuff happening in the Pacific Northwest a couple of times. Is that more because that's a region that you're personally working on? Or is that region interesting for some reason, as opposed to the Atlantic coast of the US, or the California coast?

Libby Jewett: I think one of the motivators for Congress passing an ocean acidification law, which they did in 2009, was what was happening in the shellfish industry in the Pacific Northwest. So it's just an example of economic repercussions of this phenomenon. So it seemed like a natural place to focus our initial attention, but we've since expanded out. NOAA actually has a laboratory in Seattle, which is handy: the Pacific Marine Environmental Lab. And they have been very involved in leading the science on OA, leading the open ocean and also now even the coastal ocean understanding.

As the NOAA program, one of our responsibilities is long-term monitoring of ocean acidification around our coast. So we have moorings, and ship cruises, and autonomous vehicles, and underway systems, which we put in ships that are doing other activities, happening around all of our coasts and out into the remote Pacific islands, on routine periodic survey. So we're trying to cover all the bases with the resources that we have, to try and track this phenomena over time.

Ariel Conn: So since we've started talking about the NOAA ocean acidification program that you're running, why don't we keep going with that? What all are you guys working on?

Libby Jewett: We have a multifaceted program. As I said, we're very focused on ocean observation, so we do have that long-term monitoring program; but we also do research on impacts of ocean acidification on a whole range of species of fish, and shellfish, and crustaceans, and you sort of name it. Anything that's related to either commercial or recreational fishery species around the US — we're trying to do work on that. And that both in partnership with academic institutions and through our NOAA fisheries science centers, which are our laboratories that are all around our coasts and in the Pacific islands.

The basic aim, I would say, is that we're trying to get at understanding the vulnerability of our marine resources — and the humans that rely on them — to ocean acidification. So we do work monitoring, understanding the stress that species are experiencing, or will experience; and then doing actual laboratory experiments, or sometimes in situ experiments, on the species to figure out their response. And then looking at human communities as well: for instance, we funded a project that's working with four tribes in the Pacific Northwest, to try and look at their reliance on coastal ecosystems and figure out what we know about those species that are culturally important to them. And we hope that that will help inform the research that we do in the future, and what adaptation strategies we might help develop for those communities. So it's sort of the gamut from socioeconomics all the way back down into the ocean and how the chemistry is changing.

And I will say, so when we first started this work, when we founded the program in 2011, people were doing experiments and they were using treatments that were really based on open ocean levels of ocean acidification. And that is actually, as I said, very different than what happens in the coastal ocean. And so by doing this monitoring more locally to where the species actually live, we've over time been able to develop more appropriate treatment, so that we know that the results of the experiments that we do are actually showing what we think are the vulnerabilities in the future.

I think it's a good robust approach. And we work, again, with academic institutions; we also are part of leading a global effort called the Global Ocean Acidification Observing Network. We helped found that, and it's been around since 2012. And we now have over 700 scientists from 93 countries that are part of the network, and they really look to NOAA and the US, really, to help define and lead the research, and help them have the capacity to do the monitoring they may need in Africa, or Latin America, or small remote Pacific islands. So we're very excited and proud about the leadership we've been able to show on that.

Ariel Conn: Why is it so important for us to understand this? We can see that it impacts local coastal communities, but why is it so important for all of us to understand and be concerned about ocean acidification?

Libby Jewett: We need to know what impact we're having on the ocean. I mean the ocean is important, not only because of the seafood that we eat from it, but because it's a driver of larger processes on the earth. And every other breath, they say, that we breathe comes from phytoplankton in the ocean. So the fact that we might be having this negative impact, that we might in some cases be able to remedy through local approaches. In the case, for instance, of the Pacific Northwest, where those hatchery failures were happening, we didn't know what the phenomena was at first and we didn't know what to do. But as that became clear over time, we actually brought that industry back from the brink.

We can't manage what we don't understand. And so by understanding this phenomenon is happening — we don't know exactly what all those adaptations might be. But I think as our population is growing, there are more and more people living at the coast, there's more reliance on food protein from the sea. I would say in the US, maybe because we're a wealthier nation, maybe we have more flexibility to switch to other protein sources. But a lot of places around the world don't have that flexibility. And so trying to provide them, equip them with the resources that they need to understand what this phenomenon is and how they might adapt to it — anticipating that, at some point, we will bring emissions down to zero, and the oceans will begin to basically off-gas.

We need to understand it to be able to forecast it, to be able to buy time, to be able to prepare communities for the changes that are coming. I think it's better to know than not to know.

Ariel Conn: Are there ways to try to actually address ocean acidification? Or can we just try to help marine life adapt?

Libby Jewett: The big solution is to reduce CO2 going in the atmosphere, and to bring emissions to zero eventually. I think that is the large solution. That's the solution for climate change; that's the solution for ocean acidification as well. However, again, as we understand more what is driving species change, what their physiology is, what the responses are, new techniques may become apparent to us. And one of the things that we do know is that plant life does take up CO2. It takes it out of the water  We talked about that before. So phytoplankton does that, seagrasses do that: they sequester carbon. That's how they're thriving. They're putting out oxygen and taking in CO2.

There have been, and there continue to be, investigations into how we could use those natural approaches to pull CO2 out of the water around other pieces of the ecosystem that might be more vulnerable. For instance, can we support the growth of seagrasses close to coral reefs that we're trying to protect? And does that do enough to reduce the CO2 around them to enhance their grip? And there's some indication that corals that are around seagrasses actually do do better; but seagrasses are also hard to keep going with all of the changes happening. So I think we're going to see more and more effort being focused on those kinds of approaches, to understand from a research perspective how to approach that.

For shellfish as well, I mean we at least for the moment have figured out options for hatcheries — but those are enclosed systems. What happens next is that they take those oysters and they actually plant them out on the flats where they can be naturally growing and eating phytoplankton. What we can do in that case might be that we need to be growing kelp alongside the oysters. And this has actually been done for eons: in China, for instance, they do a lot of multi-trophic shellfish aquaculture, I believe. In their case, and what we're increasingly looking at is, can we harvest both the kelp and the oysters so that they grow side by side, and then you pull the kelp out before it starts decomposing at the end of the season. Or finally, should we be trying to put oyster shells back into the systems where we take the oysters out — because when they're in that system, they're actually creating some buffer as they break down.

There are some rules about that, and you obviously worry about transmission of viruses and stuff. So if suddenly you're eating oysters on the East Coast that were harvested on the West Coast, you may not want to put those shells in the water, because they might actually bring something new to the Eastern oysters that they hadn't seen before. So you have to be careful about the approaches; that's why you need to do some research around these options. But these are all very local, but they're also very valid. It seems overwhelming and sad that we've gotten to that point, but at least we're embracing the task.

Ariel Conn: So one of the things that I've heard, I think for sea level rise, is that planting mangroves more along coastal areas can help protect the inland coastal regions a little bit more. Does that have any impact on the acidification levels?

Libby Jewett: If I'm remembering correctly, there have been some studies in the Caribbean that have looked at ocean acidification parameters in and outside of mangrove areas, and the pH is actually higher amongst those roots that are sitting down in the water for mangrove. So yes, I think that is a double win there because it's protecting communities, creating habitat for fish, and also has this environment that's more healthy, I guess. There have been studies that have actually shown that in some of the mangroves, they're beginning to see corals that have migrated in. It may have been that they weren't really looking at this in the long-term, but it seems like it's becoming a novel habitat where it's actually cooler under the mangroves, and the pH is more amenable. We may see these shifts in habitats that we hadn't really considered viable before, and that's where nature is just doing its own thing without us having to assist it.

Ariel Conn: These are starting to seem like almost magical plants.

Libby Jewett: Right.

Ariel Conn: So coming back to sort of broader questions about ocean acidification: is it actually only just oceans?

Libby Jewett: In fact, freshwater bodies are also just as in touch with the atmosphere as the oceans are. Some monitoring work has been done in the Great Lakes. And the prediction is that basically the Great Lakes are, and will be, acidifying at the same rate as the open ocean. NOAA, I guess I should say, is not responsible for long-term monitoring the lakes. That's actually more of an Environmental Protection Agency and a US Geological Survey responsibility.

One thing to keep in mind is that the Great Lakes, and also a lot of northern lakes, were very affected by acid rain. And a lot of the original research on effects of lowering pH on organisms came out of that period when industries were emitting those sulfur compounds that were causing acidification, in the same way that CO2 is doing it on a global scale. And so obviously, industries installed scrubbers and they weren't emitting that any more and the lakes were able to rebound to a certain extent. So there is a precursor insight into the future story there that I think we need to probably keep in mind.

Ariel Conn: So in the time that you've been looking at ocean acidification, what has surprised you?

Libby Jewett: So one of the pieces of research — and this wasn't even work that we did in NOAA; this was originally work that came out of Australia — was work done on clownfish. They determined that fish exposed to high CO2 levels actually had an impact on their neurotransmitters. And so that would be clownfish being attracted to their predator, instead of swimming the other way. Now, whether they adapt over time, and maybe those fish that are attracted get eaten and then the ones who are resistant — there's a lot of variability in biology. That is the good story, right? That there's potential for acclimation and natural selection. 

Ariel Conn: Is there anything else that you think is important to cover that we didn't get into?

Libby Jewett: Can I touch on geoengineering for a second?

Ariel Conn: Yes.

Libby Jewett: That was a topic of interest definitely in the last year or so, and I just want to make the point that a lot of the geoengineering solutions that people are talking about, which are more focused on keeping the temperature of the planet cooler, and putting things up in the atmosphere that might reflect back the solar radiation that's incoming. I think it's sort of obvious, but it's also important to point out that that's not going to do anything for ocean acidification. Because unless we reduce CO2 — unless we figure out, maybe from a geoengineering point of view, how to take CO2 out of the atmosphere — or at the very least reduce our emissions to zero, we're not going to have an impact on ocean acidification. Now temperature's very important to focus on as well, so I'm not necessarily saying not to do that, but just we need to know that we're still going to have ocean acidification happening.

Ariel Conn: Yeah, that one seems good to know. Are there efforts underway to do the equivalent of geoengineering for ocean acidification?

Libby Jewett: Not that I'm aware of. Years ago though — and I haven't seen any recent literature on it — there were some thought experiments on what it would take to buffer the ocean, which would basically be mining limestone on land and spreading it over the ocean. And the long and short is that we determined that the amount of energy that it would take to actually do that would defeat the purpose. You can maybe do it, as I said, like putting oyster shells back in local embayments. You could do it on a very local scale, but trying to do that on a global scale.

So I will say, however, the earth is doing it naturally itself. So if we were not emitting at the rate that we're emitting, and the levels of CO2 were going up over millions of years — instead of tens and hundreds of years — the earth has the capacity to buffer the oceans through the weathering of limestone and other substances, through those rivers that we were just talking about. So as they are making their way over land, they're taking buffering substances with them into the ocean. We've seen events in the geological history where there's been increase in CO2, but even when there were massive increases in CO2, we're fairly certain they were happening over millions of years. And so the pH was not as diminished. But even then we actually were seeing some massive extinction. So it's not great. It's not a great story.

But the long and short is that the earth has a capacity to heal itself. And so if we can bring emissions down, and really bring them down to zero, we're still going to look at temperature change, sea-level rise, but eventually the earth will come back into equilibrium at the pre-industrial levels because of that system that I talked about, the cycle. So that is good news, but it's a long time away and it's better to stop now because if we stop now — it's like a car going really fast — if it stops, it's still going to skid for awhile. It's better to stop now and have that skid now rather than getting going really even faster. Then the recovery is even going to be longer.

Ariel Conn: All right. So, on that note, what gives you hope?

Libby Jewett: Well, I do feel like humans have a capacity for transformational change. I think my kids would be okay with me saying this: I will say that both of my children actually work in solar energy now. So I feel like I said the right things over time and influenced them that that was the way to make a difference. And there was actually an article in the New York Times by Al Gore, in which he was pointing out that even from an economic point of view, the number of solar installer jobs is growing faster than any job in the US — or maybe on the planet, but definitely in the US. And the second one is the number of wind turbine installers. So there's a win-win here, in that there's economic potential. But we need to make sure that these transformational changes to renewable energy are happening even faster than they're happening now. I am hoping that we can do that. We have to. So we will. The political environment is in our favor around the globe, and that's it. It's the future.

Ariel Conn: I like the, "We have to, so we will." All right. Well, I think that's it for me. Is there anything else?

Libby Jewett: No, this has been a pleasure. I hope that I haven't been too raving and long-winded.

Ariel Conn: No, this was great. This was great. I really enjoyed it. This is one that I've personally been interested in learning a lot more about, so I really appreciate you taking the time to talk with us today.

Libby Jewett: My pleasure. Thank you so much.

Ariel Conn: I hope you enjoyed this episode of Not Cool, a climate podcast. On episode 22, we’ll be joined by Cullen Hendrix who will talk about his work looking at the potential for climate change to increase the risk of armed conflict.

Cullen Hendrix: The world has become significantly more complicated. Whether or not that's due to climate change, or whether or not that is a long tail response to the seismic events associated with the global financial crisis and the great recession is anyone's guess. But we are dealing with a very different reality in terms of the nature of geopolitical risk.

Ariel Conn: I hope you’ll join us for the next episode, and as always, if you’ve been enjoying these podcasts, please like them, share them, and maybe even leave a good review.

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