READ & WATCH Ocean Acidification Exceeded the Planetary Boundary Back in 2020, according TechTonic nsights, Newest Research [Paul Beckwith Professor of climate science from Ottawa Canada Joined YT Sep 16, 2011 46.6K subscribers 1,635 videos]
Part 1 https://cityofangels25.blogspot.com/2025/12/ocean-acid-1-of-3-same-emissions.html
Hello everybody. I'm Paul Beckwith. I haven't talked about ocean acidification for a while on this channel and that's what I'm going to do in this video. A paper came out recently titled Ocean Acidification, another planetary boundary crossed. So, I'll explain what's going on in the surface of the ocean and down through the water column and at the equator versus the poles.
Because there are all of these different effects occurring. Of course, the basic premise is that as our CO2 emissions increase ever more in the atmosphere, there is a dynamic balance and exchange between CO2 and the atmosphere. A lot of it is dissolved into the oceans, absorbed into the oceans where it forms carbonic acid basically and it drops the pH level of the ocean and that makes it very difficult for marine creatures that depend on aragonite or calcite which are two different forms of calcium carbonate. Basically, those that calcium carbonate is in the shells or backbone of or or the structural material of coral reefs. It's in tetrapods. It's in all kinds of different marine creatures.
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And as the ocean is acidifying, then there's less ability of these organisms to survive basically. So let's talk about this new paper, fairly recent paper and the planetary limits idea. I'll revisit- I've talked about it in the past but it's very important.
So this is the paper it's open source so it's free everybody can get it and let's have a look first of all are you know- The Potsdam Institute in Europe and they came up with this concept of planetary boundaries; so what are these planetary boundaries. you may recall seeing diagrams like this okay, so the planetary boundaries it's a framework, just basically quantitative limits on key earth system processes that are essential for maintaining a stable and resilient planet.
So it was first established around 2009. It's updated regularly. There's nine core biophysical systems and processes that regulate the Earth's life support system. So, of course, we're talking about climate change, biosphere integrity, land system change, freshwater use, biogeochemical flows, nitrogen and phosphorus cycles, ocean acidification, atmospheric aerosol loading, aerosols in the atmosphere, stratospheric ozone depletion, and other novel entities like synthetic chemicals, endocrine disruptors, microplastics. Okay.
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So these boundaries basically define a safe operating space for humanity. Okay. So let's just have a look at some of the figures. So this is where we are at the moment. So we've got these different planetary boundaries. There's a safe operating space here, the inner circle. And then when you exceed this dashed line, you go into dangerous areas. So, stratospheric ozone depletion, we're right here. We're within the boundary at the moment. Atmospheric aerosol loading is a new one. It's not really quantified yet. Ocean acidification, we were right within the safe zone. And actually, this paper is arguing that we're pushing out into the nonsafe zone.
Then you've got the biogeeochemical flows, the nitrogen and phosphorus cycles well exceeding the safe zone. novel entities like microplastics exceeding the safe zone, land system change, biosphere and climate change of course. So, and freshwater change.
So, so many of these parameters are exceeding the boundaries, safe boundaries. So, which ones are? Well, this is a good summary right right here. This figure here. So, this is where we are in 2020 where we were in 2023. This thing's updated fairly frequently. six boundaries crossed., go back to 2022, five boundaries crossed. 2015, four boundaries crossed. And in 2009, there are only three that cross.
So, we're crossing more and more of these planetary boundaries. We're going into, you know, now people are talking about overshoot, and saying we got to pull ourselves back from overshoot. Well, we passed these boundaries. Okay, so that's a key factor.
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So we're talking about ocean acidification. We need to talk about the pH. Okay, so in chemistry, pH is a logarithmic scale that is used to specify the acidity or basicity of aqueous solutions. Acidic solutions have higher concentrations of hydrogen H+ cations ions ions lower pH values than basic. Basic is seven- scale goes from 0 to 14 basically and you can calculate it if you remember your chemistry. Okay, I'm not apart from that
I'm just going to go down to the chart here to give some examples I think right here. So this is the average pH of some common solution. So, battery acid in your car, don't touch it. PH is less than one, very acidic. Gastric acid, stomach juices, very low pH. Vinegar, 2 to three. Orange juice, very acidic, 3.3 to 4.2. Black coffee 5 to 5.03. Milk is just slightly acidic, 6.5 to 6.8. And then pure water at 25 Celsius is neutral. Seven.
Seawater 7.5 to 8.4 depending on where you are. It's more acidic as you go to colder water at the poles, less acidic at the equator. Ammonia very strong base 11 to 11.5. Bleach 12.5 and lie is at 14. very very you don't want to mess with fluids at both extremes. So these are bases anything higher than seven neutral seven acids less than seven. Okay. So it's an excellent Wikipedia page that goes into how to calculate it and it talks about different you know what we call ultra acidic versus hyper alkaline and so on. and it talks about soils, the pH in plants, pH in the ocean, but there's a whole separate thing on pH in the ocean. So, let's have a look at that now. So, that's right here.
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So, ocean acidification. Now, this is a fantastic Wikipedia page. Very, very impressive. So, we'll go over this and then we'll get back to the paper and show the key results. So ocean acidification, it's the ongoing decrease in the pH of the earth's ocean. Between 1950 and 2020, it fell from 8.15 to 8.05. CO2 emissions from human activities are the primary cause, right? So the CO2 in the air is exchanging and being absorbed into the dissolved into the water column. Atmospheric CO2 levels exceeded 422 parts per million as of 2024. We're seeing record growth of those. CO2 from the atmosphere is absorbed by the oceans and the chemical reaction. It produces carbonic acid H2 CO3 which can then dissociate into HO3 minus and a hydrogen ion. This is a bicarbonate ion. The presence of these free hydrogen ions lowers the pH of the oceans, increasing acidity, right?
But the seawater is not acidic. It's still just it's still basic. It's over seven, but it's getting closer and closer. The acidification is increasing. It's becoming more and more acidic as time goes on as more and more CO2 is being absorbed. So, this is a plot. This shows Hawaii annual average and Hawaii monthly pH measurement. So you can see the scatter and variability.
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Now why is it important? Marine calcifying organisms like mollusks and corals are especially vulnerable because they rely on calcium carbonate to build their shells and skeletons. Now the pH scale as I mentioned is logarithmic. So a change in pH by 0.1 is a 26% increase in hydrogen ion concentration in the world's oceans. The pH scale is logarithmic. So a change of one in pH units is equivalent to a 10-fold change in hydrogen ion concentration.
And the sea surface pH and the carbonate saturation states vary depending on ocean depth and location because they depend on things like ocean temperature, a lot of other factors. So colder, higher latitude water is capable of absorbing more CO2. The interesting thing about water is when you have lower temperature water, you can absorb more dissolved gases, right?
The solubility of dissolved gases goes way up as the water's colder. The opposite is true for solids like salt. Okay? So, as you go to higher and higher temperature, the water is able to dissolve more and more of solid materials like salt for example, but less gases. Okay? So, the atmosphere ocean CO2 exchange whatever affects that affects the acidification. So local ocean ri ocean ocean ocean acidification.
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So things like ocean currents, upwelling zones, proximity to large continental rivers feeding into the ocean, sea ice coverage, atmospheric exchange with nitrogen and sulfur. All those factors affect the ocean pH. A lower pH has a range of potentially harmful effects for marine organisms. So, there's reduced calcification. marine creatures can't form their shells. They're deformed. Or if they do have shells, those shells just dissolve. They have lowered immune responses. These creatures reduced energy for basic functions such as reproduction. Acidification of the oceans is very harmful for these marine creatures. Very, it can impact marine ecosystems that provide food and livelihoods for many people.
So roughly about a billion people or 12 and a half% of the global population, right, we're over 8 billion now, is wholly or partially dependent on the fishing, tourism, and coastal management services provided by coral reefs, for example. Ongoing acidification of the oceans may therefore threaten food chains. I'll have to do separate videos on coral reefs soon because there's lots of significant things happening with that that I should really cover.
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The only thing that really addresses the root cause of ocean acidification is reducing carbon dioxide emissions. It's one of the main objectives of climate change mitigation, right? Removal of CO2 from the atmosphere. So, they do talk about carbon dioxide removal that would help reverse ocean acidification. They talk about some ocean based mitigation methods like alkalinity enhancement adding substances enhanced weathering to absorb CO2 put the CO2 in the rock and take it out of the earth out of the atmosphere ocean system. Okay. we've had ocean acidification before in Earth's geological history and it's led to some mass extinctions.
So here's the spatial distribution of global surface ocean pH. this is for the roughly the pH of the oceans of the world in 1770 the year 1770. Okay. So much of the ocean 8.2 8.25 some areas slightly lower. This is where we are right now. This is the difference between the pH in 2000 and in 1770 and it's of course much worse than in 2000 now. But you can see a drop of pH. The yellower the area the larger the drop of pH. So huge drop of pH in the southern oceans which is a huge carbon sink.
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And also big drop in smaller not so big a drop in the North Atlantic but the North Pacific very significant drop. Okay. of course CO2 has risen from 280 parts per million in the pre-industrial era to over 420 today because of fossil fuel combustion and deforestation. And these elevated levels and rapid growth rates of CO2 are unprecedented in the past 55 million years of the geological record.
Sources of the CO2 are clearly anthropogenic fossil fuel industry emissions, industrial land use and change emissions. Okay. So, so this is a really good chart here. This shows the fast carbon cycle. Okay. So the reservoirs are in are of of carbon are in white. Soil is a huge reservoir. The fossil pool huge sediment the deep ocean. Look at the deep ocean. 37,000 huge because of all the downwelling of the carbon from the surface into the deep ocean. So we need that thermohaline circulation to bring the carbon down.
If this thing shuts off, expect CO2 in the atmosphere and oceans to skyrocket. Okay, yellow numbers are natural fluxes occurring from you know photosynthesis, plant respiration, growth of biomass, microbial activity, ocean uptake and so on. The red numbers are human contribution. So fossil fuel, cement and land use change, atmospheric carbon net annual increase, and then the oceans are getting a lot more CO2 being absorbed also into the oceans. Okay. accumulated since 1850, the ocean sink holds up to 175 gigatons of carbon. That's more than 2/3 of the amount of carbon in the ocean sink has been taken up since only 1960. So recent decades only in the last 65 years right we've had exponential increase in anthropogenic emissions and therefore exponential increase in the sinks of what's going into the oceans although there's signs that that is slowing down.
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From 1850 until 2022 the oceans absorbed 26% of the total anthropogenic emissions. The emissions were 670 gigatons, 41% in the atmosphere, 26% in the oceans, the land and the soils, 31%. Okay, so we can talk about the overall carbon cycle describing the flux of carbon dioxide between the oceans, the terrestrial biosphere, the lithosphere or surface of the earth and the atmosphere. Okay. Okay. And the carbon cycle is both organic compounds like cellulose, inorganic carbon compounds like CO2, carbonate ions, bicarbonate ions. There are they're referred to as DIC, dissolved inorganic carbon. Okay. So when the CO2 dissolves, it reacts with water, forms a balance of ions and non ions. You get dissolved free carbon dioxide. You get carbonic acid, bicarbonates, and carbonates. Okay? Okay. And the ratio of these different elements depends on things like seawater temperature, pressure and salinity and something called the begerum plot. Okay. So it's called the the different forms of dissolved inorganic carbon are transferred from an ocean surface to its interior by the solubility pump. Right?
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This is the downwelling of the ocean bringing this carbon down below. Okay? So we can talk about the there's also something called there's also these calcium carbonate mineral saturation states and these are very important. They're declining because we're taking as we take more and more CO2 into the ocean over the past 270 years since around 1750. This ocean acidification process, it's making it harder for marine calcifiers to build shells. Endangers coral reefs and marine ecosystems in general. This is good description.
Ocean acidification has been called the evil twin of global warming. Have to remember that. I don't use that, but it's a very telling expression. It's also called the other CO2 problem. So increased ocean temperatures and oxygen loss act concurrently with ocean acidification. So the oceans are under stress. We have higher water temperatures. There's oxygen loss within the ocean because of stratification. And there's also ocean acidification. That's a deadly trio of climate change pressures on the marine environment.
Okay. and they go into some of the chemistry of of what's happening the decreased calcification in marine organisms. So this is various types of forams. You can see through a microscope what's happening to them. Their structure is changing. There's something called the Begeurum plot which shows how CO2 bicarbonate and carbonate changes at different pH’s. this is the oragonite saturation depth.
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So the saturation state known as omega of seawater for a mineral is it's a measure of the thermodynamic potential for the mineral to form or to dissolve in the water. So there's an equation the oragonite saturation. It's the product of the concentrations of the calcium and the carbonate divided by some reaction rate. It's called the solubility product at equilibrium and when when both precipitation and dissolution are equal so you get a stability of the levels of the oreagganite. So there's a boundary there's a saturation horizon above the horizon in shallower water the value of of omega is greater than one calcium carbonate does not readily dissolve.So the shellfish etc are okay.
Most calcifying organisms live in such waters. Below the depth this depth omega has a value of less than one. So calcium carbonate dissolves. So there's no calcium carbonate in the sediments on the seafloor etc. because it's it's too acidic. The carbonate compensation depth is the ocean depth at which this dissolution balances the supply of carbonate below. Therefore, sediment below this depth is void of calcium carbonate.
So, when we increase CO2 levels, we're lowering the pH of seawater. So, we're increasing the dissolution, the the dissolving of the calcium carbonate. And as this shallows, as this saturation horizon shallows and shallows and shallows, eventually when it reaches the surface, goodbye coral reefs completely. goodbye sea life that uses calcium.
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Now there's two common polymorphs crystal forms of calcium carbonate. There's the oraggonite is one of them. Kind of looks like this. Okay, oraggonite very common mineral and then there's calcite here. Okay, calcite is is the crystals and and it has something called bioringence. I've talked about it in some previous videos. Oraganite is much more soluble than kelsy. So the oraggonite saturation horizon is always nearer the surface in the calsite one. And as they both move up as the ocean acidifies, it means that the organisms that need these minerals in their in their life life structure will be out of luck.
Okay. So it's going it's it's going to have it's causing a huge problem. There's already large quantities of of water unsaturated in oraggonite in the Pacific continental shelf area of North America. Right? The continental shelfs are important. Most marine organisms live or spawn there. So, you know, at depths of thousands of meters, calcium carbonate shells begin to dissolve, increasing water pressure, decreasing temperature, shift the chemical equilibria, controlling the calcium carbonate. Okay, I've talked about the carbonate compensation depth.
Okay, so this is happening. It talks about some of the variants we're see in the North Pacific for example, the carbonate saturation depths are getting shallower at the rate of a couple meters a year. Ocean acidification in the future is going to cause a huge effect. So here's a time series of CO2 at Mauna loa in the atmosphere. This is an increase of dissolve the the the seawater partial pressure of CO2 micro atmospheres coming up here tracking so CO2 in the air it's exchanging with the water being dissolved rising it and this is the pH dropping so this is a a station in Hawaii and it's accelerating and the IPCC assessment report talks about it.
This is the change in seawater pH caused by the anthropogenic impacts of CO2 and they take it from 1700s to 1990. And you can see these areas here are getting very very acidic. The pH is dropping significantly in those regions. They give some locations and time periods and you know there's a lot of good references on the measurements etc ref heavily referenced and it shows you you know the areas there's Bermuda and you it shows you areas both at the poles at the poles and also at near the equator and there's subor equatorial Pacific and so on Okay.
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And you can look at the big five mass extinctions, rapid increases of CO2, rapid acidification of the oceans. Okay. The Paleocan thermal maximum 56 million years ago, massive carbon entered the atmosphere and ocean led to the dissolving of carbonate sediments across many ocean basins. so they're getting more and more data on that from the paleo records and then it predicts the future values and we know under these high emission scenarios we're getting- we're likely to it's it's estimated that surface ocean pH could decrease by as much as 0.44 units by the end of this century. That would mean a pH as low as 7.7. So that would be a huge detrimental effect to marine life.
And they give you some examples here. And this is really this is this is what you have with the terrapods. So in the polar regions, you don't have coral reefs. You have these terrapods and their shell starts to dissolve into mush basically as the oceans get more and more acidic. So here's a shell dissolved in seawater. dissolving and losing all its shape, form and function. Okay.
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And this is an unhealthy terrapod showing effects of ragged dissolving shell ridges and things like that. So it's starting to degrade here. Okay., cocoithophores right they use calc they form calcium for their backbones and they the backbones in in this structure you know the average cocoa lith mass is increased by 40% but the the the shell is significantly decreasing. So things are evolving. Coral reefs of course are on their way out. I'll have to do a separate study se separate video on the latest. I mean they talk about great barrier reef and brittle stars terrapods form the base of the Arctic food web. They're both seriously damaged from acidification. And then there's other impacts. This is changes in araggonite saturation. so the saturation level is shallowing. interesting. I never expected this, but as ocean acidification increases, you alter the acoustic properties of seawater. It allows sound to propagate further. Okay? And that increases ocean noise. So animals that use sound for echolocation and communication like whales can run into problems because of the acidification. Algae and sea seaggrasses, fish larvae. They talk about acidification effects on all of these things. And this is good.
This shows you, you know, continental shelf winds here. You get nutrients upwelling. You get a phytolanton bloom. The fish are here. So, you can look at the drivers of hypoxia and ocean acidification, intensification, and upwelling shelf systems, right? dissolved oxygen, dissolved inorganic carbon. they talk about the effects and of course it has a huge detrimental effect on different fisheries and they talk about that and they talk about different carbon removal technologies to make the o to add alkalinity to the oceans. things that people are considering even electrochemical methods to strip CO2. Right. right policies right so there's lo loads of stuff here.
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It's just fantastic- that's why I've spent some time on it so we'll go back to the paper I mean I basically shown you know so let's just- so what does this paper say it says that we were close to the planetary boundary for ocean acidification according to the institute classification system on planetary boundaries St. Joanne Rostrom, etc. And now we've passed it. So, ocean acidification has been identified in the planetary boundary framework as a planetary process approaching a boundary that could lead to unacceptable environmental change. This was before this paper. This paper was published showing we've crossed it. They used revised estimates of pre-industrial oraggonite saturation states, data models, uncertainties. they improved on the ocean acidification modeling. They show that by 20 in 2020 the average global ocean conditions had already crossed into the uncertainty range of the ocean acidification boundary. So we crossed that boundary back in 2020 about 5 years ago.
And they extended the analysis to the subsurface ocean up to 60% of the global subsurface ocean down to 200 meter water depth had crossed a boundary compared to over 40% of the global surface ocean. Okay. So not all parts of the ocean have crossed it but more than 50 you know significant parts have. there's been a 43% reduction in habitat for tropical and subtropical coral reefs. 61% loss for in the polar regions for the terrapods, 13% loss for coastal byvalves shellfish and you know there there so so so they talk the planetary boundaries first proposed in 2009 by Rostrom at all in in Europe. Okay, they talk about the nine large scale earth system processes. I've just discussed those things already. So let's just look at the results here. Okay. we'll just scroll down to the figures here. Charts.
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They show the Arctic at the surface, 50 m, 100 meter, 200 meter water depth, and then the changes in percentage change. this is the different areas in percentages. And let's go. Okay. So here is the CO2 presented reduction in oragganite this the saturation 2020 to pre-industrial so versus pre-industrial pre-industrial 276 to 288 and you can see you know how how much things have changed. This is showing you how significant changes in the Arctic the different parts of the ocean where acidification is the worst. This is the surface water aragonite. So huge reduction in the red areas.
So at the poles it is very bad. The equator is the least acidic area. But as you go to the because the dissolved CO2 is much much higher in colder water near the poles as I've already mentioned. This is oraggonite saturation pre-industrial and look at the changes to the 80s the 2000s and the 2020s. Okay. So a huge reduction in the saturation state. Okay. is more and more of the ocean is unable to have marine creatures that form shells. And this is the depth 0 to 25 m average pre-industrial 2020. If we had a 10% reduction from pre-industrial, it would look like this. 20% reduction from pre-industrial. Right? So they look at all of the the the details. They have these plots with all the different boundaries at surface or well no this is a different plot. This is showing geographic areas and a circle here at the surface 50 m 100 meters 200 m down just another way to depict the data. Okay.
So that's basically the paper. Where's my scroller on the right? I can't see it. Okay. So, you know, let's let's go to the beginning here. Okay. Well, okay. I'll scroll up. For some reason, it's not going up to the top on me. I don't have my slide my slider disappeared. Okay. So, this is the paper., very significant, but I would urge you to, you know, research some things yourself if you don't understand some of the jargon, etc. in the paper. you know have a look at the PH Wikipedia page on the pH but this is the most important one this has everything in it the Wikipedia page on ocean acidification great details on exactly what's happening with the ocean so unfortunately the data from today shows that we probably crossed this planetary boundary of ocean acidification about 5 years ago. Okay. Well, thank you for listening. Please consider going to my website, paulbeckwith.net, and do donating to PayPal to support my research and videos. Thank you again for listening and bye for now.
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