The CO2 link to ocean acidification and 19 'mass extinctions' with CO2 levels we're now heading toward

I came across this on the Live Science web page.

19 ‘mass extinctions’ had CO2 levels we’re now veering towards, study warns | Live Science

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Thanks for sharing. Good article. I find Live Science to be one of the better on-line sources for science news.

And, for those who may wish to dig deeper in understanding this analysis, it does not seem to be behind a paywall:

Mass Extinctions and Their Relationship With Atmospheric Carbon Dioxide Concentration: Implications for Earth’s Future (

I would suggest going to the discussion section first, because they have included a lot of information there that will inform you on alternative hypotheses, other factors looked at, etc.


Greg thanks for posting that link. It is the actual study not the media version.

Funny how “media versions” of the same study can be poles apart depending on the core audiences of different media outlets.
On second thought, it’s not so funny after all.


I thought I would quote this statement from the study.

“As suggested here and by previous authors, however, extinction of biodiversity has been associated in the past with the demise of marine phytoplankton and the consequent loss of up to half the oxygen in the atmosphere (Falkowski et al., 1998; Field et al., 1998). Should this recur, it could render Earth uninhabitable to “advanced” life forms, particularly large, oxygen-intensive homeothermic species such as humans.”

They conclude that we should be reducing by 2% a year the amount of CO2 we are currently producing. That this would best balance the economic impacts with the rate of extinction that’s reducing marine species diversity.

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That got me to thinking so I did a google search on O2 atmospheric levels. Let me point out It takes two oxygen atoms and one carbon atom to make CO2.

Here is a quote from the link below.

" Atmospheric oxygen levels are very slowly decreasing today due to the burning of fossil fuels, which consumes oxygen, and deforestation which reduces oxygen production, but not enough to alter biological processes."

Oxygen levels - Understanding Global Change (


Another tidbit.

“Scientists estimate that roughly half of the oxygen production on Earth comes from the ocean. The majority of this production is from oceanic plankton drifting plants, algae, and some bacteria that can photosynthesize. One particular species, Prochlorococcus, is the smallest photosynthetic organism on Earth. But this little bacterium produces up to 20% of the oxygen in our entire biosphere. That’s a higher percentage than all of the tropical rainforests on land combined.”

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I’m trying really hard not to get into these discussions because I have strongly (and long held) opinions on many of the topics that are being discussed here recently and I know they tend to be polarizing - and there’s currently plenty of polarization without my contributing to it.
During the Carter administration and for a while after I worked darned hard to make a career of solar installation - and did quite well at it for a while. During those years the bulk of our customers were motivated by concern over rising energy costs (long gas lines brought the subject into focus) and a laudable desire to help the country move toward energy independence. Some saw limiting emissions as another argument for installing solar and wind machines (which we did as well) but it wasn’t the primary reason most made installations. (Back then the state offered rebates that partially covered costs and the feds offered tax breaks as well. There was an actual energy policy that directly helped individual home/small business owners with the initial costs.) Most folks were acting out of concern about shortages and costs, not environmental concerns.

During the late 90s and early 2000s I returned to the university and studied biology with a goal of getting into the systematics of fish classification. Those studies involved a graduate level course in algae. (And, yeah, I aced it.)
At the time there was a good deal of talk about the roll of marine algae in carbon absorption as a possible mitigating influence on global CO2 levels. I went in hoping to hear something that held promise but, alas, the course left me skeptical about the hope that algae will “save us”. Nitrogen and/or phosphorus limitations as well as temperature tolerances of the myriad species of algae create very good grounds for skepticism of that hope - at least short of large scale artificial (and expensive) “algae farming” operations. That said, there are others who hold out hope, but it seems likely to be a false hope from what I know.

But I do have to ask, Castoff, Have you revisited any of the sites you used to collect? How are they doing? Have you personally seen evidence you could share - however anecdotal it might be?


I have been so long away from those days I couldn’t tell you. In FL where I worked with freshwater fish there were already numerous tropical introductions that drove diversity up. LOL Talking the marine environment, the Lion Fish’s predation is impacting fish populations of some reef species. Neither of them are climate driven.

However, while down at Ft. Desoto, FL to watch the check in and start of the EC 300, dead fish from a red tide episode happening south of Tampa Bay had washed up on the beach blown there by a strong south wind. Sargassum weed was also present. While I lived and worked down there, red tide was all but nonexistent. It did happen but not for long periods or large areas. Sargassum weed was also rare on the St. Pete beaches. However, it was common in summer on the Atlantic coast. But nothing like this year. As a kid I could pick up floating clumps and shake them out in a bucket of sea water, and all kinds of Sargassum specific species would come out. I even had a baby sea turtle once show up in the bucket.

Well later this summer I believe an exceptionally large area was covered by Sargassum weed in the Atlantic, Carribean, and Gulf of Mexico and washing up on FL shores in vast quantities. I had never seen anything like it while living there. Then later in the summer it just seemed to rapidly shrink in size. They were surprised by that. Strong winds were suggested as a possible reason. They didn’t mention rising sea temps over the region which is the case. But it had been years since I have been in the area and doesn’t represent what might have changed over time.

Seaweed Blob Headed to Florida Shrinks Dramatically - The New York Times (

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Wow, I read some of that Mass Extinction article. Paradoxically it made me feel more pessimistic, despite the author’s conclusion that meaningful limitation of species loss is still possible, since the seemingly doable suggestion of a 2% per year reduction of C02 emissions starting in 2023 has yet to manifest and seems to be not even close to ever happening. This is depressing!

Yet it also made me a bit happier since reading about extinction events hypothetically occurring in 26 million year cycles because of astrophysics puts human life in a rather different perspective.

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People change behaviors when they believe doing so is in their own best interest. The 70’s oil embargo motivated people to find ways to use less petroleum, and the same will be true for reducing CO2 emissions. When people see a direct benefit, they’ll change.


I agree that most people are motivated to make changes in their own habits based on cost, less so by altruistic motivations.

That’s completely understandable, but when greenbadgers start posing as environmentally superior when it really was only about price, I cry “HYPOCRITE!”

Example: Large SUVs became a longlasting craze that only dipped when hurricane-caused gasoline prices shot up and stayed up for a few years. People were buying scooters to (allegedly) use instead of driving automobiles. (Didja notice that when gas prices decreased, there were fewer people commuting by scooter? Hmm.)

During the mortgage crisis, dealers began drastically cutting prices on SUVs, and then began the frenzy to snatch a bargain, at least where we lived. I had a hard time believing how many people bought large guzzlers during that time.

Then gas prices dropped ridiculously low. Seems people had become too broke to take as many long road trips.

We had kept our at-that-time 12-yr-old SUV through all the ups and downs, and we still have it now. (It was not a daily driver, so mpg was less important.) Someone we knew had made many pointed, politically-driven comments about it, but…when gas prices dropped below $3/gal, suddenly he wanted us to take him skiing, using the SUV. He also asked if we would tow or carry a scooter for him. I refrained from pointing out that no matter what the price of gas was, the mpg and emissions were still the same, and why was it “greener” to drive to the ski resort just because gas was cheaper?

Would you buy something more expensive if it is better for longterm health of the planet? That’s worth asking.


Yes, and I have done that in the past as well.


Me too. Though it’s hard.


I tend to agree but there is a lot of room for nuance here.
Burning anything is tied intimately with CO2 production. And we all burn stuff - from wood stoves, to furnaces, water heaters, electricity from fossil fuel fired power plants. Burning less of it saves both money, non-renewable resources, and CO2 emissions. However valid or spurious the arguments, its logically the right thing to do.

We figured energy resources, however large they may be, are in the end finite. Our capacity for energy consumption is, and will always be, infinite. (So the sooner we start switching to renewables, to the extent we can, the better off we’ll all be, both to extend our stores of non-renewables, lower our long-term costs, and to cut our emissions.)

Often people (possibly even myself… :wink:) do the right thing, the thing that works for the benefit of all, for less than purely altruistic (and this is a matter of opinion rather than strict fact) reasons. I believed, and still believe, that what we were doing back then was a worthy endeavor and I think its tragic that we haven’t continued on the path that was established during the Carter years. But I confess I also had the feeling that I was like an electrician who got in on the ground floor during rural electrification. And I wouldn’t have objected to pay raises, some job security, and a pension plan should they be offered. It wasn’t pure altruism. But all that’s gone now - a pretty dream I once had.

But heck, even while we were installing those solar systems (BTW, mostly hydronic domestic hot water in those days) we went to and from those jobs in pretty sizable trucks that got pretty poor fuel economy. I suppose we could be accused of hypocrisy for doing so. But we burned less fuel in one trip with those large gas guzzling trucks, and took less time, than hauling the requisite quantities of pipe, plumbing fittings, storage tanks, etc in multiple loads with smaller more fuel efficient trucks. And It takes energy to mine and smelt the copper pipe and the aluminum that those systems were made of. Glass manufacturing isn’t without energy costs and the associated emissions either. But I still can’t bring myself to think of that we were doing as exactly hypocritical, though there was energy expended and the associated emissions weren’t trivial.

Perhaps this is some sort of rationalization, but we figured that if we spent some fuel installing a system that paid for itself in four years, heated water that would otherwise require two or three thousand watts of electricity (or its equivalent in gas) for 75 watts, and had an operational life expectancy of 75 years, it was a pretty good trade off.

PS: Photovoltaics and wind machines both came in at about a 12 year pay off back then - and wind machines had maintenance requirements, photovoltaics a shorter useful life.


So humans cause global warming and global warming causes extinctions. Fewer humans equals less warming. Humans have evolved to breed and breed and breed.

You suppose there’s any chance we could control our numbers… without killing one another?

EDIT! I see killing one another as a very BAD thing. Something to be avoided.

(I’m just a soul whose intentions are good. Oh lord, please don’t let me be misunderstood)


Yes for populations, based on an least two pieces of evidence. The first is the population predictions that castaway shared in the other thread.

Second is the often made correlation that as the standard of living improves people have fewer children, which is probably the driver for the above.

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Are you arguing we should allow global warming to lower human populations as a means to lower global warming?

The answer to that is yes and goes back more than 100 years. The term is Eugenics and at one point in time was widely held. As an example the founder of Planned Parenthood Margaret Sanger was a true believer in the process. Much has been written on her and others desires to just not control populations but to remove undesirable traits from the population. Planned Parenthood has finally stopped denying their beginnings and you can read their take on it on their web site under “Our History”

Soylent Green was of course fiction, and in 1972 seemed pretty far out there.

In 2023 only a year after the time the movie was staged to take place in we have technologies now to do such things if say someone was to release a novel virus on the world novel being a virus that has never been found in humans. If such a virus or combination of viruses was altered in such a way to effect male fertility then population growth could be slowed. It sounds now that pandemic could be created that genetically could avoid spreading to some races and not others. This would be a way to target and slow population. Of course if you wanted a more aggressive method you would tailor the virus to not say kill 1% but make it 50%.

This is scary stuff maybe more scary than climate change to me. This is what I was saying the other day when I said often the cure is worse than the disease.

People you wouldn’t think about like George Bernard Shaw the playwright of My Fair Lady believed in eugenics and ridding the population of older or useless people that consume more than they produce. Here is a snippet of him talking about it.

Not sure what eugenics has to do with any of this. Fortunately, science advances and thinking evolves. The Earth is neither flat nor the center of the universe. Mice do not spontaneously generate in a box of wheat and scraps of fabric. Young women are no longer executed for witchcraft in Massachusetts.
One thing that has been consistent around the world: When women are accorded equal access to education, the birth rate drops.