> Hence, ozone loss during rapid warming is an inherent Earth system process with the unavoidable conclusion that we should be alert for such an eventuality in the future warming world.
Did not know this worrisome hypothesis. The idea that a warming world could inject more reactive material into the stratosphere via convective storms seems reasonable. Thanks a lot for one more reason not to sleep tonight.
Fixing the ozone layer is far easier than moving a substantial of the earth's population off-planet. The total amount of gas is not extreme, which makes it so delicate but also means that we may be able to artificially manage it.
I'm not sure what you are saying here. What this paper is saying is that at some point the planet (before homo sapiens) had an "event" of some sort that basically removed the ozone layer and killed off most of what was living on the surface.
People don't have a mechanism to "inject ozone" into the stratosphere (we count on the Sun to do that) so if it were removed again, we would all likely die.
Similarly, at least one extinction event was due to volcanism, another thing we puny humans have no means to control (as much as I would love to be able to).
It is not disloyal to the global warming cause to acknowledge that there are things that we aren't responsible for that could kill us too.
Even if the Earth loses all its ozone we would still be more protected here than anywhere else in the Solar System. So any solution you come up with for, for example, living on Mars would work here as well and be cheaper. If you live in shelters covered in 2 meters of dirt on Mars, you could do that here too and not have to generate oxygen to breath.
People don't have a mechanism to "inject civilization" into Mars either. Pushing massive quantities of ozone into the stratosphere sounds solvable in a year or two, since we already know how to make it. Making a self-supporting Martian colony is a multi-generational project that we can't even begin yet. Let's do it, but these other threats are going to be extinction-level for a long time.
This is not a high profile paper. The accompanying domain to this post is (unintentionally) misleading: the actual journal that this paper is published in is ’Science Advances’, not ’Science’ (the prestigious one).
I thought there was something funny about the abstract...most abstracts in high profile journals have a much different tone.
The underlying dataset is fascinating and supports the UV-B damage hypothesis while also falsifying the mega-volcano hypothesis. It took a great deal of Wikipedia research for me to get a feel for the paleo geography and paleo climate of East Greenland 359 Mya. The “warming causes ozone collapse” meme seems aimed at gaining media attention but that tactic seems to be the norm now in scientific papers.
Sometimes the curation role of a journal is important and peer review can identify errors. In this case it seems like access to the right geological formations by competent scientists is key and I read nothing in the paper made me question the science. I don’t think the lack of journal prestige diminishes the significance of this specific paper; it probably reflects the modern relevance of this extinction event.
Both 'Science' and 'Nature' have prestige, but people get confused because same domains are used for multiple journals.
Open access journals like Advances or Nature Communications are not that bad, but Nature Scientific Reports is horrible.
It's very low impact journal with minimum review. It's intended to be place for grey literature where technical reports and scientific reports with no importance go. Unfortunately it has started to publish junk science too. Those pieces get posted into HN frequently. All that happens under nature.com that makes them seem legit.
This is not entirely true. It has a low impact, but is still reasonable. Nature Scientific Reports is still published by nature and does peer review. Granted the content is not on the level of nature itself.
They are supposed to do very light peer review just trying to check if the article is technically sound. Apparently even that review process is broken.
Technical soundness is not light peer review. It's the core of peer review. Everything else is editorializing and selling "importance".
As a matter of fact you can get plenty of crap into the higher tier Science/Nature journals if you just tell a good enough story about importance. You can leave the real work to disentangle whether the story is true to others that can publish in lower impact topical journals.
Generally speaking I believe Science and Nature, and the role they occupy in academia, are a major problem for science. They are huge contributors to overselling and hype driven research.
This domain name issue also comes up with PubMed, which uses the nih.gov domain, making people think it's actually endorsed by NIH.
I think it's not just a problem on this website; social news link previews also show the domain and favicon which might mislead people as to how high-profile the paper is.
of course, being in a high-impact journal doesn't guarantee good science at all. but it still does lend some credibility.
PubMed looks pretty much like an official publication of the NIH to me:
“Available to the public online since 1996, PubMed was developed and is maintained by the National Center for Biotechnology Information (NCBI), at the U.S. National Library of Medicine (NLM), located at the National Institutes of Health (NIH).” [1]
the website itself is, but it aggregates journal articles which are not. there are a lot of academic journals with very low standards for peer review, but PubMed doesn't make any editorial choices.
That's the ref in the paper. It's a bit confusing because they're looking at chemical processes taking place at 15-20km altitude. Temps there are around -55C maybe, 200K).
They plot changes for activation of the process, but I don't have enough knowledge about it to understand the implications. The bottom axis of their graph runs from 195K - 210K though so clearly it's not a big delta. They seem much more interested in the amount of water vapor at altitude.
The other thing is that it seems like the process has a fairly short cycle time. By which I mean they mention changes on the order of days. When I think about ozone holes I think mainly in the context of decades.
So I'm not sure how much the mention of warming and ozone loss in the OP paper was a 'hey that might be of note,' or was a more substantially linked relationship.
(I kind of wonder if pole reversal/magnetic field weakening or solar events could play into the loss of ozone during the extinction in the original paper?)
The paper makes this statement at the end:
Last, we emphasize that because chlorine ac-
tivation depends exponentially on water vapor
and temperature, and in turn that the forcing of
climate may well control the convective injec-
tion of water into the lower stratosphere, the idea
that ozone “recovery” is in sight because we have
controlled chlorofluorocarbons and halon release
is a potential misjudgment.
Ok so I think the parameter you want to be looking for is the temperature (not necessarily at altitude) that results in some particular amount (ppmv) of water vapor at altitude. With the understanding that the hotter it is at altitude the worse the mechanism is for ozone.
I'm wondering how modern species would be differently vulnerable to a similar UV challenge. The paper specifies the evidence they found and a mechanism being DNA corruption in plant spores which were very exposed – well today most of those plants (like all sorts of ferns) are extinct and replaced by flowering plants with their much hardier seeds.
The lifecycle of ferns is a bit exotic and familiar.
It's classified as alternating between two generations, the one which produces the familiar large plant, and one that produces tiny plants.
It's something like "sexual reproduction with extra steps".
The fern chops its genome in half and produces spores with these haploid genetics. The spores grow into tiny plants (< 1 cm) which grow leaves and roots and then produce the sperm and/or eggs (the sperm actually swims to the egg!) which fertilized, grow into a new familiar fern.
In flowering plants, seeds are the result of fertilization which happens in the plant, they're bigger, contain food, and protective shells. The living cells which carry life are hidden inside. Pollen is a bit like a spore in that it's tiny and contains haploid genes, but still I'm guessing that process of reproduction is considerably more durable to increased UV.
Oh hey, another bad thing to worry about happening in 2020.
But it's a cool paper. It would be interesting to see if they can find more instances of this sort of damage over various, widely space geographic areas. And especially in other species/other external signs of UV damage.
Even though they do analysis to try to eliminate other possible explanations, I'm not sure I'm super on board with immediately accepting the UV/ozone explanation whole sale. I always like to see bets hedged with "lends further evidence to support...." language.
I'd also love to hear from anyone with domain knowledge that might be able to add their perspective on the paper.
I have searched for, but been unable to find, a chart of estimated UV levels at ground level over the past few hundred years.
I'm interested in it because suntans seem so much worse now than in the past, where people didn't have access to suncream, yet still spent lots of time outside.
"I got used to it by spending my whole life outside" doesn't seem to fully explain it.
I don't know if they even have that data for that length of time. You might find some info in literature regarding the difference in UV exposure in areas under the ozone hole vs areas of more normal exposure.
As an aside, don't get misled by nutters talking about ground level UVC levels. They don't know what they're talking about and are citing people who don't know how to use their UV-C meters (which are sensitive at wavelengths other than UVC and therefore require extensive filtering).
Further edit: I should mention total solar irradiance has remained relatively consistent over time (and continues to). I bring up these things because I've talked to some nutty people about this stuff in the past and those are common stepping off points into la-la land.
>I should mention total solar irradiance has remained relatively consistent over time (and continues to).
It should be noted that the 11-year solar cycle is much stronger in the shorter wavelengths, especially below 200nm. Since that is absorbed in the ozone layer there is a change of up to 2K max in the stratopause (~50km). It doesn't really appear to propagate down, and is rather on the level of a scientific curiosity, but still. [0] (Longer-term changes than the 11-year oscillation seem to be much lower, but this is hard to determine.)
If you want to have information about UV at ground level you can look at proxy data. [1][2][3]
Of course there are some complications with that as always though, and it's not that easy to interpret.
But it looks like while there is variation it is mainly along the 11-year cycle. (I can't say much about the strength of the change on ground level without further reading. It's in the low percent range on top of the atmosphere, but almost all of that will be stopped in the ozone layer.)
Hopefully this time we'll be able to geoengineer our way out of it. I would think pumping out tons of ozone is significantly easier than removing atmospheric CO2 or, you know, burning less carbon(how absurd, right?).
> I would think pumping out tons of ozone is significantly easier than removing atmospheric CO2 or, you know, burning less carbon(how absurd, right?).
That reminds me of the Simpsons episode where they bring in a serious of increasingly more absurd animals to deal with a small invasive species they find.
Oh, we can already build planes that use high-efficiency propellers (with efficient and lightweight gear-less axial flux motors) and soar above the clouds 24/7, using height instead of batteries and ultra-light back-ground solar cells laminated into a giant flying wing (or at least much more wing than fuselage, because the motors should be distributed to reduce demands on wing stiffness). A weight of less than 2.5kg/m^2 in the wing should be feasible with large, monolithic carbon fiber sections, joined by narrow engine segments. Overall it should be possible to stay below a wing loading of 5kg/m^2, so a 100m span, 1m chord 500kg plane gets about 18h out of 10km height, see https://www.rcgroups.com/forums/showthread.php?2601411-Is-wi... .
Don't ion drives have ozone as a side-effect? Balloons with solar-powered ion drives might do the trick then - they don't even need to be lighter than air, the ion drive should give it enough thrust
> But you have to avoid generating nitrogen compounds
What if we reverse the polarity on the main deflector dish.. I mean emitter wire?
> The effect is not directly dependent on electrical polarity, as the ions may be positively or negatively charged. Reversing the polarity of the electrodes does not alter the direction of motion, as it also reverses the polarity of the ions to match. Thrust is produced in the same direction, either way. For positive emitter polarity, nitrogen ions are the main charge carriers, while for negative polarity, oxygen ions are the main carriers and ozone production is higher.[citation needed]
Actually spark gaps are less efficient than corona discharge. Usually ozone generator just apply high electric field to plates and run air/oxygen through it.
Now I'm curious what the energy efficiency of this process is.
I wonder if the rarefaction at that altitude makes it easier or more challenging.
Did not know this worrisome hypothesis. The idea that a warming world could inject more reactive material into the stratosphere via convective storms seems reasonable. Thanks a lot for one more reason not to sleep tonight.