I believe ozone depletion reduced between 2015 and now, so we're back to headed in the right direction. While much of the world adhered to the CFC ban, China had a brief resurgence of usage that created a temporary increase in depletion.
It’s not. The ozone issue is very much improved. But there are also plenty of things that affect ozone coverage so it doesn’t “get better” by a steady state percentage each year in a straight line.
> it doesn’t “get better” by a steady state percentage each year in a straight line
It sort of does [1]. The Antarctic ozone layer should recover to 1980 levels within 50 years.
As of 2022, "the overall concentration of ozone-depleting substances (ODSs) in the mid-latitude stratosphere had fallen just over 50 percent back to levels observed in 1980, before ozone depletion was significant" [2]. It should recover to 1980 levels by 2050 [3].
(1) The ozone molecule is O3 and is
unstable so we can have the reaction
2O3 --> 3O2
where ozone returns to just ordinary
oxygen.
(2) Ozone can be generated by sunlight in
the reaction
3O2 --> 2O3
(3) For ~6 months of each year, Antarctica
gets nearly no sunlight.
(4) For ~6 months of the rest of the year,
Antarctica has sunlight for 24 hours a
day.
Soooo, for about half of each year
Antarctica generates ozone and for the
rest of the year "depletes" ozone. We
expect this.
(5) Ozone absorbs UV (ultraviolet)
radiation from the sun. UV radiation can
cause skin cancer.
Apparently some laboratory experiments
have confirmed that CFCs
(Chlorofluorocarbons) speed up the
depletion reaction.
It might take careful, difficult science
to say in kilograms how much ozone is
depleted by how many kilograms of CFCs and
how much in Watts and percentage UV
results.
I am unsure about such careful, difficult
science.
But I am fully sure about some people
forming quasi religious, fanatical,
extreme, unscientificmovements based
on claims that greedy, irresponsible, evil
humans are destroying the delicate, pure,
pristine, fragile planet we need for human
life and, in the process, getting
publicity from the media and money and
power from political systems. Since the
media likes to get eyeballs, ad revenue,
and influence by writing stories about
evil and disaster, we get stories about
ozone depletion -- to me such stories have
low credibility. No surprise since to me
the media fails even common high school
standards for term papers and has very low
credibility -- worse than just "low
credibility" since I have to conclude that
commonly the media is trying to trick,
fool, deceive, and lie to me, do me harm,
etc.
As we have seen in the US, the media
stories can result in money and power from
the political systems. The stories are
old, go back at least to the claims of
Chicken Little that the sky is falling and
... to the Mayans who killed people to
pour their blood on a rock to keep the sun
moving across the sky [1].
In short: There is ozone depletion over
Antarctica? No surprise since for ~6
months of the year, Antarctica gets nearly
no sunlight. What about ozone depletion
over the US, e.g., likely the largest
source of CFCs? Somehow the CFCs from the
US generate legs and run ASAP down to
Antarctica? And, no, I won't send all my
money now or vote for some politician who
wants to give money and power to protect
ozone in Antarctica.
[1] Susan Milbrath, 'Star Gods of the
Maya: Astronomy in Art, Folklore, and
Calendars (The Linda Schele Series in Maya
and Pre-Columbian Studies)', ISBN-13
978-0292752269, University of Texas Press,
2000.
And furthermore https://earthobservatory.nasa.gov/world-of-change/Ozone with an animated plot of ozone concentrations. Please note the dates at each step, and how they correspond to the "Minimum Ozone / Minimum Daily" chart on the page I linked to in my previous paragraph.
> I am unsure about such careful, difficult science.
That's fine, and in general a pretty good policy. In this case seems to me that your reasoning is something like "this sounds complicated, my ideological enemies are endorsing the result, therefore it must be fundamentally flawed or irrelevant," That's a common enough stance, but in general I don't think it's particularly wise.
When it is late summer in the northern
hemisphere, e.g., August, it is late
winter in the southern hemisphere and
Antarctica with some months of low
sunlight. Indeed, winter in Antarctica
can mean some days of 24 hours with no
sunlight. So, with no sunlight we don't
get the reaction
3O2 --> 2O3
that makes ozone but do continue the
reaction
2O3 --> 3O2
that sees unstable ozone convert back to
oxygen. Similarly for low sunlight.
Soooo, we get an "ozone hole".
We agree -- no surprise.
But in this case, in this Hacker News
thread, the main issue was the effects of
CFCs (Chlorofluorocarbons). As I recall,
some laboratory studies showed that CFCs
can speed up the reaction
2O3 --> 3O2
that destroys ozone. Maybe my memory is
correct that there was a Nobel prize for
that result.
Sooo, okay, CFCs contribute to ozone
holes.
Then a question is, how much? How much do
CFCs contribute to ozone holes? I.e., 1
kilogram of some CFC destroys how many
additional kilograms of ozone per day
causing how many additional Watts of UV
(ultraviolet) light hitting the ground?
And what is the increase in percent?
Uh, and maybe what is the stochastic
process of ozone concentration considering
solar flairs, sun spots, the standard 11
year cycle of sun spots with or without
CFCs?
I remember ozone -- it has a distinctive
odor. As a child I had an electric train,
and sparks from its electric motor
generated some ozone, enough to smell.
But the ozone didn't last very long, e.g.,
was gone within a few minutes, certainly
in less than an hour, of stopping the toy
electric train. Uh, I just looked it up:
Google search
"half life of ozone in air"
yielded
"Under normal conditions, the half-life of
ozone indoors is between 7 and 10 min and
is determined primarily by surface removal
and air exchange. ..."
Point: Ozone is unstable and doesn't last
very long. So, I can believe that with 24
hours a day of low or no sunlight over
Antarctica, the ozone doesn't last very
long, with or without CFCs.
Uh, but with low sunlight, there is little
UV to cause skin cancer, whatever the
ozone concentration!
So, to get concerned about CFCs and an
ozone hole in August (late winter after
some months of low or no sunlight) over
Antarctica, I would want a good actual
scientific answer to the question of how
much?
For the media, much of the media I don't
like. I've had decades where I concluded
their content is usually (a) without
credibility and (b) deliberately
deceptive.
While I like entertainment, mostly what I
want from the media is credible, relevant
content. The deliberately deceptive parts
I won't accept or excuse.
Maybe you suspected that I am angry with
much of the media -- that would be
correct.
I know something about writing credible
content: I hold a Ph.D. in applied math
from a world famous research university,
have published peer reviewed papers of
original research in applied math,
statistics, and artificial intelligence,
have taught at Indiana University, Ohio
State University, Georgetown University,
while at IBM's Research division gave
talks at Stanford, Wharton, etc. The
paper in applied math was on the
Kuhn-Tucker conditions but also solved a
problem stated but not solved in a paper
by Arrow, Hurwicz, and Uzawa -- Arrow won
his Nobel prize in economics long before
and Hurwicz won his more recently and
separately.
An analysis is that the media wants to
make money and to do this pursues some old
techniques of journalism that involve
fooling people, grabbing them emotionally
by the heart, the gut, and below the belt.
Such journalism is not nearly new: E.g.,
there is a movie from ~1941 Meet John
Doe about a newspaper getting several
months of twice as much circulation from a
continuing but fake story about a John
Doe committing suicide. Of course the
reason there could be a movie about fake
news is that the movie audience knew
enough about journalism to accept that
fake news was common. There was also
yellow journalism. And tabloids.
Etc.
Of course, the technique of getting
attention, power, and money by scaring
people with threats from evil is much
older even than fake, deceptive
journalism, goes back 2000+ years --
apparently it's part of human nature and
society, but we can try to fight it with
good judgment, science, insisting on
credible content, and rejecting fake
content.
So, people who want to create political
movements and, thus, get money and power
have natural colleagues in fake journalism.
And, indeed and specifically, for CFCs,
there was a movement with the media and
politics: Due to the media touting
threats to ozone, CFCs were actually
outlawed.
So, when I look at claims of threats of
CFCs causing a worse ozone hole I see two
possibilities: (1) As loudly claimed by
some of journalism, CFCs make the ozone
hole significantly worse and, thus,
contribute significantly to skin cancer in
the southern hemisphere. (2) We have no
good scientific evidence that CFCs
contribute significantly to either ozone
holes or skin cancer, and the claims of
threats are fake journalism trying to make
money by grabbing people emotionally by
the gut.
> So, when I look at claims of threats of CFCs causing a worse ozone hole I see two possibilities:
This is exactly what I mean, you've decided that 'the media' is your enemy and therefore any claims they make or report can be attacked and demolished without actually trying to understand what they're actually saying.
> Maybe my memory is correct that there was a Nobel prize for that result.
More of the same. Have you never once for a moment thought 'Huh, surely they wouldn't have given a Nobel Prize in Chemistry for something as basic as "CFCs speed up this reaction," maybe there's something to this atmospheric ozone thing' ?
Do you think the Nobel Prize Committee (Chemistry) was bamboozled by "the media", or do you think they were in on it? Are there any other Chemistry prizes in the last few decades that you would put in the same category
> I hold a Ph.D. in applied math from a world famous research university, have published peer reviewed papers of original research in applied math, statistics, and artificial intelligence, have taught at Indiana University, Ohio State University, Georgetown University, while at IBM's Research division gave talks at Stanford, Wharton, etc. The paper in applied math was on the Kuhn-Tucker conditions but also solved a problem stated but not solved in a paper by Arrow, Hurwicz, and Uzawa -- Arrow won his Nobel prize in economics long before and Hurwicz won his more recently and separately.
Were you expecting me to be impressed? I've also got a PhD in mathematics, and in the years since I've met literally hundreds of mathematicians with better careers than this.
(1) Yes, there is ozone in the atmosphere
of the southern hemisphere, and the
concentration of the ozone varies with
month of the year and altitude.
(2) The ozone is created by ultraviolet
(UV) from the sun.
(3) Ozone converts back to oxygen via
2O3 --> 3O2
(4) When it is late summer, August, in the
northern hemisphere, it is late winter in
the southern hemisphere with some months
of much less sunlight, so little that many
days go 24 hours with no sunlight. Thus,
by August ozone has been converting back
to oxygen as usual; ozone creation has
been way down; and, no surprise, there is
an "ozone hole" over Antarctica.
(4) CFCs (chlorofluorocarbons) do cause
destruction of some ozone. I see:
> Increased levels of human-produced gases
such as CFCs (chlorofluorocarbons) have
led to increased rates of ozone
destruction, upsetting the natural balance
of ozone and leading to reduced
stratospheric ozone levels. These reduced
ozone levels have increased the amount of
harmful ultraviolet radiation reaching the
Earth’s surface.
All of this is just as I claimed.
And the reference does not answer the
crucial, central question I asked, "how
much", how many kilograms of CFCs are
destroying how many kilograms of ozone per
day and, thus, letting how many Watts of
UV radiation reach Antarctica, and what
are the effects in percent of ozone and UV
radiation?
So, that reference does not give credible
scientific data that CFCs destroying ozone
are a threat.
And there are hints in the text there that
my concern is appropriate, that is, ozone
concentration varies:
> Uh, and maybe what is the stochastic
process of ozone concentration considering
solar flairs, sun spots, the standard 11
year cycle of sun spots with or without
CFCs?
Thus, 100% of my claims are supported by
the reference, and, net, we are left with
no credible scientific evidence that CFCs
are a threat.
And the reference did not claim, as you
did, that the Nobel prize is good evidence
that the CFCs are a threat.
> This is exactly what I mean, you've
decided that 'the media' is your enemy and
therefore any claims they make or report
can be attacked and demolished without
actually trying to understand what they're
actually saying.
No, you are wrong: Maybe the media is my
"enemy", but I'm setting that aside and
paying attention just to the media claims
that there is an ozone hole. Of course
there's an ozone hole -- so what? The
media has been claiming that there is a
threat from CFCs, but they didn't make
their case: The situation and the
standards and criteria for making a case
are simple and old: If the media wants to
claim that there is some threat, then they
need to follow at least common high school
standards for term papers -- e.g.,
references to primary sources.
> actually trying to understand what
they're actually saying.
What they are "actually saying" has low
credibility, e.g., is just not solidly
rational. Again, for a creditable case,
rational, scientific, detailed, they just
didn't make it or give references to such
a case.
I outlined what would be part of a
credible case -- from 1 kilogram of some
CFC, how many kilograms of ozone and how
many Watts of UV ....
> for a moment thought 'Huh, surely they
wouldn't have given a Nobel Prize in
Chemistry for something as basic as "CFCs
speed up this reaction," maybe there's
something to this atmospheric ozone thing'
Yes, maybe there is "something", in which
case the media claiming a threat needs to
make a case, give the "something", or at
least give some good primary references.
For
> surely they wouldn't have given a Nobel
Prize ...
That's not good evidence that CFCs cause a
significant problem. If there is good
evidence, then give it.
> Were you expecting me to be impressed?
No, not at all. My purpose and claim were
clearly stated right at the beginning of
the paragraph:
> I know something about writing credible
content:
For your
> I've also got a PhD in mathematics, and
in the years since I've met literally
hundreds of mathematicians with better
careers than this.
Irrelevant. Apparently you mean a
"better" "career" as an academic, research
mathematician.
Actually, I never once, not even for a
nanosecond, ever had any desire to have a
career in academics or in research
mathematics.
My main reason for going to graduate
school was simply the old idea that a
better education would lead to a better
job; academics was not such a candidate
job. Since this idea seemed to work for
my father, I tried it.
The Indiana University teaching was as a
graduate student. For the three courses
they had me taking, two of them were
beneath what I'd done in college, and the
third was by a prof who was ready to fail
me until I read my solution to him and he
saw that my solution was correct and one
step shorter than his. He was nasty to me
for no good reason. I never saw him
again.
There were some topics I wanted to study
in math and physics, but the best way was
just to get a job and study on evenings
and weekends.
Then I got strongly recruited for work in
math, physics, and computing for US
national security near DC and also did
well in much of the independent study I
had in mind. And I got into scientific
computing -- Assembler, Basic, Fortran,
Algol, PL/I, numerical analysis,
statistics, the fast Fourier transform,
digital filtering, phased arrays, lots of
algorithms, etc.
At Georgetown I was hired into the
computing center. I did too well and
scared the head of the center. Then the
university needed someone to teach
computer science so gave the job to me.
Then I helped start FedEx -- with some
computing and applied math, saved the
company twice. The promised stock was
late, and I was commuting from DC where
my wife was in her Ph.D. program. So, I
got a Ph.D. Just as a reading course,
in two weeks I did the work on the KTC.
Mathematical Programming wanted my Lemma
to be named a Theorem, and I didn't get
around to fixing that and publishing until
much later. While I've published some
papers, I am not now nor have I ever been
at all interested in publishing anything.
I took the job at Ohio State so that my
wife, who suffered in graduate school,
could be near her home and family farm.
I had 0.000 interest in the academics.
Now I'm doing what I always should have --
I'm an entrepreneur doing a startup. The
foundations are some math, computing, and,
now, the Internet.
Again, I don't want a career in math --
never did, still don't. At times, some
math did me some good in school: My math
SAT scores and the GRE math score were
good enough to damp down nasty politics,
get people out of my way, and open
doors. Some of the independent study I
did let me blow away the rest of the
students -- I was best in the department
on 4 of the 5 Ph.D. qualifying exams and
for the 5th had already written the first
draft of my Ph.D. dissertation. There was
a LOT of nasty politics. The thing I did
with the KTC beat down nearly all the bad
politics, eased my path through my Ph.D.
Somehow doing something independent and
publishable in a good journal in two weeks
was a magic wand. Silly.
Instead of publishing papers, I want to be
successful in business.
In my brother's side of my family, there
are three kids. I give them little
encouragements to know some math and
science but NO WAY would I encourage them
to try for an academic "career".
Again, once again, over again, yet again,
one more time, my background in math was
to support my claim
> I know something about writing credible
content:
in particular to critique the media claims
that CFCs are a threat. To me their
claims are not what I regard as "credible
content".
