Emissions of banned, ozone-depleting chemical CFC-11 have climbed 25% since 2012

Can't say if it is just cheaper, but it is more efficient. It has a high boiling point, so you don't need as high of a pressure. That means can design the installation with less tolerances, not as powerful of a compressor etc.

Moreover if you already have setup that works, you don't have to spend money to retrofit it.

Maybe you people are the ones Feynman was criticising? He certainly wasn't hard on ignorant people looking for answers, he was hard on smart arrogant people who thought they couldn't be wrong.

>chlorine and bromine reactions to produce the ozone hole in Antarctic springtime

Why isn't chlorine and bromine considered just as bad as CFCs, if they are in fact the chemicals causing the problem?

>...most of the emissions occur in the Northern Hemisphere."

>...winds and convection redistribute and mix air efficiently throughout the troposphere on the timescale of weeks to months*

The paper indicates that there's an equal amount of these gases all over, and that they _aren't_ congregating at the south pole.

Yet, go read the comments on this board, so many people that shout me down don't seem to know this. It's incredible how so many "smart" people are convinced of something, and get raging mad when questioned. Is it because they believe it without actual proof, or haven't researched it thoroughly themselves?

>Stratospheric air motions then transport these gases upward and toward the pole in both hemispheres.

One guy here claimed it was "mountains" that moved the air. Which is silly, because of all kinds of reasons, the least of which is that mountains would only cause a localized updraft, not a planet wide updraft.

I am starting to think HN is fully of "true believers" that will hunt anyone down for questioning anything at all.

There are references in this document to other sources that are not included here. And obviously to question many scientists work these days is tantamount to blasphemy regardless.

>Once formed, PSC particles fall to lower altitudes because of gravity.

Why does gravity affect one type of element but not others?

>The most common source of CFCs are refrigerants, but fire suppression systems for aircraft and aerosols also emit CFCs into the atmosphere.

https://sciencing.com/sources-cfcs-8405334.html

How much CFCs in the air does it take to create a hole _and_ maintain that hole for decades? This is almost where every discussion from the effects of homelessness, government budgets, wars, etc... all fall apart. No one has any real numbers. It's all "guessing", yet we are "certain" enough say "don't you dare question the orthodoxy".

>"...the highly reactive chlorine gas ClO remains chemically active for a longer period, thereby increasing chemical ozone destruction."

51.4524 g/mol Chlorine Monoxide, ClO (The CFC gas from the article)

70.9056 g/mol Cl2 (mustard gas)

44.0095 g/mol Carbon Dioxide, CO2

14.006747 g/mol Nitrogen, N

18.01528 g/mol Water, H2O

Again, I am an ignoramus, but ClO looks to be quite a heavy gas. Cl2 stayed in the trenchs in WWI, carbon dioxide is heavy enough to pour like "water".

Yet the claim is that PSCs (which are made of water) "fall from gravity" yet their molar mass in a fraction of the other gases. Again, I think it's possible to have every gas everywhere. But a single gas 4 times heavier than something that "gravity" pulls from the sky, stays up in air for months wreaking havoc?

That was the lesson I was taught yes. But consider how much scent would have to be released to smell that same smell for 70 years, across the whole planet.

I've read some articles on this linked here, and I see that there are many claims about what is happening, but in one PDF linked above this statement was made.

>The role of PSC particles in converting reactive chlorine gases to ClO was not understood until after the discovery of the Antarctic ozone hole in 1985. Our understanding of the chemical role of PSC particles developed from laboratory studies of their surface reactivity, computer modeling studies of polar stratospheric chemistry, and measurements that directly sampled particles and reactive chlorine gases, such as ClO, in the polar stratosphere"

I get that science has to extrapolate effects, because they simply can't sit in the sky and test the air all day long, it's not possible. But go look through history, how many times have scientists thought they understood something until later they changed their minds when more data was available.

Note the source and timing of the ozone hole discovery:

>* Joe Farman of the British Antarctic Survey discovered the Ozone Hole in 1984"

https://en.wikipedia.org/wiki/Dobson_ozone_spectrophotometer

Within 1 year of discovering the "ozone hole" they had an answer that hasn't changed to this day, based on computer modeling from the 80s.

>*Total ozone was lower in these months [in 1984] compared with previous observations made as early as 1957."

https://www.esrl.noaa.gov/csd/assessments/ozone/2010/twentyq...

We have a record of only 27 years of likely minimal data (from what I have read, no one was looking for a hole) where a difference was only discovered at the end of this data set, to which all the conclusions we have now are based. And everyone replying to me is saying this is absolutely settled science? No room for questioning this at all?