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Ozone: The Earth's protective shield is repairing (bbc.com)
247 points by pseudolus 14 days ago | hide | past | web | favorite | 121 comments

If only we could get such swift global action on greenhouse emissions. Both problems are essentially the same yet the difference in action couldn't be wider.

One of the significant differences is that in the 1980s when the issue of ozone depletion was being confronted, politics was not as polarized. One of the great successes of those arguing for action was recruiting Conservative British Prime Minister Margaret Thatcher, a trained chemist, as an advocate


There is another major difference:

Fossil fuels contribute a lot of energy to the needs of people and organizations. Solar and wind will take time to take over the infrastructure. CFCs on the other hand could be much more easily replaced.

That's the key part. What CPC case teaches us, is that if we could find a good alternative to Fossil fuels, we could likely eliminate their use.

We have a good alternative. France produces ~80% of its electricity with nuclear power.

Transportation makes up 25% of the carbon emissions worldwide.

Cows make up like 8%.

The US military is the world's largest polluter. Most of their most serious crime against the environment is detonation of nuclear warheads.

Here are citations to my numbers (since I seem to be downvoted):

* Transportation: 28%


* Livestock is 14.5% of all GHG emissions, cows are 65% of that:


* Stories on how the US Military is the world' biggest polluters:




Regarding specifically my nuclear detonation comment:


In addition, the U.S., which has conducted more nuclear weapons tests than all other nations combined, is also responsible for the massive amount of radiation that continues to contaminate many islands in the Pacific Ocean. The Marshall Islands, where the U.S. dropped more than sixty nuclear weapons between 1946 and 1958, are a particularly notable example. Inhabitants of the Marshall Islands and nearby Guam continue to experience an exceedingly high rate of cancer.

The American Southwest was also the site of numerous nuclear weapons tests that contaminated large swaths of land. Navajo Indian reservations have been polluted by long-abandoned uranium mines where nuclear material was obtained by U.S. military contractors.

TLDR: there's more to greenhouse gas then pollution from power plants. And nuclear power isn't problem free.

Slight correction:


> All of agriculture accounted for a total of 9 percent. All of animal agriculture contributes less than half of this amount, representing 3.9 percent of total U.S. greenhouse gas emissions.

> To its credit, the FAO immediately owned up to its error. Unfortunately, the agency’s initial claim that livestock was responsible for the lion’s share of world greenhouse gas emissions had already received wide coverage.

Thanks, I didn't know of that error. I wish they'd fix the original report!

Cows just confuse the issue though since they’re mostly producing methane which although a ghg doesn’t stick around too long.

Methane is far more potent as a greenhouse gas

And the best case scenario is burning it somehow in which case it just has a CO2 byproduct

Weirdly, burning methane gives you both energy and decreases its carbon footprint by ~30x (the mole ratio is 1:1).

Methane decaying just means the atmospheric concentration doesn't increase as fast. But if you emit more than the previous year then levels will go up. And indeed, levels are currently 3 times what they were from pre-industrial levels [0].

The EPA says its Global Warming Potential over 100 years is 28-36 times CO2 [1]. 100 years sounds like a very relevant time period to me.

[0] https://en.wikipedia.org/wiki/Atmospheric_methane#Patterns_o...

[1] https://www.epa.gov/ghgemissions/understanding-global-warmin...

I hadn't heard that methane didn't last too long in the atmosphere before. What happens to it?

The UV part of sunlight breaks it down into CO2 and water. And before you get too worried about the CO2, that's from "current" carbon in the environment (the grass that the cows ate) not fossilized carbon. So it's not a net addition of carbon to the atmosphere.

The carbon is coming from the methane, though. I don't have a degree in chemistry, but the carbon from the grass doesn't end up in the atmosphere naturally, does it?

The issue is that "green" parties in Europe (and maybe the US) do not want to hear about nuclear either. Germany even had to shut their nuclear power plants down and go back to coal (!!) which is considered as major victory for the environment by the green parties.

It seems impossible to find green political leaders willing to improve our CO2 emissions while accepting that we can't just rely on renewable energy only right now.

Is it a good alternative if it is much more expensive?

France’s energy prices are lower than Germany, Belgium, Italy and Spain.


Italy (where nuclear power was banned by referendum many years ago) is not able to meet its internal demand, and need to source energy from neighboring countries (including France), not really surprising.


Germany and Belgium are phasing out their own reactors:


Does that include government subsidies?

What I'm getting at, is: will governments be supporting nuclear, even if it's considered safe enough? As far as I know the Dutch government has cleared the way for a new nuclear power plant, but no company is willing to build it because they can't recoup the investments. If governments have to subsidise it more than they subsidise wind and solar energy, will they do it?

I don't know if I would call that a good alternative. How many places on the Earth can you no longer go due to radiation? Chernobyl, Fukushima, Three Mile Island and the list will go on. Also it seams very short sided in terms of planning for out of control cosmic events such as asteroids or coronal mass ejections which could wipe out our grid, leading to nuclear leaks worldwide. If we were to get something like the Carrington Event of 1859 [1] we would be much worse off for centuries if we rely on nuclear energy rather then finding a safer fuel source.

[1] https://www.sciencealert.com/here-s-what-would-happen-if-sol...

You can go to Three Mile Island just fine as long as you don't go inside the Unit 2 containment vessel itself. The meltdown was fully contained inside said containment vessel. Unit 2 has since had its core removed from the site entirely and has had its electrical generator moved to another reactor (in North Carolina), so it's not like people haven't been going in it either. Unit 1 (the other reactor right next to the one that had a meltdown) has remained a fully operational power station and is used as such today; people go there all the time.

Chernobyl and Fukushima I will grant (especially Chernobyl!) but Three Mile Island has a no-go zone that's far smaller than most people think. And it's only sort of no-go at that.

> which could wipe out our grid, leading to nuclear leaks worldwide

Sorry, but citation needed for the causal mechanism via which the grid going down would lead to "nuclear leaks".

I admit a little bit of that is pessimism from what happened at Fukushima from when the plant lost power to run the cooling pumps. from Scientific American

> Pushing water past the core means pumps that are generally run by electricity. What happens when a reactor gets disconnected from the grid? There are emergency diesel generators. You also have a battery system to keep instruments running, but that can also provide power to safety systems [which prevent a meltdown by cooling the reactor core]. It's all meant to provide defense in depth. First you rely on the grid. If the grid is no longer available, you use diesel generators. If there is an issue with the diesels, you have a battery backup. And the batteries usually last long enough for you to get the diesels going. [1]

All I'm saying is that we have a very short term understanding of cosmic events and extreme space weather events [2] and maybe a good percentage of nuclear power plants could withstain these types of events, but I don't see it as a viable long term option.

[1] https://www.scientificamerican.com/article/how-to-cool-a-nuc...


Right, at Fukushima it wasn't just loss of power that was the problem, it was the loss of all the backup power sources too, _combined_ with a design that required power to operate the cooling system.

I agree that this is something we should be keeping in mind as we build new reactors. And people have in fact kept it in mind. Modern reactor designs use passive cooling systems that don't need power to operate properly.

The single best thing we could do for nuclear safety, including from extreme space weather effects, is replace decades-old plants with modern ones. Unfortunately, people tend to react to that with "we shouldn't build any new nuclear plants, even if we're replacing old and less safe ones".

Just to put this in perspective, the first ever commercial nuclear plant was opened in 1956. Fukushima construction began in 1967, finished in 1971, 40 years before the meltdown. We've learned a good bit about safety in reactor design in the 50+ years that have passed since Fukushima was designed...

Better a hundred Chernobyls than what will happen to the earth if we continue using fossil fuels at the current rate.

Death toll from Chernobyl is presently at 31 with an estimated number of 4000 premature deaths.

So, yeah.

15,000 died from the tsunami that caused Fukushima, radiation exposure killed 1 volunteer cleanup worker.

TMI has already been addressed in sibling comments but I just wanted to point out that both Fukushima and Chernobyl were outdated reactor designs with active cooling. A modern reactor has much safer failure mode - but the hysteria about nuclear means that they don't get built and we keep these dangerous old designs running instead.

There are currently zero reactors worldwide which are using up-to-date designs i.e. Gen IV, as it is still being designed with the first reactor expected to be built by ~2030. All reactors worldwide are Gen II (designed in the 50s), Gen II+ (updated Gen II with a end-of-life extension to 60 years instead of Gen II's 40) or Gen III, which have relatively minor differences according to the World Nuclear Association[0]. The last Gen I reactor finally went offline in 2015.

> Due to the prolonged period of stagnation in the construction of new reactors and the continued (but declining) popularity of Generation II/II+ designs in new construction, relatively few third generation reactors have been built. Generation IV designs are still in development as of 2017, and are not expected to start entering commercial operation until 2020–2030.[1]

[0]: http://www.world-nuclear.org/information-library/nuclear-fue...

[1]: https://en.wikipedia.org/wiki/Nuclear_reactor#Reactor_types

> wipe out our grid, leading to nuclear leaks worldwide.

I don’t understand how nuclear leaks could be a result of grid failure.

Also, I read recently that CME could cause DC charge to occur on very long power lines, but that modern systems can handle this. There was a HN thread about this couple days ago, can anyone find it?

Dr. Margaret Thatcher

EDIT I must apologise to my parent, and to HN in general. Her thesis was undergraduate:

> ... four-year Chemistry Bachelor of Science degree, specialising in X-ray crystallography under the supervision of Dorothy Hodgkin. Her dissertation was on the structure of the antibiotic gramicidin. https://wikipedia.org/wiki/Margaret_Thatcher

She may have received honorary doctorates and she was a research chemist, but not a PhD.

Surely the Prime Minister title wins out?

Actually, that’s an interesting question: since “Dr” usually replaces “Mr” for a man, would a male president with a doctorate be “Dr President”?

Probably not. President would take precedent. See Chancellor Merkel for a good example (she has a PhD).

I was under the impression that German titles stacked up rather than overriding one another, like "Herr Professor Doktor". Is that wrong?

Generally that's correct, albeit pretty much only used in writing. There are, however, political titles for which, to my knowledge, that does not apply. Minister, Chancellor and President (of the BRD) should all supersede a PhD title.

Bundeskanzlerin Dr. Angela Merkel is the official formal title.

See the header here: https://www.bundesregierung.de/breg-de/service/bulletin/rede...

For University presidents, in the USA, they usually have both. Though I'm not sure that they always use both at the same time.

Couldn't see from her wikipedia page where she gained her doctorate?

I find it funny that you would try to correct such a small insignificant detail

Tackling ozone depletion is a lot easier: we stop using some chemicals. Not a big deal.

Tacking climate change is asking everyone to stop using energy (as we know it) which is fundamentally existential.

They're not in the same category of proportional impact.

It's not quite that severe, but as you note the substitutes are a lot more painful than they were with CFCs. Plus the problem is much much larger. We aren't getting out of this with just a little sunburn.

One big difference is that you could prove the ozone layers thining and so it was easy to get political backup, plus the solution was fairly simple. The climate debate is mostly political and there is no way to prove the effects only speculate. If just people would let scientists do science and not mix in political agendas we would have been much better of and money could have been spent for things we can actually do rather than being wasted on lofty political projects.

If the environmentalists had concentrated their efforts into educating people about CO2 as a pollutant that causes the acidification of the oceans, I think increases in CO2 emissions could have been slowed and reversed a long time ago. The chemistry is very straight forward and the damage to the oceans very easy to show and explain.

Unfortunately, instead of trying to find replacements for the energy produced by fossil fuel(nuclear was just sitting their, ready), it seems to me the most vocal environmentalists were basically anti-technology and anti-human and hoped the the huge fear of global warming would be enough to get a huge range of policies they had been pushing of decades passed. No such luck and the other side has now politicize global warming to their benefit.

No way to prove the effects? That's a controversial statement, considering the 99%+ scientific consensus that we are headed towards a global catastrophe.

1) There isnt a 97% consensus on what you think 2) Science does not work by consensus but falisifaction 3) climate debate is not scientific but political in its core.

Are you being facetious and saying you can’t prove climate change in the same way you can’t prove gravity exists? Or are you for real? Scientific proof has a different general meaning than what the general population calls proof, but the claim that more CO2 in the atmosphere leads to a warmer planet, and we can quite accurately project that correlation, is not remotely controversial. After a life of following this closely both in and out of academics I’m curious what makes you think differently to everyone that has looked into this closely, including unlikely people like oil companies and Jim Breidenstein. Read Merchants of Doubt if you’re interested in how it got so politicized.

I am saying that the climate debate isn't primarily scientific but poltical as most people (including many of the "climate scientists") are not actually engaging in a scientific debate but in a political one.

This is a very important distinction because most people debate it as if they are debating science.

The 97% is not agreeing that the world is going under in 20 years if we don't do anything. In those 97% there are plenty of so called "climate deniers" who are agreeing that the climate is changing, heating and humans have some effect.

However how much and how catastrophic it's going to be isn't even close to being a consensus or for that matter scientific. The actual science is a small part. The larger part is speculated not demonstrated.

That's fair. The question of what to do about it is purely political - let's take our best estimates of what the effects of climate change are going to be, our best estimates of the cost and ways to reduce the bad effects, and come up with an approach.

I think you're understating the amount of real science that is available for the effects of continued GHG emissions on our climate. Agreed that the effect it will ultimately have on our civilization is truly speculation because that depends on our response over the next 50-100 years.

Your comment made me think of people who say we need to move to Mars because of climate change... there's no shortage of dumb arguments on both sides of the debate. But to be clear, based on what I know, I would still advocate an aggressive move towards decarbonization.

It's not that there isn't real science available it's just that it's not very conclusive besides some obvious trends.

So I am not so sure the current focus on reducing co2 emissions is as rational and useful as many seem to think.

Furthermore, the real question no one asks themselves is what is the goal of this and what is the price (not just economically) you are ready to pay.

I don't see any way to stop co2 right now without putting a ban on residential and industrial heating and electricity and transportation and you don't do that without putting the economy to a halt. You would literally have to eradicate CO2 emission for those categories to get close to anything substantial.


Cause if this problem is really as dire as some claim then removing the current Paris agreement isn't even close to going to cut it. Especially since more and more people get into the middle class and they want part of the spoils too.

Furthermore it's not just that we would financially become much much poorer the result would be a giant fluctuating food supply and most poor countries are not going to agree that it's ok we can have what we have and they are not allowed to do anything.

So if you are really serious are you ready to hinder them if necessary by force to grow their own economies and secure their own people?

Cause that's the kind of actions you should be ready to take if you are truly worried about CO2 emissions and want to do something about them right now.

I am not too worried about CO2 emissions in fact for some things it's going to be good (14% increase so far in vegetation). That doesn't mean that I am not aware that rising sea levels might have an effect on local areas but I would rather approach that like the Dutch than involve the whole world.

I am also completely agreeing we should decarbonize but the problem right now is that the environmental organizations and the current political climate works against that because of it's opposition to nuclear which is the only real alternative energy to fossil fuels we have which is both reliable, scalable, cheap (at scale), safe and provides 0% CO2 emissions.

They would rather continue to primarily support wind and solar even though it means increased use of coal and oil because of the unreliable nature of wind and solar.

In the current political climate whatever is currently done is doing more harm than good both to the environment, the climate and to the poorest nations. Wind and solar are both linear solutions to exponential problems.

If you truly want to reduce carbon emissions then dedicate all your time to nuclear, fusion, fission, thorium figure out how we can contain plasma in a magnetic field in big enough scale.

I am not too worried although I am aware of the dangers, but if you really are worried you should probably drop everything you have visit the nearest energy lab and offer your help cause there are no feasible political solutions just waiting to be implemented least of all the paris agreement.

P.S. I upvoted you, not because I agree with you 100% but because you aren't just jumping to conclusions. Good style more people could learn from.

They are qualitatively the same, but the public and scientific case for ozone depletion is a lot stronger. If I had to guess there is like 5-sigma significance that (1) CFCs damage the ozone layer (2) the ozone layer is worth saving and (3) regulating CFCs will help.

Even if you fully accept that regulating CO2 is a good idea, the beneficial effects of that action will barely be noticeable for decades.

There’s a scale difference.

CFC was a small part of the economy.

As a first approximation, burning fossil fuel is the economy.

They are not really the same: eliminate the accidental release of niche refrigerant substances for which substitutes are available, versus the mass spewage of CO2 and hydrocarbons.

Note that refrigerants can be substituted without changing the refrigeration hardware at all. No infrastructure changes are required. There is no "tech stack disruption" at all.

I don't totally agree. Modern fridges are worse than old ones in terms of noise and I think that has something to do with replacing CFCs with less effective coolants.

I know this because I tried several of newest quietest models before discovering ammonia absorption cooling.

During the eighties, when I was young, the river Rhine in the Netherlands was a very polluted river where fish had all but disappeared. Trees in forests were dying because of acid rain. The ozone layer was shrinking and exposing people to lethal levels of UV. Those were scary problems. Now the Rhine has salmon swimming in it. Trees seem to have mostly recovered and the ozone layer is also recovering.

People argued that these problems couldn't be fixed, that they would be too expensive to fix, etc. But now there is good progress. That gives me hope about other problems on this planet.

My view of addressing climate change because of global warming is that it is going to require a bit more effort but that it is fundamentally just as doable. Better still, we are actually doing it. The question is are we doing it fast enough and are going about it as efficient as we could. People sure seem to waste a lot of time defending the status quo, arguing for inaction, or questioning whether there even is a problem to solve.

The core problem as I see it is addressing our energy needs and kicking off a second industrial revolution in the process. That's exactly what is happening right now. For me that prospect is the main goal. Saving our planet is a nice side effect though.

If we solve the technical problem of producing as much clean energy as we could possibly need, we could all have air-conditioning in our houses, terrace heaters in our gardens in the winter, irrigate our deserts with desalinated water from the sea, supply our industries with clean carbo hydrates produced straight from the air, etc. These things are all very energy intensive.

Demand for energy is outstripping our ability to conserve it. Therefore solving clean plentiful energy is key. It's the only thing that will get us results.

But the BBC reported earlier this year that somebody is cheating and making CFC-11 - banned by the Montreal Protocol.


It's home insulation production in China. The culprits are fully aware it's illegal, but China has some problems in getting compliance to its own laws.


You would think China with all that control over businesses and their population could prevent people from polluting their rivers with plastic and spewing it into the Pacific Ocean!

Systemic corruption makes the rule of law "difficult" to enforce. And by difficult I mean this is a feature not a bug for the huge interconnected web of power that actually runs the country.

PS: The fact China is not a democracy which has some unpleasant results: https://www.youtube.com/watch?v=rStL7niR7gs

All it takes is one party member (out of 80M) lodging a complaint with the central committee.

Just like USA would be a very different place if 300M people had a vote that mattered, China would be a very different place if 80M people had a complaint mechanism that mattered. We'll never hear of the city clerk who complains about the excesses of the latest giant project imposed upon local citizens. There are probably hundreds of those people, and they have all been taken care of. (Most of them in standard bureaucratic politicking fashion: "she said this terrible thing about Xi" "there is corruption in his office" etc. Kicking down is a great way to move up, when an official a couple rungs up approved the project and wants the complaints to go away.)

Yes because they read all missives personally. And no one ever interferes with those missives or those who send them. And no one ever lies in them for personal gain or joy in chaos.

Quick, do a good job and renovate everything, hide or move anything annoying or embarrassing while the boss is here is part of Chinese management everywhere from Xi Jinping on down. Supervision and management are hard, especially when your subordinates are constantly shading the truth and covering things up.

Thanks for the video. It's very educational.

The other side is true as well. The Boss of Bosses can get a call from Trump and that factory owner is arrested in 15 minutes.

Pretty sure even "democratic" countries has so much difficulty with corruption. Then there is the Federal Reserve..

My true definition of democracy is direct democracy. Once you start giving power to a representative then you stop being democratic. And that includes power to survive, eat, have shelter, have vacation, have time to study and pursue creative things.

But unless we can instantly communicate like the Protoss can then no, we can't achieve 'rule by the people'. However, it's not simply a choice of Direct Democracy, 3-branch system, 1-party system. We can have system where there is way less concentrated power (again, emphasis on power including many things like education in critical thinking).

Having said that. Yes China is not a democracy. Nor any other country. It is a question of how power (again, my emphasis) is concentrated and the potential of corruption.

In the United States, the Founding Fathers debated the idea of direct democracy at length and rejected it. Their reasons included preserving state sovereignty/local governance, and protecting rural minorities. Here's an article by George Friedman at Stratfor which serves as an introduction to the discussion: https://m.huffpost.com/us/entry/us_13051196

The only thing which can reliably be said about modern debate on how to structure a good representative government, is that the participants are rarely informed about the 500 years of debate on the subject that occurred before they were born

I keep being amazed how Americans treat anything said or done by the Founding Fathers (with two capital Fs even) as holy scripture.

They were just some guys drafting a law, get over it. People draft laws all the time.

You might be interested in the idea of a delegative democracy: https://en.wikipedia.org/wiki/Delegative_democracy

In theory it has the advantages of direct democracy, without requiring telepathy. Of course, that's not necessarily to say that it would work well, but it's an interesting concept at least.

China is a democracy. https://en.m.wikipedia.org/wiki/Elections_in_China

Funny thing is, people say one party system is not a democracy. What about USA's two party system? Both of them have representatives elected by people (baring the violence).

But in both, people can't realistically get a new party in government, let alone run the country. Yet new parties get elected in other parts of the world, even if they don't run the government as a majority.

Our parties change around every half century or so. The US has gone through several rearrangements of parties.

https://en.wikipedia.org/wiki/First_Party_System https://en.wikipedia.org/wiki/Second_Party_System

We're arguably currently on the sixth one.


That's not a fair comparsion as the current Chinese party has only been in power 'democratically' since 1949.

That said, my above point is about non ruling party representatives. In Europe, there tends to be more than 5 different parties, showing plenty of voter choice is possible.

The constitution defines China as "a socialist state under the people's democratic dictatorship led by the working class and based on the alliance of workers and peasants" [1]. It may be "democratic" in the sense that elections are held, but it's not a democracy in the modern sense.

[1] https://en.wikipedia.org/wiki/People's_democratic_dictatorsh...

Intersting, as per your link, the dictatorship is for the people. Seems similar to commander in chief role but without congress?

What is democracy in a modern sense?

Chinese Communist Party is weak. Their authority dissolves like sugar in the face of US Dollars.

Now that I've read both articles (mistaking yours as the OPs for a second and getting really confused)... I think this paints a pretty clear picture in my head, ignoring the spin, that while yes the ozone layer has been improving, there are still risks, and potentially bad players we need to continue to be vigilant for.

How are these incompatible stories? Worldwide ozone destroying chemical production is way down, which is allowing the ozone layer to regenerate back to pre-industrial levels. Meanwhile, some polluters are cranking out banned CFCs and freeriding on the worldwide reduction efforts.

Much like CO2 production, some level of emissions are well within the ability of the biosphere to deal with without harm. But if everyone emits willy nilly then we'll end up well past those limits.

How much CFC production was accounted for in the models that predicted the O3 layer healing? How much production can be handled and what is current production? Those are the answers one would have to have before writing this off.

> How much CFC production was accounted for in the models that predicted the O3 layer healing?

I thought ozone layer density (is that the right term?) was directly measurable?


Yes, and it is not even that hard. But we cannot measure the future, thus we use models to predict, and those need inputs (such as emitted CFCs) which can be wrong.

Ah, right, yes, that makes sense now. Thanks.

Before writing what off?

The major contributor to ozone depletion is probably CFC-12, which has a much lower boiling point than CFC-11 and was far more widely used (and vented into the atmosphere) for refrigeration.

CFC-11 boils at 24C. CFC-12 boils at -30C.

I'm not an expert, but repairing/healing seems like a misleading analogy for what's happening

Ozone is produced naturally, the ozone layer will return itself to pre-industrial ozone concentrations simply by leaving it alone. You can call it regeneration or repair or healing or whatever you like.

No expert either, but it seems fairly apposite. The atmosphere is continuously generated by a vast complex system. This incorporates many homeostatic mechanisms tending to push the system back to its dynamically stable state. As long as we don't push the system too far, removing recent perturbations will result in auto-repair.

This is one of the few sources of hope that we can step back from the ecological-collapse abyss. In many cases we just have to get out of the way. Unfortunately, we probably won't. Replacing complex evolved enduring systems with primitive technological short-lived ones makes heaps of cash.

Ok, now that refrigerates are ozone safe can we get all the regulations removed from them? At least for the safe ones?

Right now if you don't reclaim the R-134A from your car AC or fridge it is a $27k fine while you can buy cans of it to blow out your keyboard. Same goes for propane. This makes the new fridges that use propane almost impossible to work on since nobody has the reclamation equipment for R290.

R-134A has a global warming potential of 1550 over 100 years [1], i.e. about 45 times more effective than methane, so while it's not eating the ozone layer you probably shouldn't be spraying it around by the tonne either.

Edit: and CO2 has a GWP of 1 (as the reference point for GWP), so R-134A is way more effective than that.

1: https://en.wikipedia.org/wiki/Global_warming_potential#Value...

Judging by the duster cans I have here [0] it looks like they've switched to HFC-152a which has GWP but does not deplete the ozone layer.

But the point is that they're the same exact substances, given different designators depending on the use. HFC-134a is perfectly legal to vent into the atmosphere, yet if it's in a refrigeration system (and thus called R-134a) it is not.

R-290 is just the refrigeration name for plain propane. I don't know the GWP etc of propane, or the relative amount that would be contributed by deliberate venting of refrigeration systems. But I do know that a $27k fine for doing so is nonsensical - given gas grills, blow torches, and industrial/distribution gas leaks.

[0] I didn't buy them. I personally have never had a problem using an air compressor (the traditional worry is condensation droplets), but if you're paranoid go get something like the Metro DataVac.

> HFC-134a is perfectly legal to vent into the atmosphere

The argument, I guess, is “it shouldn’t be”, but it’s better than R-12 (for the ozone layer anyway; R-12 has a GWP of 2400) so turning a blind eye to relatively small-scale use is better for the ozone layer.

Propane’s GWP is 3.3, so it’s a bit worse than CO_2 but much better than -134a or methane. A fine does seem odd for venting it although as long as it’s cheap there’s probably not much other incentive to try to conserve it. Taxes which made the gas valuable enough to be worth capturing (charge for the externality and all that) seem more sensible but are politically unlikely and I’d be wary of unintended consequences like accidentally incentivising ozone-depleting gases instead.

The laws were made in the context of ozone depletion, rather than global warming. In that context 134a is inert, which is why it was then purposely sold in spray duster cans - while venting 134a from a refrigeration system remained illegal for no good reason.

The modern analog with respect to GWP is propane ("R-290"). With a GWP of 3.3, it looks like venting raw propane is basically equivalent to the CO2 created by burning that same propane.

In isolation, putting more propane into the atmosphere is worse than not. But on the whole, we'd much rather see propane used for refrigeration than R-152a or whatever other new proprietary (hydrofluoric acid combustion product !) refrigerant system Dow (et al) come up with. And not requiring the purchase of expensive "reclamation equipment" for propane-used-as-refrigerant would go a long way to encouraging that.

In a perfect world, requiring reclamation would help. In the real world it just pushes this off to gray market recycler. They will come by and pick up your broken fridge for free for the recycle value but most will just vent the refrigerant no mater what. They just claim it was zero pressure when they found it. Hooking up a reclamation machine and paying for the refrigerant disposal would take all the profit out of this service.

So the fine mostly just stops the fridge from being worked on by qualified professionals. Perfectly fixable items are going in the trash because nobody wants to buy dedicated equipment for every refrigerant used. R134A is common enough to make the equipment worthwhile to own but not so much for propane and other less common refrigerants.

Agreed down thread that after the fact enforcement action doesn’t seem like a sensible way to do this but political reality is what it is and I expect most of these regulations were intended to encourage people to use non-ozone depleting refrigerants with their global warming potential a problem for another day.

> Hooking up a reclamation machine and paying for the refrigerant disposal would take all the profit out of this service.

Fixing this (Make it cheaper to reclaim? Make the refrigerant more valuable? Some combination of the two?) seems like the way to go rather than just removing all the regulations and hoping for the best.

> Perfectly fixable items are going in the trash

Which results in the refrigerant being released anyway once the item deteriorates enough.

Anecdotally, the techs that I've seen servicing AC are pretty casual about venting excess pressure or purging lines into the air.

When I was a brewer, we retrofitted our chiller from R22 to R410A (had to change compressor oil to POE, but was otherwise a seamless transition). The techs from the shop we contracted to do the changeover let all that R22 bleed off into the atmosphere because they forgot their reclamation cylinder.

Any truth to the theory that the banned refrigerants were about to lose patent protection while the "better" ones still had plenty of years left on their patent?

But let's not mess it up again, please?

My father-in-law firmly believes that the hole in the ozone was caused by space shuttle reentry, and that's why it's patching now, and also that CFCs couldn't possibly make the hole because they are heavier than air. Does anyone have the data to refute these claims?

Ideally the person who claims something needs to provide the data to back it up.

My father-in-law doesn't believe that the moon landings took place. All the data in the world cannot convince him otherwise. The only good strategy in the face of these types of claims is to go up the crazy scale. For example when he tells me that the moon landings didn't happen, I tell him he's naive it he thinks the moon exists. The moon was blown up in the 50's due to a nuclear test gone wrong and what we're seeing now is an artificial projection.

Does that strategy work?

Considering the amount of "moon hoaxer" videos on youtube (no I'm not joking, go look) I think it might be counter-productive.

For what definition of "work" ?

> Does anyone have the data to refute these claims?

I firmly believe that gravity is caused by a bunch of invisible garden gnomes that hold you down. Does anyone have the data to refute these claims?

"Chlorofluorocarbons (CFCs) are heavier than air, so how do scientists suppose that these chemicals reach the altitude of the ozone layer to adversely affect it?"


Also, see the definition of homosphere:


"The homosphere and heterosphere are defined by whether the atmospheric gases are well mixed. The surface-based homosphere includes the troposphere, stratosphere, mesosphere, and the lowest part of the thermosphere, where the chemical composition of the atmosphere does not depend on molecular weight because the gases are mixed by turbulence. This relatively homogeneous layer ends at the turbopause found at about 100 km (62 mi; 330,000 ft), the very edge of space itself as accepted by the FAI, which places it about 20 km (12 mi; 66,000 ft) above the mesopause."

Note that the ozone layer is well within the homosphere so CFCs readily mix into it from surface emissions.

> ... because they are heavier than air. Does anyone have the data to refute these claims?

Going up the crazy scale: Has he burst into flames? If no, then air mixes heavier and lighter components. If yes, then the 21% O2 is actually at the bottom and should be 100% as it is heavier than N2.

Gases have a thermodynamic tendency to mix, despite weight differences. The atmosphere isn't a layer cake of heavy gases below light gases. If it was, we wouldn't be able to breathe because the ~1% of argon (and all the heavier gases) would sit below the oxygen layer.

Does he have data to back up those claims?

I guess I'm more looking for a response to "yes CFCs can destroy ozone even though they are heavier than air," and "here is a graph of the size of the ozone vs space shuttle reentries" that shows a non-correlation.

The hole was pretty much the size of Antarctica at its peak, how could something the size of a small aircraft flying through the atmosphere 135 times cause such a huge hole!?

Also if you lie down on the ground do you suffocate to death because of all of that heavy ozone hanging around there? No, because it's dispersed throughout the atmosphere.

Ultimately it sounds like the kind of situation where no amount of logic is going to change his mind and that you're probably better off avoiding the subject entirely for the sake of your own sanity.

Have you tried just getting him to read the Wikipedia page? It describes how those gases circulate and how it was discovered. Particularly the "Misconceptions" section. Also the shape of the depletion is not shuttle-sized AFAIK. Finally remind him of rain, or a house in a tornado. https://en.wikipedia.org/wiki/Ozone_depletion

If he's into correlations point him at http://tylervigen.com/spurious-correlations - Nicholas Cage films cause drownings, Cheese leads to bedsheet entanglement, and norway oil causes traffic accidents.

Water is heavier than air, but that doesn't stop the rain, does it?

That's not a good counterexample because rain comes down. Water vapor, which goes up, is actually lighter than air by a large margin (0.804g/L versus 1.225g/L) at the same temperature and pressure.

Liquid water is certainly denser than air, and the fact that it vaporizes before rising up into the atmosphere is immaterial to the point that it ends up there anyway. The process (evaporation and subsequent fluid mixing) is not significantly different from the process which puts ozone in the upper atmosphere.

Water vapour is water.

This is kind of funny. Until you realize that some people actually believe this stuff. Either way, burden of proof should always work the other way around. Other than strong believe, did this father-in-law actually offer some scientific evidence/proof to support his theory?

This is not to say that established theories would always hold scrutiny. Thinking of e.g. what we thought about tectonic plate movements/continental drift only ~100 years a go.

At the large scale of the atmosphere and in the lower layers, the relative weight of gases doesn't matter (otherwise Oxygen and Nitrogen would seperate out and there wouldn't be a mix of other gases in it either).

The makeup down here is largely controller by convection and turbulences, only farther up the relative weight starts to matter.

Does he think the space shuttle was/is the only craft reentering the atmosphere?

What if the space shuttle is powered by CFC? /s

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