Increase in global emissions of HFC-23 despite near-total expected reductions

From Nature Communications



Under the Kigali Amendment to the Montreal Protocol, new controls are being implemented to reduce emissions of HFC-23 (CHF33 ), a by-product during the manufacture of HCFC-22 (CHClF22 ).

Starting in 2015, China and India, who dominate global HCFC-22 production (75% in 2017), set out ambitious programs to reduce HFC-23 emissions. Here, we estimate that these measures should have seen global emissions drop by 87% between 2014 and 2017. Instead, atmospheric observations show that emissions have increased and in 2018 were higher than at any point in history (15.9 ± 0.9 Gg yr−1± 0.9 Gg yr−1 ).

Given the magnitude of the discrepancy between expected and observation-inferred emissions, it is likely that the reported reductions have not fully materialized or there may be substantial unreported production of HCFC-22, resulting in unaccounted-for HFC-23 by-product emissions. The difference between reported and observation-inferred estimates suggests that an additional ~309 Tg CO2CO2 -equivalent emissions were added to the atmosphere between 2015 and 2017.


Due to their influence on climate, the major hydrofluorocarbons (HFCs) were regulated under the Kyoto Protocol of the United Nations Framework Convention on Climate Change (UNFCCC) and have recently been included in the Kigali Amendment to the Montreal Protocol to ensure that their radiative forcings does not offset climate gains provided by the phaseout of chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs)1,2,3.

With a long atmospheric lifetime (∼∼ 228 years1,4), and high radiative efficiency, HFC-23 has the highest global warming potential (GWP) among HFCs (100-year GWP, 12,6901). It is primarily produced as an unwanted by-product during the manufacture of the refrigerant HCFC-22, via the over-fluorination of chloroform (CHCl33 )5. Smaller emissions of HFC-23 are associated with its use as a feedstock for halon-1301 (CBrF33 ) production, plasma etching and chamber cleaning in the semiconductor industry, very low-temperature refrigeration and specialty fire suppression1,5,6,7.

Previous studies, based on in situ atmospheric observations and firn air measurements, have shown an increase in the global annual mean mole fraction of HFC-23 from near zero in early 1960 to 28.9 ±± 0.6   pmol mol−1−1 by the end of 20161,5,6. These data, when combined with a model of atmospheric transport and chemistry can be used to infer global emissions.

Such top-down methods have previously shown that global HFC-23 emissions grew from 4.2 ±± 0.7 Gg yr−1−1 in 1980 to 13.3 ±± 0.8   Gg yr−1−1 in 2006, before declining rapidly to 9.6 ±± 0.6 Gg yr−1−1 in 2009 in response to emission reductions from developed countries and as a result of the UNFCCC Clean Development Mechanism (CDM)6,8. As the CDM period ended, HFC-23 emissions grew to 14.5 ±± 0.6 Gg yr−1−1 in 2014, before declining again, to 12.7 ±± 0.6 Gg yr−1−1 , in 20166.

Here, we present an update of global HFC-23 emissions derived from atmospheric observations, based on new data from 2015 to the end of 2018. In addition, we compile a new inventory-based HFC-23 emissions estimate through to the end of 2017 that includes reported emission reductions by China and India. We find that in 2018, observation-based HFC-23 emissions are higher than at any point in history (15.9 ± 0.9 Gg yr−1± 0.9 Gg yr−1 ), whilst inventory-based emissions are at the lowest in the past 17 years (2.4 ± 0.9 Gg yr−1± 0.9 Gg yr−1 in 2017) when reported emission reductions were included.

Due to the magnitude of the discrepancy between reported emissions reductions and emissions inferred from the atmospheric data, it is highly likely that developing countries have been unsuccessful in meeting their reported emissions reductions. Alternatively, or additionally, there may be substantial unreported production of HCFC-22 at unknown locations resulting in unaccounted-for HFC-23 by-product being vented to the atmosphere.

Full paper here.


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Ron Long
January 23, 2020 2:23 am

“…it is likely that the reported reductions have not fully materialized…” is a polite way of saying “the cheating SOB´s are lying to us!”. Now you know the essence of why the USA refused to confirm Kyoto and Trump withdrew from Paris agreements. Where I live, and some near-by countries I visit, CFCs are sold openly in hardware stores.

January 23, 2020 2:29 am

Unsurprisingly, the actual emissions of China are likely much more than the reported emissions. This is in large part due to Chinese officials just reporting what their superiors want to hear.

Greta must be furious …. wait, never mind.

Reply to  MarkH
January 23, 2020 8:09 am

The Confucius Institute is alive and well…..
…and a lot more dangerous than we even know

Jonas Acme
Reply to  MarkH
January 23, 2020 8:25 am

You are undoubtedly correct. In the late 1990’s I was advising a Chinese enterprise regarding coal fired power production. One facility they operated was equipped with a limestone slurry based process system for reducing sulfur emissions. Yet it was never placed in service. The Chinese manager said the limestone costs and the parasitic power usage were too high – and anyway they were getting credit by the government for being a low sulfur emissions facility whether it was in service or not. The sulfur emissions reported were faked to mimic the numbers recorded during the initial testing phase of the equipment.

Ben of Houston
Reply to  Jonas Acme
January 23, 2020 10:35 pm

I am reminded of the Japanese Navy during WW2. They consistently over-reported sinkings and under-reported damage taken, to the point where clear losses were framed as overwhelming victories.

The high command in Tokyo were drawing up battle plans with ships that didn’t exist or were barely operational fighting an American force that they thought had already been decimated but was twice the planned size. This was how sea battles became progressively more and more of a slaughter, culminating in Sao Mar, where the Americans lost three minor ships at the cost of almost the entire functional Japanese Navy.

Reply to  MarkH
January 23, 2020 12:19 pm

All those wind turbine and solar panel parts manufacture.

Reply to  MarkH
January 23, 2020 4:51 pm

“Chinese officials just reporting what their superiors want to hear them to say.”

Serge Wright
Reply to  MarkH
January 24, 2020 3:51 am

The Chinese have no care for what they pump out into the atmosphere. Thir unfiltered coal stacks are a good example. The addition of a partical filter is a very simple inclusion as noted in all coal power plants in western countries.

January 23, 2020 2:43 am

That’s CHF3 and CHClF2. Was this really published with these obvious errors in the abstract?

Charles Higley
Reply to  Merrick
January 23, 2020 5:10 am

The upper tropical troposphere is where the AGW “science says it should be warming faster than the surface. As it is always colder up there (-17ºC) than the surface (15ºC), no gas of any kind at any concentration can warm the surface. Any downwelling radiation will be reflected by the surface as those colder energy levels would already be full. This is the basic junk science of AGW.

As the hot spot in the upper tropical troposphere has never been detected and, in fact, that region has been cooling gently for over 30 years, according to NASA, the AGW crowd simply do not talk about it and assume that greenhouse gases are a done deal. That is why they refuse to debate the real science.

The icing on the cake is that CFCs do not break down ozone. That is also junk science, as it was fake science paid for and produced by Dupont to force the use of a new patented and more expensive refrigerant. 20 years later, the scientist who fabricated the results admitted to the fraud. The patent had run out by then, after 17 years.

Reply to  Charles Higley
January 23, 2020 6:17 am

You’re way off base on your generalizations of CFCs and patents. It’s radical species that react with ozone in this chemistry. U.S. patents had 20 year terms after issuance before the PCT was ratified. If you have statements from scientists who admitted fraud in this matter, please post a reference.

Reply to  Scissor
January 23, 2020 7:33 am

Have any of the climate scientists admitted to fraud?

Reply to  MarkW
January 23, 2020 10:34 am

I don’t think so. People usually don’t admit to their misdeeds, though they do sometimes to plead for a lighter sentence or to clear their conscience if they are truly repentant. Maybe even to brag amongst other thieves. It seems like some climate scientists admitted things within their climategate emails. I suppose Peter Gleick did to some extent after he was caught.

Reply to  Charles Higley
January 23, 2020 6:37 am

You are not recognizing that infrared radiative gas at -17 between the surface (+15) and outer space (-270 ), significantly reduces the heat transfer rate between the surface and outer space….
Do some basic stefan-boltzmann calcs to prove it to yourself.

Crispin in Waterloo
Reply to  Charles Higley
January 23, 2020 9:47 am


The claim is not that the “hotspot” is hotter than the surface, it is that the rate of rise in the hot spot will be three times faster than at the surface. There is an excellent article on this matter on Monckton’s website.

The action of CFC’s on the ozone in Antarctica is not as great as advertised, but it is not zero. See the papers by Prof Q. Lu, University of Waterloo. He lays out the chemistry well. The factors not usually considered include polar cosmic rays, plus bromine and chlorine from the ocean.

Remote sensing of the Antarctic atmosphere shows Prof Lu is correct on the chemistry and heat loss going on in that region. It is very interesting. He replicated these reactions in an atmospheric chamber at the university. Not just theory and models.

Reply to  Crispin in Waterloo
January 23, 2020 10:30 pm

Crispin in Waterloo
January 23, 2020 at 9:47 am

Yes, Lu’s studies at Waterloo were most interesting…I can’t understand why he didn’t/doesn’t get more publicity. He totally challenges the meme. We need more people like him to expose the nonsense in AGW and the ozone scare/scandal. To this geologist his comments always made a lot of sense and were very thought provoking.

He’s lucky he doesn’t work at James Cook University or he’d be long gone!

Reply to  Merrick
January 23, 2020 5:30 am

“… really published with these obvious errors … ? ”

No, they are mangled versions of the markup-notation that was used to render chemical formulae.

Reply to  Merrick
January 23, 2020 6:09 am

It’s correct in the Nature Communications article that is online.

Reply to  Scissor
January 23, 2020 7:29 am

It may look “correct” in your browser, but the meta-data looks like this, before rendering by MathJax (or whatever typesetting scheme):
HFC-23 (CHF$${}_{3}$$), a by-product during the manufacture of HCFC-22 (CHClF$${}_{2}$$).

On my browser I see this unrendered meta-data for a second or two because it is slow. Some browsers can render it back into displayable Unicode text, but others must transform it into an image format using SVG.


Reply to  Merrick
January 23, 2020 10:56 pm

It’s a character set problem. The poster cut and pasted this article from Nature Communications, and posted it without looking at the result.

January 23, 2020 2:49 am

So are these banned just because of AGW ? Or also because of ozone depletion ??

Reply to  ggm
January 23, 2020 4:16 am

It plays into both but they are banned under the Montreal Agreement.

January 23, 2020 3:19 am

We’ve been here before:

“The essence of the scam is that a handful of Chinese and Indian firms are deliberately producing large quantities of an incredibly powerful “greenhouse gas” which we in the West – including UK taxpayers – then pay them billions of dollars to destroy.”

2010 – “Another Day Another Dollar – CFC’s And The UN”

Reply to  dennisambler
January 23, 2020 4:13 am

thanks for that
I knew Id read re china being paid to process and instead producing more;-)
nice work if you can get it huh?

Reply to  ozspeaksup
January 23, 2020 4:19 am

Yes and those that were just venting them have continued to do so and so all the money achieved nothing which is basically what the report is saying. Same thing that will happen to any carbon trading scheme.

January 23, 2020 3:54 am

Was it this site over a decade ago that reported CFC smuggling into California to clean printed circuit boards was second only to drugs in value?

Jean Parisot
January 23, 2020 4:10 am

“These data, when combined with a model of atmospheric transport and chemistry can be used to infer global emissions.”

No, they cannot. The models were designed and validated to identify timing and general locations of periodic events. They were not intended to provide quantitative information about long term sources.

However, most of these HFCs have nice IR spectral peaks which makes in situ atmospheric measurements possible. Floating IR spectrometers in balloons for lateral sampling or ground to the deep sky background open path methodologies are well understood and have been practiced for decades.

Looking forward to the papers with actual data collection, and then the revalidation of the transport models.

Reply to  Jean Parisot
January 23, 2020 6:21 am

They used mass spectrometry for the measurements in this study. MS is inherently higher in resolution and more sensitive, though heavy and expensive so not amenable to balloon use.

January 23, 2020 4:33 am

Thus, the ozone depletion mitigation fairy tail thanks to the Montreal Protocol is a complete fraud.

And so is the Nature sharticle that claims that “Climate mitigation is in action as we speak because these [Ozone Depletion] substances are decreasing in the atmosphere, thanks to the Montreal Protocol.” :

What a pathetic farce.

Reply to  Petit_Barde
January 23, 2020 5:49 am

Actually, CHF3 (“flouroform”) is not ozone depleter itself, but used as a CFC “tracer”. And is potent GHG.

It has been monitored since 1978 by AGAGE global network of gas-chromatographs, The AGAGE plots seem to portray familiar “hockey-stick” growth since 2008. (But the “handle” is missing. Hmm)

Some plots e.g. on researchgate (qv) seem to contradict this smooth exponential growth.

Reply to  Petit_Barde
January 23, 2020 7:35 am

Depending on the type of fairy, some of them have cute tails.

January 23, 2020 5:28 am

China is something like the wild west. You can get away with an amazing amount of not-quite-legal activity … until you can’t … and then they might lynch you. Anyway, some folks in China continue to make foam insulation using banned CFCs. link

The advice to foreigners in China is to keep your nose clean, in spite of what you see going on around you.

John Shewchuk
Reply to  commieBob
January 23, 2020 6:35 am

Regarding China … all this talk of CO2 and CFC dangers are nothing-burgers compared to the ongoing coronavirus outbreak in China. It’s airborne. Maybe our Congress can create a CO2/CFC compound to battle the outbreak.

Ashok Patel
January 23, 2020 8:50 am

Either there is a problem with WordPress formatting or there are many typos in the above Paper, especially with Formulas and units.

Reply to  Ashok Patel
January 23, 2020 10:41 am

The math formulas are expressed in MathJax, a popular latex-like typesetting syntax for webpages. (You can see the raw MathJax expressions if you do a ‘view source’ (ctrl-u in Chrome)).

[Attention MODS: MathJax is not viewable from default HTML browser. Need to render the formulas first with MathML plugin, which is available for WordPress here:

January 23, 2020 9:41 am

In essence, attributing HFCs, like CFCs, to some role in climate change is absurd from the point of view of common sense. At concentrations of the order of parts per trillion, the molecules of these substances absorb an immeasurably small fraction of the reflected infrared radiation (according to the theory of the greenhouse effect). In this case, each molecule can absorb only a strictly defined amount of energy, while solar energy enters the Earth continuously.
  However, even within the framework of the theory of the greenhouse effect, the enormous values ​​of the global warming potential attributed to HFCs and CFCs have no physical explanation. The absorption bands in the IR spectrum for the bonds of C-F and C-Cl are 1000-1400 and 600-800 cm-1, respectively.
This region is overlapped by the absorption bands of water vapor (0-1000, 640-2800 and 200-1200), СО2 (540-800 and 850-1250), СН4 (950-1650), etc. (Table 6.2). Selection of HFCs and CFCs in the IR spectrum of atmospheric gases is almost impossible. Therefore, the statement about the “high radiation efficiency” of HFC-23 is not based on real facts.

Stephen Wilde
January 23, 2020 9:51 am

Just recently it was being boasted that the recent shrinking of the ozone hole was a result of the Montreal Protocol.
Clearly, it wasn’t.
So will they now admit that the ozone hole was nothing to do with CFCs in the first place ?

January 23, 2020 11:49 am

Completely OT But a suggestion for future generations worried about trash plastic waste, pollution ect. Why not organize worldwide collections per country and throw it all in Volcano Calderas for complete combustion back to Nature??? In other words throw all rubbish which does not degrade rapidly into calderas

Roger Knights
Reply to  Eliza
January 23, 2020 6:23 pm

Or run it through a fusion torch at 30,000 degrees F. It’ll reduce the input to its elements rather than combusing them. See the book, “Prescription for the Planet.”

January 23, 2020 12:06 pm

Friends, although the history of the ozone hole and Montreal protocol may be interesting, the primary impact of this article, in combination with yesterday’s article on these substances causing one third to one half of climate warming, is to greatly reduce the climate sensitivity of CO2. This calls into question most of the CMIP climate models and their projections. If the models cannot explain the past temperature history with their CO2 sensitivity assumptions, they will have to be retuned or discarded. Bottom line is that the science is NOT settled.

Robert of Ottawa
Reply to  Casey
January 23, 2020 4:20 pm

Oh no, you are wrong, it is not only settled, it is worse than was thought.

January 23, 2020 12:14 pm

I believe there was never a hole it was just a convenient term for thinning

January 23, 2020 1:46 pm

28.9 ±± 0.6 pmol mol−1−1
lifetime (∼∼ 228 years1,4)

Please get rid of all these spurious repetitions. Discover the “sup” html tag or use “/”.

pmol mol−1

Reply to  Greg
January 23, 2020 2:45 pm

The spurious repetitions happen because the underlying MathJax meta-data for these mathematical expressions are not correctly handled. I don’t think WUWT is using the MathML plugin to render these properly. 😐

To see this, do a ‘view source’ to reveal the raw meta-data for the two snippets you quoted above: \pm is ‘plus-minus’ and \sim is ‘similar’ etc.
28.9 <span class=”mathjax-tex”>\(\pm\)</span> 0.6  pmol mol
lifetime (<span class=”mathjax-tex”>\(\sim\)</span>228 years

January 23, 2020 2:26 pm

The effect of CFCs on ozone decay in the stratosphere was the same fiction as the greenhouse effect of CFCs is now. Then initially scientists did not pay due attention to two fundamental errors made in the original article
M. Molina and F. Rowland (1974). First, these authors claimed that CFCs, although they are 4-5 times heavier than air, can enter the stratosphere due to vertical diffusion. Secondly, they believed that the stratospheric photolysis of CFC-11 and CFC-12 occurs in the wavelength range 175-220 nm, while the calculation of the maximum wavelength for breaking the C – Cl bond in these substances yields 392 nm and 376 nm. Consequently, CFC photolysis occurs already in the lower troposphere.

Robert of Ottawa
January 23, 2020 4:17 pm

Due to their influence on climate, the major hydrofluorocarbons (HFCs) were regulated under the Kyoto Protocol

Er, no, their influence on climate is zero. They were blamed for the existance of the perpetual “ozone hole” which was going to make us all die of Andean frog disease or something.

January 23, 2020 6:27 pm

So we’re doomed again.

Rudolf Huber
January 24, 2020 10:55 am

So much for trusting that China will do what it says it does without forceful prodding. Good luck with any other agreement that anyone has with them. Like Paris. Making all the right noises and no action to back it up.

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