Scientists find ozone depletion began decades before discovery of ozone hole and was caused by carbon tetrachloride since the 1930s

Amazing stuff!

These authors seem to be obsessed with the instrument of a thought experiment! In this particular study it might have been overused.

"... In a study ... the scientists suggest that the first signs of ozone depletion appeared as early as 1957 — about 30 years before the ozone hole was discovered. And, this first signal of ozone loss popped up not in the Antarctic, but in the upper stratosphere of the tropics. What’s more, the cause of this early depletion was not due to CFCs, but to another industrial chemical: carbon tetrachloride.  ..."

From the significance and abstract:

"Significance

This paper examines the earliest emergence of human-caused ozone depletion: the when, the where, and the why.  ...

The “when” is as early as the late 1950s—about 30 y before the Antarctic ozone hole was discovered and 20 y before the Molina–Rowland theory. The “where” is the tropical upper stratosphere, where a relatively small signal stands out against even smaller noise, allowing the earliest emergence. The “why” is the use of carbon tetrachloride as a solvent decades before chlorofluorocarbons became common in refrigeration and spray cans.

Abstract

The Antarctic ozone hole was first reported in 1985, and small ozone losses at the global scale were also observed in the late 1980s. The combination of field and laboratory measurements, together with modeling, quickly established anthropogenic chlorofluorocarbons (CFCs) as the cause of both the Antarctic and global ozone depletion.

However, when, where, and why the earliest ozone depletion could have been detected has not been determined.  ...

We find that human-caused ozone depletion was likely identifiable as early as 1957 in the tropical upper stratosphere. This region’s low internal variability enables the earliest detection of the anthropogenic signal, even though tropical ozone losses in the upper stratosphere were smaller than those in higher-latitude regions. ... 

Further, while CFCs are widely recognized as the primary drivers of current ozone depletion, we find that early ozone loss was primarily caused by human-made carbon tetrachloride (CCl4), used mainly as a solvent. These findings suggest that a clear human influence on the stratospheric ozone layer began nearly 70 y ago, even before substantial emissions of CFCs from spray cans or air conditioning."

Scientists find ozone depletion began decades before discovery of ozone hole | MIT News | Massachusetts Institute of Technology "Using modern tools, they also determined that carbon tetrachloride, used as a dry-cleaning and degreasing agent as early as the 1930s, was at the root of early ozone loss."

The emergence of human influence on the ozone layer by the 1960s

Resonance structures of ozone with lone pairs indicated (Source)

Polarity of Carbon Tetrachloride (CCl4) (Source)

NASA, NOAA 2025 Ozone Hole Update

Does anyone remember that scare from the 1980s? Very similar to today's global warming/climate change alarmism and hysteria!

An increase in rocket launches would harm the ozone layer. Really!

Ever since the widening ozone layer hole was first discovered in 1985, the ozone layer is another favorite when it comes to alarmism and hysteria.

As usual, this alarmism and hysteria is based on (flawed) computer model simulations or in other words, this research is speculative if not junk! Human ingenuity can easily handle the ozone layer!

There is probably little doubt that e.g. satellite launches will increase in coming years. 

From the abstract:

"Rocket emissions thin the stratospheric ozone layer. To understand if significant ozone losses could [???] occur as the launch industry grows, we examine two scenarios [???]. 

Our ‘ambitious’ scenario (2040 launches/year) yields a −0.29% depletion in annual-mean, near-global total column ozone in 2030. Antarctic springtime ozone decreases by 3.9%.

Our ‘conservative’ scenario (884 launches/year) yields −0.17% annual, near-global depletion; current licensing rates suggest this scenario may be exceeded before 2030.

Ozone losses are driven by the chlorine produced from solid rocket motor propellant, and black carbon which is emitted from most propellants. The ozone layer is slowly healing from the effects of CFCs, yet global-mean ozone abundances are still 2% lower than measured prior to the onset of CFC-induced ozone depletion.

Our results demonstrate that ongoing and frequent rocket launches could [???] delay ozone recovery. Action is needed now to ensure that future growth of the launch industry and ozone protection are mutually sustainable."

 

An increase in rocket launches would harm the ozone layer

Near-future rocket launches could slow ozone recovery (open access)

The Ozone cycle

Musk's many Starlink Satellites Are Falling Back to Earth Damaging the Ozone

It seems concerning, but I am not sure it is as serious as portrayed in this video.

Lack of a stable ozone layer: Explaining the delayed rise of plants, animals on land by a about 2 billion years

Amazing stuff!

"... And now we may have a better idea of why that took so long — more than 2 billion years — to happen.

According to a new ... study, Earth’s early atmosphere  ... effectively delaying the creation of a stable ozone layer that would shield complex life from much of the sun’s ultraviolet radiation (UVR). ...

a mystery that has puzzled scientists for hundreds of years.

“The origin and diversification of complex life on Earth remains one of the most profound and enduring questions in natural science,”  ...

Indeed, scientists have long wondered why land plants did not emerge on Earth until 450 million years ago, even though their progenitors, cyanobacteria, had been in existence for 2.7 billion years. Likewise, there are no fossils for complex land animals or plants before the Cambrian era (541 to 485 million years ago) despite the evidence of much older microfossils.

“The only existing explanation states that this delay is an intrinsic characteristic of evolution — that an enormous amount of time is required,”  ..."

From the significance and abstract:

"Significance

... The resulting elevated flux of UV radiation may have restricted complex life to the ocean and potentially explains the relatively late colonization of multicellular life on land.

Abstract

The origin of complex life and the evolution of terrestrial ecosystems are fundamental aspects of the natural history on Earth. Here, we present evidence for a protracted stabilization of the Earth’s ozone layer. The destruction of atmospheric ozone today is inherently linked to the cycling of marine and atmospheric iodine. Supported by multiple independent lines of geological evidence and examined through an iodine mass balance model, we find that elevated marine iodide content prevailed through most of Earth’s history. Since the rise of oxygen ~2.4 billion years ago, high marine iodide concentrations would have led to significant inorganic iodine emissions to the atmosphere, facilitating catalytic ozone destruction and resulting in atmospheric ozone instability with periodic or persistently lower ozone levels. At a global scale, unstable and low ozone levels likely persisted for about two billion years until the early Phanerozoic, roughly 0.5 billion years ago. The delayed stabilization of the Earth’s ozone layer holds significant implications for the tempo and direction of the evolution of life, in particular life on land."

Earth’s air war: Explaining the delayed rise of plants, animals on land | Yale News "A new Yale study finds that a destabilized ozone layer may have delayed the rise of land animals and plants on Earth."

Evolution of the iodine cycle and the late stabilization of the Earth’s ozone layer (no public access)

NASA, NOAA 2024 Ozone Hole over the Antarctica Update

I believe, I have not heard or seen anything about the infamous Ozone Hole in years! This Ozone Hole was one of the big alarmism and hysteria of the 1980s!

Looks like the Ozone Hole is doing fine since the early 2000s!

ESA - Ozone hole goes large again

The infamous ozone hole of the 1970-1980s that led to the Montreal Protocol  in 1987 "to protect the ozone layer by phasing out the production and consumption of these harmful substances".

I suspect, it is e.g. this ozone hole that has contributed to the now so common anthropogenic or manmade accusations e.g. surrounding the Global Warming hoax and Climate Change religion.

I blogged here recently about the much underreported massive eruption of the submarine Hunga-Tonga volcano in January 2022. Almost like a blindspot in our climate crisis obsessed times. We can be lucky it was a submarine volcano.

"Measurements from the Copernicus Sentinel-5P satellite show that this year’s ozone hole over Antarctica is one of the biggest on record. The hole, which is what scientists call an ‘ozone depleting area,’ reached a size of 26 million sq km on 16 September 2023. This is roughly three times the size of Brazil. ...
The size of the ozone hole [naturally] fluctuates on a regular basis. From August to October, the ozone hole increases in size – reaching a maximum between mid-September and mid-October. ...

Although it may be too early to discuss the reasons behind the current ozone concentrations, some researchers speculate that this year’s unusual ozone patterns could be associated with the eruption of the Hunga Tonga-Hunga Ha'apai in January 2022. ... “The eruption of the Hunga Tonga volcano in January 2022 injected a lot of water vapour into the stratosphere which only reached the south polar regions after the end of the 2022 ozone hole. ..."

ESA - Ozone hole goes large again

Earth’s ozone layer is on track to recover within decades

This is quite a success story! A triumph of human ingenuity!

In my opinion, the depletion of the ozone layer and the Global Warming hoax and Climate change religion are quite often confused if not intentionally conflated although they are very different issues.

"... Scientists first identified a hole in the ozone layer, a thin part of the Earth’s atmosphere, back in 1985. Chlorofluorocarbons (CFCs), a group of chemicals that were commonly found in spray cans, fridges, foam insulation, and air conditioners, were largely blamed. International cooperation then stepped up to try to revert the damage. ...

The phase-out of the chemicals will also avoid an estimated 0.5 degrees Celsius of warming by 2100 ... The depletion of the ozone layer isn’t a big driver of climate change [??? Really! Most a likely ridiculous claim!] ...
The fixing of the ozone layer is also an example that we can, through international cooperation, solve environmental problems. It’s exactly the type of approach we need to deploy with climate change. [??? Wrong!] ..."

Earth’s ozone layer is on track to recover within decades Almost all the ozone-depleting substances have been phased out

Scientific Assessment of the Ozone Layer Depletion: 2022

The Ozone Layer Revisited

Posted: 9/14/2014

Trigger

Just read Earth's ozone layer on track to recovery, scientists report. The summary reads (emphasis added): “Earth's protective ozone layer is well on track to recovery in the next few decades thanks to concerted international [government] ]action against ozone depleting substances, according to a new assessment by 300 scientists.”

It refers to “The Assessment for Decision-Makers, a summary document of the Scientific Assessment of Ozone Depletion 2014, is being published by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO)”

Further: “Without the Montreal Protocol [on Substances that Deplete the Ozone Layer of 1987] and associated agreements, atmospheric levels of ozone depleting substances could have increased tenfold by 2050. According to global models, the Protocol will have prevented 2 million cases of skin cancer annually by 2030, averted damage to human eyes and immune systems, and protected wildlife and agriculture, according to UNEP.”

The Playbook For CO2 Government Intervention

Again, the Montreal Protocol apparently relied on computer model forecasts etc. like the Global Warmists. We know how inaccurate these computer models are at least since the Club of Rome Limits to Growth Report of 1972. These reports are in general very self serving for all the central planners of all stripes.

In essence this Protocol mandated a forced phase out of certain chemicals. I am not sure whether other options were seriously contemplated or pursued.

I am afraid the Montreal Protocol served as a model for continued heavy government intervention in the environment see e.g. the irrational CO2 craze.