Thongchai Thailand


Posted on: November 24, 2020

The science checklist applied: CFCs and the destruction of the ozone layer


The devil in the details


Mario Molina’s Life Understanding, Protecting Our Atmosphere
October 13, 2020 David Doniger Amanda Maxwell

Dr. José Mario Molina Pasquel y Henríquez, who won the Nobel Prize in Chemistry for his 1974 discovery of the mortal threat to the earth’s protective ozone layer from chlorofluorocarbons (CFCs), died October 7 at the age of 77. As a post-doc at the University of California, Irvine, Dr. Mario Molina collaborated with Dr. F. Sherwood Rowland on a paper published in Nature in June 1974 proposing that seemingly inert CFCs—released from aerosol sprays, refrigerators and air conditioners, and many other products—were rising high into the atmosphere and destroying the thin layer of stratospheric ozone that shields us from the sun’s dangerous ultraviolet radiation. For these insights Molina and Rowland shared the 1995 Nobel Prize in chemistry with a third atmospheric scientist, Paul Crutzen. It is devilishly, almost poetically clever. Ozone is an unstable variant of oxygen—three oxygen atoms bound together instead of the more common two-atom molecule that we breathe. In the stratosphere, starting roughly six miles overhead, UV radiation is constantly making ozone molecules from oxygen, and constantly breaking those ozone molecules back down to oxygen. We’re safer down below because those ozone reactions absorb most of the UV and keep it from reaching the earth’s surface. Molina and his partner saw that the chlorine atoms in CFCs could upset the stable balance of ozone formation and destruction and erode the ozone shield. Nothing in the lower atmosphere harms CFCs. They break apart only when bathed in strong UV radiation upon reaching the stratosphere. Then their chlorine atoms react catalytically to destroy ozone molecules, turning them back into oxygen faster than nature makes new ones, and throwing the ozone layer out of balance. Rising CFC production would mean steep ozone losses, more UV radiation reaching the earth’s surface, more skin cancer, and a host of dangerous health and environmental impacts. As it happens, NRDC played a key role in bringing their scientific findings to public attention. An NRDC scientist, Karim Ahmed, arranged a press conference for Rowland in September 1974, which brought their findings to broad public attention, and an NRDC attorney, Tom Stoel, filed the first petitions asking federal agencies to ban CFC-containing aerosol sprays. Big news stories led to congressional hearings, consumer shifts away from aerosol sprays, and eventually government action. There are many fine tellings of the story from then on, in books like Between Earth and Sky and documentaries like Ozone Hole: How We Saved the Planet. It took courage for Molina and Rowland to speak out. They were harried by the industries that made and used CFCs and shunned by scientific societies shy of controversy. It took 13 years of advocacy by NRDC and other nongovernmental organizations before the world responded, when some 40 countries agreed in 1987 on the Montreal Protocol, a treaty that as amended has since phased out CFCs and other ozone-destroying chemicals worldwide. The vindication of the Nobel Prize did not come for 21 years. More than 30 years later, every country on earth is a party to the ozone treaty, and we have eliminated 97 percent of all ozone-destroying chemicals world-wide.

There has been damage—most visibly the gaping ozone hole that opens over Antarctica each September and will not disappear until after 2050—but we have largely avoided the worldwide public health catastrophe that Molina warned of. Dr. Molina did not limit his research or public advocacy to protecting the ozone layer. He was deeply engaged in combatting climate change. The connection is obvious, since CFCs and their substitutes, including the hydrofluorocarbons (HFCs), are also powerful heat-trapping greenhouse gases. Molina co-authored an important scientific paper on the importance of quick action to curb HFCs—findings that helped lead to the global HFC phase-down agreement adopted in 2016, in the Kigali Amendment to the Montreal treaty. Molina spoke out frequently on the need to cut emissions of carbon dioxide and methane from fossil fuels, as well as these industrial chemicals. He co-wrote What We Know: The Reality, Risks, and Response to Climate Change, for the American Academy for the Advancement of Science. He received the Presidential Medal of Freedom from President Obama in 2013. Dr. Molina also dedicated himself to addressing air pollution and climate issues in his home country of Mexico. In 2004 he established the Mario Molina Center, a non-profit, non-political institute focused on improving the well-being of all Mexicans by connecting scientific research with environmental and energy policies. With programs focusing on energy, air quality, sustainable cities and education in addition to climate change, the center has built a strong reputation as a solid, credible and positive source of research and policy solutions. In 2007, NRDC joined the Mario Molina Center and other groups in calling for stricter efficiency and emissions standards for Mexico’s vehicles. We argued that raising standards for heavy-duty vehicles to U.S. levels would avoid 55,000 premature deaths and deliver more than $120 billion in net benefits for the country. That effort has lasted years, transcending three different presidential administrations, and Molina’s work has remained at the center of the conversation. Molina spoke out against the Trump administration’s climate denial, abandonment of the Paris Accord, and regulatory rollbacks.The message they are sending to the rest of the world is that they don’t believe climate change is serious. It’s shocking to see such a degree of ignorance from the United States,” Molina said. As recently as August 2020, Dr. Molina addressed the grave need to improve air quality in Mexico and for new technological innovations to do so. This is a stark contrast to the policies of the current Mexican president, Andrés Manuel López Obrador, who is like President Trump in championing the fossil fuel industry and ignoring climate change. It is our job to carry on his legacy and get Dr. Molina’s two countries back on the right side of science and history.



Mario Molina, 77, Dies; Sounded an Alarm on the Ozone Layer - The New York  Times




(1) HISTORY OF THE OZONE DEPLETION ISSUE The ozone story goes back to the 1960s when there was a plan to develop high altitude supersonic airliners. The high cruising altitude of the SST raised alarms that SSTs would cause both climate change and ozone depletion. The alarm related to chemicals and aerosols in SST exhaust and the science of their impact on the atmosphere. The climate change theory was quietly shelved and forgotten and the alarm later focused on ozone depletion with a forecast of 40,000 additional cases of skin cancer every year in the USA alone. In 1971 a theory was proposed that Nitric oxide (NOx) in the SST jet exhaust will cause ozone depletion because NOx acts as a catalyst to destroy ozone according to computer models. The model forecast said that there will be a 50% ozone depletion and a worldwide epidemic of skin cancer. Animals that venture out during daylight will become blinded by UV radiation. Ozone science deniers pointed out that the ozone had survived the NOx in the fireball of open air nuclear tests, but by 1972, the ozone depletion activism against the SST had won and the SST program died because we were too frightened by the ozone depletion scare. 1972 was the first “Montreal Protocol”.In 1973 fear mongering ozone depletion scientists turned their attention to the proposed Space Shuttle program. The shuttle design included two solid fuel rockets that emit hydrogen chloride (HCl) which the scientists said would cause ozone depletion. The space shuttle miraculously survived the 1973 scare but the ozone depletion game was now in full gear, having tasted the power of being able to inflict debilitating fear of ozone depletion. 1973: In a now famous paper {Lovelock, Maggs, and Wade 1973}, he presented the discovery that air samples above the Atlantic ocean far from human habitation contained measurable quantities of HHC. This was he first of three key events that led to the Montreal Protocol and its worldwide ban on the production, sale, and atmospheric release of HHC and the rise of the UN as a global environmental regulator. 1974 a new candidate of ozone depletion was identified. Environmentalist James Lovelock studied the unrestricted release of halogenated hydrocarbons (HHC) into the atmosphere from their use as aerosol dispensers, fumigants, pesticides, and refrigerants. {Halogenated hydrocarbons (HHC) are also described as HFC}. Lovelock was concerned that these chemicals were man-made and they did not otherwise occur in nature and that they were chemically inert and that therefore their atmospheric release could cause irreversible accumulation. However, since HHCs were non-toxic and environmental science knew of no harmful effects of HHC, the environmental concern expressed in Lovelock etal 1973 about their accumulation in the atmosphere remained an academic curiosity. This changed in 1974 with the publication of a paper by Mario Molina and Frank Rowland in which is contained a theory of ozone depletion by HHC. According to the Rowland-Molina theory of ozone depletion (RMTOD), the extreme volatility and chemical inertness of the HHCs ensure that there is no natural sink for these chemicals in the troposphere and that therefore once emitted they may remain in the atmosphere for 40 to 150 years and be transported by diffusion and atmospheric motion to the stratospheric ozone layer where they are subjected to solar radiation at frequencies that will cause them to dissociate into chlorine atoms and free radicals. Chlorine atoms can then act as a catalytic agent of ozone destruction in a chemical reaction cycle described in the paper. It proposed that such ozone depletion by HHC poses a danger because the ozone layer protects life on the surface of the earth from the harmful effects of UVB radiation. It is often thought that “Rowland and Molina, discovered that CFCs released from aerosol sprays could rise miles over our heads into the stratosphere and destroy ozone molecules. This statement is false. They did not” discover“ this relationship between CFCs and ozone. They proposed it as a theory. The theory required validation by empirical evidence.

1985: The RMTOD was later considered to have been validated with empirical evidence in a 1985 paper by Farman etal . “Large losses of total ozone in Antarctica reveal seasonal ClOx/NOx interaction J. C. Farman, B. G. Gardiner & J. D. Shanklin, Nature volume 315, pages207–210(1985) Abstract
Recent attempts to consolidate assessments of the effect of human activities on stratospheric ozone using one-dimensional models for 30° N have suggested that perturbations of total ozone will remain small for at least the next decade. Results from such models are often accepted by default as global estimates. The inadequacy of this approach is here made evident by observations that the spring values of total ozone in Antarctica have now fallen considerably. The circulation in the lower stratosphere is apparently unchanged, and possible chemical causes must be considered. We suggest that the very low temperatures which prevail from midwinter until several weeks after the spring equinox make the Antarctic stratosphere uniquely sensitive to growth of inorganic chlorine, ClX, primarily by the effect of this growth on the NO2/NO ratio. This, with the height distribution of UV irradiation peculiar to the polar stratosphere, could account for the O3 losses observed. The Farman etal 1985 paper was the third and final key event in the sequence Lovelock to RMTOD to Farman, that led to the Montreal Protocol. It established that the atmospheric accumulation of HHC found by Lovelock (1) is not harmless by providing the RMTOD theoretical framework (2) that links HHC to ozone depletion and finally with the theory validated by empirical evidence in Farman etal.

An undeniable problem in Antarctica

(2) THE PROBLEM WITH FARMAN ETAL 1985: In a related post LINK: we show that the declining levels of total column ozone in Antarctica during the months of October and November over a 6-year period prior to 1985 found by Farman etal 1985 do not serve as empirical evidence that can be taken as validation of the Rowland-Molina theory of chemical ozone depletion (RMTOD).

The RMTOD chemical theory of ozone depletion implies a gradual decline in mean global total column ozone over time periods longer than 40 years. This means that ozone depletion must be measured across the full range of latitudes and across time spans longer than 6 years. This is not what we find in Farman etal 1985. And yet, this paper serves as the sole basis for the validation of the RMTOD ozone depletion hypothesis. Stranger yet, this paper serves as the sole empiric al support for the Montreal Protocol and the ascendance of the UN as a global environmental authority.

In a related post#2 on the ozone hole: LINK: we show that the claim by NASA that the periodic and brief ozone hole event serves as evidence of ozone depletion is fatally flawed because ozone hold events are localized and brief, that is they are both time and geography constrained and that therefore they do not provide evidence of long term declining trends in global mean total column ozone.

In related post#3 LINK: we present the overall structure of changes in total column ozone levels over a 50-year sample period from 1966 to 2015 and across a range of latitudes from -90 to +71degrees latitude. Our findings show that the data from Antarctica prior to 1990 represent a peculiar outlier condition specific to that time and place and not an enduring global pattern. The finding is inconsistent with the claim that the Farman etal 1985 paper on a South Pole ozone event serves as empirical evidence for the Rowland-Molina theory of chemical ozone depletion.

(3): A post on this site on the passing of Mario Molina: LINK:

There we note as follows:



Here we use ozone data from ground stations to carry out an empirical test of the RMTOD. Total column ozone (TCO) measurements made with Dobson spectrophotometers at twelve ground stations are used in this study. The stations are selected to represent a large range of latitudes with the latitudes classified into five groups as (1) high southern latitudes (90S to 60S), (2) mid- southern latitudes (60S to 30S), (3) Tropical (30S to 30N), (4) mid- northern latitudes (30N to 60N), and (5) high northern latitudes (60N to 90north). The data are provided by the NOAA and the BAS (British Antarctic Survey).

As in Farman etal 1985, the ozone data are studied as five year (Lustrum) averages and not as annual data to smooth out data availability differences. These period definitions are not precise for the first and last Lustra. The first Lustrum is longer than five years for some stations and shorter than five years for others. The last Lustrum is imprecise because of the variability in the last month of data availability. The calendar month sequence is arranged from September to August in the tables and charts presented to maintain seasonal integrity. The seasons are roughly defined as follows: September-November (northern autumn and southern spring), December-February (northern winter and southern summer), March-May (northern spring and southern autumn), and June-August (northern summer and southern winter).

Daily and intraday ozone data are averaged into monthly means for each period. These monthly means are then used to study trends across the ten Lustra for each calendar month and also to examine the average seasonal cycle for each Lustrum. Trends in mean monthly ozone and seasonal cycles are compared to examine the differences among latitudes. These patterns are then used to compare and evaluate the chemical and transport theories for changes in atmospheric ozone. The chemical explanation of these changes rests on the destruction of ozone by chlorine atoms derived from HHC (Molina, 1974) while the transport theory describes them in terms of the Brewer-Dobson circulation (BDC) and polar vortices that transport ozone from the tropics where they are formed to the greater latitudes where they are more stable (Kozubek, 2012) (Butchart, 2014) (Tegtmeier, 2008) (Weber, 2011).

Details of these data, station by station, are presented numerically and graphically here LINK: AND SUMMARIZED IN THE CHARTS BELOW.


The concern about ozone depletion is derived from the finding by Farman et al in 1985 that ozone levels at HLB fell by 6DU per year from the 1957-1973 average to the 1980-1984 average. The data presented HERE show that ozone depletion rates of 6DU/year and higher are seen only at the South Pole. Outside of the South Pole the mean ozone depletion rate is close to zero with an uncertainty range of +/- 1DU per year, a range perhaps indicative of random natural variability.

It is therefore not likely that the HLB data reported by Farman et al can be generalized globally. Yet, it served as the sole basis of validating the Rowland Molina theory of ozone depletion. This event then gave rise to the ozone depletion alarm that in turn led to a global environmental role of the UN and the Montreal Protocol, and eventually an assumed authority of the UN over global environmentalism and the climate change alarmism of our time.


September | 2020 | Thongchai Thailand

(4) FEAR BASED ACTIVISM FUNNELLED THROUGH THE MEDIA: The media then stepped in with an intensive exercise in fear based activism to promote compliance with the Montreal Protocol. Here are some examples: March 10 1987: Skin cancer is increasing in the United States at a near epidemic rate, outstripping predictions made as recently as five years ago, a research physician testified Monday before a House panel examining threats to the Earth’s protective ozone layer. Malignant melanoma, the deadliest form of skin cancer, has increased 83 percent in the last seven years alone. Melanoma is increasing faster than any other cancer except lung cancer in women.: March 12, 1987 Consensus among scientists: If harmful UV radiation reached the Earth, it would cause monumental problems, including rampant skin cancer and eye cataracts, retarded crop growth, impairment of the human immune system and damaging radiation doses to all forms of life. Although many Americans and the people of other nations are still not listening or taking the ozone threat seriously, the Earth’s protective shield is getting thinner and developing mysterious holes. There is a growing consensus among scientists that ozone destruction is caused by the accumulation in the upper atmosphere of chlorofluorocarbons (CFCs), a class of industrial chemicals used for refrigerants, aerosols, insulation, foam packaging and other uses.: August 23, 1987: Ozone Hole: Scientists have begun the largest study ever of the depletion of the ozone layer in the atmosphere by sending a modified spy plane on missions 12 1/2 miles above Antarctica. The flights this past week were part of a $10-million project being carried out by a 120-member team of scientists, engineers and technicians who hope to decipher a mysterious ozone hole that has been detected over Antarctic each winter for the past eight years.

PDF) The United Nations: What Prospects for Reform? | Graham Hassall -
PDF) The United Nations: An Unconstrained Bureaucracy


How do very heavy CFC molecules make it to the stratosphere in any significant amounts?

They are claimed to be light in the rowland and molina paper. In any case we don’t have any evidence that they really did make it up there nor any evidence that they caused ozone depletion. Thank you for bringing this up.

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