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Stratospheric Ozone Depletion

Stratospheric Ozone Depletion is one of 9 interplanetary boundaries.

Introduction to Planetary Boundaries

Planetary Boundaries is a concept where each of the nine boundaries are interconnected with one another. It was proposed by a group of earth system and environmental scientists led by Johan Rockström from the Stockholm Resilience Centre and Will Steffen from the Australian National University.

When one boundary is pushed beyond it’s limits, it can cause catastrophe for the other boundaries. It’s a bit like looking at the planet as a whole ecosystem.

Some people argue and say that using planetary boundaries implies that humans can continue their destructive ways up until a determined limit and thus not change methods entirely. I agree with them. I believe we should be altering our methods so that we are healing the planet and not taking without replacing.

I do, however find the planetary boundaries concept interesting because it alerts us to the dangerous territory we are embarking on that could cause the life, including human life, on our blue planet to collapse.

Business as usual in a system that is based on infinite resources is leading us to the depths of Modor, to put it figuratively. We are dancing on the edge of a cliff and we must find our way back to the laws of nature.

Nature is a wonderful thing. She is fruitful, rewarding and can pour abundant doses of happiness into our souls. That sentence only applies when we treat her with respect. If we abuse her, punish her, force her and overpower her, she will become hostile. Unfortunately many innocent lives are at stake for the actions of a few people orientated by money and immediate gratification. We must look into the future and think ahead. Immediate gratification is like an addiction and it will make us sick.

Our Ozone Layer


The ozone layer encircles the Earth, and it is a gaseous layer situated at the lower end of the stratosphere. Ozone is a molecule made up of 3 oxygen atoms. The oxygen we breath is made up of molecules with 2 oxygen atoms. The ozone layer has more ozone in it than any other atmospheric layer around the earth. Ozone serves an important purpose for life on earth. It blocks harmful ultraviloet radiation that comes from the sun.

It is compelling to know that ultraviolet radiation from the sun actually forms the ozone molecules in the ozone layer. Ozone forms when radiation or electrical discharge separates the two atoms in an oxygen molecule (O2), and these free oxygen atoms can form with other oxygen molecules (O2) to form ozone (O3).

The general public became more aware of the ozone layer when scientists discovered that certain chemicals manufactured by humans destroyed some of our ozone. These harmful chemicals include chloroflurocarbons (CFCs) and caused a ‘hole’ (or rather a considerable less amount of ozone) in our ozone layer that sits over Antartica during the spring time.

After an outcry, an international treaty was signed in 1973 called the Montreal Protocol, and the manufacture of these chemicals was greatly reduced.

The ozone layer destruction has slowed down significantly and we are hoping that it will continue to heal with humanity’s cooperation. There is some science that suggests that major volcanic eruptions (mainly El Chichon in 1983 and and Mt. Pinatubo in 1991) may have also contributed to the ozone depletion.

If the ozone layer continued to deplete, humans would be susceptible to various cancers, cataracts and plants would not grow well thus impacting our food supply. Whales have also shown signs of skin damage due to the hole in the ozone layer.

While stratospheric ozone which protects us from the sun is good, there is also ozone produced near the ground from sunlight interacting with atmospheric pollution in cities that is bad for human health. It causes breathing problems for some people, and usually occurs in the summertime when the pollution over a city builds up during stagnant air conditions

The planetary boundary for the ozone layer is recorded in Dobson Units and is currently 276 Dobson units. That means if we fall under 276 units, we have passed the threshold. The current reading accorning to Wikipedia is 283 Dobson Units. The value before industrial times was 290.



Here is an interesting timeline of the history of the ozone layer from Note Du Pont’s role in this, who is also responsible for biodiversity loss in food by producing pesticides, herbicides and genetically modified food to survive these poisions.


600,000,000 B.C. Ozone layer forms
1839 Christian Schöenbein identifies ozone in the laboratory
1845 Auguste de la Rive and Jean-Charles de Marignac suggest ozone is a form of oxygen; confirmed by Thomas Andrews in 1856
1858 Andrei Houzeau finds ozone present in natural air
1865 Jean-Louis Soret proves that ozone is O3
1879 Marie Alfred Cornu measures solar spectrum and finds sharp cutoff in ultraviolet (UV) light
1881 Walter Hartley recognizes cutoff corresponds to UV absorption by ozone
1913 John William Strutt (Lord Rayleigh) shows absorption is not in lower atmosphere
1919 Charles Fabry makes first spectrometric measurements of “thickness” of ozone layer
1924 G.M.B. Dobson develops ozone spectrophotometer and begins regular measurements of ozone abundance (Arosa, Switzerland)
1925 Jean Cabannes and Jean Dufay show ozone is about 10 miles high
1928 Thomas Midgley synthesizes chlorofluorocarbons (CFC’s)
1929 Umkehr method for Dobson instrument establishes that ozone maximum is below 15 miles altitude
1930 Sydney Chapman describes theory that explains existence of an ozone “layer”
1934 Ozonesonde (balloon) measurements establish the ozone concentration is maximum around 12 miles up
1930’s GM develops applications for CFC’s
1950 David Bates and Marcel Nicolet propose catalytic (HOx) ozone destruction
1957 Global network of Dobson spectrophotometers established during the International Geophysical Year (IGY)
late 1950’s CFC market expands rapidly
early 1960’s Catalytic destruction is necessary in order to explain ozone amounts
1960’s Boeing proposes supersonic transport (SST) fleet of 800 aircraft
1969 Paul Crutzen discovers NOx catalytic cycle
1971-74 Dept of Transportation sponsors intensive program of research, The Climatic Impact Assessment Program (CIAP)
1971 Congress axes funding for the SST
1971 Johnston calculates that NOx from SST’s could deplete ozone layer
1973 Rick Stolarski and Ralph Cicerone suggest catalytic capability of Cl
1973 James Lovelock detects CFC’s in atmosphere
1974 Sherwood Rowland and Mario Molina warn of ozone depletion due to CFC’s
March 1977 First international meeting (Washington DC) to address issue of ozone depletion held by the United Nations Environmental Programme (UNEP)
March 1978 US bans non-essential use of CFC’s as aerosol propellant
1978 Total Ozone Mapping Spectrometer (TOMS) is launched aboard NIMBUS-7 spacecraft giving global coverage of ozone layer thickness
1980’s Renewed expansion of CFC market
Oct 1982 Shigeru Chubachi measures low ozone over Syowa, Antarctica (reported at Ozone Commission meeting in Halkidiki, Greece in Sept 1984)
1984 British Antarctic Survey scientists discover recurring springtime Antarctic ozone hole (published in Nature May 1985)
March 1985 Vienna Convention for the Protection of the Ozone Layer
Sept. 1987 Montreal Protocol on Substances That Deplete the Ozone Layer (Amendments – London 1990; Copenhagen 1992)
March 1988 DuPont agrees to CFC production phase-out
late 1980’s Ten years of satellite data begin to show measurable ozone depletion globally
1991 DuPont announces phase-out of CFC production by end of 1996
1992/3 Abnormally low ozone observed globally
1995 Crutzen, Rowland, and Molina win Nobel Prize in Chemistry
mid-1990’s springtime Arctic ozone dent appearing
Jan. 1996 CFC production ends in US and Europe
2000 Maximum CFC concentrations in stratosphere are reached
Today The Ozone Layer – Global Map


2010 CFC production ends world-wide
2030 Hydrochlorofluorocarbon (HCFC) alternatives are phased out
2040 HCFC production ends world-wide
2050 Springtime Antarctic ozone hole disappears

I did find a video that states that the ozone layer is not healing and I cannot ignore it from this article. To view it, click here.

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