Vital Ozone Graphics 3

07 mobilization 2 The Montreal Protocol on Substances that Deplete the Ozone Layer ranks as one of the great success stories of international environmental diplomacy, and a story that is still unfolding. The protocol, along with its processor the Vienna Convention, is the international response to the problem of ozone depletion agreed in September 1987 following intergovernmental negotiations stretching back to 1981. Following the confirmation of the ozone destruction theory with the discovery of the Antarctic ozone hole in late 1985, Governments recognised the need for stronger measures to reduce consumption and production of various CFCs and halons. The Montreal Protocol came into force on 1 January 1989andfirst reacheduniversal ratification inSeptember 2009. successful environmental diplomacy 22

It is widely believed that without the Protocol, ozone deple- tion could have risen to around 50 per cent in the northern hemisphere and 70 per cent in the southern mid-latitudes by 2050. This would have resulted in twice as much UV-B reaching the Earth in the northern mid-latitudes and four times as much in the south. The implications of this would have been horrendous: 19 million more cases of non mela-

noma cancer, 1.5 million cases of melanoma cancer, and 130 million more cases of eye cataracts.

Instead, atmospheric and stratospheric levels of key ozone depleting substances are going down, and it is believed that with full implementation of all of the provisions of the Proto- col, the ozone layer should return to pre-1986 levels by 2065.

THE OZONE INTERNATIONAL AWAKENING

Fabry and Buisson use UV measurements to prove that most ozone is in the stratosphere.

Cornu theorizes that a gas in the atmosphere filters UV-radiation. Hartley identifies ozone as this filtering gas.

Fabry and Buisson take quantitative measurements of total ozone column in Marseille.

Swarts pioneers fluorocarbon chemistry.

Methyl bromide and carbon tetrachloride introduced as fire-extinguishing agents, solvents, plastic ingredients.

Dobson and Harrison invent the Dobson-meter to monitor total atmospheric column ozone.

Wegener first to study the decomposition of ozone using UV light..

1879 1881

1906

1913

1924

1870 1890

1900

1910

1920

Timescale change

Science Field: Chemical firms Governments and international institutions

Source: Stephen O Andersen, K Madhava Sarma, Protecting the Ozone Layer, the United Nations History, UNEP, Earthscan Publishing, 2002; US Environmental protection Agency, Achievements in Stratospheric Ozone Prote