Montreal Protocol clear evidence of a decrease in the atmospheric burden of ozone-depleting substances and some early signs of stratospheric ozone recovery." However, a more recent study seems to point to a relative increase in CFCs due to an unknown source. Reported in 1997, significant production of CFCs occurred in Russia for sale on the black market to the EU throughout the 90s. Related US production and consumption was enabled by fraudulent reporting due to poor enforcement mechanisms. Similar illegal markets for CFCs were detected in Taiwan, Korea, and Hong Kong. . The Montreal Protocol is also expected to have effects on
Montreal Protocol Antarctic Survey scientists Joe Farman, Brian Gardiner and Jonathan Shanklin published results of abnormally low ozone concentrations above Halley Bay near the South Pole. They speculated that this was connected to increased levels of CFCs in the atmosphere. It took several other attempts to establish the Antarctic losses as real and significant, especially after NASA had retrieved matching data from its satellite recordings. The impact of these studies, the metaphor 'ozone hole', and the colourful visual representation in a time lapse animation proved shocking enough for negotiators in Montreal, Canada to take the issue seriously. Also in 1985, 20 nations,