GS1 (Geography)
Recently the ozone hole has started healing, after decades of international efforts. What is the ozone hole? How has the world tried to heal it?
Best answer
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When ultraviolet light waves (UV) strike Chlorofluorocarbons CFC* (CFCl3) molecules in the upper atmosphere, a carbon-chlorine bond breaks, producing a chlorine (Cl) atom. The chlorine atom then reacts with an ozone (O3) molecule breaking it apart and so destroying the ozone.
The ozone layer above the Antarctic has been particularly impacted by pollution since the mid-1980s. This region’s low temperatures speed up the conversion of CFCs to chlorine. In the southern spring and summer, when the sun shines for long periods of the day, chlorine reacts with ultraviolet rays, destroying ozone on a massive scale, up to 65 percent. This is what some people erroneously refer to as the “ozone hole.” In other regions, the ozone layer has deteriorated by about 20 percent.
Through the 1970s and the 1980s, the international community became increasingly concerned that ozone-depleting substances(ODS)would harm the ozone layer. In 1985, the Vienna Convention for the Protection of the Ozone Layer formalized international cooperation on this issue.The Vienna Convention is the precursor to the Montreal Protocol which signed in 1987, was the first step in international efforts to protect stratospheric ozone. Under the original Montreal Protocol agreement (1987), developed countries were required to begin phasing out CFCs in 1993 and achieve a 20% reduction relative to 1986 consumption levels by 1994 and a 50% reduction by 1998. Additionally, developed countries were required to freeze their production and consumption of halons relative to their 1986 levels. After the Montreal Protocol was signed, new data showed worse-than-expected damage to the ozone layer. In 1992, the Parties to the Protocol decided to alter the terms of the 1987 agreement to end production of halons by 1994 and CFCs by 1996 in developed countries.Because of measures taken under the Montreal Protocol, emissions of ODS are falling and the ozone layer is expected to be fully healed near the middle of the 21st century.
The ozone layer above the Antarctic has been particularly impacted by pollution since the mid-1980s. This region’s low temperatures speed up the conversion of CFCs to chlorine. In the southern spring and summer, when the sun shines for long periods of the day, chlorine reacts with ultraviolet rays, destroying ozone on a massive scale, up to 65 percent. This is what some people erroneously refer to as the “ozone hole.” In other regions, the ozone layer has deteriorated by about 20 percent.
Through the 1970s and the 1980s, the international community became increasingly concerned that ozone-depleting substances(ODS)would harm the ozone layer. In 1985, the Vienna Convention for the Protection of the Ozone Layer formalized international cooperation on this issue.The Vienna Convention is the precursor to the Montreal Protocol which signed in 1987, was the first step in international efforts to protect stratospheric ozone. Under the original Montreal Protocol agreement (1987), developed countries were required to begin phasing out CFCs in 1993 and achieve a 20% reduction relative to 1986 consumption levels by 1994 and a 50% reduction by 1998. Additionally, developed countries were required to freeze their production and consumption of halons relative to their 1986 levels. After the Montreal Protocol was signed, new data showed worse-than-expected damage to the ozone layer. In 1992, the Parties to the Protocol decided to alter the terms of the 1987 agreement to end production of halons by 1994 and CFCs by 1996 in developed countries.Because of measures taken under the Montreal Protocol, emissions of ODS are falling and the ozone layer is expected to be fully healed near the middle of the 21st century.
