<P> At Montreal, the participants agreed to freeze production of CFCs at 1986 levels and to reduce production by 50 percent by 1999 . After a series of scientific expeditions to the Antarctic produced convincing evidence that the ozone hole was indeed caused by chlorine and bromine from manmade organohalogens, the Montreal Protocol was strengthened at a 1990 meeting in London . The participants agreed to phase out CFCs and halons entirely (aside from a very small amount marked for certain "essential" uses, such as asthma inhalers) by 2000 in non-Article 5 countries and by 2010 in Article 5 (less developed) signatories . At a 1992 meeting in Copenhagen, the phase - out date was moved up to 1996 . At the same meeting, methyl bromide (MeBr), a fumigant used primarily in agricultural production, was added to the list of controlled substances . For all substances controlled under the protocol, phaseout schedules were delayed for less developed (' Article 5 (1)') countries, and phaseout in these countries was supported by transfers of expertise, technology, and money from non-Article 5 (1) Parties to the Protocol . Additionally, exemptions from the agreed schedules could be applied for under the Essential Use Exemption (EUE) process for substances other than methyl bromide and under the Critical Use Exemption (CUE) process for methyl bromide . </P> <P> Civil society including especially NGOs, played critical roles at all stages of policy development leading up to the Vienna Conference, the Montreal Protocol, and in assessing compliance afterwards . The major companies claimed that no alternatives to HFC existed . An ozone - safe hydrocarbon refrigerant was developed at a Hamburg technological institute in Germany, and in 1992 came to the attention of the non-governmental organization (NGO) Greenpeace . Greenpeace was given the patent, called it "Greenfreeze," and left the patent as open source . The NGO then worked successfully first with a small and struggling company to market an appliance beginning in Europe, then Asia and later Latin America, receiving a 1997 UNEP award . By 1995, Germany had already made CFC refrigerators illegal . Since 2004, corporations like Coca - Cola, Carlsberg, and IKEA have been forming a coalition to promote the ozone - safe Greenfreeze units . Production spread to companies like Electrolux, Bosch, and LG, with sales reaching some 300 million refrigerators by 2008 . In Latin America, a domestic Argentinian company began Greenfreeze production in 2003, while the giant Bosch in Brazil began a year later . By 2013 it was being used by some 700 million refrigerators, making up about 40 percent of the market . In the U.S., however, change has been much slower . To some extent, CFCs were being replaced by the less damaging hydrochlorofluorocarbons (HCFCs), although concerns remain regarding HCFCs also . In some applications, hydrofluorocarbons (HFCs) were being used to replace CFCs . HFCs, which contain no chlorine or bromine, do not contribute at all to ozone depletion although they are potent greenhouse gases . The best known of these compounds is probably HFC - 134a (R - 134a), which in the United States has largely replaced CFC - 12 (R - 12) in automobile air conditioners . In laboratory analytics (a former "essential" use) the ozone depleting substances can be replaced with various other solvents . Chemical companies like Du Pont, whose representatives even disparaged Greenfreeze as "that German technology," maneuvered the EPA to block the technology in the U.S. until 2011 . Ben & Jerry's of Unilever and General Electric, spurred by Greenpeace, had expressed formal interest in 2008 which figured in the EPA's final approval . </P> <P> More recently, policy experts have advocated for efforts to link ozone protection efforts to climate protection efforts . Many ODS are also greenhouse gases, some thousands of times more powerful agents of radiative forcing than carbon dioxide over the short and medium term . Thus policies protecting the ozone layer have had benefits in mitigating climate change . In fact, the reduction of the radiative forcing due to ODS probably masked the true level of climate change effects of other GHGs, and was responsible for the "slow down" of global warming from the mid-90s . Policy decisions in one arena affect the costs and effectiveness of environmental improvements in the other . </P> <P> The IMO has amended MARPOL Annex VI Regulation 12 regarding ozone depleting substances . As from July 1, 2010, all vessels where MARPOL Annex VI is applicable should have a list of equipment using ozone depleting substances . The list should include name of ODS, type and location of equipment, quantity in kg and date . All changes since that date should be recorded in an ODS Record book on board recording all intended or unintended releases to the atmosphere . Furthermore, new ODS supply or landing to shore facilities should be recorded as well . </P>

What are the problems with the ozone layer