Trends in CFCs and Their Replacements

FIGURE 13.4 Fits to monthly mean tropospheric concentrations of some CFCs and other chlorinated organics falling under the Montreal Protocol and its amendments in the Northern Hemisphere 

For example, before the Montreal Protocol, the annual growth rates of CFC-11, CFC-12, and CFC-113 were approximately 10, 18, and 6 ppt per year, respectively however, the growth rates in mid-1995 were 

SCIENTIFIC BASIS FOR CONTROL OF HALOGEN ATEL) ORGANICS 

At the same time that the production and usage of the compounds shown in Figs. 13.4 and 13.5 were decreasing due to the international agreements, the use of alternates (Table 13.1) was increasing (e.g., see Midgley and McCulloch, 1997 and McCulloch and 

FIGURE 13.5 Global mean mixing ratios for the halons H-1301, H-1211, and H-2402 from f987 to 1997 (adapted from Butler et at., f998). 

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