A sizable diminution in level of ozone in the atmosphere was

这句话的主语部分是A sizable diminution in level of ozone in the atmosphere,谓语部分是was detected,over Antarctica in 1985是时间状语和地点状语.
逗号后是现在分词短语作状语,vindicating印证scientists （who had issued warnings in the early 1970s）(定语从句修饰scientists)( that chlorofluorocarbons and other types of industrial chemicals might cause a reaction)(warning的同位语从句） which would deplete ozone in the upper atmosphere.（定语从句修饰reaction)

（A sizable diminution in level of ozone in the atmosphere） was detected over Antarctica in 1985,vindicating scientists（ who had issued warnings in the early 1970s ）that （chlorofluorocarbons and other ...