Recent marked decrease in overall Antarctic sea ice extent to record minimum levels [e.g., ( 30 )] may be an important indicator of the onset of a negative trend [e.g., ( 31 )] or of a tipping point being crossed ( 32 , 33 ).
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Recent marked decrease in overall Antarctic sea ice extent to record minimum levels [e.g., ( 30 )] may be an important indicator of the onset of a negative trend [e.g., ( 31 )] or of a tipping point being crossed ( 32 , 33 ).