A supporting structure, one with carbon, is revolutionary (8)
I believe the answer is:
anarchic
'is revolutionary' is the definition.
(I've seen this before)
'a supporting structure one with carbon' is the wordplay.
'a' becomes 'an'.
'supporting structure' becomes 'arch' (I've seen this before).
'one' becomes 'i' (Roman numeral).
'with' is a charade indicator (letters next to each other).
'carbon' becomes 'C' (C is the chemical symbol for carbon).
'an'+'arch'+'i'+'c'='ANARCHIC'
(Other definitions for anarchic that I've seen before include "Disorderly" , "Lawless, lacking government or control" , "With no ruling principles to give order" , "lacking proper rule" , "Without order or control" .)