Striking success story about storing carbon (5)
I believe the answer is:
eclat
'striking success' is the definition.
(I've seen this in another clue)
'story about storing carbon' is the wordplay.
'story' becomes 'tale' (synonyms).
'about' is a reversal indicator.
'storing' is an insertion indicator.
'carbon' becomes 'C' (C is the chemical symbol for carbon).
'tale' back-to-front is 'elat'.
'elat' placed around 'c' is 'ECLAT'.
(Other definitions for eclat that I've seen before include "French renown" , "Ceremonial elegance and splendour" , "Universal approval" , "Enthusiastic approval" , "Brilliant display or effect" .)