Like issues raised by eco-warriors showing violent manner possibly (13)
I believe the answer is:
environmental
'like issues raised by eco-warriors' is the definition.
'violent manner possibly' is the wordplay.
'possibly' indicates an anagram.
'violent'+'manner'='violentmanner'
'violentmanner' is an anagram of 'ENVIRONMENTAL'.
'showing' is the link.
(Other definitions for environmental that I've seen before include "To do with one's surroundings" , "Pertaining to the surrounding world" , "Green" .)