Online distortion for current movement that may be climate-changing (2,4)
I believe the answer is:
el nino
'current movement that may be climate-changing' is the definition.
(El Nino is a weather phenomenon)
'online distortion' is the wordplay.
'distortion' indicates anagramming the letters.
'online' is an anagram of 'EL NINO'.
'for' acts as a link.
(Other definitions for el nino that I've seen before include "Warm tropical Pacific ocean current" , "What may affect the weather" , "Pacific feature affecting climate" , "Periodic climatic phenomenon" , "Irregular Pacific climatic event" .)