'Car of sweetheart polluted' (statement about climate change) (7,8)
I believe the answer is:
weather forecast
'statement about climate change' is the definition.
'car of sweetheart polluted' is the wordplay.
'polluted' indicates anagramming the letters.
'car'+'of'+'sweetheart'='carofsweetheart'
'carofsweetheart' with letters rearranged gives 'WEATHER FORECAST'.
(Other definitions for weather forecast that I've seen before include "Met objective" , "prediction" , "item after news" , "Predicton" .)