___ Amendment (2010s extension of the Kyoto Protocol) (4)

I think it could be either:

Which length description are you looking for?:

reform

'amendment' is the definition.
(thesaurus)

This is all the clue.

(Other definitions for reform that I've seen before include "Correct(ion of) abuses" , "Mend one's ways" , "Change one's ways (for the better?)" , "Show improvement" , "Abandon evil practices" .)

I've seen this clue in The Guardian.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.