Ruedi Wragg has been found guilty of three counts of malicious damage at Jersey’s Magistrate’s Court.
The 63-year-old was arrested at the climate change mural on the Waterfront on Boxing Day 2021 after islanders tipped off police.
Wragg was found wearing a motorbike helmet with spray cans and a step ladder.
He vandalised the mural in November and December 2021.
He was given a Binding Over Order and told to pay compensation and costs.
DC Caroline Foord says unauthorised graffiti is vandalism.
"Wragg’s actions on these occasions ruined a public piece of art that had to be cleaned up and redesigned at a cost to taxpayers to over £4,000.”
The mural shows a collection of coloured stripes, which represent the year's average temperature. The most recent addition was 2022's 'very dark red stripe' for the hottest year on record.