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But he has taken another swing at his most persistent political rival - Cr Lee Vandervis - before he departs.
Mr Cull fronted media yesterday to explain his decision to stand down at local body elections in October.
The decision would end a political career as a city councillor, three-term mayor and Local Government New Zealand president.
It was a move he first confirmed to the Otago Daily Times earlier this week, when he said his age - he will be 70 next year - and desire for more family time were paramount.
Mr Cull said the mayoralty required "a lot of energy", and, while he was still motivated and enjoying the job now, he could not guarantee that would remain the case for another term.
He was proud of his time leading councils which had established "a good platform" for growth and development.
But the city faced "major challenges" from growth, the need for new infrastructure and other major developments.
And, looming over it all, was climate change, he said.
Mr Cull believed it was time for someone with fresh energy to tackle those challenges, which were not insurmountable.
But the impact of rising sea levels on South Dunedin would be "tricky" as the effects manifest themselves slowly over time, he said.
The community would need to be well informed about the issues and options, but managed retreat from some areas would be necessary, he predicted.
How soon, and how extensively, was "part of what we don't know", he said.
Another unknown - to Mr Cull at least - was the extent of criticism of him and the council on social media, including following his announcement he would stand down.
Mr Cull said he did not "do social media" and was happy to ignore anonymous and "perennially critical" correspondents.
Instead, he relied on other measures - such as the council's annual plan consultation - for public feedback, as well as the major test "once every three years".
Criticism based on "completely mistaken facts" could still rankle, as could central government's sometimes "thinly-veiled contempt" for local government, he said.
And, despite the success of Forsyth Barr Stadium, the impact of its financing on the council's books continued to linger, raising questions about the original financial assurances, he said.
But, overall, Mr Cull said he did not "tend to look back, much, and I don't tend to hold grudges".
He was yet to decide if he would endorse another mayoral candidate, but - after years of often 14-1 votes at council meetings - he had clear views on whether Cr Vandervis should succeed him.
"I don't think it would be a very wise decision on the part of the electorate. It's very difficult to understand how a mayor who disagreed with almost everything that council did could lead the council."