About 130 mainly younger students were at the University of Otago main common room for the debate, organised by the Otago University Students' Association and university.
Of the city's 14 mayoral contenders, only incumbent city councillor Andrew Whiley was absent, leaving 13 rivals to squeeze on to the crowded stage.
Each candidate had 60 seconds to answer questions from OUSA president James Heath and Vice-chancellor Professor Harlene Hayne.
On climate change, most candidates favoured more action, sooner, although opinions differed on what that should involve.
Green Party candidate Aaron Hawkins outlined the steps the council had already taken, before agreeing it needed more urgency.
Cr Jim O'Malley promised a new climate-change committee if elected, while Crs Christine Garey and Rachel Elder believed the city should tap its scientific community to help.
Others took divergent tacks, as Cr Lee Vandervis and Jules Radich argued for investment in bigger pipes or sand groynes to protect South Dunedin, while Richard Seager and Mandy Mayhem-Bullock believed in managed retreat.
Carmen Houlahan said the city needed to listen to its younger generation, while Scout Barbour-Evans believed that generation needed seats at the council table.
Finn Campbell said the council needed to move more quickly to reach its goal of carbon net-zero by 2030, while Malcolm Moncrief-Spittle recommended books by other climate-change sceptics.
Bob Barlin promised a mayoral task force to get "stuck in" to the issue.
On public transport, suggestions included rates and tax subsidies to lower fares or making bus travel free, but there was disagreement about electric vehicles.
Cr Vandervis argued new EVs would revolutionise travel, as long as there were parking spaces for them, while Cr Hawkins said they were a "band aid" for society's current pattern of behaviour.
While buses remained the responsibility of the Otago Regional Council, Cr Garey said the DCC was progressing its own initiatives, including a free central city bus loop using a low-emission vehicle.
On housing, candidates suggested a warrant of fitness scheme, including a ranking system to score flats, as among potential solutions.
However, Mr Barlin raised eyebrows when he suggested the OUSA should simply "ban" students from renting substandard flats.
"Don't keep asking us to do something. You do it," he insisted.
Cr Vandervis also drew the ire of the student crowd when candidates were asked how they would encourage more young people to vote.
Cr Vandervis rejected the notion, saying he wanted "educated" voters - not more young voters.
"They don't know enough about candidates. They don't care enough about candidates," he said, as audience members shouted "sit down" and "what about our democratic rights?"
Afterwards, an informal poll - counters placed in glass jars - showed Cr Hawkins as a crowd favourite, although Mr Moncrief-Spittle cried foul after discovering his name was missing from his empty jar.