Organisers of the global "350" event hoped to encourage events to be staged in centres around the world on October 24, to draw attention to a suggested "safe level" of carbon in the atmosphere of 350 parts per million (ppm).
The safe level was established by Dr James Hansen, a scientist with Nasa's Goddard Institute for Space Studies.
However, speaking at yesterday's council finance and strategy committee meeting, Cr Michael Guest questioned whether the council should be signing up to the initiative based only on the opinions of "one American scientist".
He was concerned a staff report to yesterday's committee meeting made no mention of whether the Ministry for the Environment supported the event.
The report listed nine centres - including Auckland, Wellington and Christchurch - which were planning events, but Cr Guest said he wanted to know the ministry's position before considering "this sort of fluffery seriously".
"It's a paper with one US scientist saying he knows it all and he wants the whole world to shut down for a day."
However, Cr Guest then decided to support the initiative, after Cr John Bezett - who expressed "some sympathy" for Cr Guest's views - said he backed the event because other credible organisations did.
Ten organisations, including the University of Otago's Centre for Science Communication, have signed up to the event in Dunedin.
The staff report, by council safe and sustainable travel co-ordinator Charlotte Flaherty, said events on Saturday, October 24 would aim to pressure world leaders ahead of a meeting in Copenhagen in December, where a new global climate treaty would be negotiated.
Dunedin's participation would include a series of events earlier in the day, including 350 surfers taking to the water at St Clair beach, followed by a "main event" in the Octagon in the afternoon.
Although yet to be planned, it was hoped the event would draw a crowd of 5000.
