New Zealand is hosting the day, on Thursday, for the first time, and it is being marked throughout the week with projects at a community and scientific level.
"Working towards a low carbon economy" is the theme with the "kick the habit" slogan aimed to highlight the issues of sustainability and climate change.
In Dunedin, the Otago Regional Council and the Dunedin City Council, along with the Department of Conservation, Fish and Game Otago, the Dunedin Environment Centre and the University of Otago, have collaborated to set up a series of events that will centre around the Kaikorai Stream on Wednesday.
The co-ordinator, Dr Simon McMillan, said about 300 pupils from Kaikorai schools would take part in activities, including cleaning up rubbish, planting trees and testing water quality.
"The stream fulfils many functions for Dunedin residents, but its importance is often overlooked. All the agencies involved in this project hope it'll go some way to raising community awareness," he said.
A youth forum would be held on June 11 at Kaikorai College to discuss the findings of the day.
A climate forum for secondary school pupils would be held on June 7 and 8.
A film by Jinty MacTavish and Otago Girls High School pupils, Lessons from a melting ice cap, would be screened at Otago Museum on Thursday and Friday.
The Queenstown Lakes District Council was staging a 10-part challenge aimed at getting the community to think about sustainability at home and at work.
It was also giving every school in the district a tree, and all pre-schools a shrub, to plant on the day.
Hampden community was planning an energy efficiency expo, a sustainability talk and a low-carbon dinner.
