People are gathering in towns and cities to join a global event called the People's Climate March.
The biggest event in New Zealand will start just before llam today in Albert Park in Auckland.
Celebrities expected to attend include Lucy Lawless and Hayley Holt and they will be joined by academics, union organisers and church leaders.
The event kicks off a weekend of marches around the world aiming to put pressure on global leaders gathering in Paris.
Fala Haulangi, a Tuvaluan and union organiser, says climate change is about the survival and "the very existence of my people".
While Sarah Thomson, a law student at Waikato University, wants urgent and meaningful action on climate change.
"As a young person, I will see the effects of climate change unfold within my lifetime. It is our generation, and our children's generation, who will pay the true cost of decisions made by generations before us."