UN Secretary-General Antonio Guterres says his generation has not shown the capability to reverse the impacts of climate change and it's up to the youth to "rescue the planet".
Guterres also called on young people to "be as noisy possible" until their leaders listen to them when it comes to the issue of climate change.
Delivering the keynote speech at an event at AUT in South Auckland today, Guterres, 70, said his generation was "not winning the battle against climate change".
"We need the leadership of the youth … because those who have to take responsibility in the world, especially Governments, are not showing enough political will," he said.
"We need to make sure that this [climate change] trend is reversed and unfortunately my generation is not showing the capacity to do so, so we need your leadership, your support, your movement and your capacity to mobilise your society to make sure we are able to reverse this trend."
When asked by a student what young people need to do to tackle the climate change problem before it was too late, Guterres said he was "waiting for you to be as noisy as possible".
He encouraged young people to "mobilise your societies, your parents, families and friends and to put your Governments under pressure – that's what I'm asking you now."
He said it was critical that climate change is "defeated – the youth is my hope for this to be possible."
Guterres' speech today comes as part of a three-day trip to New Zealand with a focus on climate change.
This morning, speaking alongside Climate Change Minister James Shaw, Guterres called on governments to adopt a pollution tax.
He said his message was that countries needed to "shift taxes from salaries to carbon. We must tax pollution, not people," he said.
This means reducing income tax as a tax on carbon is applied, Guterres said.
Despite saying his generation was not winning the battle against climate change, he has been full of praise for New Zealand's approach to making a difference.
On several occasions over the past two days he has talked highly of the zero carbon bill, introduced to Parliament last week.
Guterres finishes his New Zealand trip tomorrow with a visit to Christchurch to pay tribute to those killed in the March 15 terror attack.
He will then head to the Fijian capital Suva to attend a Pacific Islands Forum Leaders' meeting.
Speaking to a Pacific Island Round table event this morning, Guterres said smaller countries, such as those in the Pacific, face "huge challenges" when it comes to climate change.
"The Pacific Islands are the first victims of climate change," he said citing rising sea levels as well as the acidification of the oceans.
Foreign Minister Winston Peters will also be at the event.
"The visit is an opportunity to shine a spotlight on issues facing our region to the UN's top official, United Nations Secretary-General, António Guterres."
He said responding to climate change is a key focus for the Pacific and New Zealand wants to show transformative action is possible.