Actor Patrick Adams will also speak in the slot, and musician Belinda Carlisle will perform as well as hip hop artist Young Paris.
Greeting Ardern over the satellite link, former US Vice President Al Gore praised Prime Minister Jacinda Ardern, telling her he was watching the New Zealand election and "I was cheering for you even before you were elected."
He had earlier described her as a "very powerful and inspiring new voice in the world community."
He said he thought it was amazing that she put climate change at the centre of her campaign.
Ardern responded by saying New Zealand's role on climate change was anchored in its identity. She pointed to New Zealand's role at the forefront of the anti-nuclear movement and women's suffrage.
"This feels like the next stage for New Zealand as a country when it comes to standing up on something that will affect us for generations to come."
Ardern was interviewed in the hour dedicated to the Pacific Islands and Ardern said it was a "personal and national responsibility" for New Zealand to do its part, given the effects in the Pacific.
In the lead-up to the interview, Gore ran through the weather events attributed to climate change and sea warming, including Cyclone Winston in Fiji, floods in the Solomon Islands.
He also addressed sea level rise from melting glaciers, saying it was happening much faster in the Pacific than other oceans.
He spoke of its impact on countries such as Kiribati, saying it had to budget to buy land in other countries to send its citizens to.
Gore also ran through efforts for mitigation, including greater use of renewable energy sources rather than fossil fuels in the Pacific Islands.
Ardern told Gore New Zealand itself was seeing the impact in the melting of its glaciers and soil drying, as well as ocean acidity and the impact on seafood such as paua and oysters and other food sources.
She said 44,000 homes in New Zealand could be affected if sea levels kept rising. However, such impacts were already happening on the smaller Pacific islands such as Tokelau and Kiribati.
Asked about "climate refugees", Ardern said New Zealand was mindful of that. She said New Zealand already offered opportunities for Pacific Islanders to stay in New Zealand, such as through seasonal employment schemes.
"When it comes to the climate-refugee situation, we've started having the discussion 'well perhaps there are ways to adapt what we already have to take into account that potential future issue'."
Gore described the mindset of New Zealand as "deeply rooted in conscience" and Ardern said that was the case.
She said although New Zealand's emissions were minute as a percentage of the global emissions, it did not reduce the responsibility for New Zealand.
"But for New Zealand there's probably something extra in this particular international debate. We pride ourselves on our environment. It's intrinsically linked to how we see ourselves and our view of New Zealand and its place in the world is very much anchored in our perception of the beautiful environment that we're so lucky to live amongst."
She said the concept of kaitiakitanga [guardianship] ran deep in New Zealand, courtesy of Maori values. "We have a responsibility to preserve what we have for future generations."
Ardern also called for greater bipartisanship on climate change, saying it should not be an issue that was "flavour of the month" for one government but not the next.
Speaking to former US President Al Gore via a satellite link, Ardern said there needed to be greater conversation about the issue, but that would require taking politics out of it.
"There are certain issues with which I hope that as electoral cycles move we'll see less of it becoming just an issue that becomes the flavour of the month for that government but not the next because we'll never get consistency around the actions we take."
She said she hoped to get consensus on measures the Labour Government was taking, including the target of a carbon neutral New Zealand by 2050 and a new independent Climate Change Commission to look at measures New Zealand should take.
"So we as political agents can continue to be held to account for the actions we take regardless of what political party is in power."
Ardern said one of the Climate Commission's jobs would be to set 'Climate Budgets' over a five year period to get interim goals toward the carbon neutrality year of 2050.
She ran through steps such as converting the government car fleet to electric vehicles by 2025 and using 100 per cent renewable energy by 2035. "We think all of them are achievable."
She said New Zealand's biggest challenge was its agricultural emissions – and it was that that set New Zealand's emissions profile apart from others.
"Our view is if we start with having a comprehensive emissions trading scheme – and we'll leave it to the Climate Commission to tell us when it moves into that phase – will start incentivising real innovation in agriculture. It will demonstrate to the world how you can have a smart, productive primary industry. And that's the area I think we can show real strength."
Ardern also referred to NZ First's measure to plant one billion trees over 10 years.
Gore said the agriculture issue gave New Zealand the opportunity to show leadership globally. "We have a problem with agriculture world-wide and the solutions are being developed but the whole world is going to be watching what you're doing."
Gore ended the interview by saying everybody was "pulling for you" and hoping she would succeed – in return Ardern invited him to return to New Zealand for a visit.
Prior to the interview, Ardern said she would discuss the work New Zealand was doing toward facing the global challenge.
She said she wanted to reframe it from being a challenge to an opportunity for New Zealand – "to enhance our reputation as environmentalists, but also enhance our brand, which is good for exporters."
This week, a kakapo died on Hou Island which the Department of Conservation put down to heat stress. Ardern said the unusual heat for this time of year was just one of many impacts.
"We have to acknowledge as well we are seeing increased acidity in our sea, we are seeing a decrease in our glaciers, increased dryness of our soil. This is an issue which affects our wildlife, our crops, it affects our lives.
There are many reasons we need to tackle this head on."
She said it was good to be asked for the interview.
"Obviously Al Gore has been a champion of addressing climate-change issues internationally and this event is about raising the profile of that work across a number of different nations, New Zealand included."
During the election campaign, Ardern identified climate change as a priority, saying it was the "nuclear-free" moment of her generation.
The event features special performances by global music stars One Republic, Sheryl Crow, Shawn Mendes, Jay Park, Iggy Pop, The Killers among others.
This year's 24 Hours of Reality will explore the extraordinary climate activism happening all across the planet, highlighting inspiring stories of politicians, businesses, communities, and everyday people standing up and illustrating how we can all make a difference, right now, right when our planet needs us most.
The programme began at noon NZ time today and is being broadcast live from New York City's Roosevelt Island.
The broadcast will travel around the globe highlighting stories of climate activism in six regions: North America, Oceania, Asia, the Middle East and Africa, Europe, and Central and South America.
Al Gore will also share stories and statistics from the iconic slideshow presentation featured in the film An Inconvenient Truth and the recently-released An Inconvenient Sequel: Truth to Power.