Gas shortages, a reversal of the ban of offshore oil and gas exploration, and a government plan to double geothermal energy in the next 15 years… There’s been a lot in the news recently about New Zealand’s energy supply now and in the future. Claire Concannon speaks to researcher Dr Jen Purdie about our ongoing electrification of industry and transport, about our ‘dry year problem’, and what the future of supply and demand might look like in a changing climate.

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Guests:

• Dr Jen Purdie, Senior Research Fellow, Centre for Sustainability, University of Otago.
• Kirsty Johnston, RNZ In-Depth journalist

Learn more:

• Could nuclear fusion-generated energy be a way to help us power the future? Learn how New Zealand company OpenStar Technologies are trying to crack this.
• Read or listen to Kirsty’s recent reporting about what has changed in climate policies underpinning the Zero Carbon Act 2019. 
• The coalition government has stated they want to use New Zealand’s Emissions Trading Scheme (rather than the GIDI fund) to help drive the transition from fossil fuels to other forms of energy, but as climate change journalist Eloise Gibson reports, there are issues with this plan.

References

• The 2025 Energy in New Zealand report came out in August 2025.

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New Zealand’s youth vaping rates are among the highest in the world. How did we get here and what will this mean for the future of our rangatahi? A 2018 court case paved the way for a loose regulatory start for vaping in New Zealand, and rapid uptake by those aged 14–24 in the years since has led to concerns that a new generation is now addicted to nicotine. New Zealand researchers are investigating how vaping affects our lungs, and the harms young people are experiencing in terms of social connections and mental health.

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More and more of us are reaching for low or no-alcohol beers. As the market grows, the options are also expanding – but brewing beer without alcohol fermentation presents a tricky puzzle. In traditional beer brewing the conversion of sugars into ethanol and carbon dioxide through yeast fermentation is a key part of the process. How can you get the same flavour into beer without it? A team at Victoria University of Wellington, including the head of research and development at Garage Project, have begun an interdisciplinary research project to address this. They’re hoping to develop a brand-new yeast strain, one that will recreate delicious beer flavours, but without the alcohol.

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Project Tongariro was established as a living memorial for five people who died in a tragic helicopter accident. Last November, the project turned 40 years old. Over those four decades, activities have expanded beyond Tongariro National Park and into the wider area, including urban restoration through tree planting and predator trapping. Claire Concannon visits the Taupō-based projects that Project Tongariro is supporting as they prepare for Greening Taupō Day – their biggest planting day of the year.

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Guests:

• Kiri Te Wano, CEO Project Tongariro
• Robyn Ellis, Greening Taupō and Predator Free Taupō
• Rachel Thompson, Kids Greening Taupō
• Heidi Pritchard, Kids Greening Taupō
• Celia Bocket, Wicked Weeders
• Zara, Jack, Taylor and Emily, students of Taupō Intermediate School

Learn more:

• Read the article that accompanies this episode: 40 years of Project Tongariro
• Project Tongariro are also involved in a number of restoration projects near Tūrangi, including removing willows from a wetland area.
• In Kirikiriroa Hamilton, a team are also focused on urban greening as part of the People, Nature and Cities project.
• Just outside Dunedin, the Halo Project has been working to provide a safe space for birds around the Orokonui fenced ecosanctuary, as the Country Life team learned last year.

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The battle on the frontlines of conservation continues around the motu. This week we head to the central North Island to join some of the staff and volunteers of Project Tongariro. Ecologist Nick Singers is coordinating the fight against the invasive grey willow that’s taking over a wetland area, while Shirley Potter is applying a ‘let’s get it done’ attitude to reforesting a patch of public conservation land near her home in Tauranga-Taupō.

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Guests:

• Kiri Te Wano, CEO of Project Tongariro
• Shirley Potter
• Nick Singers

Learn more:

• Read the article that accompanies this episode: 40 years of Project Tongariro
• Willow is an issue in many wetland areas where it binds up waterways and transforms the land. Just outside Dunedin, a team are using drone spraying to combat it near the Te Nohoaka o Tukiauau wetland complex.
• In the Rotopiko wetland complex, near Hamilton, the pest battle is a bit unusual: conservationists are concerned about the half a million sparrows and starlings that roost at night.
• The fight for the forest also continues on multiple pest fronts in the Catlins area in Otago.

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During World War II, sonar operators discovered a ‘false seabed’ that appeared to move upwards during the nighttime. In fact, the sound waves were bouncing off huge numbers of small critters. This daily movement is the largest animal migration on the planet, consisting of deep-water animals that hide in the ocean’s twilight then move to the surface after sunset to feed. By far the most abundant fish in this crowd are the lanternfishes. New Zealand researchers are investigating what impact lanternfish migration has on the life cycle of fish we like to eat, and how it may also play a huge role in the Earth’s carbon cycle.

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Guests:

• Professor Jeff Shima, Victoria University of Wellington
• Alisha Gill, Victoria University of Wellington
• Niamh Smith, Victoria University of Wellington

Learn more:

• Read the article for this episode: Lanternfish: small fish, big impact
• Below the twilight zone, in the deepest parts of the worlds’ oceans, including in New Zealand waters, scientists continue to discover new critters.
• The deep ocean makes up the majority of the living space on our planet, where life down there has evolved to cope with the pressure, cold and darkness.
• The Southern Ocean absorbs a huge amount of carbon, but scientists are concerned that may change as the planet warms.

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For a long time, nuclear fusion was viewed as a powerful, but unachievable, energy source, because the technological challenges were just too great. But recent advances, particularly in the development of powerful magnets, have reignited the race to create the world’s first efficient nuclear fusion powerplant. Claire Concannon visits one private company just outside Wellington who have joined the nuclear fusion effort, with a unique approach they believe might be the key.

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Guests:

• Dr Ratu Mataira, Founder and CEO of OpenStar Technologies
• Emily Hunter, Lead Engineer Cryogenics and Docking, OpenStar
• Thomas Berry, Deputy Direct of Plasma Science, OpenStar

Learn more:

• Read the article that accompanies this episode: Could a Kiwi company crack nuclear fusion?
• Kim Hill had a lengthy and fascinating interview with Dr Ratu Mataira in 2023 on RNZ’s Saturday Morning show. He also spoke with Alexa Cook on Morning Report in 2024 after OpenStar achieved ‘first plasma’. 
• In 2023 Our Changing World played an episode of the ABC’s Strange Frontiers that went inside the nuclear fusion reactor ITER.
• Learn more about the simplest element, Hydrogen, from RNZ’s 2019 Elemental podcast.
• The Royal Society of New Zealand has a series of videos on Ernest Rutherford’s scientific discoveries including radioactive decay and half-life, and splitting the atom. 

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In May 2024, 100 strange rocky structures were installed along Tauranga's harbour shoreline. These flower-shaped artificial rockpools, nicknamed 'sea pods', provide prime waterfront real estate for marine life – from colourful sea slugs to sneezing sponges. Justine Murray finds out how 'living sea walls' are bringing back biodiversity to urban harbours around the world, and joins a marine scientist to check out what creatures have moved into Tauranga's sea pods.

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In this episode:

00:49 – What is a sea pod?
06:27 – Living sea walls in Sydney with Dr Aria Lee

10:25 – Sea pods around the world and in Tauranga

13:06 – Monitoring marine life in the sea pods with David Culliford

20:50 – Port of Tauranga

21:48 – Looking for critters in the sea pods
…

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Speckled, pencil-thin and sporting an underbite: the lowland longjaw galaxias is New Zealand’s rarest freshwater fish species. With just seven known populations, this species is considered nationally endangered. Join producer Karthic SS at a spring-fed stream in the wild Mackenzie Basin to meet the tiny fish, hear from a researcher studying trout-proof barriers, and chat to a ranger who for 20 years has cared for the little fish he calls 'Jaws'.

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Guests:

• Dean Nelson, Senior Ranger, Biodiversity, Department of Conservation
• Martha Jolly, PhD candidate, University of Canterbury

Learn more:

• Read the article that accompanies this episode: Looking after New Zealand's rarest freshwater fish.
• Otago farmers are looking out for another species of rare non-migratory galaxiid.
• In Auckland’s Lake Rototoa, introduced perch are the problem for the native kākahi.
• Karthic produces the Tune Into Nature podcast about New Zealand’s unique wildlife.

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Since the 1800s, tuberculosis (TB) has been responsible for an estimated 1 billion deaths. In New Zealand today, we don’t get many cases of TB, but worldwide it is the leading infectious disease killer. In the early 1900s a TB vaccine was developed. Called the BCG vaccine, it’s still used today. While it is the best TB vaccine we have, it’s not actually great at preventing TB infection, only providing some protection for the youngest of patients. However, scientists have discovered that the BCG vaccine can boost people’s immune systems in other ways. Now researchers at the Malaghan Institute in Wellington are investigating these findings further.

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Guests:

• Dr Kerry Hilligan, Malaghan Institute
• Rebecca Palmer, Malaghan Institute

Learn more:

• In 2017, Alison Ballance reported on the looming antimicrobial resistance crisis, with drug-resistant TB part of the problem.
• Other Our Changing World episodes about research at the Malaghan Institute include this 2024 episode on a new way to target rising stomach cancer rates, and this 2022 episode on next-generation cancer therapies.
• In 2021, Claire Concannon covered mRNA vaccine technology.
• The What if...? Genomics in Aotearoa series explores the different ways genomics is transforming different sectors, including infectious disease medicine.

Go to this episode on rnz.co.nz for more details