Climate Cast

Minnesota Public Radio

MPR News meteorologist Paul Huttner with the latest research on our changing climate.

  1. 3 nov.

    Three Tribes, Three Forests: Protecting the kauri from fire and disease

    In Minnesota, red pines reach high into the sky at 150-plus feet. There are even local scavenger hunts looking for a jumbo tree of each species. In South America, the Mapuche people are in awe of the monkey puzzle tree for both its size and life-giving seeds. And for Southeast Asia, the strangler fig sits as a temple guard. But these mammoth trees, revered in cultures across the world, are all under threat from wildfires. New Zealand’s own canopy king is the kauri tree. Last year, a wildfire in the coastal Waipoua grove burned many of the sacred trees. The kauri is New Zealand’s answer to the giant sequoia. The largest of the bunch, Tāne Mahuta or “God of the Forest,” survived this round. But conservationists are concerned more fire will come. “This fire wasn’t a one-off, it was a warning,” said Snow Tane, general manager of Te Roroa Group, the tribal team tasked with preserving the kauri in Northland, New Zealand. “We don’t see ourselves as owning this forest. We see ourselves as related to it.” The Waipoua Fire charred 223 acres between February and March 2025. Starting with an out-of-control trash burn, the blaze required 100 firefighters, eight helicopters and many pieces of heavy equipment to save homes and the protected trees. ​​ “It's not just a tree, it’s an ancestor, Tane said. “When a kauri is harmed, it’s not just environmental damage, it’s a spiritual wound.” Kauri trees are the apex trees of the Northland temperate rainforests. They are the true crown of the “Crown Lands,” which are federally protected spaces in New Zealand. These trees now occupy less than a tenth of their former habitat. Logging, ranching and plant disease like kauri dieback are all responsible for the decline over the last 100 years. Dieback is a microscopic pathogen that starves the vascular system of the giant trees; once the disease reaches a new tree, it’s a slow death with no cure. Not only does the fungus-like pathogen kill centuries-old trees; it also dries out the canopy, further adding to wildfire risk in Northland. The disease is often spread by invasive pests like stoats and possums. The same is true in northern Minnesota, where spruce budworm underwent its largest outbreak since 1961. The pest leaves behind dry and brittle trees, and we saw the impact during the “July Lightning Incident” fires during the summer of 2026. All told, those Minnesota fires charred nearly 70,000 acres across the Boundary Waters Canoe Area Wilderness. In New Zealand’s Opua grove, female-led volunteer groups like Bay Bush Action and Project Island Song have stepped in, helping remove pests with baited traps. Abby O’Neill and Fleur Corbett led these teams through the nearby Opua Forest, marking predator traps in the temperate rainforest. Their goal is to prevent, and even reverse, the spread of kauri dieback. They also hope to bring back native New Zealand songbirds, who also face die-offs from the pests. “It’s really calming. Especially after we come up a really steep part of the track. And we come up to the ridgeline to sit,” O’Neill said. “We were so happy and relieved that we’d made it to the top again. It was nice to just ‘be.’” Wildfires are nothing new in temperate rainforests across the globe. Many plants rely on fires to clean the underbrush, spur germination or activate soil nutrients. Throughout history, many native cultures formed a symbiosis with nature by lightly using prescribed fires. “Fire was a tool for maintaining balance,” Tane said. “Reducing fuel in open areas, encouraging certain food plants, and protecting communities. It was never about creating land at scale.” Before Europeans arrived and began large-scale burns to carve grazing lands from dense forests, some research shows that Māori had a much gentler touch with controlled burns. “The Maori used fire as their principal tool. It was used to burn paths through densely vegetated terrain and to clear land for cultivation and to live on. Fire was used in the felling of trees to make waka (canoes) and to help with bending wood for weapons and shaping bark vessels. It was also important for the propagation and storage of crops, and for cooking in earth ovens,” a report by the International Association of Wildland Fire found. A report from the prestigious Proceedings of the National Academy of Sciences casts some doubt on this theory, however. A 2020 peer-reviewed paper by Montana State scientists found: “Charcoal recovered from lake-bed sediment cores show that just a few large fires within 200 years of initial colonization destroyed much of the South Island's lowland forest. Grasslands and shrubland replaced the burnt forest and smaller fires prevented forests from returning.” Many of these temperate rainforests at relatively high latitudes share a common trait: Lightning is extremely rare, with some estimates hinting that lightning-caused wildfires burned parcels of land only every 1,000-2,000 years in New Zealand. By the time the Māori reached New Zealand, it didn’t take many controlled burns to convert some forests to cleared land. But, with careful stewardship, the Māori could safely clear paths and raise crops, all while preventing out-of-control wildfires. Other efforts to contextualize Māori usage of fire have been criticized for not including indigenous voices. In visiting these rainforests across the globe, we’ve encountered a largely unreported pattern in place after place. Settlement of livestock to clearing, then into forest succession, followed widespread wildfire. “We weren’t into fencing and chopping and sales agreements,” Dale Husband told us. Husband is an Auckland-based Māori radio host at Waatea News. He’s watched over the decades as livestock have filled in New Zealand’s land. European settlers came to New Zealand and grazed their livestock on the land. “European settlers would come in, they would bring in five or six species of domesticated animals. A whole suite of grazers and browsers had been tamed for the last 7,000 or 8,000 years. And they spread like wildfire, so to speak. They reproduced, starting with just a few brought in,” landscape fire ecologist Dr. Cecil Frost said. The livestock over-grazed in freshly cleared land. Following a retreat in plant diversity, the wildfire risk quickly rises. “But they were eating up all the fuel. So within the first 30 years, the original fire regime was broken. And what you see is the beginning of thicket-ization across the country,” Dr. Frost added. “And the thickets are much more flammable.” As some plants filled in the gaps that native trees once thrived in, faster-growing trees emerged. “A lot of regenerated forests had been burnt. And then cleared for farmland. The trees that come back first have a high oil content so they are highly flammable.” Fleur Corbett of the Northland’s Bay Bush Action said. Once fires do begin in newly-shaped forests, there are often not enough people to quickly extinguish the fires. Dale Husband has a way of looking at the trend. “All of a sudden, we (European settlers) came in, we burned all the crops, we put up fences,” Husband said. “We put cows on (the land). A lot of the problems that we’ve got in the nation at the moment environmentally stem directly from this pastoral economy that we’ve created to be the larder of Britain.” Tane, Corbett, O’Neill and Husband all shared what they call “cautious optimism” for the future of the wild forests and for Aotearoa New Zealand itself. But politics are changing fast in their country, and Husband says it’s challenging. “It’s part of the journey that we’re on as indigenous peoples,” Husband said. “There’s something special that we can offer the future globally.” Editor’s Note: This ‘Three Tribes, Three Forests’ series was produced in partnership with the Pulitzer Center. Pulitzer paid for all travel and expenses, leaving no cost to Minnesota Public Radio. There will also be news stories filed from Minnesota’s forests, along with the kauri forests of Northland New Zealand. You will here shorter climate clips during Climate Cast as we close out 2026. Editor’s Note: This ‘Three Tribes, Three Forests’ series was produced in partnership with the Pulitzer Center. Pulitzer paid for all travel and expenses, leaving no cost to Minnesota Public Radio. There will also be news stories filed from Minnesota’s forests, along with the beech temperate forests of Tierra del Fuego in Chile. You will here shorter climate clips during Climate Cast as we close out 2026.

  2. 20 oct.

    How a Minnesota wild prairie helps fight climate change

    Sitting in the driver’s seat of an antique combine east of Moorhead, Sam Stueber can see the past, present and future of Minnesota’s changing environment. On this day, she’s working in a field of ancient and unspoiled prairie in Clay County, rounding up thousands of pounds of wild grass and wildflower seeds at the Nature Conservancy’s Bluestem Prairie Scientific and Natural Area. It’s one of the few places left where you can see the sweeping native prairie that once covered much of western Minnesota. Beyond their beauty, these lands are helping in the larger fight against climate change. Grasslands are one of the world’s best places to store carbon. University of Minnesota researchers found an acre of prairie grassland can pull a ton of carbon out of the air each year. The roots of wild prairie grasses can extend 15 feet down into the dirt, trapping the carbon underground. If a wildfire comes along, grasses will burn and some carbon will escape but most of the carbon stays underground. The Nature Conservancy along with other nonprofits and the U.S. Fish and Wildlife Service collects about 15,000 pounds of wild grass seed each fall using special Allis-Chalmers combines, which are lighter than modern combines that can rut the sandy soil. Keeping the ancient prairie healthy and growing into the future is vital. As we humans continue to dump carbon into the atmosphere, trapping carbon is crucial to the future of our warming planet. Click the play button above to listen to the full podcast.

  3. 14 sept.

    Climate Cast: As ships sit in Strait of Hormuz, invasive species hitch a ride

    Invasive species play the long game. They travel well, dig in to survive wherever they’re dropped off and then start multiplying, making it nearly impossible to root them out. Scientists looking now at the current state of the Strait of Hormuz see a recipe for invasive species spread. Giant ships are stuck in the warm waters there amid the Iran War and they’re collecting critters in the ballast water and on their hulls. Those invasive creatures will end up in ports around the world once the ships start moving again, likely creating a global superspreader event, Mario Tamburri, a marine ecologist with the University of Maryland Center for Environmental Science, told MPR News. “What makes a good invasive species is one that's sort of very tolerant to extremes and robust, and that's why the the organisms we have in the Persian, Arabian Gulf are particularly concerning because they they live in really hot water, really salty conditions,” he said. “That might make them more invasive, more able to to withstand new conditions,” he added, “but what it also means is that they can bring those traits of being tolerant to higher temperature to the new environments.” In the case of freshwater Lake Superior, it would take a longer time to see impacts from the Strait of Hormuz. Many of the big boats on Superior travel domestically, but don’t head out into saltwater. Plus, the Strait of Hormuz is much warmer than the Duluth harbor. Lake Superior has seen invasives take hold, including lampreys and zebra mussels. The bloody red shrimp is the latest local example. Twenty years after reaching the Great Lakes in the ballast water of cargo ships, the crustacean native to Europe and Asia has now colonized Lake Superior, despite years of effort by ecologists to keep it away from Duluth. That pattern is unlikely to change anytime soon. New research from scientists at Toronto’s York University found Lake Superior is one of the fastest-warming big lakes in the world. Research led by a biologist at the State University of New York-New Paltz found Lake Superior has lost more than two months of ice coverage per year since 1857. And when there’s less ice coverage in winter, we also see faster winter warming on land, perpetuating the cycle a University of Minnesota research team found. Creatures living in the saline waters off the coast of Iran are incredibly resilient to climate change and able to survive in extremely tough conditions, and that could keep them alive in places like the Great Lakes one day, Tamburri said. Click play on the audio player above to listen to this episode or subscribe on Apple Podcasts and Spotify.

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MPR News meteorologist Paul Huttner with the latest research on our changing climate.

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