Climate Cast

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 paperby 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.

Minnesota has more than 100 closed landfills, but there is an approach to deal with the waste sites that also brings the state closer to energy independence. It involves repurposing these landfills into solar farms. The Anoka-Ramsey landfill has now been covered with nearly 9,000 solar panels that help power 750 nearby homes.

MPR Chief Meteorologist Ben Cathey spoke with the CEO of Conexus Energy, Brian Burant, and Hans Neve, a program manager with the Minnesota Pollution Control Agency, about how closed landfills can be transformed and what benefits they can bring to a community.

“Up front, people often say, ‘I don't want to live by solar,’” Burant said. “Then after the system goes up, we've seen housing development go all around it. And when the University of Minnesota came out and did some study and talked to those homeowners, they were happy to live by it. They now know what their neighbor is for the next 30 years. It's something that's silent. There's pollinator habitat and people tend to be happy to be living adjacent to a solar system.”

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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.

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The colors of fall foliage are important to many Minnesotans, and timing for peak colors is wrapping up in the northern portion of the state. But future generations may get to enjoy those vibrant colors later in the year.

MPR Chief Meteorologist Ben Cathey spoke with Brian Schwingle, forest health program coordinator with the Minnesota Department of Natural Resources, to see how climate change is delaying when leaves change.

“Peak color since the late ’60s up until 2025 has delayed about almost two weeks,” Schwingle said. “There are two main factors that control leaf color change: day length ... and temperature in the fall. Temperature, specifically minimum night temperatures in September and October.”

The delayed timing doesn't necessarily mean Minnesota's fall color season will become shorter. But as autumn temperatures continue to warm, the state's annual display is likely to keep arriving later in the year.

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Runners can expect seasonably cool temperatures for the 2026 Twin Cities Marathon. But the early October tradition will be moving back a week starting next year. Race officials have stated health concerns due to heat as a reason for the change.

Between 1961 and 1990, October temperatures never touched 90 degrees in the Twin Cities. But, since 2010, there has been two instances of 90-degree temperatures in October. And now it’s twice as likely to hit temperatures over 80 degrees than 50 years ago.

MPR News meteorologist Sven Sundgaard spoke with distance runner Jeff Denney and Jacob Kastner, the medical co-director of the Twin Cities Marathon, about how a changing climate is impacting long distance runners.

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The University of Minnesota is recognized as one of the top apple breeding and genetics research programs in the country. It developed the Honeycrisp apple and other flavors like the Big Flirt and the SuperSnap. But a warming climate makes the university’s work more difficult.

MPR News chief meteorologist Ben Cathey spoke with Matt Clark, the director of research at the Minnesota Landscape Arboretum, and Sarah Kostick, a member of the University of Minnesota Apple Breeding Program, about how climate is changing apples and the way you buy them.

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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.

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Derechos are devastating, fast-moving bands of thunderstorms capable of producing destructive winds. Minnesota has experienced several, including the Boundary Waters blowdown in 1999. But research suggests derechos could become twice as common in a warming climate.

MPR News chief meteorologist Ben Cathey spoke with members of the Wildlife Rehabilitation Center of Minnesota in Roseville about the impacts these storms can have on wildlife.

He also spoke with Logan Bundy, a meteorologist at Northern Illinois University, about what derechos could look like in the future.

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If you’ve attended or played in a softball or baseball game this summer, you likely share something in common with a lot of Minnesotans. The intense heat, coupled with the high humidity, has led to delays and sweltering conditions for fans, players, and umpires alike. That comes at the end of July 2026, which will go down as the warmest month in American history.

There are plenty of church leagues and beer leagues around the state, but one group that meets in the Midway neighborhood of St. Paul is a little different. They have team names like the Grand Slamphibians, Tree Huggers, and Straight A Sluggers.

These aren’t just your average Joes. These players are almost all state government workers. Many of those folks work directly on climate issues at the Minnesota Department of Natural Resources and Minnesota Pollution Control Agency.

So we ventured out to the Dunning Fields on the hottest evening of summer to talk to the experts while they were off the clock.

What would you guess is the deadliest disaster in Minnesota history? A wildfire? Blizzard? Tornado? It was none of those. In 1936, a long-term heat wave killed at least 900 across Minnesota.

Heat is America’s top weather killer, even in the age of air conditioning and community pools.

For the return of the long-running Climate Cast, we wanted to revisit the terrible cost of the 1936 heat wave that hit 90 years ago this month. On July 14, 1936, experts estimated a person was dying every three minutes in Minneapolis alone as a direct result of the heat.

In this episode, MPR News chief meteorologist Ben Cathey speaks with with Geoff Williams, the author of a new book, “The Summer of Death.” Williams calculates that at least 12,000 people died across America. He thinks Minnesota’s official death toll is likely severely under-calculated.

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For years, Climate Cast has been a place to make sense of a changing planet — explaining the science, the solutions and the people behind the issue.

MPR News chief meteorologist Paul Huttner sat down with Tom Crann during the Minnesota Climate Adaptation Awards to reflect on Climate Cast’s roughly 650 episodes and its focus on climate science, news and solutions.

“Climate change is a huge problem. We are seeing it every day,” Huttner said. “But there are so many good people working on solutions, and the technology of those solutions is here now.”

Plus, hear some former guests of Climate Cast send along their regards to Huttner.

With climate change exposing communities to more dangerous weather conditions and amplifying diseases, experts say more people need resources to adapt.

The University of Minnesota Climate Adaptation Partnership is working on creating Climate Resilience Hubs to help give people community spaces that can give support both in everyday life and during emergencies.

MPR News chief meteorologist Paul Huttner spoke with Dr. Kent Boyd, a Climate Adaptation, Resilience, and Public Health Extension Educator at the University of Minnesota, who is leading this work.

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Burning fossil fuels is one of the primary drivers of climate change, releasing large amounts of carbon dioxide into the atmosphere, causing changes including increased temperatures and extreme weather events here in the Midwest.

But recent research took advantage of a 40-year ongoing experiment at the University of Minnesota’s Cedar Creek Ecosystem Science Reserve to study how this carbon is being stored in retired croplands.

MPR News chief meteorologist Paul Huttner spoke with Eric Seabloom, a professor at the University of Minnesota College of Biological Science who was an author on the research.

Warmer waters building in the tropical Pacific Ocean are suggesting an El Nino event developing late this year. Forecasts predict an event range from a moderate El Nino, to a so-called Super El Nino event, which could have dramatic effects on weather in Minnesota, the U.S. and the world.

MPR News chief meteorologist Paul Huttner spoke with Andrew Freedman, a Senior Reporter for Climate & Weather at CNN, who has reported on the event.

The transportation sector is a large contributor to climate change, accounting for about 28 percent of total U.S. greenhouse gas emissions. Within that sector, aviation accounts for around 2 percent of carbon dioxide global emissions, according to the U.S. Department of Energy.

Looking to reduce its carbon footprint, the aviation industry is seeking fuels from more renewable biological sources. At the University of Minnesota’s Forever Green Initiative, researchers are working to commercialize winter oilseed cover crops that can keep soil healthy and also beturned into aviation fuel.

MPR News chief meteorologist Paul Huttner spoke with Mitch Hunter, co-director of the Forever Green Initiative and an adjunct assistant professor at the University of Minnesota.

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Fossil fuels are by far the largest contributor to global climate change, accounting for nearly 90 percent of all carbon dioxide emissions. But there are people here in Minnesota working on solutions for managing those emissions.

MPR News chief meteorologist Paul Huttner spoke with Paul Dauenhauer, a Distinguished McKnight University Professor at the UM College of Science and Engineering, about the start-up company Carba, of which he is a cofounder.

Through Carba, they have developed a proprietary process that converts plant-based waste material into biochar, a stable material that sequesters carbon and can be buried underground for more than 1,000 years

The United States is among the world’s largest beef producers, producing some 12 million tons in 2025. But cattle generate a lot of emissions. The beef industry alone is responsible for around 3 percent of total greenhouse gas emissions in the United States.

MPR News chief meteorologist Paul Huttner spoke with Jennifer Schmitt, senior research scientist in sustainability at the University of Minnesota’s Institute on the Environment, about what’s currently being done to reduce emissions.

Plus, a snippet from a recent episode of This Old House Radio Hour about climate preparation is reshaping the housing of America.

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Minnesota Arctic explorer Will Steger has trekked across thousands of miles of ice in both the north and South Poles, crossing the Larsen Ice Shelves a few years before they disintegrated and collapsed into the sea.

MPR News chief meteorologist Paul Huttner spoke with Steger about dramatic changes he’s seen in Arctic regions over the past several decades.

The last time Lake Superior completely froze over was 30 years ago in 1996. Around that time, Lake Superior was consistently at least 75 percent frozen over. Now, 75 percent coverage is rare, only happening about once every four years.

Ice on the Great Lakes, and Lake Superior specifically, is a great way to measure climate for our region. MPR News chief meteorologist Paul Huttner spoke with UMD professor Jay Austin, about what ice coverage can tell us about climate change.

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