
KGNU - How On Earth
The KGNU Science Show
Latest episodes

Jul 15, 2025 • 26min
Climate Science, Cutbacks, Litigation
At a protest outside NOAA in Boulder. Credit: Susan Moran
Tackling Climate Change and Science Cutbacks (start time: 7:03) In this week’s show we discuss the ongoing barrage of executive orders by the Trump administration; and the impacts of defunding of federal agencies, scientific research and scientists focusing on climate change and the environment. We also explore how the legal and political landscape, including pushback against the administration’s actions, are shifting. How On Earth host Susan Moran interviews Marc Alessi, a climate scientist at the nonprofit organization Union of Concerned Scientists (UCS); and Delta Merner, a geographer and associate director of the Climate Accountability Campaign at UCS. Dr. Alessi was an organizer of a 5-day event in May with climate scientists and meteorologists in May, called 100 Hours to Save America’s Forecasts. And Dr. Merner is an organizer of a public virtual event on Wednesday, July 16, called “Meeting the Moment Through Climate Litigation” (2:00-3:00 p.m. MDT).
Also on this week’s science calendar, check out this FDA expert panel on menopause and hormone treatment, available livestreamed on the FDA’s YouTube channel. It’ll be held on Thursday, July 17, 11:00 a.m. to 1:00 pm. MDT.
Host/Show Producer: Susan Moran
Engineer: Evan Perkins
Executive Producer: Susan Moran
Headline Contributor: Shelley Schlender
Listen to the show here:

Jul 9, 2025 • 27min
How We Grow Up: Understanding Adolescence by Matt Richtel
Teens are in Crisis – Some people warn that Cell Phones are to blame. But Colorado Native and Pulitzer prize winner Matt Richtel says our tech can be a useful tool, IF we better understand the purpose of adolescence, That’s the focus of Richtel’s brand new book – How We Grow Up: Understanding Adolescence
Hosts: Susan Moran, Joel Parker
Show Producer/Engineer: Shelley Schlender
Executive Producer: Susan Moran

Jul 1, 2025 • 27min
Bird Conservancy of the Rockies – Eric DeFonso
C Cornell Lab of Ornithology
Merlin Bird ID App (starts 1:00) Boulder Naturalists Steve Jones and Ruth Carol Cushman explore the benefits of the Merlin smartphone app, along with its sometimes hilarious mistakes.
Eric Defonso – c Highplainssnowgoose.com
Bird Conservancy of the Rockies (Start 5:48) Crew Leader Eric DeFonso explains how the Conservancy’s Integrated Monitoring in Bird Conservation Regions Program provides detailed data about birds and their habitat, to better understand the steep decline in bird populations and what birds need to thrive.
Executive Producer: Joel Parker
Show Producer: Shelley Schlender
Additional Contributions: Elena Klaver, Eric DeFonso, Steve Jones, Ruth Carol Cushman
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Jun 24, 2025 • 27min
Viruses are Us!
In this week’s science show Beth talks with genome biologist Ed Chuong of CU Boulder’s innovation incubator, the Biofrontiers Institute. Ed takes us for a whirlwind tour of the evolutionary history of these viral invaders of our genome, and some examples of how they can simultaneously be friend and foe. Teaser, did you realize that the genes that allow the formation of the placenta, the organ that nourishes human (and other mammal) fetuses, came from viruses!
Executive Producer: Joel Parker
Show Producer: Beth Bennett
Engineer: Jackie Sedley
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Jun 17, 2025 • 27min
2025 Graduation Special (part 2)
With graduation season upon us, today’s edition of How on Earth is Part 2 of our annual “Graduation Special”. Our guests in the studio today are scientists and engineers who recently received their Ph.D. from the University of Colorado in a STEM-related field. They talk about their thesis research, their grad school experiences, and what they have planned next.
Chloe Long – Aerospace Engineering
Topic: Data-Driven Asteroid Tour Design
Amin Taziny – Aerospace Engineering
Topic: Multiscale Continuum-kinetic Modeling of Ionic Emission in Electrospray Thrusters
Margaret Perkoff – Computer Science and Cognitive Science
Topic: Bringing Everyone In: The Future of Collaboration with Conversational AI
You can listen to all past year Graduation Special episodes.
Host / Producer: Joel Parker
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Jun 10, 2025 • 27min
GLP-1 and Blindness
photo of intermediate macular degeneration c National Institutes of Health
We talk with scientists who report that a common weight loss/diabetes drug known as a GLP-1 receptor agonist (Wegovy, Ozempic for instance) is associated with an increased risk of blindness. The study was published last week in the Journal of the American Medical Association Ophthalmology, about a form of blindness known as “wet” macular degeneration. The scientists we talk with today are Marko Popovic and Reut Shor. We also refer to a different, unrelated study, underway, to evaluate a ketogenic diet and eye health, specifically, whether or not a ketogenic diet can reduce diabetes while providing better protection to the eye.
Executive Producer: Joel Parker
Show Producer: Shelley Schlender

Jun 3, 2025 • 28min
Animal Pandemics?
On this week’s How on Earth, Beth talks with author and science journalist Liz Kalaugher, about her new book, The Elephant in the room:How to Stop Making Ourselves and Other Animals Sick. Think about it this way: When new diseases spread, news reports often focus on wildlife culprits–rodents, monkeys and mpox; bats and COVID-19; waterfowl and avian flu; or mosquitoes and Zika. But, as Liz points out, we see it often works the other way around–humans have caused diseases in other animals countless times, through travel and transport, the changes we impose on our environment, and global warming. In her deeply researched and often entertaining book, Liz introduces the wildlife we have harmed and the experts now studying the crosscurrents between humans, other animals, and health.
Executive Producer: Beth Bennett
Show Producer: Beth Bennett
Additional Contributions: Joel Parker and Shelley Schlender
Engineer:Jackie Sedley
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May 27, 2025 • 27min
Saving Weather Forecasting, Climate Science
Scientists speak out for science (start time: 1:00) The Trump administration has been on a dizzying streak of slashing federal funding for scientific research, and firing thousands of federal scientists. Among the casualties is the National Weather Service, which supplies critical data from air balloons and climate models to develop weather forecasts. Many cities and agencies use these data to warn the public when extreme weather, such as a hurricane, is approaching. This crisis has prompted some climate scientists and meteorologists to organize a marathon five-day event, starting May 28, to educate the public about how vital their work is to society, and to mobilize people to take action. Host Susan Moran interviews two climate scientists who are on the organizing team of 100 Hours to Save America’s Forecasts. Margaret Duffy is a postdoctoral fellow at the University of California Berkeley, and Marc Alessi works with the Union of Concerned Scientists. (Click here to see the schedule.)
Hosts: Susan Moran, Joel Parker
Show Producer: Susan Moran
Engineer/ Executive Producer: Joel Parker
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May 20, 2025 • 28min
Birds at Risk
Arvind Panjabi releasing a banded grasshopper sparrow in Chihuahua state, Mexico. Photo credit: Sujata Gupta
Birds: Risk and Resilience (start time: 5:55) What speaks of Spring more than the songs of American robins, yellow warblers, spotted towhees and other birds in the early morning? As we relish in these avians choruses, it’s also an important time to examine why bird populations in North America have, by and large, been plummeting in recent decades, due to multiple stressors, including climate change and habitat destruction. At the same time, some conservation efforts (including bipartisan legislation) on the federal, state and local levels, are bearing some fruit. And everyone can help give these winged creatures a hand, starting with their own gardens, and by getting involved in citizen science projects, such a bird-banding and bird-counting. In this week’s show, host Susan Moran interviews Arvind Panjabi, a senior research scientist at Bird Conservancy of the Rockies, a nonprofit organization devoted to the conservation of birds and their habitats. (Listen to Shelley Schlender’s sound portrait of five migratory birds that are visiting Colorado now (start time: 2:58).
Host/Producer: Susan Moran
Engineer: Jackie Sedley
Executive Producer: Joel Parker
Headline Contributors: Joel Parker, Shelley Schlender
Listen to the show here:

May 12, 2025 • 56min
Boulder Cardiologist Nelson Trujillo – Extended Version
Nelson Trujillo – Boulder Heart
This is an extended version of our interview with Boulder Cardiologist Nelson Trujillo. For the broadcast version, go here.
Producer: Shelley Schlender