The Optimist Daily’s Weekly Roundup
With Arielle Tiangco and Karissa Garcia
The world is solving hard problems. We cover them! Every Friday, Arielle and Karissa dig into the week's best positive solutions news from The Optimist Daily. Plus, monthly guest interviews with the innovators and advocates making it happen.
Episodes
October 02, 2026
A wildlife overpass, a solar train, and Japan's massive centenarian population
This week Arielle and Karissa cover the Colorado wildlife overpass that came in $15 million under budget and brought pronghorn back to habitat they hadn't reached in decades, what Japan's 107,000-plus centenarians reveal about diet and aging, Dolly Parton's Imagination Library expanding in London less than a month after her death, and more!
Transcript link: https://www.optimistdaily.com/?p=1423038
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If you have questions, comments, feedback, suggestions, or just want to say hi, send a message to: podcast@optimistdaily.com.
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The Optimist Daily is a project of the World Business Academy.
Donate link: https://www.optimistdaily.com/donate-to-support-the-optimist-daily/?lsc=41ef528d
Theme and all original music by Marvin Lanes
PLAY 30:19 min
September 25, 2026
The tilcayo, cancer-sniffing dogs, and 8 more things going right
There's a startup training dogs to detect cancer across seven types… and there's over 90 percent accuracy across six hospitals.
This week Arielle and Karissa also cover a wildcat species science just got around to naming (local communities already had a name for it), bison reshaping a Mexican desert faster than anyone expected, and what Cambridge researchers found when they actually quantified how reading protects your brain.
Transcript link: https://www.optimistdaily.com/?p=1423005
Nominate a Local Changemaker (30 and under): https://us20.list-manage.com/survey?u=d2e7810fd2bcf24fb1144a7e2&id=6e0ab37520&e=28025b5010
If you have questions, comments, feedback, suggestions, or just want to say hi, send a message to: podcast@optimistdaily.com.
Want to be part of the Optimism Movement? Become an Emissary.
Subscribe to our FREE Daily/Weekly Newsletter and follow us on Instagram, X, and Blue Sky.
The Optimist Daily is a project of the World Business Academy.
Donate link: https://www.optimistdaily.com/donate-to-support-the-optimist-daily/?lsc=41ef528d
Theme and all original music by Marvin Lanes
PLAY 25:35 min
September 18, 2026
A 450-year map mistake gets corrected by 164 countries, plus nine more solutions
Most world maps show Greenland and Africa as roughly the same size… which is kind of unbelievable considering Africa is 14 times larger! This error has been built into classrooms, boardrooms, and institutions since 1569. Last week, 164 countries finally voted to fix it.
Arielle and Karissa also cover a solar ambulance built by university students that completed its first real-world test in rural Kenya, a student baking operation in Frisco, Texas that has raised over $8,000 for food-insecure kids, and why the best time to deal with weeds is probably right now.
Transcript link: https://www.optimistdaily.com/?p=1422965
Nominate a Local Changemaker (30 and under): https://us20.list-manage.com/survey?u=d2e7810fd2bcf24fb1144a7e2&id=6e0ab37520&e=28025b5010
If you have questions, comments, feedback, suggestions, or just want to say hi, send a message to: podcast@optimistdaily.com.
Want to be part of the Optimism Movement? Become an Emissary.
Subscribe to our FREE Daily/Weekly Newsletter and follow us on Instagram, X, and Blue Sky.
The Optimist Daily is a project of the World Business Academy.
Donate link: https://www.optimistdaily.com/donate-to-support-the-optimist-daily/?lsc=41ef528d
Theme and all original music by Marvin Lanes
PLAY 23:21 min
September 11, 2026
NYC bans AI for 500,000 students, and seven other solutions
An approach to treating degenerative blindness has been in development for more than ten years across research institutions in Spain. The result is not a surgery, a gene therapy, or an implant. It is eye drops. Light-activated compounds that restored vision in blind animal models by stepping in where lost photoreceptors used to be, without disturbing the underlying disease.
Arielle and Karissa cover eight solutions this week, including the country's broadest AI ban for over half a million students, a urine test that spots bladder cancer with 92% accuracy, and what steel wind turbine foundations are inadvertently doing for marine life around Long Island.
Nominate a Local Changemaker (30 and under): https://us20.list-manage.com/survey?u=d2e7810fd2bcf24fb1144a7e2&id=6e0ab37520&e=28025b5010
Transcript link: https://www.optimistdaily.com/?p=1422924
If you have questions, comments, feedback, suggestions, or just want to say hi, send a message to: podcast@optimistdaily.com.
Want to be part of the Optimism Movement? Become an Emissary.
Subscribe to our FREE Daily/Weekly Newsletter and follow us on Instagram, X, and Blue Sky.
The Optimist Daily is a project of the World Business Academy.
Donate link: https://www.optimistdaily.com/donate-to-support-the-optimist-daily/?lsc=41ef528d
Theme and all original music by Marvin Lanes
PLAY 22:11 min
September 04, 2026
AI music banned from Australia's charts, Roman telescope launches, a biodegradable balloon and much more!
Arielle and Karissa are reunited after a few weeks apart, covering a wide range of solutions this episode: a new telescope that survived two White House cancellation attempts, the decade-long trial that settles the statin-and-dementia debate once and for all, and a biodegradable balloon that took three years and hundreds of failed experiments to get right.
Transcript link: https://www.optimistdaily.com/?p=1422883
If you have questions, comments, feedback, suggestions, or just want to say hi, send a message to: podcast@optimistdaily.com.
Want to be part of the Optimism Movement? Become an Emissary.
Subscribe to our FREE Daily/Weekly Newsletter and follow us on Instagram, X, and Blue Sky.
The Optimist Daily is a project of the World Business Academy.
Donate link: https://www.optimistdaily.com/donate-to-support-the-optimist-daily/?lsc=41ef528d
Theme and all original music by Marvin Lanes
PLAY 26:37 min
August 28, 2026
Niger restored 5 million hectares without planting a single tree plus nine other things going right
Karissa hosts solo this week while Arielle recovers, covering ten solutions including the world's first wild bird flu vaccination program for Phillip Island's little penguins, France making unsolicited telemarketing calls flat-out illegal, and what Baltimore is doing with $400 million in opioid settlement money.
transcript link: https://www.optimistdaily.com/?p=1422844
If you have questions, comments, feedback, suggestions, or just want to say hi, send a message to: podcast@optimistdaily.com.
Want to be part of the Optimism Movement? Become an Emissary.
Subscribe to our FREE Daily/Weekly Newsletter and follow us on Instagram, X, and Blue Sky.
The Optimist Daily is a project of the World Business Academy.
Donate link: https://www.optimistdaily.com/donate-to-support-the-optimist-daily/?lsc=41ef528d
Theme and all original music by Marvin Lanes
PLAY 21:00 min
August 21, 2026
(Guest Interview) Catch up with Kristy: clean energy, leaving California, and embracing the slow life
Many of the long-time listeners of The Optimist Daily's podcast will recognize Kristy Jansen's voice. She's the former co-host and Executive Director of this show, and she's back, joining Arielle and Karissa from Mérida, México, to catch them up on what happened in between: the clean energy industry from the inside, and what it's like to start over somewhere new when you didn't really pick the timing.
Transcript link: https://www.optimistdaily.com/?p=1422807
If you have questions, comments, feedback, suggestions, or just want to say hi, send a message to: podcast@optimistdaily.com.
Want to be part of the Optimism Movement? Become an Emissary.
Subscribe to our FREE Daily/Weekly Newsletter and follow us on Instagram, X, and Blue Sky.
The Optimist Daily is a project of the World Business Academy.
Donate link: https://www.optimistdaily.com/donate-to-support-the-optimist-daily/?gift=Y%20http://
Theme and all original music by Marvin Lanes
bird in rainforest.wav by reinsamba -- https://freesound.org/s/19257/ -- License: Attribution 4.0
PLAY 26:20 min
August 14, 2026
Taking our own advice on slowing down this summer
Arielle checks in solo to explain why the Kristy guest episode is getting a little more time. Both she and Karissa have been doing what they always say matters most: showing up, fully present, for the people they love. Babies, weddings, miles between people who love each other.
Sometimes slowing down really is the solution.
Transcript link: https://www.optimistdaily.com/?p=1422764
If you have questions, comments, feedback, suggestions, or just want to say hi, send a message to: podcast@optimistdaily.com.
Want to be part of the Optimism Movement? Become an Emissary.
Subscribe to our FREE Daily/Weekly Newsletter and follow us on Instagram, X, and Blue Sky.
The Optimist Daily is a project of the World Business Academy.
Donate link: https://www.optimistdaily.com/donate-to-support-the-optimist-daily/?lsc=41ef528d
Theme and all original music by Marvin Lanes
PLAY 03:16 min
July 31, 2026
Liquid air batteries, dolphins saved by plastic bottles, and an empty weekend a month
Dolphins fatally swim into fishing nets because the nylon is acoustically too similar to water for their echolocation to pick up. A researcher at Newcastle University wondered if attaching something that does produce an echo might change that. The dolphin-saving solution may surprise you.
Ten solutions this week with Arielle and Karissa. Also in the episode: energy storage technologies that sound like science fiction but are getting serious investment, India's first domestically built hydrogen train, and the garden sign that looks like a win but means your plant is struggling to survive.
Stay tuned til the end for a wonderful Emissary Shout-Out that will brighten your day!
Transcript link: https://www.optimistdaily.com/?p=1422684
If you have questions, comments, feedback, suggestions, or just want to say hi, send a message to: podcast@optimistdaily.com.
Want to be part of the Optimism Movement? Become an Emissary.
Subscribe to our FREE Daily/Weekly Newsletter and follow us on Instagram, X, and Blue Sky.
The Optimist Daily is a project of the World Business Academy.
Donate link: https://www.optimistdaily.com/donate-to-support-the-optimist-daily/?lsc=41ef528d
Theme and all original music by Marvin Lanes
PLAY 28:23 min
July 24, 2026
The science of soccer-stress, salsa dancing for depression, and why summer slips away
Watching a tense soccer match nearly doubles cardiac event risk, and cortisol could start rising fourteen hours before kickoff. With Spain just taking the World Cup, a fair portion of the world's population has basically been running a biological experiment on itself.
Arielle and Karissa also get into the neurological reason summer keeps slipping away, an Oxford trial where eight weeks of salsa classes outperformed existing tools for depression and anxiety, and a brush swab for oral cancer that returns results in under an hour — no scalpel needed.
Stay tuned til the end for a wonderful Emissary Shout-Out that will brighten your day!
Transcript link: https://www.optimistdaily.com/?p=1422640
If you have questions, comments, feedback, suggestions, or just want to say hi, send a message to: podcast@optimistdaily.com.
Want to be part of the Optimism Movement? Become an Emissary.
Subscribe to our FREE Daily/Weekly Newsletter and follow us on Instagram, X, and Blue Sky.
The Optimist Daily is a project of the World Business Academy.
Donate link: https://www.optimistdaily.com/donate-to-support-the-optimist-daily/?lsc=41ef528d
Theme and all original music by Marvin Lanes
PLAY 28:37 min