The Butterfly Effect of Apartment Vacancies

How can what's happening in the ocean directly affect the environment, the food we eat, and our health? In this episode, the "After the Fact" team travels to San Francisco to hear about harmful algal blooms (or "red tides"), which occur when certain algae grow out of control and create dangerous toxins. The effects of these blooms can harm the health of humans and marine life and affect the livelihoods of people living in coastal communities. Matthew Gribble — an environmental health scientist at the University of California, San Francisco — dives into the research behind these harmful algal blooms and shares ways that the health of people, wildlife, and the ocean are all interconnected. We also hear from a fisher about how the red tides can shorten or delay the fishing season, as well as people who rescue marine mammals that have been poisoned by these toxins.

Americans' views of religion have been changing for decades. And in 2026, the share of people who identify as "religious nones" (people who say they have no religious affiliation) is holding steady at 28%. This episode, originally released in 2019, focuses on the shifts in perspectives across generations and the nation's changing religious landscape.

The fertility rate in the U.S. hit another record low in 2025, with 20% fewer babies born that year compared to 20 years ago, indicating that women are continuing to wait longer to have children. This was a growing trend when this episode originally aired in 2019, where a Pew researcher explains the data behind this change in the American family and two mothers share why they waited to have children.

Nearly 800 million people around the world live within 62 miles of a volcano. But what if scientists could better predict a volcanic eruption before it begins? In this re-release from our "Scientists at Work" series, originally published in 2020, we go behind the scenes at the Smithsonian National Museum of Natural History to talk with geologist and volcanologist Ben Andrews. His job is to answer three key questions about volcanoes around the world: When will an eruption happen, how big could the eruption be, and how fast?

This summer, we're revisiting the ways that scientists are using artificial intelligence in their health research. Keyla Sá, a researcher at Yale University School of Medicine, discusses her work tracking how long COVID develops and an AI tool that can identify its wide variety of symptoms and patterns. Since this episode originally aired in 2024, researchers are still learning about the ways long COVID continues to affect millions of people.

America has a milestone birthday coming up: This July, the nation will turn 250. As many pause to reflect on the past 250 years, there's also an opportunity to think about our shared future. While political polarization remains one of the greatest challenges to our democracy, with 65% of Americans saying that they feel exhausted when thinking about politics because of deep partisan divisions, we have more in common than current politics suggest. According to a 2025 Gallup poll, 8 in 10 Americans support compromise between political leaders, and two-thirds agree that democracy—despite its flaws—remains the best form of government.  In this episode of "After the Fact," we speak to Pew's CEO, Susan K. Urahn, and curiosity expert Scott Shigeoka, fresh from the TED Democracy Philadelphia: Founding Futures event, about how the American "experiment" is going, the state of democracy today, and how we can collectively strengthen the foundation of our nation for the next 250 years.   

The U.S. housing shortage has rapidly increased rents in lower-income neighborhoods—making secure housing hard to find. But how does building high-end apartments address availability across income brackets? This episode of "After the Fact" explores new housing's ripple effects and its impact on affordability. The podcast team traces a chain of vacancies, starting with a new luxury apartment unit in Washington, D.C. Its opening spurred the availability of middle-income units and ultimately led to an available unit for a single mother who was able to move out of a shelter and build a new life with her son.

With the upcoming 250th anniversary of the United States, the youngest generation of lawmakers is demonstrating how they're working together more effectively and rebuilding trust in U.S. democracy.  Layla Zaidane, who leads Future Caucus, shares how the organization supports millennial and Gen Z elected leaders in Congress and state legislatures who are collaborating on bipartisan policy solutions. Amid declining trust in U.S. democracy, she tells us why its model is working and why it's a reason for hope—with data indicating that these young lawmakers are 24% more effective than their peers.

Meet the "barbie pig," "gummy squirrel," and "headless chicken monster": These fantastical-sounding nicknames belong to real creatures living in the deep sea—one of the most extreme environments on Earth. And taxonomists, the scientists who discover and name new species, are finding new life in the ocean with every expedition to its depths. In fact, the deep sea makes up 90% of the marine environment, yet recent science suggests we've seen less than 1% of it. But in the same place where a creature such as the barbie pig can survive, there's growing interest in deep-sea mining. Mineral-rich nodules that grow on the seafloor could one day help manufacture products such as cell phones and electric vehicle batteries. But scientists warn that mining could damage critical ecosystems before we fully understand them. In this episode of "After the Fact," Pew expert Julian Jackson explains what seabed mining is and what its consequences could be. We also hear from filmmakers Eleanor Mortimer and Jacob Thomas, whose documentary "How Deep Is Your Love" follows taxonomists as they discover and name new species living at the bottom of the ocean. Disclaimer: Last year, a private mining company sought U.S. approval to commercially recover deep-sea minerals in areas of the deep ocean cited in this episode. The mining application was submitted to the National Oceanic and Atmospheric Administration (NOAA), outside the framework of the International Seabed Authority—the entity responsible for overseeing future deep-sea mining in areas beyond national jurisdiction. The application continues to advance under NOAA's application and review process. Also, the documentary, "How Deep Is Your Love," is fully independent and did not receive funding or support from Pew. 

At Gallaudet University, one of the world's only universities designed to serve deaf and hard of hearing students, a groundbreaking project is underway: a campus-wide microgrid designed to power the entire school with sustainable energy. Gallaudet's microgrid can generate about 1.7 megawatts of electricity, putting its system on par with what it takes to power hundreds of homes in the United States.  In this episode of "After the Fact," join us as we visit Gallaudet University in Washington, D.C., to discover how the university is combining clean energy innovation with inclusive design. We hear from technical and policy experts, and one student intern on the project team, who explain how microgrids can make communities more self-sufficient, especially in the face of increasing electric grid failures and extreme weather events.