EarthDate

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EarthDate is a short-format weekly audio program delivering concise, science-based stories about the Earth: its geology, environments, and the processes that shape our planet over deep time and today. Beginning in 2026, EarthDate is managed by Switch Energy Alliance and hosted by SEA's founder Dr. Scott W. Tinker. Together, we explore earth systems, natural resources, and their relevance to everyday life, with a focus on clear, accessible science education for broad audiences. EarthDate is written and directed by Emmy-winning filmmaker Harry Lynch, and researched by Lynn Kistler. We search for captivating stories to remind listeners that science can enlighten, educate and entertain.

  1. 2d ago

    Dangerous Downbursts

    In 1985, a passenger jet landing at DFW airport was forced to the ground by an unusual downward blast of wind called a downburst. The plane struck cars on the highway and a water tank, then crashed on the airfield, killing more than 100 people. It was the third such fatal crash in a decade. So, the FAA set out to invent a new warning system for these dangerous wind events. A downburst is a sinking column of air within a thunder cloud that accelerates toward Earth, reaching speeds over 100 miles an hour.  When it strikes the ground, it blasts out in all directions, like a mammoth version of water splashing in a sink. These winds are strongest just 10 to 30 feet from the ground and travel horizontally outward in all directions. They can fell trees like a tornado’s whirling winds, but they all fall in the same direction, like dominoes. For aviation, the first step was training pilots to look for visual signs – expanding rings of dust on the ground below, or sharply defined shafts of intense rain. Technologically things were more complex. Vulnerable airports installed a network of wind sensors, as well as advanced Doppler radar that could track wind speeds. All fed into an early alert system. By 1994, 46 high traffic airports had installed these systems. They haven’t had a single downburst accident since -- and technology continues to improve. A triumph of aviation safety.

  2. 2d ago

    Beating the Heat

    Before modern energy gave us modern air conditioning, we had sweat to keep us cool. And shade. And maybe a jump in a lake. Animals still rely on those today to beat the heat. Horses, like humans, sweat. When the sweat evaporates, it cools the skin. Dogs, antelopes and some birds pant, drawing breath rapidly across their tongues and throats, where evaporative cooling brings down the temperature of blood near the skin surface. Other birds vibrate the flaps of skin on their throats to circulate air around blood vessels found there. Elephants do something similar, cooling blood vessels in their huge ears, by flapping them. Camels and toucans draw air across blood vessels in their noses. Rodents and amphibians burrow in the soil or under leaf litter, where it’s cooler and moister. Some toads burrow and go dormant until the next rain comes. Some even form a protective cocoon of their own shed skin. Deer, doves and many other creatures seek shade during the heat of the day, resting silently to keep metabolic rates low. Even fish seek shade underwater, under overhanging rocks or docks. Or they retreat to the dark depths, where the water’s cooler. Speaking of water, buffalo and birds splash in shallow pools. Vultures, maybe not surprisingly, go so far as to pee on their own legs to cool themselves off. Which just goes to show, when the heat rises, animals have found amazing ways to adapt.

  3. 2d ago

    Mangrove Mayhem

    If you’ve been on a boat, pretty much anywhere in the tropics, you’ve seen mangrove forests. There are at least 75 species of these small trees, evolved to live in harsh tidal conditions, their roots in sand, their trunks often submerged in saltwater. There, they can form dense thickets that protect the coast from ravaging waves and storm surges. And that’s just one of their benefits. Mangroves’ arching root networks trap and stabilize sediment to help build up the coast. In the process, they filter and clean coastal water. Those same roots serve as nurseries, sheltering the young of many fish and crustacean species. While the forests provide timber for local human populations, and store carbon. But mangroves are in peril -- from coastal development, agriculture, and especially aquaculture. Shrimp farmers in Asia are responsible for a third of global mangrove destruction, as they clear forests to build their ponds. Early efforts to replant the forests had failed. Until an innovative Florida ecologist realized that mangroves thrive best when their roots are wet only 30% of the time and dry the rest, as the tide comes and goes.  He used a backhoe to regrade the coastline to encourage those conditions. Within three years, the resilient mangroves had returned. His methods proved so successful, they’ve been adopted globally, in a preservation program that intends to bring 20% of mangrove coverage back within the decade.

  4. 2d ago

    Turning Up the Urban Heat

    On another episode, we told you about urban heat islands. Buildings and asphalt absorb summer heat -- from sun and air, cars and trucks, power plants and air conditioning -- and hold it, driving city temperatures far higher than surrounding areas, sometimes to devastating effect. Urban heat islands have killed thousands. But new studies of over 3,000 cities around the world show they’ve saved many more! That’s because heat islands also hold heat in winter, as buildings, transportation and industry ‘leak’ heat into the environment. The result, just as in summer, is that cities can be 10 degrees Fahrenheit warmer. That means less energy required for heating homes and buildings. And, it means many fewer deaths from hypothermia, heart attacks and respiratory illness. The studies show that, in the global average, urban heat islands saved four times as many lives in the winter as were lost in the summer. In cold climates, it was 11 times as many! Tropical cities may not enjoy these benefits – since their winters are not cold enough to kill. But overall, this suggests city planners should adapt regionally to urban heat islands. Warmer cities should try to mitigate heat effects... while colder cities may want to encourage them! Cities that experience both temperature extremes – and many do – may investigate changing roof colors and other flexible solutions that could reflect heat in summer, and absorb it in the winter. Changing, like nature, with the season.

  5. 2d ago

    Urban Heat Islands

    Summer in the city. It’s sweltering. The sun beats down all day. Its heat is absorbed by concrete buildings and blacktop, which hold that heat at night -- and into the next day. The heat builds over weeks and months, keeping summer city temperatures much higher than their surrounding suburban and rural areas. Cities can be 10 degrees Fahrenheit hotter, or more! That’s what’s called an urban heat island. People respond by turning down the thermostat on their air conditioning. Exhaust from AC units and heat from nearby power plants further warm the air. The increased electric load can lead to brownouts, or blackouts. And if people lose power, and air conditioning – or if they don’t have it to begin with – the high urban temps can be deadly. Thousands of people in normally temperate cities in Europe and Asia have died over the past years in summer urban heat waves. So, city planners are working to cool these heat islands. Methods can include so-called ‘cool roofs,’ which use white paint or reflective materials to radiate the sun’s heat, rather than absorb it. Cool roofs can reduce indoor building temperatures by a few degrees Fahrenheit. Green roofs, planted with gardens or even trees, can double that reduction. Likewise, creating more urban green space cools cities, as plants give off water vapor to provide evaporative cooling to their leaves, and the air. Remarkably though, these deadly heat islands may save more lives than they’re endangering – and we’ll talk about that on another EarthDate.

  6. Jun 30

    Mining, Past and Present

    Today we make stuff in three ways. Plants and animals make our food, wood and fiber. Oil and gas make plastic, fuels, chemicals and clothing.   And rocks, dug out of a mine, become metal, concrete and stone – which make our buildings and roads, planes, trains and automobiles, energy infrastructure and much more.  By weight and value, our most important mined product is coal – which makes about 1/3 of global electricity.   Coal was also the first thing humans mined at scale, 20,000 years ago in South Africa.  Around 6,000 years ago, we figured out how to smelt metal out of ore. Copper, gold, silver, tin and iron shaped civilizations in the Bronze and Iron ages, making weapons and tools, art and currency.  Today, we mine in several ways. Surface mines dig out shallow ore deposits or stone.   Underground mines dig tunnels to reach deeper reserves.   Placer mining separates minerals from erosion runoff.   Solution mining dissolves minerals in place with a solvent, which is then pumped to the surface and purified.  All forms of mining have environmental impacts. Surface mines can deforest large areas and disrupt ecosystems. Waste rock, and polluted water and air can impact local communities.   In another EarthDate, we talk about ways to address these impacts, as we ramp up mining to meet the demands of new technology.

  7. Jun 30

    Mining, The Future

    In another EarthDate, we talk about how mining provides the materials to build the modern world.  But new technology is changing that world. We’re building huge new data centers for AI; batteries to power EVs, and stabilize the power grid; and enormous volumes of solar panels and wind turbines.   All these will require a lot more mining. And all mining impacts the environment.   So engineers are working to make the process cleaner and safer.  Mine tailings – the waste rock – are today kept in huge ponds, which can spill catastrophically. New techniques dry them out for safer storage, or to use as construction materials, and recycle the water.  And more mines are capturing, treating and reusing water throughout their processes.   Many mines are working to reduce emissions at the site, switching diesel equipment and trucks for electric motors, requiring more electricity. More advanced automation makes mines more efficient. More advanced exploration uses less energy and disturbs less land to find new resources.  New technologies extract lithium directly from hot, deep brines. And use electricity, instead of high heat or strong acids, to separate metals from mining waste.  Meanwhile, improved recycling programs recover more copper, lithium and other metals from old electronics, batteries and scrap, to help reduce the need for new mines.   And we talk about that, on another EarthDate.

  8. Jun 30

    Urban Mining

    On another episode, we talk about how mines have a large environmental footprint. Think of a giant pit, with huge machines digging out ore.  By contrast, think of your old smart phone. In one ton of discarded phones there’s 80 times more gold than in one ton of ore.   Electronic waste, like phones and computers, contains gold, silver, palladium and rare earth elements.  Old batteries contain lithium, cadmium and other heavy metals.   Construction and demolition debris contains copper from piping and air conditioning, and steel from rebar and beams.   Old cars and trucks contain steel, aluminum and other metals.   This can make cities a repository of metals more concentrated than any mine. And makes this waste the resource for a new industry called ‘urban mining.’  The challenge is gathering that varied waste from across the urban environment, then sorting and disassembling it to be processed. That takes energy, time, labor and money.  But new recycling programs, often powered by AI, sort materials with magnets and robots, then use mechanical shredders and chemical solvents to break them down into simpler components.  Producing metals this way uses less energy and water than mining and processing new ore, with potentially less environmental impact – while also reducing the need for new metals, sometimes imported from unfriendly countries.   In the future, more metal will come from these sources much closer to home.

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About

EarthDate is a short-format weekly audio program delivering concise, science-based stories about the Earth: its geology, environments, and the processes that shape our planet over deep time and today. Beginning in 2026, EarthDate is managed by Switch Energy Alliance and hosted by SEA's founder Dr. Scott W. Tinker. Together, we explore earth systems, natural resources, and their relevance to everyday life, with a focus on clear, accessible science education for broad audiences. EarthDate is written and directed by Emmy-winning filmmaker Harry Lynch, and researched by Lynn Kistler. We search for captivating stories to remind listeners that science can enlighten, educate and entertain.

Information

  • Creator
    Switch Energy Alliance
  • Years Active
    2026
  • Episodes
    300
  • Rating
    Clean
  • Copyright
    © Copyright 2026 EarthDate
  • Show Website
    EarthDate