Today we’re going to take a closer look at cities, examine how these large complex structures are organized, and identify patterns and differences in land use around the world. We'll begin with a quick recap of Central Place Theory, then...

One of the most dynamic, transformative, and potentially dangerous features in North America is also responsible for some of the continent's most amazing fossil deposits. It's a supervolcano we now call Yellowstone.

About 5 million years ago, a new predator made its way from the south and onto the coastal plains of North America. It was a giant, flightless, carnivorous bird and came to be known by one of the coolest and most richly earned nicknames...

Ratites have spread to Africa, Australia, New Zealand, and South America. And there are fossils of Ratites in Europe, Asia, and North America too. That's a lot of ground to cover for birds that can't fly. So how did Ratites end up all...

With fantastic new maps that show interactive, visual representations of urban fragility, Robert Muggah articulates an ancient but resurging idea: cities shouldn't just be the center of economics -- they should also be the foundation of...

Invasive species are more than just unwelcome guests, and while some can be super harmful, others might actually be helpful!

Paul Andersen reviews the major concepts within the second unit of the new AP Biology framework. He starts by describing how life is organized into three domains. He explains how the history of life on the planet is...

This is not a Game of Thrones fan fiction episode. Dire wolves were real! And thousands of them died in the same spot in California. Their remains have taught us volumes about how they lived, hunted, died and way more about any animal's...

The ancestors of modern horses became so successful that they spread all over the world, to Europe, Asia, South America, and Africa. But in their native range of North America, they'll vanish for 10,000 years. Until another strange...

I want you to reimagine how life is organized on earth, says global strategist Parag Khanna. As our expanding cities grow ever more connected through transportation, energy and communications networks, we evolve from geography to what he...

Sara Menker quit a career in commodities trading to figure out how the global value chain of agriculture works. Her discoveries have led to some startling predictions: "We could have a tipping point in global food and agriculture if...

In a few decades, scientists predict that a widespread, severe drought will sweep across western North America -- and it'll last for decades.

Winter is upon us, and for many that includes snow! And although snowflakes are ice crystals that become flakes under the right conditions, they also have mysteries that can be less simple to explain!

In this moving yet pragmatic talk, Kevin Bales explains the business of modern slavery, a multibillion-dollar economy that underpins some of the worst industries on earth. He shares stats and personal stories from his on-the-ground...

A net-zero future is possible, but first we need to flip a mental switch to truly understand that we can stop the climate crisis if we try, says Nobel laureate Al Gore. In this inspiring and essential talk, Gore shares examples of...

If you've ever been to, or lived in, or even flown over the central swath of North America, then you've seen the remnants of what was a uniquely fascinating environment. Scientists call it the Western Interior Seaway, and at its greatest...

In the wake of Hurricane Sandy, Hank answers some frequently asked questions about it, and how it got to be so crazy. What is up with this storm? Has this ever happened before? This is global warming right?

What does environmental devastation actually look like? At TEDxVictoria, photographer Garth Lenz shares shocking photos of the Alberta Tar Sands mining project -- and the beautiful (and vital) ecosystems under threat.

There are estimated to be over 18,000 different bird species with a wide variety of nest shapes and sizes. From teeny, adorable cups to massive compost mounds, the diversity of birds’ nests is definitely impressive. Chapters 1 BALD...

Scientists have used a bacteria that commonly infects us to track how ancient humans spread to the Americas from Siberia. And other scientists have discovered a new species of hyrax in the forests of Africa by listening to their barks...

As the Roman Empire flourished, Scandinavians had small settlements and no central government. Yet by the 11th century, they had spread far from Scandinavia, gaining control of trade routes throughout Europe, conquering kingdoms as...

How could the most abundant bird in North America go extinct so quickly? Short answer: us.

In this bracing talk, coral reef ecologist Jeremy Jackson lays out the shocking state of the ocean today: overfished, overheated, polluted, with indicators that things will get much worse. Astonishing photos and stats make the case.

Camels are famous for adaptations that have allowed them to flourish where most other large mammals would perish. But their story begins over 40 million years ago in North America, and in an environment you'd never expect: a rainforest.