You've seen our illustrated history of the Keystone XL pipeline. Now, you can enjoy it with snazzy sound effects:

Close your eyes and imagine yourself at your favorite beach. Swells rise around your tanned hips. A bottle of beer and a joint are held safe and dry above your head. You’re sporting a revealing little bathing suit over a younger version of your hot self, airbrushed to perfection using the power of imagination. And there are no cops around to spoil the fun.

Now imagine what that beach would look like if the water was 15 feet higher. Your beer and your ganja are now full of saltwater, and you’re struggling just to keep your head above the waves. Unless your favorite beach is at the bottom of a cliff, nearby buildings are under water, taken over by invasive communities of pineapple-dwelling, square pants-wearing sponges.

That’s not some outrageous scenario dreamed up by liberal scientists with global warming agendas. (The sponge bit was admittedly outrageous, but you can blame me, not the scientists, for it.) No, it’s where sea levels were 120,000 years ago: 15 feet higher than they are today.

Fast forward to 20,000 years ago, when the world was nearing the end of an ice age. Vast stretches of today’s oceans were ice cubes, and as a result, sea levels were 400 feet lower than they are today. What now are tropical near-shore islands back then were frigid hills.

The seas rose again between 20,000 and 6,000 years ago. Then they started rising again early in the 19th century. (Whatever else was happening during the early 19th century, hmmm? A little polluting something called the Industrial Revolution, perhaps?) The seas have been rising ever since, and as a result, land is losing territory to the seas, which are eight inches higher now than they were in 1870.

Scientists can’t be sure how quickly or how badly the world is going to flood, but they have published a variety of estimates based on the amount of pollution we pump into the atmosphere in the coming years. All the scenarios are pretty apocalyptic, though we've factored out the possibility if sudden ice cap collapse, which would create an even more dramatic deluge. So what the hell: Have a little fun on the way down and choose your own adventure!

Ever wonder about the future of energy? Will it be wind? Solar? Geothermal? No wait, I got it, tar sands! (Let’s try that again -- tar sands!) They've got everything oil does, but they’re harder to get, crappier when you get them, and leave a much bigger mark on the climate. Sounds like a winner. Let's look a little closer, shall we?

First off, what are tar sands? Tar sands are deposits of about 90 percent sand or sandstone, water, and clay mixed with only about 10 percent high-sulfur bitumen, a viscous black petroleum sludge rich in hydrocarbons, also known as “natural asphalt.”

The Athabasca reserves, in Alberta, Canada, estimated to hold about 170 billion barrels, are the site of the only commercial tar-sands operation in the world. (Though, spoiler alert, that’s about to change.) It’s one of the largest industrial programs on the planet and could eventually cover an area larger than the state of Florida -- and it’s sprouting an enormous oily ganglion known as the Keystone XL pipeline, which, if completed, would pump 1.1 million barrels of bitumen sludge a day, crisscrossing much of the continent’s freshwater supply, all the way to the Gulf of Mexico.

Sound like a complicated way to create oil, gasoline, and diesel? Naw. Ain’t no thing. Just follow these simple instructions:

You learned it in preschool, and now it’s back in a more grown-up way. From cars to kids’ clothes to cold hard cash, sharing is caring more than ever before. The sharing economy builds and leverages social bonds, creates a more democratic marketplace, reduces the sheer amount of stuff we need to buy, and creates more resilient communities in the process. It’s the bastard child of market disruption that began on the web decades ago (Napster, anyone?), but it's a child with a conscience.

The kind of "collaborative consumption" we see in services like Zipcar and Airbnb has the potential to revolutionize the way we live our lives. But it's not all bartered canning equipment and blissful couchsurfing, folks -- the sharing economy is a serious moneymaker for individuals and companies who “share” their stuff for a price. Investors, who prefer the wonktastic phrase "underused asset utilization" to "sharing economy," say the market amounts to $100 billion to $500 billion worldwide, and it’s growing fast.

Here’s a breakdown of the various sharing philosophies, a few of the reasons that sharing is blowing up right now, and some ways that you can get in on the action. Just drag your pointer over the pictures for more info.

Every morning, I wake up and dump three cups of Quaker brand instant oatmeal into my fish tank. It’s a lifestyle I’m comfortable with, but it turns out oatmeal does terrible things to water clarity and African cichlids positively hate it.

Now a sane person might decide, “You know, maybe I should stop dumping all this oatmeal into my fish tank.” But I am not a sane person. I am a geoengineer, and I can think of far better solutions.

So I’ve built a pump and a series of injectors to fire delicious cinnamon into my fish tank in the hopes that it will bond with the oatmeal molecules and make the whole concoction more appealing to ferrets. I’ve also purchased a skindiving ferret who I’ll introduce to the aquarium ecosystem. I’ve run the numbers on my Commodore VIC 20, and the models all point to a healthy, happy, largely oatmeal-free fish tank in under a fortnight!

I’ve solved everything. Geoengineering, HUZZAH!!!

Geoengineering, for the uninitiated, is “the deliberate large-scale manipulation of the planetary environment to counteract anthropogenic climate change.” (This, directly from the Royal Society). Thus far, it breaks down into two main categories, solar radiation management and carbon dioxide removal. It’s all highly sciumtifical, so let me explain.

You've heard the term "ocean acidification," and I know what you've been thinking: "It can't be as bad as they say. I remember the ’90s. I made it to a few Phish shows. I've seen what goes on in the parking lots, and there's nothing wrong with a little 'acidification.' So the Ocean drops out of Brown for a semester and stares at its belly button. The Ocean's belly button has the Great Barrier Reef in it. The Ocean will enjoy that."

But there is a lot more at stake than the Ocean dropping out of school to make burritos and follow a jam band. Ocean acidification is known as "climate change's evil twin," and considering what a swell fella climate change is, this should give you an idea of just how dangerous ocean acidification may be.

Photo by Shutterstock.

By now, you know that not all meat is created equal. That familiar fable about Old MacDonald and his happy barnyard menagerie is a far cry from the cruel reality of factory farms, where cows, pigs, and chickens are crammed together in giant warehouses, fattened on grain, and pumped full of antibiotics, then rolled out to the slaughterhouse to become the next Big Mac or box of McNuggets.

In regulatory lingo, these meat factories are called “concentrated animal feeding operations,” or CAFOs. (Pronounced "cay-fo.") Here's everything you ever wanted to know about them -- and a few things you'd probably rather not know.

"Fracking": It sounds more like a comic-book exclamation (kapow! boom! frack!) than a controversial method for extracting natural gas and oil from rock deep underground. By turns demonized as a catastrophic environmental threat and glorified as a therapy for our foreign oil addiction, fracking has become a flashpoint in our national energy policy.

First developed in the 1940s, fracking -- literally, "hydraulic fracturing," or "smashing rock open with lots of water" -- only began to boom around 2005, but today, it's used in nine out of every 10 natural gas wells in the U.S. As many as 35,000 wells are fracked each year [PDF], according to the Environmental Protection Agency (EPA). And shale gas (often fracked) now accounts for 15 percent of total U.S. natural gas production, up from virtually nil a few years ago.

Scientists assure us that fracking can be done safely -- at least in theory. They are still working to understand the long-term implications of using this technology at large scale in the real world, however, where things spill, accidents happen, and people have their health, homes, schools, airports, groundwater, and even cemeteries to worry about.

We know scientists aren't the only ones looking for answers. So below, we tackle six key questions about fracking.

1. How does fracking work?

In 2000, Nobel Prize-winning chemist Paul Crutzen suggested that humans have had such profound and far-reaching impacts on the planet that we have ushered in a new geologic age – the Age of Man, or, as Crutzen called it, the Anthropocene. The idea has been bouncing around the halls of academia ever since, and in the last few years, it has jumped from the ivory tower into popular literature and a few geek-tastic conversations over beer. The notion that humans now run this joint seems to have struck a chord.

Just getting up to speed? The team from the Generation Anthropocene podcast at Stanford University sat down in the recording studio and tried to explain everything in five short minutes. (It ended up taking seven, but who’s counting?) Just for fun, they did it game-show style.