Scientists try to explain the long seasons on Game of Thrones

Yes, Game of Thrones is a work of fiction. But that doesn’t stop people from trying to make logical sense of some of its more fantastical elements, such as the nature of the world’s long and unpredictable seasons. Vanity Fair decided to explore the topic, interviewing a pair of climate scientist fans who refuse to stop analyzing the mind-boggling irregularities of Westerosi weather patterns.

First, let’s meet our scientists. Peter Griffith specializes in the carbon cycle and climate while Thomas Douglas is an environmental chemist who studies snow, ice, and permafrost characterization for the Department of Defense’s U.S. Army Cold Regions Research and Engineering Lab in Alaska. “As a scientist, I’m intrigued to come up with a biogeochemical climate explanation for what’s happening in Westeros,” Griffith explains.

These guys have theories. Get ready to hear about meteorites, asteroids, volcanoes and something called the Milankovitch cycles.

MOUNTAINS OF FIRE

“In Game of Thrones, volcanic eruptions caused the end of the Valyrian civilization,” Griffin says. “So we know the planet has undergone massive volcanic eruptions.” He goes on to explain how volcanoes on Earth “can cause mini-winters or years without spring.” The pyroclastic surges spewing from volcanoes hurl sulfur dioxide gas miles up into the troposphere and stratosphere. Sulfuric acid builds up in layered clouds, deflecting the sun’s rays. “It’s like putting a mirror into the high atmosphere.”

The sulfuric acid doesn’t descend quickly. In fact, the high-level winds spread it like wildfire. Griffin points to the 1883 eruption of Krakatoa, a small island west of Sumatra. This was the most powerful eruption in recorded history: five cubic miles of earth were thrown 50 miles into the air. The volcanic debris blocked sunlight as far away as Western Europe and reduced temperatures all around the world; the chaotic weather patterns didn’t cease until 1888.

We can say that the Doom of Valyria is similar to the Krakatoa event. In the Song of Ice and Fire books, the Valyrian peninsula is devastated by the line of volcanoes — the Fourteen Flames — that constitute its mountainous spine. The cataclysm would have also generated massive tidal waves and earthquakes, just as Krakatoa created a series of tsunamis.

Valyria’s ruined landscape may still be producing sulfuric acid; in the Song of Ice and Fire novels, the few who dare journey through it return with stories of crimson skies and stupendous clouds of ash. This parallels the example of Krakatoa in the real world: its volcano is still active, with its last major eruption occurring in 2008.

Douglas also names volcanoes as the main culprit, using the Deccan Trap rock formations in India, created by volcanoes, as an example:

"Some geochemists believe that the volcanic emissions that caused the Deccan Traps led to gas and particulates in the atmosphere that plunged Earth into winter for years. So if there were volcanoes erupting every year or two, for 10 years, on or near Westeros, it could shroud them in winter for years on end."

Griffith adds that George R.R. Martin’s books only reference the known Valyrian event, saying “there’s a great big unknown planet out there that could have other regions with active volcanoes too.”

A BAD OMEN FELL FROM THE SKY

It is now widely believed that an asteroid strike caused the extinction of the dinosaurs. It wasn’t the impact itself that did it, but rather the drop in temperatures caused by the huge amount of debris blasted into the upper atmosphere. “Asteroids can send a lot of dust up into the sky, which will cool the Earth for what could be multiple years,” Douglas says.

Asteroid hits on Earth are few and far between, and notoriously irregular. Douglas proposes a theory that the Game of Thrones planet has an orbit that carries it through an asteroid belt on a predictable timetable. “If the planet got whacked by a giant meteorite every 10 years, it would then have winter for several years,” Douglas suggests. And the bigger the meteorite, the longer the winter.

Game of Thrones fans are familiar with the Red Comet, a celestial visitor loaded with supernatural meaning. When Melisandre interprets her visions, she says “Darkness will fall heavy on the world. The stars will bleed. The cold breath of winter will freeze the seas. And the dead will rise in the north.” The “stars will bleed” comment might refer to the Red Comet, and everything that could potentially come with it.

We’re told that, at one point, there was a winter known as the Long Night when an entire generation lived out its life without ever seeing daylight. I don’t know what the average life expectancy is in Westeros (dying by natural causes seems rare) but let’s guess it’s about 45 years. That’s an insanely long time for a planet that seems, like Earth, to rotate between day and night, to be locked in unrelenting darkness. The sky being full of dust, ash and acid seems to be the best explanation. How this generation or anybody might survive that long in gloom (without sunlight for plants to grow) opens up another can of worms Griffiths and Douglas don’t get into.

EVERYBODY KNOWS ABOUT MILANKOVITCH CYCLES …

What the heck are Milankovitch Cycles? “These are really cool,” says Douglas, sounding like a scientist. Essentially, they describe changes in Earth’s orbit and rotation that repeat themselves over and over, and which can cause big alterations to our climate.

Employing the three factors of eccentricity (the shape of a planet’s orbit), obliquity (orbital tilt) and precession (axial tilt), a Serbian mathematician named Milutin Milankovitch worked out what would happen when all three cycles hit their most extreme points at the same moment in time. He then proposed that Earth was locked in to these multiple extreme cycles during its Ice Ages. In 1976, deep-sea sediment samples confirmed Milankovitch’s theory: the convergence of these cycles matches every serious climate shift in the last 450,000 years. It’s easy to apply Milankovitch’s theory to the Game of Thrones planet, as Douglas does:

"You can imagine that if Westeros were on a planet for which these cycles were way faster or way stronger, then the continent could go in and out of extreme winter or summer on a decade-long scale. And you would have extreme seasonalities."

SOMETIMES, IT’S ALL JUST A FANTASY

The struggle to apply real-world science to a made-up universe is fun, if perhaps pointless. Here’s what Martin himself said on the subject in the 2011 book Speaking of the Fantastic III: Interviews with Science Fiction Writers:

"I have gotten a number of fan letters over the years from readers who are trying to figure out the reason for why the seasons are the way they are . . . I have to say, ‘Nice try, guys, but you’re thinking in the wrong direction.’ This is a fantasy series. I am going to explain it all eventually, but it’s going to be a fantasy explanation. It’s not going to be a science-fiction explanation."

But fans are fans, and both Douglas and Griffith are having a blast trying to prove Martin wrong. “Martin is a brilliant author who can bend the laws of physics and chemistry as much as he wants in his storytelling,” Douglas says. “But we on planet Earth can’t ignore science. We don’t have another option to explain how our climate functions.”

Next: Video: HBO takes us behind Jon Snow’s big moment with Drogon

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