Note: this article is spoiler-free.

The epic television series Game of Thrones makes compelling viewing for many reasons. Exotic locations and cutting edge visual effects have spectacularly translated George R R Martin’s vision onto the small screen. These production values have made the series one of the most expensive ever made and allowed the attention to detail required to build an immersive world of humans, dragons, the old gods and the new.

But as fantastic as this conjured world is, recent research seems to prove the old adage that fact can indeed be stranger than fiction. Because while the lands of Westeros and beyond experience dramatic shifts in weather and seasons, changes in climate here on Earth are even weirder.

Death and taxes and dragons

Other than constant politicking and backstabbing (not to mention front stabbing, decapitation, and immolation) there are few constants in Game of Thrones. Long running shows typically assure us that our favourite characters will carry on and that their lives will span seasons. But anyone who has been keeping up with the Starks and Lannisters will be well aware by now that playing a central role provides no guarantee of longevity. Remember the Red Wedding? But throughout this maelstrom there is an ever present factor. A brooding menace that belittles all the squabbles and fighting.

The threat of winter’s return.

“Oh, my sweet summer child,“ Old Nan said quietly, “what do you know of fear? Fear is for the winter, my little lord, when the snows fall a hundred feet deep and the ice wind comes howling out of the north.”

Winter in Westeros is a serious business. The larger towns and citadels survive with stockpiles of food and firewood. Small communities either flee or perish. What makes winters so harsh is that they can last for many years. The opening book of A Song of Ice and Fire – A Game of Thrones from which the television series takes its name – opens with concerns that the winter is due to return after nine years of summer. Such a long summer heralds an equally long winter.

Why the change of seasons is so unpredictable is subject of speculation in the real world and in the books. Some claim it was a consequence of a battle some 8,000 years ago. The scholars, healers, and learned men – the Maesters – discount this as a fable with no supporting evidence. How could humans alter the seasons? What’s intriguing is that this Game of Thrones myth may have some basis in reality. Because something happened here on Earth about 8,000 to 12,000 years ago that could have profoundly affected the Earth’s climate and the history of all civilisations.

Putting the next ice age on ice

Glaciations, or ice ages, have been a regular occurrence on Earth for the past 2.6m years, the geological period known as the Quaternary. Due to a combination of orbital mechanics, tectonic processes, and ocean currents, the Earth’s climate periodically is thrown into a reinforcing feedback loop that plunges temperatures lower and lower. The polar ice caps and glaciers expand while sea levels fall as much as 120 metres.

Periods between ice ages – interglacials – have lasted around 10,000 years in Earth’s recent geological history. Given that it’s been more than 12,000 years since the last glacial maximum, one may conclude that a new ice age is overdue. However, that may not be the case. We may have stopped it.

Humans began farming almost as soon as the last ice age ended. Although the numbers of humans were small, land use change such as burning fields and forests would have released carbon dioxide into the Earth’s atmosphere, which along with methane from the increased number of cattle, could have been sufficient to effectively put the next ice age on hold, so delicate was the balance between the two climate states. It’s worth pointing out that the difference in global temperatures between our current climate and the depths of the previous glacial maximum is about 5℃. Consider how different a world that is 5℃ warmer than today would be.

A long hot summer

A study published in the journal Nature at the start of 2016 contained the even more remarkable conclusion that human activity since the Industrial Revolution has not only paused but indefinitely delayed the series of ice ages. In fact, it may be that by elevating atmospheric carbon dioxide to levels not seen on Earth for millions of years, humans have ejected the Earth out of the Quaternary ice ages. Think about that for a moment. The process of industrialisation that began some 300 years ago has disrupted a 2.6m-year-old climate state. No more ice ages.

But isn’t that good news? The dawn of a new ice age would plunge civilisation into chaos. We may not have intended to, but our actions have avoided such a calamity. Unfortunately, it’s possible to have too much of a good thing.

Now we fear not winter, but a period of rapid warming, the likes of which our civilisations have never experienced before. It seems unimaginable that we could effect such significant change over such a short period of time. Harder still to acknowledge is that if we are to avoid dangerous climate change, then we must radically change how we power our industrialised societies.

Such change will not be easy to effect. As Tyrion Lannister once observed:

“Most men would rather deny a hard truth than face it.”

An adage that could apply to some of those who wish to become the most powerful person on Earth, as much as whoever vies to sit on the Iron Throne.

James Dyke, Lecturer in Sustainability Science, University of Southampton

This article was originally published on The Conversation. Read the original article.