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Winter is Coming! The Science of Ice and Fire

December 17, 2014

The HBO series, Game of Thrones, the television adaptation of the book series, A Song of Ice and Fire, has captured the imagination of over 24 million viewers for the last four years. Though the show takes place in the fictional seven kingdoms of Westeros, there are parts of the show that can be paralleled to Earth science today.

The HBO series, Game of Thrones, the television adaptation of the book series, A Song of Ice and Fire, has captured the imagination of over 24 million viewers for the last four years. Though the show takes place in the fictional seven kingdoms of Westeros, there are parts of the show that can be paralleled to Earth science today.

The words, winter is coming, used frequently in this fantasy TV show, proclaim that the nine-year summer is over, and winter is literally coming. It also brings the fear of giants, mythological frightening characters and dark magic to the people of Westeros.

As in Game of Thrones, our world is affected by weather and climate.


Winter and Climate Change

Unlike in Westeros, where nine-year summers are possible, the first day of winter in the Northern Hemisphere occurs each year on December 21. Earth’s elliptical orbit and natural tilt on its axis cause the annual seasons.

When winter is coming, phenological events – changes in the timing of life-cycle events — are easy to notice. We can see how the outside world changes throughout the year, and now we can document and report the annual environmental trends as the climate changes.

Climate change is affecting our nation in far-reaching ways. Impacts related to climate change are evident across geographic regions and in many sectors important to society—such as human health, agriculture and food security, water supply, transportation, energy, ecosystems, and others. These impacts are expected to become increasingly disruptive throughout this century and beyond.

The White House Climate Action Plan recognizes that even as we act to curb the carbon pollution that helps drive climate change, we must also prepare citizens and communities for the climate impacts that are already underway. The Climate Data Initiative (CDI), part of the Climate Action Plan, is a broad effort to leverage the federal government’s extensive, freely available climate-relevant data resources to stimulate innovation and private-sector entrepreneurship in support of national climate-change preparedness.

Effects of global climate change are clear in Glacier National Park, MT, where glaciers are shrinking and many have already disappeared. Shrinking glaciers reflect changes in temperature and precipitation. Scientists estimate there were approximately 150 glaciers in the park in1850; most of them were still present in 1910 when the park was established.

In 2010, the USGS concluded there were only 25 glaciers larger than 25 acres remaining in the park. A computer-based climate model predicts that some of the park’s largest glaciers will vanish by 2030. This is only one model of prediction but, if true, then the park’s glaciers could disappear in the next several decades. However, glacier disappearance could occur even earlier, as many of the glaciers are retreating faster than their predicted rates.

Image: Muir Inlet
This ship-deck-based photograph of Muir Glacier and Muir Inlet, Glacier Bay National Park and Preserve, St. Elias Mountains, Alaska, is taken towards the north-northwest and shows the nearly 50-m-high retreating tidewater terminus of the glacier with part of its face capped by a few angular séracs. Note the icebergs, especially in the smoother, arcuate ship’s wake in the lower right side of the photograph. The location of Muir’s terminus is less than a kilometer from the landward end of Muir Inlet.Bruce Molnia, USGSPublic domain

















Ice and Fire

“Ice” was not only the name of the long sword of House Stark, it is a major player in climate history, and the USGS Climate and Land Use Change Mission Area conducts extensive ice research.

Ice caps influence the weather and have a direct effect on other aspects of the water cycle. Ice is very white, of course, and since white reflects sunlight (and thus, heat), large ice fields can determine weather patterns. Air temperatures can be higher a mile above ice caps than at the surface, and wind patterns are affected by the presence or absence of ice sheets.

Even though the amount of water locked up in glaciers and ice caps is a small percentage of all water on (and in) the Earth, it represents a large percentage of the world’s total fresh water. Although the amount of water locked up in ice and snow is only about 1.7 percent of all water on Earth, the majority of total fresh water on Earth, about 68.7 percent, is held in ice caps and glaciers.

USGS scientists will never actually study the mythological fire-breathing dragons of House Targaryan, but they do research wildfires in drier parts of the nation throughout the year.

The cold weather months have a high number of fires, both natural and man-made. USGS fire ecologists found that wildland fires are an important ecosystem process throughout the western United States and elsewhere. In parts of California, fires assist in the evolution of plant life and serve as an ecological regulator; however in desert habitats, fires are less frequent and often more damaging.

As many as 90 percent of wildland fires in the United States are caused by people, primarily through campfires left unattended, burning of debris, negligently discarded cigarettes, and intentional acts of arson. The USGS provides tools and information before, during, and after fire disasters to identify wildfire risks and reduce subsequent hazards, including delivery to fire managers of up-to-the minute maps and satellite imagery about current wildfire extent and behavior.


“Valyrian” Steel

In the fictional world of Westeros, the greatest swords are forged from Valyrian steel, a metal that is exceptionally sharp, strong, and lightweight.

Valyrian steel swords are similar in design and composition to Damascus steel blades, a Middle Eastern design. Though Damascus steel went out of production circa 1750, similar steel is still used today when crafting blades.

The element iron is one of the most abundant on earth, but it does not occur in nature in a readily useful metallic form. Iron ore is the term applied to a natural iron-bearing mineral in which the content of iron is sufficient to be commercially usable. Metallic iron, from which steel is derived, must be extracted from iron ore.

Obsidian, or volcanic glass, from Napa Glass Mountain.

Steel, an alloy of metallic iron and carbon, is one of the commodities that the USGS Minerals Resources Program tracks each year. Last year, the iron and steel industry produced goods valued at an estimated $116 billion.

Iron and steel comprise about 95 percent of all the tonnage of metal produced annually in the United States and the world. On average, iron and steel are by far the least expensive of the world’s metals. In some applications, such as steel framing for large buildings, no other materials are suitable to meet strength requirements.

There are also other natural materials that can be used to produce strong and sharp blades. Since the Stone Age, humans have used obsidian to make sharp blades and arrowheads, because it can be fractured and shaped into useful tools and weapons­. In Game of Thrones a fictional ancient dragon glass is used to make the only blade that can kill the White Walkers, an odd species of humanoids that exist in the north of Westeros.

Obsidian is dense volcanic glass, usually rhyolite (thick and rich in silica) in composition and typically black in color. Obsidian forms in lava flows where the lava cools too fast for crystals to grow. Today obsidian is sometimes used to produce surgical scalpel blades.

The Science of Ice and Fire

USGS scientists are committed to understanding the real science of ice and fire. For those who watch Game of Thrones, there are, indeed, parts of the show that can be paralleled to Earth science today.