Could Humans Survive Arrakis? A Climate Model Tests Dune's Desert World

A climate model that normally simulates Earth's weather ran for more than three weeks on a supercomputer, and the planet it was describing was Arrakis, the desert world of Frank Herbert's Dune. The question the researchers wanted answered was simple: if you keep Earth's physics and feed in what the novels say about the planet, does the result look like Herbert's world or something strange?

The team is Alex Farnsworth and Sebastian Steinig of the University of Bristol, and Michael Farnsworth of the University of Sheffield. They began with a model commonly used to predict weather and climate, and kept the same physical laws that govern Earth. Their reasoning was that an exotic result would suggest either different physics on Arrakis or that Herbert's vision was pure fantasy. They then supplied details from the main novels and the Dune Encyclopedia: the planet's topography and its orbit, which is essentially circular, like Earth's today.

The atmosphere was the last input. It is broadly Earth-like, with less carbon dioxide, 350 parts per million against Earth's 417. The big difference is ozone. Earth's lower atmosphere holds only about 0.000001 percent, while Arrakis has 0.5 percent. That matters because, over a 20-year period, ozone is about 65 times more effective than CO2 at warming the atmosphere.

The results largely held up. In the tropics, the warmest months reach around 45°C and the coldest do not fall below 15°C, similar to Earth. The extremes come elsewhere. In the mid-latitudes and polar regions, summer sand can reach 70°C, which the book also suggests, while winters drop as low as -40°C in the mid-latitudes and -75°C at the poles. That seems backward, since the equator gets more sunlight. But in the model the polar regions carry much more atmospheric moisture and high cloud, and water vapor is a greenhouse gas that warms the climate.

The model departs from the books in a few places. The novels say there is no rain, whereas the model produces very small amounts, limited to higher latitudes in summer and autumn and only over mountains and plateaus. There would also be some clouds in the tropics and polar latitudes, varying by season. The biggest conflict concerns the northern polar ice cap that the books describe as long-standing. In the model, summer temperatures would melt polar ice, and no winter snowfall would replenish it.

The researchers then asked whether humans could live there, assuming the people of Dune have thermal tolerances like ours. Contrary to the book and film, the tropics come out as the most habitable region. Humidity is so low that survivable wet-bulb temperatures, a measure combining heat and humidity, are never exceeded. The mid-latitudes, where most Arrakis residents live, are the most dangerous for heat. Lowland monthly averages are often 50 to 60°C, with daily maximums higher still, which is deadly for humans.

That is where the stillsuit comes in. In the books, all humanoid life outside habitable places must wear one to stay cool and reclaim moisture from sweat, urine and breath. This matters because the novels describe no rainfall, no open standing water and little atmospheric moisture to capture. Cold is a problem as well: outside the tropics, winters would be uninhabitable without technology. Cities like Arrakeen and Carthag would face both heat and cold stress, like an exaggerated version of parts of Siberia.

The authors note that Herbert wrote the first novel in 1965, two years before the recent Nobel laureate Syukuro Manabe published his seminal first climate model, and without any computer. Given that, they say, his world looks remarkably consistent six decades later.

The work was done in the authors' spare time as an outreach piece showing how climate scientists use mathematical models to understand Earth and exoplanets. They say it will feed into future academic work on desert worlds and exoplanets.