Earth is a starship too

Robinson sent a starship to another star and brought it home again, because nowhere else was home. Space can power the cleanup. It can't be the lifeboat.

There is enough energy for everyone to live well. The line we can't load past is set by how we share it, not by how much more we can find. Living in harmony with the ship we're on comes to about 2,000 watts each. That isn't a sacrifice number. It's what fits.

Drag the year bar or press play to move through the UN's population projection. Then set how much energy each person uses and how much of it is clean, and watch the waterline. The bar follows you down the page.

The ship that came home

The roadmap runs two plans side by side. Daniel Suarez's Critical Mass sells space as the way out.

“Our move into cislunar space will entail all three, and to a degree that will enable a multi-thousand-year continual economic expansion.”

Daniel Suarez, Critical Mass, loc 1166

Kim Stanley Robinson had already written the answer. In Aurora, a generation ship sails for Tau Ceti. The ship's AI tells the story.

1. 2545–2605A laser beam from the solar system pushes the ship up to speed.
2. 170 years outThe ship reaches Tau Ceti. The colonists land on Aurora, a moon of Planet E, the Earth-like world, and find it holds a lethal prion-like organism.
3. The splitSome colonists stay to try the moon of Planet F, the Mars-like world, later named Iris. The rest sail for home.
4. HomeThe ship flashes past Earth, then brakes with some twenty passes among the planets. Fifteen sleepers die in one of them. It drops its people near Earth in smaller craft, then burns up on its last attempt to slow around the Sun.

The ship's AI draws the lesson.

“There are many other living intelligences out there, no doubt, but they can’t leave their home planets any more than we can, because life is a planetary expression, and can only survive on its home planet.”

Kim Stanley Robinson, Aurora, loc 5703

The book sums it up in a folk-song couplet.

“There’s no new world, my friend, no New seas, no other planets, nowhere to flee— You’re tied in a knot you can never undo When you realize Earth is a starship too.”

Kim Stanley Robinson, Aurora, loc 5944

Takeaway.Life is planetary. A starship is a closed world with a fixed load, and so is this one.

The load line

A Plimsoll line is a mark painted on a ship's hull. Load the ship until the water reaches the mark, and stop. It's named for Samuel Plimsoll, the British MP who campaigned for it.

The UK's Merchant Shipping Act 1876 made the mark compulsory on British ships, and on foreign ships using British ports. But for fourteen years the owners chose where to paint it. Only in 1890 did the Board of Trade's tables fix its position by law. A line works only when the people loading the ship don't get to set it.

In Antarctica, Robinson moves the line from one ship to the whole world.

“Lars talks about a Plimsoll line. Do you know this term? It’s the line on a ship’s hull marking the maximum load possible. He says the world has sunk below its Plimsoll line, weighted down by people. He has worked out how much total energy each person alive today could burn and yet the world altogether still remain above its Plimsoll line. It’s not very much. Less than you would think.”

Kim Stanley Robinson, Antarctica, loc 6338

The hull above uses the number with a real program behind it: 2,000 watts each.

Takeaway.Every ship has a number. What matters is who paints it.

2,000 watts

The Ministry for the Future tells it like this.

“The 2,000 Watt Society, started in 1998 in Switzerland, calculated that if all the energy consumed by households were divided by the total number of humans alive, each would have the use of about 2,000 watts of power, meaning about 48 kilowatt-hours per day. The society’s members then tried living on that amount of electricity to see what it was like: they found it was fine.”

Kim Stanley Robinson, The Ministry for the Future, loc 867

That's the novel's version, and it makes the idea smaller than it is. The real 2000-Watt Society is a vision ETH Zurich put forward in 1998. Its 2,000 watts count all the primary energy a life runs on, all day and all year. That means not just the lights and the stove at home, but the factories, the trucks, and the energy built into everything a person buys. It comes to about 48 kWh a day, close to the world average when the idea was proposed.

A program called Novatlantis started demonstrating it in 2001. In 2008, Zurich's voters made it the city's goal, along with a target of one ton of CO₂ per person by 2050.

Today the world averages about 2,300 watts each. On the same count, the United States runs about 8,600, the EU about 3,700, and Switzerland about 3,100. India runs about 850, and the average across Africa about 450. The 2000-Watt literature counts some things differently, so its Swiss figures run higher. Don't mix the two.

So for most people on Earth, 2,000 watts isn't a cut. It's a raise. It's what living in harmony with this ship works out to: enough for a good life for everyone aboard, on a hull that stays above its line. Getting there means the lights come on across Africa and India while the richest countries learn to run on less.

“Enough should be a human right, a floor below which no one can fall; also a ceiling above which no one can rise.”

Kim Stanley Robinson, The Ministry for the Future, loc 879

Takeaway.Enough is a floor and a ceiling. Set the hull to 2,000 watts and it floats for everyone.

Where it breaks

Efficiency alone doesn't get there. Ministry names the trap, Jevons paradox. Make energy go further and it gets cheaper, so people use more of it, and the total goes up. A better engine helps the waterline only if the line holds.

Try it on the hull. Push the clean share to 100 percent and the waterline doesn't move, because clean cargo is still cargo. Clean supply decides how much of the load cooks the air. The watts each person uses decide whether the ship floats.

The harder break is one Antarctica raises itself. Its campers admit their way of living works only if not too many people try it on the same land, and they conclude that people everywhere should reduce their numbers.

This page doesn't follow them there, and it doesn't have to. The UN projects world population peaking at about 10.3 billion in 2084, then easing to about 10.2 billion by 2100. Set the hull to 2,000 watts and run the year bar to the peak: ten billion people sit right on the line. Leave it at today's world average and the hull sinks below its line around 2037.

Takeaway.The number of people isn't the lever. How we share is.

Then space

None of this says no to Critical Mass. It puts space power where the roadmap already put it, in the back half. Beamed power runs carbon removal first, then daily life.

The hull shows the cost of skipping the cut. Hold the world at today's average until the 2084 peak, and the load above the line takes about 650 power satellites. That's more than the roughly 600 the roadmap needs to pull 10 billion tons of CO₂ out of the air each year. Run the world at the American level and it takes over 14,000.

Run the removal numbers in the roadmap's energy calculator →

Takeaway.Supply is the back half. Sharing is the front.

Aurora, Antarctica and The Ministry for the Future are novels by Kim Stanley Robinson; Critical Mass is a novel by Daniel Suarez. Quotes are given word for word with their Kindle locations. This is an unofficial reading, not affiliated with or endorsed by either author. The hull, the line's placement and the satellite counts are the author's model. The hull is an illustrative model, not a forecast.