The Man With the Sulfur

A pack of feral hogs opens the book, and a man whose job is to kill them. That tells you what sort of thriller Termination Shock wants to be: one that takes its time, enjoys its logistics and trusts you to follow a very large amount of information.

Neal Stephenson's 2021 novel is set in a near future he doesn't date, in which the heat is already costing lives and the diplomats have stopped pretending the targets will be met. Its hero is a scheme. T.R. Schmidt, a Texan oil billionaire, has built a launcher on the Texas-Mexico border that fires sulphur into the upper atmosphere, to do on purpose what Mount Pinatubo did by accident in 1991. Around that scheme Stephenson arranges his people: Rufus Grant, the hog exterminator, who gets drawn in; Queen Saskia of the Netherlands, whose low country has the most to lose from rising water; and Laks Singh, a Canadian Sikh who ends up on the disputed China-India border, where much of the book's moral weight sits. Punjab, where his story begins, is among the places Schmidt's cooling would hurt: the scheme helps low-lying countries and threatens a drought in India.

The title is the sting. If a sulphur programme runs for years and then stops, the warming it was holding back arrives in a rush. Stephenson understood that this makes the thing a trap as well as a fix, and the best parts of the book are about the trap.

The art: a book that is right to be long and wrong to end

It's a very big novel (published by William Morrow in November 2021), and the first two-thirds earn that size. Stephenson is at his best when he's explaining. How would you build a launcher? Who'd sign off? What does a queen's staff actually do all day? He writes these passages the way other thrillers write chases, and they move. The slow reveal of what Schmidt has built, and why, is the best sustained sequence in the book. Chad Orzel, reviewing it on his Substack, called the build-up terrific, and he's right.

Then the plot has to land. Threads that have spent hundreds of pages in different countries are hauled together for a finale of drones and a shaft under the launcher, and it doesn't hold. The same reviewer found it "rushed and confusing and not especially satisfying", and I'd only add that the book has spent most of its length showing that it is interested in systems, so it's odd to end on a stunt. The people also stay thinner than the machinery. Rufus is a pleasure. The Queen is a good idea for a character and something less than a person. Laks is the book's heart and gets the least attention from it.

That's the gap between 7 and 8. It's the work of a writer who is brilliant at the first half of a thriller and impatient with the second.

The prophecy: the hard part isn't the sulphur

Stephenson has said in interviews that the book is about the geopolitical reaction to warming and to geoengineering, more than about the engineering. That is the right subject, and the reason the novel has aged well.

The rogue. The book's premise is that one very rich man doesn't wait for a treaty. In 2021 that looked like a thriller's convenience. It looks less like one now. Make Sunsets, a two-person US start-up, says it has launched 147 balloons carrying sulphur dioxide since February 2023 and sold 128,000 "cooling credits"; the company says its biggest balloons carry under two kilograms each. That's a pinprick, a rounding error beside a coal plant. But it was done without a licensing regime to ask, and when Mexico, where early launches took place, announced a ban on solar geoengineering experiments in early 2023, the company said its launches there were on hold. In April 2025 the US Environmental Protection Agency sent it a formal demand for information. Then, in October 2025, Stardust Solutions, a start-up headquartered near Tel Aviv, raised $60 million, taking its total to $75 million, and reported plans for outdoor experiments from a modified aircraft flying about 11 miles up as early as April 2026, though it has also said it will not run them without government approval. Schmidt is still fiction. His business plan has been tried out by people with smaller budgets.

The price. Stephenson's other bet is that it's cheap. A 2018 study by Wake Smith and Gernot Wagner put the first fifteen years of a high-altitude aircraft programme at about $2.25 billion a year on average, with around 4,000 flights in the first year. That's a sum a handful of governments, or conceivably one very rich man, could find. The book was right to say the barrier is permission and not engineering.

The block. Here the book is more optimistic than reality. It imagines a coalition of exposed countries pushing ahead. The real exposed countries have mostly gone the other way. In 2024 at the UN Environment Assembly, Vanuatu, Fiji, Colombia, Mexico, Pakistan and others supported calls for non-use of solar geoengineering, after African environment ministers had asked for a global non-use mechanism in 2023. Harvard's SCoPEx, the highest-profile attempt at a small outdoor test, was shut down in March 2024 without ever flying, after years of opposition. So the actual fight is less about who would dare, and more about whether anyone has the right.

The border. The most striking thing in the book is that India and China contest a disputed Himalayan frontier with fists and sticks, which turns out to be close to true. A 1996 agreement bars firearms near the Line of Actual Control, and in the Galwan Valley clash of June 2020 troops fought hand to hand, with 20 Indian soldiers killed. Stephenson sends volunteers from both sides to fight there with non-lethal martial arts, and makes a hero of Laks. The real version had no volunteers and no hero, only the same restraint and the same dead.

What it didn't foresee is how ordinary the argument would become. In the novel geoengineering is a sudden event. In life it has been a slow series of small, boring, legally ambiguous steps, and nobody can say which one was the decision.

The reading

Termination Shock is baggy, brilliant and badly finished, and it's the best fictional account of what it would be like to live next to somebody else's thermostat. Its prophecy is stronger than its plot. The rogue operator is here in small form, the money is easy, and the governance is exactly as missing as Stephenson feared. What hasn't happened is the scale, and the one thing that would make the title real: a programme large enough that stopping it hurts.

The book's last lesson is the one worth keeping. Nobody has to want to cool the planet for it to be done. It only needs one person with the money and no one with the standing to stop them.