The geoengineers offer us a third way, and their pitch is seductive, even flattering. Human ingenuity landed us in this pickle, they say. Maybe human ingenuity will set us free. Maybe we can deploy a technical fix, something that will buy us enough time to phase out fossil fuels, without crashing civilization in the process.

Maybe we can spray a mist of particles into the stratosphere, to block sunlight that would otherwise beam down to Earth’s surface. Maybe we can use drone ships to pump chemical glitter into clouds that hover over the oceans, so they reflect sunlight back into black space. Maybe we can nourish massive plankton blooms in the Southern Ocean, to suck CO2 straight out of the sky.

At universities across the world, well-funded, tenured scientists are working hard on these ideas. For the past 6 years, Oliver Morton, a longtime editor at The Economist, has been following their work, testing their ideas, thinking about the practical implications of geoengineering—and the philosophical implications, too.

Earlier this week we talked about his new book, The Planet Remade, at length. What follows is a transcript of our conversation, condensed and edited for clarity.

Ross Andersen: In your book, you use the word geoengineering in a more expansive way than most people. Why is that?

Oliver Morton: Well, there's a way of talking about geoengineering that's too large for me. There's a way that you sometimes hear people who are naively in favor of geoengineering say “well, we're already geoengineering the earth system—we should just do it better.”

There are various problems I have with that thinking. There are bits of the earth system that humans are just making a mess of. I would put the carbon balance of the atmosphere in that category. But that’s not deliberate.

When I sat down to write this book, I wondered if there were parts of the earth system that humans are deliberately changing, with forethought. The one I develop most in the book is the example of the nitrogen cycle, which was once driven by soil bacteria, but has been absolutely taken over by human fertilizer factories.

That wasn’t something that just happened. It was something that senior chemists wanted to happen. It was something that institutions like the Rockefeller Foundation, and the U.S. government, and the Central Committee of China's Communist Party wanted to happen. This was a willed thing.

And although it's not a perfect analogy to the geoengineering people might use to mitigate climate change, it does reset your thinking. It frames geoengineering within this broader question about what kinds of choices people should make in the anthropocene, when the earth is under human dominion, to some extent.

Andersen: One of the pleasures of your book is its emphasis on the intellectual history of geoengineering. How long have humans been thinking about doing something like this?