Stripe—and now Frontier—aims to be a “buyer of first resort,” sending a demand-side signal to entrepreneurs and investors that a large market for permanent carbon removal exists.

Banks and investors tend to be uncertain about lending to carbon-removal companies that want to build a facility to test their ideas, Ransohoff said. But with an offtake agreement from Frontier, a carbon-removal start-up can prove to a bank that it will have a customer once the facility is up and running.

The new subsidy, modeled broadly on ones for renewable energy, gave developers a credit topping out at $50 for every ton of waste carbon dioxide they captured and geologically stored.