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.

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.

The business model envisions that polluters will collect the carbon—and the tax credit—and then pay Bayou Bend a transport-and-disposal fee that Tiller says is likely to be $20 to $25 per ton.