Let’s look at a small sample of headlines relating to quantum computing: “Quantum Computing Just Might Save the Planet”, “Quantum Computing Could Change the Way the World Uses Energy”, “Quantum Computing will be Bigger than the Discovery of Fire!” People with longer memories may recall: “Saving the Planet with Robots, Microbes, and Nanotechnology.” Should we pay attention this time? Or is this just another red herring trotted out by tech optimists? Separating uncritical, unbridled enthusiasm from realistic expectations around benefits and risks is difficult at early stages of technology development. It is a challenge that, with quantum computing, is complicated by an impenetrable vocabulary, i.e. terms like qubits, entanglement, superposition, and decoherence, and a theory that has led scientists like Richard Feynman to utter, “Quantum mechanics describes nature as absurd from the point of view of common sense.” This talk presents a case study supported by the Internet Society Foundation which was designed to develop some realistic estimates of quantum computing development and deployment - from timing, to impacts, to addressing a more general question: How could society support the development of sustainable quantum computing?