  Much emotion is expended on the dangers of carbon dioxide, but solutions
require reason and recognition of facts: (1) The cost of developing options is
approximately a thousand times less than their deployment. (2) Timescales
involve two questions: (a) How quickly can an option be demonstrated? (b) How
quickly can the required equivalent of thousands of units be built. Two
questions are implied: (1) What options would most fundamentally change the
carbon-dioxide problem? (2) For each option, how could it be demonstrated most
quickly? An option of fundamental importance is direct air capture of carbon
dioxide. The option that appears most attractive for carbon-free energy
production is the stellarator fusion concept, which is poised for a rapid
demonstration.
