Technology increases consumption but can create or mitigate existential risk to human civilization. Though accelerating technological development may increase the hazard rate (the probability of existential catastrophe per period) in the short run, two considerations suggest that acceleration decreases the probability that an existential catastrophe ever occurs. First, acceleration decreases the time spent at each technology level. Second, given an endogenous policy choice to sacrifice consumption for safety, acceleration motivates greater sacrifices by decreasing the marginal utility of consumption and by increasing the value of the future. Under broad conditions, optimal regulation thus produces an “existential risk Kuznets curve”, in which the hazard rate rises and then falls with the technology level and acceleration pulls forward a future in which risk is low. These effects are offset only when acceleration makes a direct contribution to cumulative risk, in that “experiments” are more hazardous performed in parallel than sequentially, that is sufficiently extreme.