Most longtermist interventions focus on trajectory changes, including but not limited to existential risk reduction.
Does existential risk reduction qualify as a trajectory change? It seems not, by the definition given:
a trajectory change is a persistent change to total value at every point in the long-term future.
On a related note, this definition of trajectory change and the usage Will MacAskill uses in What We Owe the Future (similar if not identical) are not what I intuitively assumed when I first heard the phrase "trajectory change."My layperson understanding was that if we change the trajectory of civilization in these next few decades, we may for example increase the probability of successfully navigating some critical period of high existential risk.In WWOTF MacAskill says (IIRC) that it's a positive trajectory change only if the total welfare per year is higher, but we could imagine that the change in the trajectory of civilization in the next few decades actually involves decreased welfare for people in the next few decades, but nevertheless prepares us better for existential risks, such that the long-term future is higher EV. I'd want to call this a positive trajectory change, but the definition given here and in WWOTF doesn't want to call it that.