Free Will and Nuclear Winter

I've been thinking, lately, about free will -- and I recalled this article that I read last year. It's a good, concise analysis of causality (particularly the bits about levels of complexity), and addresses some of the fallacies of breaking down human behavior into ever-smaller constituent components:

http://www.slate.com/articles/health_and_science/science/2013/09/free_will_debate_what_does_free_will_mean_and_how_did_it_evolve.html

The question is a version of "are we more than the sum of our parts?" Many people attempt to derive an answer from religion, espousing a concept of "soul," a metaphysical quantity that science is -- by definition -- unable to prove or disprove. But in the absence of such a belief, are we not just collections of atoms? Isn't each of our thought processes a mere chemical reaction in our neurons? It's a chilling way to think about ourselves; the idea that there is only one possible course of events because our actions are governed by a set immutable physical laws, that each circumstance leads logically into a specific next circumstance, is essentially a secular version of the idea of fate or predestination.

But there's a scientific argument against fate: the multiverse. If there is an infinite number of possible universes, infinitely many points at which one universe becomes multiple, then there isn't one logical state for the universe at any given point in time. The possibility of parallel universes implies, if not conscious choice at all times, then at least many possible outcomes, none of which are certain to happen. Quantum physics likewise deals with uncertainty -- with thought experiments such as Schroedinger's Cat, in which a situation manifests both possible outcomes simultaneously. Science, it appears, disproves fate.

Then, there are situations like this one, in which one person's choice, a split-second decision in a situation of incomplete information, may have prevented all-out nuclear destruction:

http://www.bbc.co.uk/news/world-europe-24280831

Given a circumstance like this, it's hard not to believe in free will. I'm sure that there's a parallel universe out there in which the world ended on September 26, 1983.