Quantum mechanics underlies all chemical reactions, yet long-lived quantum coherence is unlikely to have played a sustained role in the emergence of life. Instead, early Earth environments may have repeatedly generated transient molecular excitations that underwent decoherence, energy relaxation, and chemical transformation. Here I propose that environmentally structured decoherence forms part of a broader process in which environmental structure constrains dissipative molecular dynamics and thereby influences chemical evolution. In structured settings such as ice matrices, auroral particle precipitation zones, magnetically focused atmospheric regions, and gas–liquid interfaces, environmental organization may bias reaction pathways through confinement, electric fields, proton gradients, and magnetic topology. Across these diverse environments, a common principle emerges: structured environments repeatedly favor particular reaction pathways and the persistence of selected products, providing a potential physical basis for directional prebiotic chemical evolution before genetic replication. This framework integrates quantum physics, prebiotic chemistry, and environmental structure into a unified perspective in which environments actively shape, rather than merely host, chemical evolution.