Solar-driven distillation is a promising technology for energy-efficient freshwater generation, but salt accumulation on solar absorbers and system longevity are major challenges that hinder its widespread application. In this study, we present a novel Janus wood evaporator that overcame these challenges and achieved record-high evaporation efficiencies in high-salinity brine, one of the most difficult water sources to treat using desalination. The Janus wood evaporator had an asymmetric surface wettability, where the top layer acted as a hydrophobic solar absorber with enhanced thermal insulation, while the bottom hydrophilic wood layer allowed for rapid water replenishment. An evaporation efficiency of 82.0% was achieved for 20% NaCl solution, and superior salt-resistance was observed during a 10-cycle longevity test. To ensure the environmental sustainability of the new Janus wood evaporator, a life cycle assessment (LCA) was conducted to compare this Janus wood evaporator to emerging Janus evaporators. Results showed that Janus wood evaporators could emit up to two orders of magnitude less CO2 equivalents than an aerogel Janus evaporator (AJE) and up to 80% fewer emissions than an electrospun Janus mat (EJM), indicating a functional and more sustainable opportunity for off-grid industrial applications and humanitarian efforts.