Under an applied potential and in the presence of an appropriate catalyst, carbon-dioxide (CO2) and water can be electrocatalytically converted into syngas (CO + H2), ethylene (C2H4), methane (CH4), ethanol (C2H5OH) and formate (HCOOH) among other products. The collective market size of these reduction products is >500 Mton/year, indicating the potential scale of a commercially competitive CO2 electrolyzer; 1 in the process, and of utmost importance and urgency, this process may aid in reducing fossil fuels by supplanting current production routes. Excitingly, CO2 electroreduction catalysts have shown enough promise that we are beginning to see the first steps towards commercial application of the technology, including more and more start-ups (see OPUS12, CERT, Dioxide Materials) and established companies (Siemens) focusing on system design and engineering. As a result, researchers are now targeting lower overall cell potentials by improving other parts of the conversion unit, while looking to more efficiently integrate electrochemical CO2 conversion units with upstream and downstream processes. Future devices will also need to demonstrate stable long-term operation (>20,000 hours) at substantial current densities (>200 mA/cm 2 ) to minimize the capital-expenditure of a conversion unit to economically-compelling levels. Due to the low solubility of CO2 in aqueous-fed systems that limits CO2 conversion to current densities of ~35 mA/cm 2 , researchers have turned to pressurized electrolytes and gas-diffusion layer-based systems to supply enough CO2 to the catalyst layer to sustain higher current densities. Despite these capabilities, an overwhelming percentage (>95%) of fundamental studies and catalytic materials are still developed, tested and characterized in classical H-cell configurations, where current densities are limited. The local catalytic environment, and subsequently the energetics of the reactions occurring on a catalyst's surface, are known however to be highly sensitive to changes in reaction rate. Therefore a fundamental question remains: how representative are the conclusions from aqueous-fed systems that are constrained to ~35 mA/cm 2 when the goal is to achieve >200 mA/cm 2 ? This article seeks to shed light on this question by summarizing how the local reaction environment is known to vary as a function of current density, and how these changes may impact reactions occurring on a catalyst's surface when pushed to commercial current densities. To aid in the analysis we draw upon recent literature findings from electrochemical experiments, transport phenomena and Density-Functional Theory (DFT) modelling.