Acrylic acid is a valuable platform chemical with significant potential for conversion into commercially essential products, including acrylates, sodium polyacrylate, polyacrylic acid, acrylamide, and polyacrylamide. Currently, the primary method for industrial acrylic acid production involves catalytic oxidation of fossil-based propylene, a process associated with stringent safety requirements and substantial environmental impact. Alternatively, bio-based acrylic acid production from wheat straw through thermo-mechanical pulp mill side streams offers a more sustainable pathway. A prospective life cycle assessment (pLCA) is an essential approach for early-stage evaluation of this innovative biochemical pathway, allowing for a comparative analysis between bio-based and fossil-based acrylic acid production. This assessment provides valuable insights to guide and support stakeholders and decision-makers in advancing sustainable production methods. The study aims to identify environmental hotspots during the initial development phase, using a cradle-to-gate system boundary and a functional unit of 1 kg of acrylic acid. Two-time horizons are considered: the present year, 2024, and future years up to 2050, when industrial-scale implementation of this biochemical pathway is anticipated. The assessment incorporates three prospective scenarios, aligned with the Paris Agreement’s climate targets for energy system development, based on scenarios of an integrated assessment model (IAM), the REMIND model, which are the i.e.,REMIND-SSP2-Base (projecting a 3.5°C temperature rise by century’s end), PKBudg1150 (targeting below 2°C by 2100), and PKBudg500 (aiming for a cap below 1.5°C by 2100), corresponding to milestones in 2030, 2040, and 2050. Using the ReCiPe 2016 v.1.03 life cycle impact assessment (LCIA) method, this study performs a hierarchical midpoint assessment to quantify environmental impacts, focusing on global warming potential (GWP) measured in CO₂ equivalents. Results reveal that the primary contributor to GWP is the energy-intensive evaporation process required to concentrate the diluted side stream, marking it as an environmental hotspot. Findings also indicate that as future energy production becomes more sustainable, the viability of bio-based acrylic acid production improves. Overall, bio-based acrylic acid demonstrates a lower GWP than fossil-based acrylic acid for both current and future scenarios.