Lignin-based asphalt pavements can create permanent carbon storage and substantial climate benefits

Abstract

Lignin-based asphalt pavements are increasingly recognized for their potential to mitigate climate impacts through biogenic carbon sequestration, unlike degradable bio-products like wooden beams. However, oversimplifying lignin's temporal dynamics could lead to an overestimation of these benefits. We employ both static and dynamic life cycle assessments (LCAs) to evaluate the climate impacts of conventional and four types of lignin-based asphalt pavements, incorporating stochastic uncertainties through Monte Carlo simulations and examining various scenarios influenced by factors like tree rotation periods and pavement lifetimes. Our results indicate that lignin-based pavements generally have lower climate impacts than conventional ones, with dynamic LCA showing up to an 81.7 % increase in impacts due to temporal factors. Using recycled lignin further enhances environmental benefits. Strategic adoption of lignin-based asphalt could potentially offset over 2.0 Gt CO2-eq globally. Sensitivity analysis suggests optimizing lignin sources and extending pavement lifetimes as effective strategies for reducing climate impacts.