Dynamic life cycle assessment of fibrous agricultural residues for long-lived carbon storage in building materials

This study combines a global mass-flow analysis of technically recoverable agricultural residues with dynamic life cycle assessment to quantify climate benefits of diverting biomass into long-lived building products. Annual flows were linked to the Bern Impulse Response Model (BernSCM), radiative forcing and temperature response under different scenarios diverting biomass from combustion routes such as open burning, combined heat and power and biofuel production to long-term storage. The assessment showed that a complete diversion from combustion with renewable energy backfill provides persistent cooling with a median radiative forcing of -0.6 W.m -2 and -0.35°C at 100 years. Allocating an additional 50 Mha of high-yield crops increases long-term cooling but is offset by early land-use emissions. Scenarios, constrained by projected global building materials demand produced much smaller effects in the range of 0.0041-0.0082 W.m -2 in radiative forcing and 0.0031-0.0062°C cooling for bio-based market increasing from 1% to 25% and 50% in the next 25 years. Sensitivity analysis shows uncertainty dominated by service life and end-of-life scenarios, while substitution credit and allocation shares resulted in a smaller influence. The results indicate that while fibrous residues could act as a significant carbon sink, their full potential requires expanding beyond insulation materials or deployment into other long-lived construction applications. • Global MFA shows 4.4 Gt.y -1 of fibrous residues suitable for long-term storage. • Diverting residues to buildings provides cooling up to -0.41 °C over 100 years. • Renewable backfill preserves biogenic gains while grid energy erodes benefits. • Results show limits of building demand and need for complementary carbon sinks.