1. Great question! Different academic experts claim lignin would be very stable in roads and stay there for a long time, and that when some degradation eventually happens, it will sequester downwards and become part of the soil. Deepdive: We have made roads 14 years ago which are still stable and in good quality today, indicating there hasn't been much degradation of the lignin to speak of. Adding here also a quote from an academic paper: “... the end-product of lignin decomposition in nature contains partially decomposed, fragmented lignin (humus) that enters the soil cycle, and remains in this layer for many years. Release of H2O and CO2 as decomposition products in this layer is extremely limited. Soil bacteria, microfauna, and even physical processes may play important roles in the final breakdown of humus. This is a slow process and some lignin degradation products have soil residence times of centuries (Ziekus, 1981).” - So, while we don't have the complete answer to speed of degradation yet (workin on it!), it seems it would stay beneath the ground far more than long enough to help our planet.
gus_massa|3 years ago
hansarne|3 years ago