Increased carbon capture by a silicate-treated forested watershed affected by acid deposition

• Published in: Biogeosciences
• Main Authors: Taylor, Lyla L., Driscoll, Charles T., Groffman, Peter M., Rau, Greg H., Blum, Joel D., Beerling, David J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2021
• Subjects: article; Verlagsveröffentlichung; Carbonic acid
• Online Access: https://doi.org/10.5194/bg-18-169-2021; https://noa.gwlb.de/receive/cop_mods_00055234; https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00054885/bg-18-169-2021.pdf; https://bg.copernicus.org/articles/18/169/2021/bg-18-169-2021.pdf

Meeting internationally agreed-upon climate targets requires carbon dioxide removal (CDR) strategies coupled with an urgent phase-down of fossil fuel emissions. However, the efficacy and wider impacts of CDR are poorly understood. Enhanced rock weathering (ERW) is a land-based CDR strategy requiring large-scale field trials. Here we show that a low 3.44 t ha−1 wollastonite treatment in an 11.8 ha acid-rain-impacted forested watershed in New Hampshire, USA, led to cumulative carbon capture by carbonic acid weathering of 0.025–0.13 t CO2 ha−1 over 15 years. Despite a 0.8–2.4 t CO2 ha−1 logistical carbon penalty from mining, grinding, transportation, and spreading, by 2015 weathering together with increased forest productivity led to net CDR of 8.5–11.5 t CO2 ha−1. Our results demonstrate that ERW may be an effective, scalable CDR strategy for acid-impacted forests but at large scales requires sustainable sources of silicate rock dust.