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

Journal Article
Abstract

Abstract. 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.

Year of Publication
2021
Journal
Biogeosciences
Volume
18
Issue
1
Pages
169-188
Publisher
Copernicus GmbH
ISSN
1726-4189
DOI 10.5194/bg-18-169-2021