TY - JOUR
T1 - The Carbon-Capture Efficiency of Natural Water Alkalinization
T2 - Implications For Enhanced weathering
AU - Bertagni, Matteo B.
AU - Porporato, Amilcare
N1 - Funding Information:
We acknowledge fruitful discussions with S. Calabrese and financial support by the BP through the Carbon Mitigation Initiative (CMI) at Princeton University , the US National Science Foundation (NSF) grant nos. EAR1331846 and EAR-1338694 , and the Moore Foundation .
Funding Information:
Amilcare Porporato reports financial support was provided by BP Plc. Amilcare Porporato reports financial support was provided by National Science Foundation.
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/9/10
Y1 - 2022/9/10
N2 - Enhanced weathering (EW) is a promising negative-emission technology that artificially accelerates the dissolution of natural minerals, promotes biomass growth, and alleviates the acidification of soils and natural waters. EW aims to increase the alkalinity of natural waters (alkalinization) to promote a transfer of CO2 from the atmosphere to the water. Here we provide a quantification of the alkalinization carbon-capture efficiency (ACE) as a function of the water chemistry. ACE can be used for any alkaline mineral in various natural waters. We show that ACE strongly depends on the water pH, with a sharp transition from minimum to maximum in a narrow interval of pH values. We also quantify ACE in three compartments of the land-to-ocean aquatic continuum: the world topsoils, the lakes of an acid-sensitive area, and the global surface ocean. The results reveal that the efficiency of terrestrial EW varies markedly, from 0 to 100 %, with a significant trade-off in acidic conditions between carbon-capture efficiency and enhanced chemical dissolution. The efficiency is more stable in the ocean, with a typical value of around 80 % and a latitudinal pattern driven by differences in seawater temperature and salinity. Our results point to the importance of an integrated hydrological and biogeochemical theory to assess the fate of the weathering products across the aquatic continuum from land to ocean.
AB - Enhanced weathering (EW) is a promising negative-emission technology that artificially accelerates the dissolution of natural minerals, promotes biomass growth, and alleviates the acidification of soils and natural waters. EW aims to increase the alkalinity of natural waters (alkalinization) to promote a transfer of CO2 from the atmosphere to the water. Here we provide a quantification of the alkalinization carbon-capture efficiency (ACE) as a function of the water chemistry. ACE can be used for any alkaline mineral in various natural waters. We show that ACE strongly depends on the water pH, with a sharp transition from minimum to maximum in a narrow interval of pH values. We also quantify ACE in three compartments of the land-to-ocean aquatic continuum: the world topsoils, the lakes of an acid-sensitive area, and the global surface ocean. The results reveal that the efficiency of terrestrial EW varies markedly, from 0 to 100 %, with a significant trade-off in acidic conditions between carbon-capture efficiency and enhanced chemical dissolution. The efficiency is more stable in the ocean, with a typical value of around 80 % and a latitudinal pattern driven by differences in seawater temperature and salinity. Our results point to the importance of an integrated hydrological and biogeochemical theory to assess the fate of the weathering products across the aquatic continuum from land to ocean.
KW - Alkalinization
KW - Enhanced weathering
KW - Natural waters
KW - Negative-emission technology
KW - Ocean
KW - Soils
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U2 - 10.1016/j.scitotenv.2022.156524
DO - 10.1016/j.scitotenv.2022.156524
M3 - Article
C2 - 35714488
AN - SCOPUS:85132712584
SN - 0048-9697
VL - 838
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 156524
ER -