Final published version
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Anthropogenic Water Withdrawals Modify Freshwater Inorganic Carbon Fluxes across the United States
AU - Flint, Elizabeth M.
AU - Ascott, Matthew J.
AU - Gooddy, Daren C.
AU - Stahl, Mason O.
AU - Surridge, Ben W. J.
PY - 2025/3/4
Y1 - 2025/3/4
N2 - Quantifying inorganic carbon fluxes to and from freshwater environments is essential for the accurate determination of the total amount of carbon exported to both the atmosphere and oceans. However, understanding of how anthropogenic freshwater withdrawals perturb land-freshwater-ocean and freshwater-atmosphere inorganic carbon fluxes is limited. Using the United States (US) as an exemplar, we estimate that fresh surface water withdrawals across the country during the year 2015 resulted in a median gross dissolved inorganic carbon (DIC) retention flux of 8.2 (uncertainty range: 6.7–9.9) Tg C yr–1, equivalent to 28.3% of the total export of DIC to the oceans from US rivers. The median gross retention flux due to fresh groundwater withdrawals was 6.9 (uncertainty range: 5.3–8.8) Tg C yr–1, over eight times the magnitude of the DIC flux to the oceans by US subterranean groundwater discharge. The degassing of CO2 supersaturated groundwater following withdrawal emitted 3.6 (uncertainty range: 2.2–5.5) Tg of CO2 yr–1, 112% larger than previous estimates. On a county level, these CO2 emissions exceeded CO2 emissions from major emitting facilities across 45% of US counties. Reported results and a data analysis framework have important implications for the accurate development of carbon budgets across the US and around the world.
AB - Quantifying inorganic carbon fluxes to and from freshwater environments is essential for the accurate determination of the total amount of carbon exported to both the atmosphere and oceans. However, understanding of how anthropogenic freshwater withdrawals perturb land-freshwater-ocean and freshwater-atmosphere inorganic carbon fluxes is limited. Using the United States (US) as an exemplar, we estimate that fresh surface water withdrawals across the country during the year 2015 resulted in a median gross dissolved inorganic carbon (DIC) retention flux of 8.2 (uncertainty range: 6.7–9.9) Tg C yr–1, equivalent to 28.3% of the total export of DIC to the oceans from US rivers. The median gross retention flux due to fresh groundwater withdrawals was 6.9 (uncertainty range: 5.3–8.8) Tg C yr–1, over eight times the magnitude of the DIC flux to the oceans by US subterranean groundwater discharge. The degassing of CO2 supersaturated groundwater following withdrawal emitted 3.6 (uncertainty range: 2.2–5.5) Tg of CO2 yr–1, 112% larger than previous estimates. On a county level, these CO2 emissions exceeded CO2 emissions from major emitting facilities across 45% of US counties. Reported results and a data analysis framework have important implications for the accurate development of carbon budgets across the US and around the world.
U2 - 10.1021/acs.est.4c09426
DO - 10.1021/acs.est.4c09426
M3 - Journal article
C2 - 39960379
VL - 59
SP - 3949
EP - 3960
JO - Environmental Science and Technology
JF - Environmental Science and Technology
SN - 0013-936X
IS - 8
ER -