CO 2 Outgassing from Spring Waters

CO 2 released from lakes, rivers, and estuaries has been included in estimates of the global CO 2 budget; however, CO 2 released from carbonate springs has not been routinely included in the estimate of the global CO 2 budget. The omission of carbonate spring water as a source of CO 2 might result in an underestimation of the overall flux of CO 2 from surface waters to the atmosphere. In this study, the flux of CO 2 from carbonate springs was calculated and compared to the rate of outgassing of CO 2 reported in the literature for other surface water bodies. The calculated fluxes of CO 2 from carbonate springs ranged 280–380,000 mmol m −2 d −1 . A range that is larger than the range of CO 2 fluxes reported for estuaries (100–1900 mmol m −2 d −1 ), headwater streams and rivers (100–1600 mmol m −2 d −1 ), freshwater lakes (−300 to 3200 mmol m −2 d −1 ), and saline lakes (−300 to 9900 mmol m −2 d −1 ). This work demonstrates that the outgassing of CO 2 from springs should be included in the global CO 2 budget.