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GLOBAL GREENHOUSE GAS EMISSIONS FROM RESERVOIRS: A MATTER OF METHANE
Citation:
Deemer, B., J. Harrison, J. Beaulieu, S. Li, M. Santos, J. Neto, S. Powers, J. Vonk, T. DelSontro, AND N. Barros. GLOBAL GREENHOUSE GAS EMISSIONS FROM RESERVOIRS: A MATTER OF METHANE . Presented at Aquatic Science Meeting, Granada, SPAIN, February 22 - 27, 2015.
Impact/Purpose:
To inform the public
Description:
More than a decade ago, St. Louis et al. demonstrated that, collectively, manmade reservoirs play an important role in the global balance of greenhouse gases (GHGs). To update and build upon this important seminal work, we compiled reservoir CO2, CH4, and N2O flux estimates from 202 additional reservoir systems. Average reservoir greenhouse gas fluxes were 350 mg CO2-C m-2 d-1 (S.E. 32, n=196), 65 mg CH4-C m-2 d-1 (S.E. 17, n=119), and 0.35 mg N2O-N m-2 d-1 (S.E. 0.13, n=57), which correspond to approximately 547 Tg CO2 equivalents yr-1. The average reservoir CH4 fluxes we report are comparable to median CH4 fluxes from wetlands. CH4 accounted for the majority of GHG forcing due to reservoir emissions (>57% of CO2 equivalents), but was also the most variable GHG flux from system to system (276% coefficient of variation). There is a critical need for additional CH4 ebullition measurements as this flux is clearly important but under-sampled (available as an independent measurement in just 30% of sampled reservoirs), and hence underrepresented in global reservoir GHG flux estimates.
