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Large Methane Emission Fluxes Observed From Tropical Wetlands in Zambia
Author(s) -
Shaw Jacob T.,
Allen Grant,
Barker Patrick,
Pitt Joseph R.,
Pasternak Dominika,
Bauguitte Stéphane J.B.,
Lee James,
Bower Keith N.,
Daly Michael C.,
Lunt Mark F.,
Ganesan Anita L.,
Vaughan Adam R.,
Chibesakunda Francis,
Lambakasa Musa,
Fisher Rebecca E.,
France James L.,
Lowry David,
Palmer Paul I.,
Metzger Stefan,
Parker Robert J.,
Gedney Nicola,
Bateson Prudence,
Cain Michelle,
Lorente Alba,
Borsdorff Tobias,
Nisbet Euan G.
Publication year - 2022
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/2021gb007261
Subject(s) - wetland , environmental science , greenhouse gas , eddy covariance , methane , atmospheric sciences , carbon dioxide , atmospheric methane , flux (metallurgy) , climatology , ecosystem , oceanography , ecology , geology , chemistry , biology , organic chemistry
Methane (CH 4 ) is a potent greenhouse gas with a warming potential 84 times that of carbon dioxide (CO 2 ) over a 20‐year period. Atmospheric CH 4 concentrations have been rising since the nineteenth century but the cause of large increases post‐2007 is disputed. Tropical wetlands are thought to account for ∼20% of global CH 4 emissions, but African tropical wetlands are understudied and their contribution is uncertain. In this work, we use the first airborne measurements of CH 4 sampled over three wetland areas in Zambia to derive emission fluxes. Three independent approaches to flux quantification from airborne measurements were used: Airborne mass balance, airborne eddy‐covariance, and an atmospheric inversion. Measured emissions (ranging from 5 to 28 mg m −2 hr −1 ) were found to be an order of magnitude greater than those simulated by land surface models (ranging from 0.6 to 3.9 mg m −2 hr −1 ), suggesting much greater emissions from tropical wetlands than currently accounted for. The prevalence of such underestimated CH 4 sources may necessitate additional reductions in anthropogenic greenhouse gas emissions to keep global warming below a threshold of 2°C above preindustrial levels.