African rice cultivation linked to rising methane
Zichong Chen, Harvard University, zchen1@g.harvard.edu (Presenter)
Daniel Jacob, Harvard University, djacob@fas.harvard.edu
Nick Balasus, Harvard University, nicholasbalasus@g.harvard.edu
Haipeng Lin, Harvard University, hplin@g.harvard.edu
Hannah Nesser, JPL, hannah.o.nesser@jpl.nasa.gov
The accelerating rise in atmospheric methane since 2007 remains poorly understood and poses a major challenge for achieving the goal of the Global Methane Pledge (30% decrease in methane emissions by 2030). Recent studies have identified Africa as a major driver of the recent rise, and this has been attributed to emissions from natural wetlands and livestock. We show that rice emissions in Sub-Saharan Africa (SSA) could be a significant but previously unrecognized contributor. SSA countries are undergoing a rice farming revolution. Harvested rice area in Africa increased by 68% from 2008 to 2018 to reach 16 million ha, compared to a total rice area of 30 million ha in China. It is slated to further double from 2018 to 2028. Rice cultivation has further converted from upland to irrigated lowland rice to achieve higher yields. Current methane emission inventories underestimate African rice emission and its trend because they fail to account for the recent increases in both cultivated area and emission factors. Here we improve the estimate of African rice emission to reflect these recent trends, and apply emission factors accounting for different practices and environmental conditions specific to Africa. We find a rice emission trend of 0.20 ± 0.04 Tg a-2 in Africa for 2008-2018, accounting for a third of the rise in African methane emissions and 7% of the global rise. The sustained increase in African rice emissions expected over the next decade will require even greater reduction of methane emissions from other sectors to meet the goal of the Global Methane Pledge.
Associated Project(s):
Poster Location ID: 30
Presentation Type: Poster
Session: Poster Session 1
Session Date: Wednesday (9/27) 1:15 PM