Detecting methane emissions from palm oil mills with airborne and spaceborne imaging spectrometers

Abstract

Methane (CH _4 ) emissions from human activities are a major cause of global warming, necessitating effective mitigation strategies. In particular, the palm oil industry generates palm oil mill (POM) effluent, which continuously emits methane into the atmosphere. Satellites are becoming a powerful tool to detect and quantify methane emissions, but there is no evidence of their ability to monitor those from POM ponds. In this work, we have tested the potential of methane-capable satellite instruments to detect and quantify emissions from these ponds. We have focused on the satellite missions with the highest sensitivity to methane emissions, namely the GHGSat commercial constellation and the PRISMA, EnMAP, and EMIT imaging spectroscopy missions. We have also tested the AVIRIS-NG airborne imaging spectrometer. We report three methane plumes from POMs in Indonesia with GHGSat and two in Colombia with AVIRIS-NG. In the cases of EnMAP, PRISMA and EMIT, we observed substantial methane concentration enhancements over several ponds in Indonesia, Malaysia, and Colombia. It remains unclear whether they are due to retrieval artifacts caused by the particular albedo of the ponds, although the low spatial correlation between those enhancements and the ponds suggests that at least a fraction of the enhancements is caused by real emissions. By leveraging advanced imaging techniques and satellite data, this research contributes to progressing strategies to address new methane emissions sources with high mitigation potential, providing a first step toward the satellite-based monitoring of methane emissions from POMs.

Keywords

• methane emissions
• palm oil
• imaging spectrometers
• AVIRIS-NG
• GHGSat
• EnMAP