Methane Emissions Monitoring: Satellites Track 8.3 Million Tonnes

8.3 million tonnes. That is the estimated volume of methane detected by the GHGSat constellation in 2023 alone (margin of error +/- 0.24). By focusing on 3,114 specific point sources across the energy sector, this data represents a stark upgrade in methane emissions monitoring capabilities. The findings offer a granular view of where the energy sector is failing to contain this potent greenhouse gas.

The frequency of detection tells a damning story. Precision is power. The study found that oil and gas sites emitted plumes 16% of the time. Coal sites? 48%. This indicates that coal infrastructure is a persistent, rather than sporadic, polluter. While the specific mechanical causes remain unverified by satellite imagery alone, the data shows a clear divergence in emission behaviour between fuel types.

The Precision Gap in Methane Emissions Monitoring

Current global inventories are blunt instruments. The satellite measurements comprise only 12% of the total emissions estimated by the Global Fuel Exploitation Inventory (GFEIv3). However, when restricted to the specific locations GHGSat observed, that figure rises to 24%. This discrepancy highlights a major blind spot in current accounting methods.

The spatial data presents a challenge for policymakers. At a national scale, the satellite data correlates well with existing inventories. Yet, at the local 0.2-degree grid scale, the correlation is weak. This implies that while we know which countries are emitting, our maps of exactly where the plumes originate are flawed. We are regulating based on low-resolution estimates.

This study suggests that bottom-up inventories may be misallocating emission sources or overestimating diffuse emissions while missing concentrated point sources. High-resolution monitoring provides the verification layer necessary to correct these maps. Without it, capital spent on abatement may be targeting the wrong coordinates.