Methane Emissions Reconciliation Goes Top Down, Bottom Up

Methane emissions tracking and reporting is notoriously difficult. Industry experts discuss on-site measurement, aerial measurement, continuous monitoring, existing estimate frameworks and reporting standards. 

From Reuters

An umbrella discussion falls under whether top-down or bottom-up reporting is better and how the two approaches can be used together. Research has shown that bottom-up methods consistently report lower emissions compared with top-down assessments, but a single explanation can’t be pinpointed. Industry leaders are turning to reconciliation as a next challenge to tackle for more accurate reporting. 

According to the IPIECA Methane Emissions Glossary:

Top-down studies are performed on a regional scale using various remote sensing techniques such as satellite and aircraft to measure ambient methane concentrations, calculate methane flux based on atmospheric, and meteorological conditions, and attribute the emission to different activities.

Bottom-up estimates rely on direct measurements, engineering calculations, manufacturer data, and emissions factors for emissions sources and activities, compiled based on a representative sample to develop an aggregated account of emissions from a producing region or asset.

There’s no single best solution for emissions measurement. Quite the opposite—there are many ways to track, measure, and report emissions. Within each, there are levels of uncertainty that need to be addressed to understand the true impact. 

With each producer taking on its own approach to methane emissions measurement, industry evaluators are looking for ways to take the data collected and reconcile it into standardized, more accurate reports. 

While there are voluntary emissions reporting frameworks that help producers report on their emissions, each has different goals and areas of focus and recommendations for reconciliation. Thomas Fox from Highwood Emissions Management broke down three of the common ones. 

• The Oil & Gas Methane Partnership 2.0 (OGMP 2.0) encourages reconciliation between source-level inventories and site-level measurements to complement—and potentially improve—source-level inventories.

• Reconciliation in Veritas differs by supply chain segment and offers three pathways.

• MiQ requires source-level and site-level inspections, including classifying emissions as either purposeful or unintentional, to achieve more accurate methane intensity estimates. 

Read the full Highwood Emissions Management emissions reconciliation article. 

With super emitters and “missing” emissions, the industry is motivated to find reconciliation frameworks that work. The Methane Collaboratory recently closed an RFP for development and validation of a top-down and bottom-up methane emission reconciliation framework—with funding ranging from $250,000- $350,000. 

Early adopters are jumping head-first (you could say top-down) into the challenge, while others are more cynical about reconciliation.