Are we underreporting greenhouse gas emissions?

Although emissions of greenhouse gases continue to climb year on year, there is evidence to suggest we might not even be reporting all of them. Jed Thomas 

Despite international commitments to cut greenhouse gas (GHG) emissions, recent studies and independent monitoring efforts suggest that a substantial portion of emissions—particularly methane—remains unreported or underreported.  

Estimates suggest that oil and gas industries, coal mining operations, and even national inventories may be missing significant amounts of emissions, casting doubt on the accuracy of global climate targets and policies. 

In a moment when some climatologists are suggesting that we’re under-estimating climate sensitivity, it could not be more important to increase our monitoring of greenhouse gas emissions so that we can better regulate them. 

How do we monitor climate tipping points effectively?

Besides global average surface temperatures, successful climate action is going to need more knowledge of of how close we're getting to certain crucial tipping points - but how do we monitor them... Read More

What percentage of GHG emissions go unreported? 

According to a 2023 report by Climate TRACE, a coalition of researchers and NGOs using AI and satellite technology to track emissions, approximately 3 billion tons of CO₂-equivalent emissions went unreported globally in 2021 alone.¹ This amounts to nearly 5% of total global emissions that year.  

The most significant discrepancies were found in methane leaks from oil and gas production, coal mines, and refineries. The organisation found that such discrepancies through 2024.²  

A similar study by the Superpower Institute (TSI) in Australia, utilizing its Open Methane monitoring tool, found that major fossil fuel emitters may be releasing more than twice as much methane as officially reported in the country’s National Inventory.³ 

The primary reason? The inventory relies on self-reported data from fossil fuel companies, often using outdated methodologies with little to no external verification. 

Methane reporting is particularly poor 

Methane (CH₄) is 80 times more potent than CO₂ in the short term, making it a critical target for emissions reductions. Yet, it is also one of the most inconsistently reported greenhouse gases.  

Many national emissions inventories, including Australia’s, estimate methane emissions using decades-old "scaling factors" rather than real-time measurements.  

For example, a coal mine might calculate its methane emissions based on industry-wide assumptions rather than direct monitoring, leading to significant underreporting. 

Climate TRACE’s findings align with research showing that methane leaks from oil and gas fields are frequently three times higher than official reports.⁴ Satellite-based monitoring has revealed that many of the world’s top emitters—including Russia, the United States, China, and Saudi Arabia—are systematically underestimating their methane footprints. 

A 2025 study from University College London (UCL) and Imperial College London estimated that the global methane reporting gap could be anywhere from 170 million to 3.3 billion tons of CO₂-equivalent emissions over a decade, depending on which global warming potential metric is used.⁵ 

The financial implications of correcting this underreporting are substantial—between $1.6 billion and $40 billion in carbon costs, depending on carbon pricing models. 

Google announces groundbreaking AI-equipped methane leak detection satellite

In an ambitious move to confront the escalating climate crisis, Google has announced a groundbreaking partnership with the Environmental Defense Fund (EDF) to launch MethaneSAT, a pioneering satell... Read More

Why are emissions underreported? 

Emissions are often underreported due to a combination of self-reporting practices, outdated measurement techniques, regulatory loopholes, and geopolitical factors.  

Many industries and governments rely on companies to report their own emissions, often without external validation, which creates an incentive to minimize reported figures. 

Measurement techniques also remain outdated, with many national inventories still relying on old methodologies that fail to account for real-world variations in emissions.  

This results in significant discrepancies, particularly for methane, where emission estimates are frequently based on decades-old assumptions rather than real-time measurements. 

Regulatory loopholes further contribute to the problem. Some emissions sources, such as methane leaks from pipelines and fugitive emissions from oil fields, are either exempt from reporting or fall outside the scope of existing regulations.  

This allows industries to downplay or ignore emissions that would otherwise be included in national inventories. 

Geopolitical considerations also play a role in underreporting. Some countries, particularly those with large fossil fuel industries, may intentionally underreport emissions to avoid scrutiny or economic penalties.  

This is particularly relevant given the implementation of mechanisms like Europe’s Carbon Border Adjustment Mechanism (CBAM), which seeks to impose costs on carbon-intensive imports. 

Why we need independent monitoring and standardized reporting 

Experts argue that the only way to close the emissions reporting gap is through independent verification and more rigorous measurement techniques. The Superpower Institute and Climate TRACE both call for: 

• Mandated source-level monitoring: Industries should be required to measure emissions directly rather than rely on outdated estimates. 

• Investment in monitoring infrastructure: Networks of ground-based sensors, satellites, and AI-driven modeling tools could provide real-time data on emissions. 

• Harmonization of reporting standards: The lack of standardized global accounting rules for methane emissions makes it difficult to compare data across countries and industries. The adoption of more consistent methodologies, such as those outlined by the IPCC, could help improve accuracy. 

Four Talks on Detecting Fugitive Methane Emissions

At ILM Exhibitions' Industrial Methane Measurement (IMM) conference, Cindy Verhoeven of The Sniffers, Peter Evans, Ph.D. of BP, Hossein Maazallahi of the University of Utrecht and Clay Bell, Ph.D.... Read More

Reporting transparency is essential to climate action 

The widespread underreporting of GHG emissions, especially methane, poses a major challenge for achieving global climate goals. Without accurate data, countries and industries risk making ineffective policy decisions, failing to meet climate commitments, and damaging their credibility on the international stage. 

With the emergence of satellite monitoring and independent verification initiatives like Climate TRACE and Open Methane, the days of "greenwashing by omission" may be numbered. However, closing the emissions gap will require stronger regulations, technological investment, and a global commitment to transparency. 

If emissions data remains inaccurate, climate targets may be little more than wishful thinking. 

¹ Climate TRACE Unveils Open Emissions Database of More Than 352 Million Assets. 2023.  

² Climate TRACE data reveal high-impact opportunities for cutting greenhouse gas emissions. 2024.

³ Open Methane’s First Results Build the Urgent Case for Improved Emissions Measurement. Professor Peter Rayner. 2024.  

⁴ US oil and gas system emissions from nearly one million aerial site measurements. Sherwin et al. Nature. 2024.  

⁵ Lack of harmonisation of greenhouse gases reporting standards and the methane emissions gap. Simone Cenci and Enrico Biffis. Nature Communications. 2025.