Until recently, methane emissions received too little attention. Plans to reduce
greenhouse gas emissions largely concentrated on carbon dioxide (CO2), a more
abundant and longer-lived pollutant. But in the past few years, scientists have made
significant progress in highlighting the scale of methane emissions. Studies estimate
that methane emissions account for 25–30 percent of global warming since the pre-
industrial era. Global methane emissions dropped in 2020 due to Covid-19, but the IEA
estimates that they rose again last year as economic activity and energy output picked
up. China, Russia, and the United States were the top three methane emitters last year,
collectively accounting for about 47 percent of the global total.
Methane emissions occur naturally and from human activity. Natural sources
such as wetlands and permafrost account for about 40 percent of global methane
emissions. In terms of anthropogenic methane emissions, approximately 25 percent to
30 percent come from the agricultural sector, 25 percent from oil and gas, 15 percent
from coal mining, and the remainder from waste and other sources.
The IEA estimates that oil and gas make up more than 60 percent of total energy emissions.
Emissions in the sector occur from venting, incomplete or inefficient flaring that fails
to combust methane, or fugitive emissions. The last category includes unintentional
leaks from many sources, such as pneumatic controllers, valves, pumps, and storage
tanks. The extent of emissions from the oil and gas sector is still being uncovered.
Recent studies suggest that “bottom-up” inventory-based estimates have significantly
underestimated oil and gas methane emissions.
The rapid technological developments create several challenges for regulators.
Regulatory agencies need to know which data to trust. An ever-growing number
of start-up companies are offering new detection systems, but regulators need to
compare results before deciding which technology or platforms are reliable. It is
challenging to design regulations that encourage operators to adopt the best possible
detection technology without being overly prescriptive.
Companies are sorting through many providers and technology platforms.
Continuous monitoring will soon provide companies with a wealth of data on methane
emissions, but for now it is difficult to decide which vendor to choose and how much
to invest in various technologies. It also remains uncertain how companies can best
integrate ground-based monitoring data, aerial surveys, and satellite data. Oil field
service and cloud computing companies are tackling the issue of data analysis and
integration in decisionmaking. Transnational collaborations like the International
Methane Emissions Observatory (IMEO) are working on generating comprehensive
methane emissions data sets (see following section).
What is clear is that both the scale of the methane emissions challenge and
the technology and knowledge to address it are developing quickly. New rules and
regulations, as well as investor pressure, are leading companies—especially upstream
producers—to set more ambitious targets to cut methane emissions.