Oil and gas production in the Gulf of Mexico is belching out significantly higher levels of potent, planet-heating gas than previously thought, according to new research, which found the climate effects of the operations are twice that of official estimates.
The report comes as the Biden administration last month put millions of acres of water in the Gulf of Mexico up for auction to offshore oil and gas drilling, and has plans for further auctions.
In August 2020, scientists spent 10 days doing airborne surveys of more than 50 platforms in the Gulf of Mexico. Flying in concentric rings around the facilities, they measured plumes of carbon pollution from burning processes as well as methane pollution from leaks and venting.
They combined the findings with previous emissions surveys and inventories to calculate the “carbon intensity” of oil and gas operations — the total amount of planet-warming pollution released for each unit of energy produced.
Their results revealed a climate impact twice as large as that estimated by government inventories, driven by high levels of methane — a powerful greenhouse gas more than 80 times more potent than carbon dioxide in its first two decades in the atmosphere.
Methane pollution in the Gulf of Mexico totaled 600,000 metric tons a year, according to the report, which found that average methane levels in federal waters were three times higher than official inventories, and 13 times higher in state waters.
“Inventories are generally challenged by methane,” said Alan Gorchov Negron, a study co-author and climate science researcher at the University of Michigan. Unlike carbon pollution, which comes from burning the fuel, methane from oil and gas operations escapes into the atmosphere — either through deliberate venting and flaring or accidentally through dilapidated equipment or unknown leaks.
The study found that the worst climate performers were platforms in shallow waters, which include older style “central-hub platforms” that collect oil and gas from smaller platforms for processing. These have an “extraordinarily high” carbon intensity that far exceeds that of deeper water facilities, according to the report’s authors.
There are multiple reasons for this outsized climate impact of shallow-water platforms, according to the report, including persistent venting, emissions associated with equipment as well as the tendency of the facilities to be older and sometimes poorly maintained.