Emissions of methane and ethane from oil production have been substantially higher than previously estimated, particularly before 2005.
Global methane and ethane emissions from oil production from 1980 to 2012 were far higher than previous estimates show, according to a new study which for the first time takes into account different production management systems and geological conditions around the world.
Methane is a potent greenhouse gas, which scientists rank as the second-most important contributor to climate change after carbon dioxide. Yet while methane concentrations in the atmosphere can be easily measured, it is difficult to determine the contribution of different sources, whether human or natural. This is necessary information for reducing emissions.
“In an oil reservoir, there is a layer of gas above the oil which has a methane content of 50 to 85 percent. When you pump the oil to the surface this associated gas will also escape,” explains IIASA researcher Lena Höglund-Isaksson, who led the study. In oil production facilities in North America, almost all of this gas is recovered and what is not recovered will for the most part be flared to prevent leakage (and potential explosions), while a very small fraction is simply vented. In other parts of the world, where recovery rates are lower, much larger quantities of this gas are released into the atmosphere.
“Existing global bottom-up emission inventories of methane used rather simplistic approaches for estimating methane from oil production, merely taking the few direct measurements that exist from North American oil fields and scaling them with oil production worldwide,” says Höglund-Isaksson. This approach left a large room for error, so Höglund Isaksson decided to develop a new method that could better account for the many variations in oil production around the world.
In the new paper, published in the journal Environmental Research Letters, Höglund-Isaksson estimated global methane emissions from oil and gas systems in over 100 countries over a 32-year period, using a variety of country-specific data ranging from reported volumes of associated gas to satellite imagery that can show flaring, as well as atmospheric measurements of ethane, a gas which is released along with methane and easier to link more directly to oil and gas activities.
She found that in particular in the 1980s, global methane emissions were as much as double previous estimates. The study also found that the Russian oil industry contributes a large amount to global methane emissions. A decline in the Russian oil industry in the 1990s contributed to a global decline in methane emissions which continued until the early 2000’s. At the same time, Höglund-Isaksson found, methane recovery systems were becoming more common and helping to reduce emissions. Yet since 2005, emissions from oil and gas systems have remained fairly constant, which Höglund-Isaksson says is likely linked to increasing shale gas production which largely offsets emission reductions from increased gas recovery.
Höglund-Isaksson points out that her estimates are only as good as the data allow and that there is still uncertainty in the numbers. She says, “To improve the data, a close collaboration between the scientific measurement community and the oil and gas industry would be needed to make more direct measurements available from different parts of the world.”
Höglund-Isaksson L, (2017). Bottom-up simulations of methane and ethane emissions from global oil and gas systems 1980 to 2012. Environmental Research Letters, doi.org/10.1088/1748-9326/aa583e.
Katherine Leitzell | idw - Informationsdienst Wissenschaft
Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University
Climate change: Urban trees are growing faster worldwide
13.11.2017 | Technische Universität München
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses