A recent synthesis of site-level data by Alvarez et al. Some recent studies have used a meso-scale site-level approach which measures CH 4 down-wind of facilities (e.g., well-pads) to estimate total emissions of an entire site or facility (e.g. Top-down studies determine total emissions from multiple sites via measurements from aircraft, satellites, or weather stations (e.g. This difference is sometimes referred to as the top-down/bottom-up gap 11– 17, based on the differences in approach between the GHGI and the conflicting studies. 11 summarize the literature, and observe that national-scale estimates from large-scale field studies exceed the GHGI by ~1.5 times. However, a recurrent theme consistently found in the literature is that the GHGI underestimates total US O&NG CH 4 emissions compared to observed values 10. The GHGI uses a data-rich, bottom-up approach to estimate national CH 4 emissions by scaling up CH 4 emissions measurements from activities like well completions and gas-handling components like valves or seals. The US Environmental Protection Agency (EPA) estimates O&NG CH 4 emissions in an annual Greenhouse Gas Inventory (GHGI) 9. To this end, significant research in the past decade has investigated CH 4 emissions from the O&NG system. However, the uncertainty in this estimate, data gaps, and inconsistency with alternative approaches suggested a need for further evidence 5– 8. At the international level the contribution is approximately 5% (based on estimates from 3 and 4). According to the official United States (US) GHG inventory, CH 4 from O&NG operations are estimated to contribute ~3% of national GHG emissions (with 100 year GWP = 25, 2). During production of oil and natural gas (O&NG), some processes are designed to vent CH 4 to the air, and CH 4 is also emitted unintentionally via leaks in the system. Methane (CH 4) is the principal constituent of natural gas and is also a potent greenhouse gas (GHG) 1. If our proposed method were adopted in the United States and other jurisdictions, inventory estimates could better guide CH 4 mitigation policy priorities. We find that unintentional emissions from liquid storage tanks and other equipment leaks are the largest contributors to divergence with the GHGI. Based on an updated synthesis of measurements from component-level field studies, we develop a new inventory-based model for CH 4 emissions, for the production-segment only, that agrees within error with recent syntheses of site-level field studies and allows for isolation of equipment-level contributions. In the United States, recent synthesis studies of field measurements of CH 4 emissions at different spatial scales are ~1.5–2× greater compared to official greenhouse gas inventory (GHGI) estimates, with the production-segment as the dominant contributor to this divergence. In the meantime there is far more at the gallery than on the website so please feel free to call or check in and see what is available.Methane (CH 4) emissions from oil and natural gas (O&NG) systems are an important contributor to greenhouse gas emissions. After a recent second surgery I am not taking on custom work aside from updating and replenishing current designs. artisans and features beautiful handmade jewelry, pottery, glassware, paintings, carvings and more! Owner, Lydia Podobnik, offers custom designs and repairs, along with many beautiful ready to wear pieces to choose from.ĭue to the handmade nature of the work at the gallery pieces are created one at a time which means you may see "sold out"-feel free to contact me to custom order a sold out ually completion times vary depending on the availability of stones and my current workload. Opening it's doors in January 2015, the gallery is now home to over 50 local B.C. Welcome to Little Gypsy's, situated in a tiny 1920's era house in "Old Town", Port Moody, BC. I, and the over 50 local artists represented within these walls, are forever grateful! Thank you to everyone for all your support in committing to supporting local small businesses.
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