The unitised deepwater Jubilee Field is located 60 km offshore Ghana andcommenced production in late 2010. An FPSO has been installed with oil capacityof 120,000 barrels per day. This was a major oil project execution carried outin a country new to such activities. It was clear from the time of discoverythat expectations in Ghana regarding a positive impact being made by theproject would be high. In the initial project phase of just over 2 years, the Unit Operator (UO) wasresponsible for carrying out the in-country activities, including build of theorganisation required, well drilling and completion execution with severalrigs, the infrastructure build required to support the project team's work andto prepare for the production phase. The UO is now producing the field andexecuting further well and facility expansion work following handover of theproject's facilities from the IPT- Technical Operator. The project was executed at a record pace; success with in-country activitybeing critical in any final judgment of the project as an overall success. Thein-country work set out to ensure that positive precedents, standards andlegacies were set. At all times the highest international standards wereapplied. For example, from the very start due consideration was applied in HSEimpact assessments and required capabilities, local content and capacitydevelopment, national employment and development, and community engagement. Anextensive Environmental and Social Impact Assessment (ESIA) was carried outwith thorough public consultation. The field is run under an independentlyverified Safety Case creating a new standard; currently not a statutoryrequirement. This paper describes the in-country implementation, the high standards appliedto deliver success, the precedents set and examples of the challenges facedwhere activities did not proceed as expected. The implementation ofleading-edge project and field management technologies was carried out in a newcountry setting in a fast moving project. Examples of this are presented inwell engineering, logistics planning and field management information systems. The new country setting was a success factor and was an enabler where a longterm view is taken of the need to involve and benefit all stakeholders. Workcontinues to progress the field development and also the long term developmentof local personnel competency and capability, local content and communityprograms. The Jubilee project stands as a successful modern case history in a country newto major oil production. The approach taken was supported consistently andactively by the Government of Ghana and the Ghana National PetroleumCorporation. The impact has raised Ghana's profile and its level of economicactivity; encouraging further investment. The project establishes a base linefor the expected future growth of the Ghanaian oil industry. Introduction The Jubilee Field was discovered in June 2007 in the Gulf of Guinea, approximately 60 km offshore Ghana. It is a very large, light, sweet oilaccumulation in 1200-1500m of water. The Jubilee Partners including the GhanaNational Petroleum Corporation (GNPC) decided in January 2008 to develop thefield using a phased approach, after just one appraisal well. Kosmos Energy wasappointed Technical Operator to lead an Integrated Project Team (IPT) inexecuting the delivery of the development project and Tullow Ghana wasappointed UO to execute in-country activities, deliver wells and operate andmanage the field in the future. A third major Partner, Anadarko, providednumerous key project personnel. The IPT developed a plan to target just under300 million barrels in Phase 1 with a 17-well subsea well system and 120,000bopd FPSO. Phase 1 was approved by Partners in August 2008, and First Oil wasachieved in November 2010, within the aggressive time goal set by GNPC and theJubilee Partners. The Jubilee project background regarding its characteristicsand the project execution is described in references [1], [2], [3], [4], [5]and [6].

Abstract. The Arctic is warming two to three times faster than the global average, partly due to changes in short-lived climate forcers (SLCFs) including aerosols. In order to study the effects of atmospheric aerosols in this warming, recent past (1990–2014) and future (2015–2050) simulations have been carried out using the GISS-E2.1 Earth system model to study the aerosol burdens and their radiative and climate impacts over the Arctic (>60° N), using anthropogenic emissions from the Eclipse V6b and the Coupled Model Intercomparison Project Phase 6 (CMIP6) databases. Surface aerosol levels, in particular black carbon (BC) and sulfate (SO42−), have been significantly underestimated by more than 50 %, with the smallest biases calculated for the nudged atmosphere-only simulations. CMIP6 simulations performed slightly better in simulating both surface concentrations of aerosols and climate parameters, compared to the Eclipse simulations. In addition, fully-coupled simulations had slightly smaller biases in aerosol levels compared to atmosphere only simulations without nudging. Arctic BC, organic carbon (OC) and SO42− burdens decrease significantly in all simulations following the emission projections, with the CMIP6 ensemble showing larger reductions in Arctic aerosol burdens compared to the Eclipse ensemble. For the 2030–2050 period, both the Eclipse Current Legislation (CLE) and the Maximum Feasible Reduction (MFR) ensembles simulated an aerosol top of the atmosphere (TOA) forcing of −0.39±0.01 W m−2, of which −0.24±0.01 W m−2 were attributed to the anthropogenic aerosols. The CMIP6 SSP3-7.0 scenario simulated a TOA aerosol forcing of −0.35 W m−2 for the same period, while SSP1-2.6 and SSP2-4.5 scenarios simulated a slightly more negative TOA forcing (−0.40 W m−2), of which the anthropogenic aerosols accounted for −0.26 W m−2. Finally, all simulations showed an increase in the Arctic surface air temperatures both throughout the simulation period. In 2050, surface air temperatures are projected to increase by 2.4 °C to 2.6 °C in the Eclipse ensemble and 1.9 °C to 2.6 °C in the CMIP6 ensemble, compared to the 1990–2010 mean. Overall, results show that even the scenarios with largest emission reductions lead to similar impact on the future Arctic surface air temperatures compared to scenarios with smaller emission reductions, while scenarios no or little mitigation leads to much larger sea-ice loss, implying that even though the magnitude of aerosol reductions lead to similar responses in surface air temperatures, high mitigation of aerosols are still necessary to limit sea-ice loss.

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<p>In order to study the future aerosol burdens and their radiative and climate impacts over the Arctic (>60 °N), future (2015-2050) simulations have been carried out using the GISS-E2.1 Earth system model. Different future anthrpogenic emission projections have been used from the Eclipse V6b and the Coupled Model Intercomparison Project Phase 6 (CMIP6) databases. Results showed that Arctic BC, OC and SO<sub>4</sub><sup>2-</sup> burdens decrease significantly in all simulations following the emission projections, with the CMIP6 ensemble showing larger reductions in Arctic aerosol burdens compared to the Eclipse ensemble. For the 2030-2050 period, both the Eclipse Current Legislation (CLE) and the Maximum Feasible Reduction (MFR) ensembles simulated an aerosol top of the atmosphere (TOA) forcing of -0.39±0.01 W m<sup>-2</sup>, of which -0.24±0.01 W m<sup>-2</sup> were attributed to the anthropogenic aerosols. The CMIP6 SSP3-7.0 scenario simulated a TOA aerosol forcing of -0.35 W m<sup>-2</sup> for the same period, while SSP1-2.6 and SSP2-4.5 scenarios simulated a slightly more negative TOA forcing (-0.40 W m<sup>-2</sup>), of which the anthropogenic aerosols accounted for -0.26 W m<sup>-2</sup>. The 2030-2050 mean surface air temperatures are projected to increase by 2.1 °C and 2.4 °C compared to the 1990-2010 mean temperature according to the Eclipse CLE and MFR ensembles, respectively, while the CMIP6 simulation calculated an increase of 1.9 °C (SSP1-2.6) to 2.2 °C (SSP3-7.0). Overall, results show that even the scenarios with largest emission reductions lead to similar impact on the future Arctic surface air temperatures compared to scenarios with smaller emission reductions, while scenarios with no or little mitigation leads to much larger sea-ice loss, implying that even though the magnitude of aerosol reductions lead to similar responses in surface air temperatures, high mitigation of aerosols are still necessary to limit sea-ice loss. </p>