Offshore Energy Strategic Environmental Assessment (SEA): An overview of the SEA process
Source: gov.uk (2025-07-01)

An explanation of the offshore SEA  process, including documentation of the most recent assessment and related consultation.

Overview

Strategic Environmental Assessment (SEA) is the process of appraisal through which environmental protection and sustainable development may be considered, and factored into national and local decisions regarding Government (and other) plans and programmes – such as oil and gas licensing rounds and other offshore energy developments, including renewables and gas and carbon dioxide storage.

The SEA process and legislative context

The SEA process aims to help inform ministerial decisions through consideration of the environmental implications of the outcome of a proposed plan/programme. The Department for Energy Security & Net Zero (DESNZ) formerly DTI, BERR, DECC and BEIS (the department), as the principal environmental regulator of the offshore oil and gas industry, has taken a proactive stance on the use of SEA as a means of striking a balance between promoting economic development of the UK’s offshore energy resources and effective environmental protection. Although the European Strategic Environmental Assessment Directive (Directive 2001/42/EC) was not incorporated into UK law until 2004 (The Environmental Assessment of Plans and Programmes Regulations 2004, and equivalent Regulations of the devolved administrations (the SEA Regulations)), SEAs have been carried out since 1999 in accordance with its requirements.

The SEA Regulations set out the information to be included in the environmental report of the Strategic Environmental Assessment, namely:
- An outline of the contents, main objectives of the plan or programme and relationship with other relevant plans and programmes.
- The relevant aspects of the current state of the environment and the likely evolution thereof without implementation of the plan or programme.
- The environmental characteristics of areas likely to be significantly affected.
- Any existing environmental problems which are relevant to the plan or programme including, in particular, those relating to any areas of a particular environmental importance, such as areas designated pursuant to Directives 2009/147/EC and 92/43/EEC (the Birds and Habitats Directives).
- The environmental protection objectives, established at international, Community or member state level, which are relevant to the plan or programme and the way those objectives and any environmental considerations have been taken into account during its preparation.
- The likely significant effects on the environment, including issues such as biodiversity, population, human health, fauna, flora, soil, water, air, climatic factors, material assets, cultural heritage including architectural and archaeological heritage, landscape and the inter-relationship between the above factors.
- The measures envisaged to prevent, reduce and, as fully as possible, offset any significant adverse effects on the environment of implementing the plan or programme.
- An outline of the reasons for selecting the alternatives dealt with and a description of how the assessment was undertaken, including any difficulties (such as technical deficiencies or lack of know-how) encountered in compiling the required information.
- A description of the measures envisaged concerning monitoring.
- A non-technical summary of the information provided under the above headings.
These effects should include secondary, cumulative, synergistic, short, medium and long term, permanent and temporary, positive and negative effects.

The department undertook a sequence of oil and gas SEAs considering various areas of the UKCS (SEA areas 1-8), in addition to an SEA for Round 2 wind leasing. The more recent offshore energy SEAs (OESEA, OESEA2, OESEA3 and OESEA4) incorporated the entire UKCS (with the exception of Northern Ireland and Scottish territorial waters for renewable energy, and Scottish territorial waters for carbon dioxide transport and storage), for technologies including oil and gas exploration and production, gas storage and offloading including carbon dioxide transport and storage, renewable energy (including wind, wave and tidal power), and offshore hydrogen production and transport. A summary of the areas covered by previous SEAs, when they were undertaken and for which sectors, and an overview of each of the technologies covered by the latest offshore energy plan/programme is provided in the documents below.

(https://assets.publishing.service.gov.uk/media/5a7f15c540f0b6230268d586/HAL_OESEA3_G83_VER02.pdf)

Previous offshore SEAs (https://assets.publishing.service.gov.uk/media/5a7f15c540f0b6230268d586/HAL_OESEA3_G83_VER02.pdf)

PDF, 625 KB, 1 page

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As these SEAs have been carried out, the process has evolved and been improved. The evolution and refinement of the process will continue. A required part of SEA is consultation with the public, environmental authorities and other bodies, together with such neighbouring states as may be potentially affected.

In conducting the SEA process, the Department is guided by the SEA Steering Group (https://www.gov.uk/government/policy-advisory-groups/offshore-energy-sea-steering-group), composed of departmental representatives, conservation and other agencies, NGOs, industry representatives and independent experts. The diverse members’ role is to act as technical peers, guiding the selection of SEA methods and identifying the right information sources.

Completed studies relating to earlier SEAs are located on the British Geological Survey (BGS) SEA archive (https://www.bgs.ac.uk/technologies/databases/strategic-environmental-assessment-sea-data-portal/).

SEA Recommendations

A series of recommendations have been made in the previous offshore energy SEA Environmental Reports on SEA processes and conclusions, the natural and wider environment, and regulatory and other controls. A compilation of these recommendations and their current status (whether closed, in progress or still open) is available for download below.

(https://assets.publishing.service.gov.uk/media/5a74af4eed915d7ab83b5b63/OESEA_Recommendations_Status_July_2017.pdf)

Offshore Energy SEA Recommendations and their status (https://assets.publishing.service.gov.uk/media/5a74af4eed915d7ab83b5b63/OESEA_Recommendations_Status_July_2017.pdf)

PDF, 287 KB, 16 pages

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Offshore Energy SEA: the current SEA

The Department conducted a Strategic Environmental Assessment (OESEA4) (https://www.gov.uk/government/consultations/uk-offshore-energy-strategic-environmental-assessment-4-oesea4) of a draft plan/programme to enable future renewable leasing for offshore wind, wave and tidal devices and licensing/leasing for seaward oil and gas rounds, hydrocarbon and carbon dioxide gas storage and offshore hydrogen production and transport. The scope of the draft plan/programme and approach to SEA were subject to public consultation between 29 March and 7 May 2021 (https://www.gov.uk/government/consultations/offshore-energy-strategic-environmental-assessment-4-scoping). Public consultation on the OESEA4 Environmental Report took place between 17 March and 27 May 2022 (https://www.gov.uk/government/consultations/uk-offshore-energy-strategic-environmental-assessment-4-oesea4), and the plan/programme was adopted in September 2022 (https://questions-statements.parliament.uk/written-statements/detail/2022-09-22/hcws295). The renewable energy elements of the plan/programme cover parts of the UK Exclusive Economic Zone and the territorial waters of England and Wales (the Scottish Renewable Energy Zone and Scottish and Northern Irish waters within the 12 nautical mile territorial sea limit are not included in this part); for hydrocarbon gas and carbon dioxide storage it applies to the UK Exclusive Economic Zone and the territorial waters of England and Wales (with the exception of the territorial waters of Scotland for carbon dioxide storage); and for hydrocarbon exploration and production it applies to all UK waters.

Following the adoption of the plan, and as with previous SEAs, the Department intend to maintain an active SEA research programme; identifying information gaps (some of which were outlined in the last set of SEA Recommendations), commissioning new research where appropriate, and promoting its wider dissemination through a series of research seminars. This has also involved continued engagement with the SEA Steering Group and review of the information base for the SEA, including the environmental baseline, other relevant plans and programmes, and policy and regulation.

Offshore Energy SEA: research programme

The department has maintained an active SEA research programme; identifying information gaps (some of which are outlined in previous SEA Recommendations) and commissioning new research where appropriate. This has been part of the department’s offshore SEA programme since 1999.

A summary of recent research and its status is provided in the document below, and final reports (where published) are available for download (https://www.gov.uk/government/publications/uk-offshore-energy-strategic-environmental-assessment-research-projects). Completed studies relating to earlier SEAs are located on the British Geological Survey (BGS) SEA archive (https://www.bgs.ac.uk/technologies/databases/strategic-environmental-assessment-sea-data-portal/) or the research page for OESEA2 (https://www.gov.uk/government/publications/uk-offshore-energy-strategic-environmental-assessment-2-supporting-documents).

(https://assets.publishing.service.gov.uk/media/6863a9b308bf2f5376121a75/Offshore_Energy_SEA_-_Recent_Research_Summary_April_2024.pdf)

Recent Offshore Energy SEA funded projects (https://assets.publishing.service.gov.uk/media/6863a9b308bf2f5376121a75/Offshore_Energy_SEA_-_Recent_Research_Summary_April_2024.pdf)

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The authors and researchers involved in SEA studies have been encouraged to submit papers for peer reviewed publication. A list of recent publications is given below.

(https://assets.publishing.service.gov.uk/media/68653cb0e6557c544c74db4d/DESNZ_Offshore_Energy_SEA_-_Recent_Papers_July_2025.pdf)

Recent Papers from DESNZ Offshore Energy SEA funded projects (https://assets.publishing.service.gov.uk/media/68653cb0e6557c544c74db4d/DESNZ_Offshore_Energy_SEA_-_Recent_Papers_July_2025.pdf)

PDF, 343 KB, 12 pages

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Appropriate Assessment

Following announcement of a Seaward Oil and Gas Licensing Round, an offshore Carbon Storage Licensing Round, or following receipt of applications for licences made to the North Sea Transition Authority (NSTA), a screening assessment is undertaken by the department. The screening assessment determines whether the award of any of the Blocks/carbon storage areas offered or applied for would be likely to lead to a significant effect on a relevant site, either individually or in combination with other plans or projects. Those sites and related Blocks/carbon storage areas for which a potential for likely significant effect is identified at the screening stage are subject to further assessment (Appropriate Assessment (AA)) prior to the NSTA making a decision on whether to grant licences. These assessments are undertaken to comply with obligations under the Offshore Petroleum Activities (Conservation of Habitats) Regulations 2001 (as amended).

The 33rd Seaward Licensing Round closed for applications on 12th January 2023. Applications were received covering 258 whole or part Blocks. It was concluded that further assessment (AA) was required for 96 Blocks that were applied for, of which the NSTA has been considering up to 72 Blocks for potential licence award. The assessments covering these Blocks have been documented in three draft regional reports covering areas of the Southern North Sea and Mid North Sea High, Central North Sea and West of Shetland, and Eastern Irish Sea, and were subject to public consultation. The reports were revised as appropriate in light of comments received during the public consultation which ended on 15th September 2023.

The reports listed below document the further assessment undertaken in relation to Blocks/carbon storage areas subject to Appropriate Assessment in the previous eleven Seaward Oil and Gas Licensing Rounds, and the 1st Carbon Storage Licensing Round.

25th seaward oil and gas licensing Round Appropriate Assessment (https://www.gov.uk/government/consultations/25th-seaward-licensing-round)

26th seaward oil and gas licensing Round Appropriate Assessment (https://www.gov.uk/government/consultations/26th-seaward-licensing-round)

27th seaward oil and gas licensing Round Appropriate Assessment (https://www.gov.uk/government/consultations/27th-seaward-licensing-round)

28th seaward oil and gas licensing Round Appropriate Assessment (https://www.gov.uk/government/consultations/28th-seaward-licensing-round-appropriate-assessments)

29th seaward oil and gas licensing Round Appropriate Assessment (https://www.gov.uk/government/consultations/29th-seaward-licensing-round-appropriate-assessment)

2016 Supplementary Licensing Round Appropriate Assessment (https://www.gov.uk/government/consultations/2016-supplementary-licensing-round-draft-screening-appropriate-assessment)

30th seaward oil and gas licensing Round Appropriate Assessment (https://www.gov.uk/government/consultations/30th-seaward-licensing-round-appropriate-assessment)

31st seaward oil and gas licensing Round Appropriate Assessment (https://www.gov.uk/government/consultations/31st-seaward-licensing-round-appropriate-assessment)

31st supplementary oil and gas licensing Round HRA screening (pdf) (https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/806839/31st_supplementary_Round_HRA_Screening_Report.pdf)

32nd seaward oil and gas licensing Round Appropriate Assessment (https://www.gov.uk/government/consultations/32nd-seaward-licensing-round-appropriate-assessment)

33rd seaward oil and gas licensing Round Appropriate Assessment (https://www.gov.uk/government/consultations/33rd-seaward-licensing-round-appropriate-assessment)

1st carbon dioxide storage licensing Round Appropriate Assessment (https://www.gov.uk/government/consultations/1st-offshore-carbon-dioxide-storage-licensing-round-appropriate-assessment)

MCZ and MPA Assessment

To satisfy the duties under the Marine and Coastal Access Act 2009 and the Marine (Scotland) Act 2010, a Marine Conservation Zone and Marine Protected Area assessment has been undertaken in relation to the 33rd Seaward Licensing Round (which closed for applications on 12th January 2023) and the assessment is available below:

(https://assets.publishing.service.gov.uk/media/64c77b5ff92186000d8667b6/33R_Round_MCZ_MPA_Assessment_Report.pdf)

33rd Seaward Oil and Gas Licensing Round MCZ & MPA Assessment (https://assets.publishing.service.gov.uk/media/64c77b5ff92186000d8667b6/33R_Round_MCZ_MPA_Assessment_Report.pdf)

PDF, 4.51 MB, 82 pages

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The report listed below documents the further assessment undertaken in relation to carbon storage areas subject to MCZ & MPA Assessment in the 1st Carbon Storage Licensing Round.

(https://assets.publishing.service.gov.uk/media/64652ad4d3231e000c32dbac/CS_Round_MCZ_MPA_Assessment_Report.pdf)

1st Offshore Carbon Dioxide Storage Licensing Round MCZ & MPA Assessment (https://assets.publishing.service.gov.uk/media/64652ad4d3231e000c32dbac/CS_Round_MCZ_MPA_Assessment_Report.pdf)

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How do you get involved?

Consultation

The OESEA consultation process has been designed to be in keeping with the Cabinet Office guidance on Consultation Principles (https://www.gov.uk/government/publications/consultation-principles-guidance) for engaging stakeholders when developing policy and legislation. The guidance does not have any statutory basis and therefore where there are mandatory consultation requirements set out in legislation, or other requirements which may affect a consultation such as confidentiality, these must be adhered to.

The main elements of public and stakeholder consultation and input to the offshore energy SEA process are:
- Publication through the Department’s offshore SEA webpages
- Scoping
- Stakeholder meetings and expert assessment workshops
- A suitable public consultation period following publication of the Environmental Report
- Post consultation report
Scoping

The objective of scoping is to identify the main issues of concern at an early stage so that they can be considered in appropriate detail in the SEA. Scoping also aids in the identification of information sources and data gaps that may need to be filled by studies or surveys to underpin the assessment. The SEA process includes a formal scoping step, the principal purposes of which are to:
- Promote stakeholder awareness of the SEA initiative
- Ensure access to all relevant environmental information
- Identify opportunities for potential collaboration and the avoidance of duplication of effort
- Identify information gaps so these could be evaluated and filled if necessary
- Identify stakeholder issues and concerns which should be considered in the SEA
Stakeholder and other workshops

A number of workshops have been undertaken prior to each SEA. These have included expert assessment workshops, which bring together the expertise of the SEA Steering Group (https://www.gov.uk/government/policy-advisory-groups/offshore-energy-sea-steering-group), the authors of underpinning technical reports, other users of the offshore area and the SEA team to bear on the assessment process for the particular SEA. Additionally, stakeholder workshops are held involving a wide variety of potential stakeholders, drawn from other government departments, local authorities, other industry bodies, academics and NGOs. The objectives of SEA stakeholder workshops are to provide stakeholders with updates on:
- UK offshore energy supply context
- The outcome of scoping
- How issues raised in scoping are being addressed in the SEA process and consultation document
- The outcomes of the assessment workshop
- Initial conclusions of the overall assessment
Stakeholder input and a summary of issues raised in the meeting is used to inform the SEA process, and is document and included in an appendix to the environmental report.

Formal consultation

The environmental report is published for formal public consultation. The publication of the environmental report is advertised in the popular press and specialist journals. Copies of the report are made available free of charge as electronic copies which can be requested via email or downloaded directly from gov.uk, and as paper versions provided by post, provided that it is reasonably practicable to do so. Comments are invited by post or email.

Government Response

Following closure of the consultation period, the comments are given due consideration and a Government Response is then produced. The Government Response is published on the offshore SEA consultation webpage. A compilation of the consultation comments is also published verbatim (according to the authors’ wishes) on the offshore SEA consultation webpage.

Adoption statement

Following publication of the post consultation report, a ministerial statement is made to confirm the outcome of the SEA process (e.g. on adoption of the plan/programme, to proceed with further oil and gas licensing).

Contacts

Please direct queries to the Environmental Policy Unit:

xxx@xxx.xx (mailto:xxx@xxx.xx) xx-xxxx-xxxx