1.17. Climatic Effects

  1. Climate change refers to the long term shifts in temperatures and weather patterns that are fundamentally driven by human activities.
  2. Climate change in the context of the Array assessment can be considered in two parts:
  • the effect of greenhouse gas emissions arising from the construction, operation and maintenance and decommissioning of the Array, which may contribute to climate change; and
  • the potential effects of the future climate on the Array.
  1. The greenhouse gas emissions arising from, and avoided by, the Array were characterised via a series of desk-based assessments and articles using published data to determine the impact of the Array on climate change. The potential risks of the Array from a changing climate have also been assessed and reported in a risk assessment format, with the future climate conditions characterised using Met Office modelling.
  2. The current baseline with regards to the assessment of greenhouse gases arising from the Array is defined as areas that would be occupied by the Array, thereby changing the seabed use. The current baseline largely comprises sandy sediments with no areas with high levels of ‘blue carbon’ (i.e organic carbon that has been captured and stored through biological processes in the coastal and marine environment, for example, seagrass habitat) anticipated to be disturbed. Nevertheless, the sandy sediments do contain stores of blue carbon, which have been assessed. The future baseline for existing seabed use without the Array is expected to remain similar to the current baseline.
  3. The current baseline with regards to the assessment of climate on the Array are current climate observations within the area local to the Array. Air temperatures in the local area (central North Sea) range from 1°C to 16°C. Precipitation rates follow a seasonal trend with April to June tending to be the driest months, and October to January being wetter. Wind speeds have been recorded up to 31.5 m/s. Average wave heights are in the region of 1.87 m to 2.05 m, but in storms wave heights can reach 8.96 m. Global sea level rose by 0.2 m between 1901 and 2018. The future baseline has been informed by climate projections, showing worst case predictions of climate (including temperature, precipitation and wave height) over the Array’s lifetime. It is expected that sea surface temperatures will continue to increase in the 21st century, with sea surface temperatures in Northern Europe predicted to increase by approximately 3.4°C by 2100 as a worst case. The east coast of Scotland can expect to see an average sea level rise of approximately 0.5 m to 0.6 m by 2100.
  4. A number of potential impacts on and from climate change, associated with the construction, operation and maintenance, and decommissioning phases of the Array, were identified. The impacts assessed include:
  • greenhouse gas emissions arising from disturbance to blue carbon stocks during the construction, operation and maintenance and decommissioning of the Array;
  • greenhouse gas emissions arising from the manufacturing and installation of the Array;
  • greenhouse gas emissions arising from the consumption of materials and activities required to facilitate the operation and maintenance of the Array and estimated abatement of UK Grid emissions;
  • greenhouse gas emissions arising from decommissioning works of the Array;
  • effects of climate change on the Array; and
  • net greenhouse gas impacts of the Array.
  1. With the proposed designed in measures in place, all of these impacts result in either negligible or minor adverse  or beneficial significance, which are not significant in EIA terms.
  2. Cumulative effects as a result of the Array and the Proposed offshore export cable corridor(s), and Proposed onshore transmission infrastructure have been assessed and are expected to result in a beneficial net effect owing to the contribution toward the UK and Scotland achieving their net zero goals and policy, and the high sensitivity of the climate as a receptor.