Description

The possible future, and evidence for past, long-term change of global climate.

Category

Categorisation as a Feature, Event and/or Process.

  • Features are physical components of the disposal system and environment being assessed. Examples include waste packaging, backfill, surface soils. Features typically interact with one another via processes and in some cases events.
  • Events are dynamic interactions among features that occur over time periods that are short compared to the safety assessment timeframe such as a gas explosion or meteorite impact.
  • "Processes" are issues or dynamic interactions among features that generally occur over a significant proportion of the safety assessment timeframe and may occur over the whole of this timeframe. Events and processes may be coupled to one another (i.e. may influence one another).

The classification of a FEP as an event or process depends upon the assessment context, because the classification is undertaken with reference to an assessment timeframe. In this generic IFEP List, many IFEPs are classified as both Events and Processes; users will need to decide which of these classifications is relevant to their context and its timeframes.

  • Process

Comments

The “Comments” field, when present, contains any additional explanation of the IFEP, beyond that implicit in the FEP's description and provided in the “Relevance to Performance and Safety” field. This additional explanation may include, where appropriate, the IFEPs characteristics, the circumstances under which it might be relevant and its relationship to other (especially similar) IFEPs.

Global climate change (this FEP, 1.3.1) is distinct from changes that may occur at specific locations according to their regional setting and also local climate fluctuations, c.f. FEP 1.3.2 (Regional and local climate change). FEP 1.3.1 concerns climate change due to global processes other than plate tectonic processes, such as variations in solar insolation or anthropogenic CO₂ emissions. In contrast, FEP 1.3.2 covers climate change due to local or regional processes other than plate tectonic processes, such as weathering and erosion affecting local topography and hence local atmospheric circulation. Climatic responses to geological processes related directly to plate tectonics, such as volcanic activity or orogeny, are covered by FEP 1.2.14 (Climatic response to geological changes).

Relevance to Performance and Safety

The “Relevance to Performance and Safety” field contains an explanation of how the IFEP might influence the performance and safety of the disposal system under consideration through its impact on the evolution of the repository system and on the release, migration and/or uptake of repository-derived contaminants.

Global climate change could impact upon repository performance and safety by: 1) influencing the fluxes and patterns of groundwater flow in and/or around a repository; 2) influencing the chemistry of the groundwater in and/or around the repository; and 3) influencing the nature and spatial distribution of receptors that could be impacted by any radionuclides or contaminants that are transported from the repository. These influences arise from the effect of global climate change on regional and local climate near the repository (FEP 1.3.2), global sea level change (depending on the repository’s location relative to the coast and the topography, FEP 1.3.3) and glacial loading / unloading (depending upon the repository’s latitude and the local topographical elevation, FEP 1.3.5). Effects on the groundwater flow regime in and /or around a repository could arise from changes in the geographical distribution and rate of recharge. Changes in the flow regime could influence the transport of radionuclides and other contaminants from the repository to the locations of groundwater discharge. Changes in recharge could also lead to changes in the chemical conditions in and / or around the repository (e.g. higher recharge leading to fresh, oxidising, meteoric water penetrating to greater depth). Changes in temperature and/or the magnitude and kind of precipitation (i.e. rain or snow) could also influence the rates of erosion or sediment deposition, which could affect the depth of the repository below the surface in the long term. Global climate change could lead to changes in erosion/sedimentation, glaciation / deglaciation, sea level change and development/drying out of surface water bodies (i.e. lakes). All these factors have the potential to influence mechanical loading of a repository.

2000 List

A reference to the related FEP(s) within the 2000 NEA IFEP List.

1.3.01

Related References