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Internal climate variability

'Internal climate variability' is used to describe variations in the climate due to natural processes inherent to the climate system.

In detail

Internal climate variability relates to the inherent variability in the average climate on all temporal and spatial scales beyond that of an individual weather event due to natural processes within the climate system.

Uncertainties remain in estimates of natural internal climate. Internal variability is difficult to estimate from available observational records since they are influenced by external forcing. Estimations of internal variability are further complicated because records of instrumental data are not long enough, and proxy reconstructions from palaeological data are not precise enough, to provide complete descriptions of variability on decadal and longer time scales.

Find out more


  • An overview of the uncertainties associated with climate modelling is described in  of the UKCP09 Briefing Report.
  • More details about uncertainties are provided in  of the UKCP09 Climate Change Projections report. A discussion of sources of uncertainty in the UKCP09 probabilistic projections is available in .
  • IPCC Fifth Assessment Report, Working Group 1 report The Physical Science Basis , Chapter 8