Internal climate variability

Variations in climate due to natural internal processes within the climate system.

In detail

Internal climate variability relates to the inherent variability in the average and other statistics (e.g. standard deviation, the occurrence of extremes, etc.) of the climate on all temporal and spatial scales beyond that of an individual weather event due to natural internal processes within the climate system.

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

• An overview of the uncertainties associated with climate modelling is described in Section 3.1 of the UKCP09 Briefing report.

• More details about uncertainties are provided in Chapter 2 of the UKCP09 Climate Change Projections report. A discussion of sources of uncertainty in the UKCP09 probabilistic projections is available in Annex 2.4.

Find out more

• IPCC Fourth Assessment Report, Working Group 1 report The Physical Science Basis, Chapter 9