English: This image shows the instrumental record of global average temperatures as compiled by the
Climatic Research Unit of the
University of East Anglia and the
Hadley Centre of the
UK Meteorological Office.
Data set HadCRUT3 was used.
HadCRUT3 is a record of surface temperatures collected from land and ocean-based stations. The most recent documentation for this data set is
Brohan, P., J.J. Kennedy, I. Haris, S.F.B. Tett and P.D. Jones (2008-04-03). "Uncertainty estimates in regional and global observed temperature changes: a new dataset from 1850". J. Geophysical Research 111: D12106. DOI:10.1029/2005JD006548. Following the common practice of the
IPCC,
the zero on this figure is the mean temperature from 1961-1990.