Editor's Summary
29 May 2008
Global temperatures: A glitch in the forties
The record of global sea-surface temperatures spanning the past century provides key evidence for global warming and is much scrutinized with a view to distinguishing between anthropogenic and natural climate variability. It has been assumed that this record is now largely free of substantial uncorrected instrument biases. Not so, according to a team assembled from four of the world's leading climate research institutes. They have identified a pronounced discontinuity in the record — a sudden drop of about 0.3 °C in global sea-surface temperature in 1945 — that coincides with a significant change in the shipboard instrumentation used to collect the data. This discontinuity is 40% as large as the century-long upward trend in temperatures, so correcting for it is likely to change the overall record and its interpretation substantially.
News and Views: Climate change: Hot questions of temperature bias
An unseen measurement bias has been identified in global records of sea surface temperature. The discrepancy will need correction, but will not affect conclusions about an overall warming trend.
Chris E. Forest & Richard W. Reynolds
doi:10.1038/453601a
Letter: A large discontinuity in the mid-twentieth century in observed global-mean surface temperature
David W. J. Thompson, John J. Kennedy, John M. Wallace & Phil D. Jones
doi:10.1038/nature06982
First paragraph | Full Text | PDF (385K)
News: Climate anomaly is an artefact
Glitch in the twentieth-century climate record is explained.
Quirin Schiermeier
doi:10.1038/453569a
