Taking short segments of temperature records (for example, considering periods shorter than a decade) emphasises year-to-year variations in climate which can be at odds with the long-term trend.
Globally, the trend of both sea surface temperatures (SST) and near-surface air temperatures is still upward. The year 2005 was the second warmest year (after 1998) in the air temperature record, which began in 1850. Eleven of the 12 warmest years in the record have occurred in the last 12 years—the exception was 1996. Since 2005, some cooling has occurred because of natural climate variations, including the current Pacific La Niña (1998 was especially warm because of a strong El Niño in that year).
The most recent Met Office Hadley Centre HadSST2 analysis shows that global average SST has risen by 0.09° C per decade since 2000.
HadSST2 is the main global sea surface temperature analysis, which is produced by taking in situ measurements of SST from ships and buoys taken from 1850 to present.
(b) Near-surface Air Temperature:
The most recent Met Office Hadley Centre and climatic research unit joint analysis shows that since 2000, global average near-surface air temperature has shown a continued warming trend of 0.16° C per decade, with seven of the eight warmest years in the record since 1850 occurring since (and including) 2000. This compares to a rising trend of just over 0.15° C per decade since the mid-1970s and 0.1° C per decade between 1998 and 2007.
Further details and tables have been placed in the Library.
In the latest IPCC report, the trend in global average near-surface temperature 1979 to 2005 is 0.163° C per decade.