Satellite measurements of the temperature of the atmosphere rank 2014 as the third warmest year in the satellite record, according to the University of Alabama in Huntsville (UAH).
The global average temperature anomaly – that is, the variance to the long term average global temperature between 1981 and 2010 – for the layer of the atmosphere from the surface up to around 8km in altitude known as the lower troposphere during 2014 was 0.27oC, according to UAH data.
This was just 0.01oC warmer than 2005 and just a few hundredths of a degree warmer than 2013 and 2002 – such small differences as to make the 2014 result statistically indistinguishable from these other years. This suggests that the so called pause or hiatus in global warming continued through 2014, at least in the satellite record.
The UAH analysis shows that the global temperature trend from 2002 through 2014 was a warming at the rate of +0.05 C per decade which is statistically insignificant. However, it is also the case that global temperatures have remained elevated throughout this period and that these years have averaged some 0.18oC above the baseline provided by the 30-year long term average and contain nine of the 10 warmest years – the warmest of all being 1998.
Dr. John Christy, professor of atmospheric science and director of the Earth System Science Center at UAH is quoted by the UAH press release issued today as saying: “2014 was warm, but not special. The 0.01C difference between 2014 and 2005, or the 0.02 difference with 2013 are not statistically different from zero. That might not be a very satisfying conclusion, but it is at least accurate”.
An analysis of essentially – but not quite – the same satellite data by US firm Remote Sensing Systems (RSS) shows that 2014 was the sixth warmest year on record.
The global average temperature anomaly for the lower troposphere in December was 0.32oC making it the second warmest December in the UAH dataset. RSS data ranks December 2014 as seventh warmest December since 1979 when satellite measurements began.
RSS tends to report data that is cooler than UAH.
It is likely that 2014 will rank higher in the surface temperature data sets managed by the National Oceanic and Atmospheric Administration (NOAA) of the US, by US space agency NASA and by the UK Meteorological Office, among others. These are expected to show that 2014 was either the warmest year on record or one of the warmest years on record.