The global temperature of 2014 is turning out to be quite warm, though with just four months of data it is still very early days to be declaring that it is heading for a record. It should be remembered at the onset that even if the rest of the year is very warm 2014 is very unlikely to be statistically significantly warmer than all the years of at least the previous decade. Much of the speculation centres around measuring global temperatures to one thousandth of a degree, which is not warranted by the measurements and their associated errors.
According to Nasa Giss there has been three warm months this year – January, March and April, with February being somewhat cooler, in fact the 18th coolest February on record. None of the three warm months have been anywhere near record breakers for that particular month. 2014 is well behind the joint warmest year of 2010 for this stage of the year but about the same as 2005 (2010 had a coolish June – September, whilst 2005 was more consistent throughout the year.)
To tie with 2010 and 2005, 2014 has to have an average monthly temperature anomaly of 0.66 for the rest of the year. Months to look out for are July which has not been that warm in the past decade, as well as July and December which have been that warm only twice during the same period. In general the warmest months are September, October and November.
Curiously, in Nasa Giss 2010 has lost 0.2 deg C in the past few months making it now equal to 2005. The reason for this data adjustment has not been explained but its effect has been to provide 2014 with a lower target to achieve a record. Had it remained at 0.67 then it would have been extremely unlikely that 2014 would have been anywhere near a record.
Noaa is seeing 2014 differently. For them April 2014 tied with 2010 as the warmest April ever recorded, although neither the land – third warmest April – nor the ocean – third highest April – set individual records. Also January – April was only the sixth warmest such period on record. Thus Noaa is not in complete agreement with Nasa Giss and leads one to have a lower confidence that a record will be established for 2014, despite April’s record.
HadCrut4 records a warm April, but it is still considerably behind 2010. January, February and March are not exceptional. It seems unlikely that the remaining months of 2014 will maintain an average of 0.55 for it to equal 2010.
The next few months will be very interesting, especially if there are signs of an El Nino.