21 November 2014

We are heading towards 2014 being hottest on instrumental record

We are heading towards 2014 being hottest on instrumental record, according to data from the leading US government climate agency for the first ten months of the year.

According to data and charts released by the National Oceanic and Atmospheric Association through its National Climate Data Center, the first 10 months of this year are the warmest on the instrumental record, and it is projected to be the warmest year on the instrumental record based on five scenarios for November and December.

Click graph to enlarge

The NOAA explains that: "The graphic above compare the year-to-date temperature anomalies for 2014 (black line) to what were ultimately the five warmest years on record: 2010, 2005, 1998, 2003, and 2013. Each month along each trace represents the year-to-date average temperature. In other words, the January value is the January average temperature, the February value is the average of both January and February, and so on." At the end of October, 2014 (black line) was the hottest for the first ten months of the year.

Click graph to enlarge
This second graphic zooms to what were ultimately the five warmest years on record, and shows several end-of-year results based on five scenarios. The anomalies themselves represent departures from the twentieth century average temperature. All five scenarios have 2014 being the hottest on the instrumental record

These include:
  • Blue dotted line: Each month matches the average of its ten warmest values. Of the last 12 months, only February 2014 has not been at least this warm. 
  • Green dotted line: Each month matches its tenth warmest value on record. Of the last 12 months, only February 2014 has not been at least this warm
The NOAA notes that: "The years 2013 and 2014 are the only years on this list not to begin during a mature El Niño event. The years 1998 and 2010, each of which became the warmest year on record at the time, ended the year in a strong La Niña event, as evidenced by the relative fading of global average temperature later in the year."

By way of contrast, there are signs of an el Nino gathering strength, which would push up temperatures at year's end.  The Australian Bureau of Meteorology this week raised its estimate of an El Nino occurring this summer to "at least 70 per cent" after temperatures in the tropical Pacific warmed further in the past fortnight, and warned that prospects of a hot and dry summer for much of Australia are increasing with "classic signs".