Guest Post By Werner Brozek, Edited by Just The Facts:
Note: Featured image and text below updated based upon input from rgbatduke. The graph shows HadSST3 Sea Surface Temperature Anomaly and RSS Lower Troposphere Temperature Anomaly since 1997, and is offset such that their means are at the same height. Note that the last two blue points for HadSST3 are higher than the highest point in 1998. The previous record anomaly was in July of 1998 at 0.526. June, 2014 had an anomaly of 0.563 and the anomaly for July of 2014 was 0.552. Furthermore, due to the high specific heat capacity of water, I would expect the August anomaly to also beat the previous record from July of 1998.
The average HadSST3 anomaly for the first seven months is 0.439 and 2014 would rank in 1st place if it stayed this way. An average of only 0.384 is needed for the next five months to set a new yearly record which looks extremely likely now. The period of a slightly negative slope for HadSST3 decreased significantly to 5 years and 5 months, which means it is negative from March 2009. The period without statistically significant warming decreased by 2 months to August 1994, or an even 20 years. (C.I. = -0.014 to 1.666)
However the record HadSST3 anomalies this year are not reflected in the RSS data set. RSS had a July, 2014 anomaly of 0.350, which was the fifth warmest July and significantly less than the prior record of 0.605 in July, 1998.
So why is there such a large divergence between HadSST3 and RSS in 2014? Bob Tisdale notes in his recent article that the north east of the Pacific ocean is quite warm at present, whereas during the 1998 El Nino, it was the tropics that were very warm. Would it make a difference to RSS if warm tropics water rose by 3 C rather than if an equal volume of a much cooler north Pacific rose by 3 C? Due to the law of conservation of energy, if more water evaporates, then more water vapor condenses in the lower troposphere. And it becomes warmer. However if a colder part of the ocean warms up, there should be less evaporation and condensation, which could explain some of the divergence between RSS and HadSST3. Also, Sea Surface Temperatures remained elevated for extended periods of time in 1997/1998 and 2009/2010, whereas the recent record HadSST3 anomalies appear to be the result of a brief spike, which could also explain some of the divergence.
Regardless, in the sections below, as in previous posts, we will present you with the latest facts. The information will be presented in three sections and an appendix. The first section will show for how long there has been no warming on several data sets. The second section will show for how long there has been no statistically significant warming on several data sets. The third section will show how 2014 to date compares with 2013 and the warmest years and months on record so far. The appendix will illustrate sections 1 and 2 in a different way. Graphs and a table will be used to illustrate the data.
This analysis uses the latest month for which data is available on WoodForTrees.com (WFT). All of the data on WFT is also available at the specific sources as outlined below. We start with the present date and go to the furthest month in the past where the slope is a least slightly negative. So if the slope from September is 4 x 10^-4 but it is – 4 x 10^-4 from October, we give the time from October so no one can accuse us of being less than honest if we say the slope is flat from a certain month.
On all data sets below, the different times for a slope that is at least very slightly negative ranges from 5 years and 5 months to 17 years and 9 months.
1. For GISS, the slope is flat since September 2004 or 9 years, 11 months. (goes to July)
2. For Hadcrut4, the slope is flat since February 2001 or 13 years, 6 months. (goes to July)
3. For Hadsst3, the slope is flat since March 2009 or 5 years, 5 months. (goes to July)
4. For UAH, the slope is flat since June 2008 or 6 years, 2 months. (goes to July using version 5.5)
5. For RSS, the slope is flat since November 1996 or 17 years, 9 months (goes to July).
The next graph shows just the lines to illustrate the above. Think of it as a sideways bar graph where the lengths of the lines indicate the relative times where the slope is 0. In addition, the upward sloping red line indicates that CO2 has steadily increased over this period.
When two things are plotted as I have done, the left only shows a temperature anomaly.
The actual numbers are meaningless since all slopes are essentially zero. As well, I have offset them so they are evenly spaced. No numbers are given for CO2. Some have asked that the log of the concentration of CO2 be plotted. However WFT does not give this option. The upward sloping CO2 line only shows that while CO2 has been going up over the last 17 years, the temperatures have been flat for varying periods on various data sets.
The next graph shows the above, but this time, the actual plotted points are shown along with the slope lines and the CO2 is omitted.
For this analysis, data was retrieved from Nick Stokes’ Trendviewer available on his website <a href=”http://moyhu.blogspot.com.au/p/temperature-trend-viewer.html”. This analysis indicates for how long there has not been statistically significant warming according to Nick’s criteria. Data go to their latest update for each set. In every case, note that the lower error bar is negative so a slope of 0 cannot be ruled out from the month indicated.
On several different data sets, there has been no statistically significant warming for between 16 and 21 years.
The details for several sets are below.
For UAH: Since March 1996: CI from -0.001 to 2.341
For RSS: Since December 1992: CI from -0.015 to 1.821
For Hadcrut4: Since November 1996: CI from -0.003 to 1.184
For Hadsst3: Since August 1994: CI from -0.014 to 1.666
For GISS: Since October 1997: CI from -0.002 to 1.249
This section shows data about 2014 and other information in the form of a table. The table shows the five data sources along the top and other places so they should be visible at all times. The sources are UAH, RSS, Hadcrut4, Hadsst3, and GISS.
Down the column, are the following:
1. 13ra: This is the final ranking for 2013 on each data set.
2. 13a: Here I give the average anomaly for 2013.
3. year: This indicates the warmest year on record so far for that particular data set. Note that two of the data sets have 2010 as the warmest year and three have 1998 as the warmest year.
4. ano: This is the average of the monthly anomalies of the warmest year just above.
5.mon: This is the month where that particular data set showed the highest anomaly. The months are identified by the first three letters of the month and the last two numbers of the year. Note that this does not yet include records set so far in 2014 such as Hadsst3 in June.
6. ano: This is the anomaly of the month just above.
7. y/m: This is the longest period of time where the slope is not positive given in years/months. So 16/2 means that for 16 years and 2 months the slope is essentially 0.
8. sig: This the first month for which warming is not statistically significant according to Nick’s criteria. The first three letters of the month are followed by the last two numbers of the year.
9. Jan: This is the January 2014 anomaly for that particular data set.
10.Feb: This is the February 2014 anomaly for that particular data set, etc.
16.ave: This is the average anomaly of all months to date taken by adding all numbers and dividing by the number of months. However if the data set itself gives that average, I may use their number. Sometimes the number in the third decimal place differs slightly, presumably due to all months not having the same number of days.
17.rnk: This is the rank that each particular data set would have if the anomaly above were to remain that way for the rest of the year. It will not, but think of it as an update 35 minutes into a game. Due to different base periods, the rank is more meaningful than the average anomaly.
If you wish to verify all of the latest anomalies, go to the following:
For UAH, version 5.5 was used since that is what WFT used.
For Hadsst3, see: http://www.cru.uea.ac.uk/cru/data/temperature/HadSST3-gl.dat
For GISS, see:
To see all points since January 2014 in the form of a graph, see the WFT graph below.
As you can see, all lines have been offset so they all start at the same place in January 2014. This makes it easy to compare January 2014 with the latest anomaly.
In this part, we are summarizing data for each set separately.
The slope is flat since November 1996 or 17 years, 9 months. (goes to July)
For RSS: There is no statistically significant warming since December 1992: CI from -0.015 to 1.821.
The RSS average anomaly so far for 2014 is 0.267. This would rank it as 6th place if it stayed this way. 1998 was the warmest at 0.55. The highest ever monthly anomaly was in April of 1998 when it reached 0.857. The anomaly in 2013 was 0.218 and it is ranked 10th.
The slope is flat since June 2008 or 6 years, 2 months. (goes to July using version 5.5 according to WFT)
For UAH: There is no statistically significant warming since March 1996: CI from -0.001 to 2.341. (This is using version 5.6 according to Nick’s program.)
The UAH average anomaly so far for 2014 is 0.208. This would rank it as 6th place if it stayed this way. 1998 was the warmest at 0.419. The highest ever monthly anomaly was in April of 1998 when it reached 0.662. The anomaly in 2013 was 0.197 and it is ranked 7th.
The slope is flat since February 2001 or 13 years, 6 months. (goes to July)
For Hadcrut4: There is no statistically significant warming since November 1996: CI from -0.003 to 1.184.
The Hadcrut4 average anomaly so far for 2014 is 0.535. This would rank it as 3rd place if it stayed this way. 2010 was the warmest at 0.547. The highest ever monthly anomaly was in January of 2007 when it reached 0.829. The anomaly in 2013 was 0.487 and it is ranked 8th.
For Hadsst3, the slope is flat since March 2009 or 5 years and 5 months. (goes to July).
For Hadsst3: There is no statistically significant warming since August 1994: CI from -0.014 to 1.666.
The Hadsst3 average anomaly so far for 2014 is 0.439. This would rank it as 1st place if it stayed this way. 1998 was the warmest at 0.416 prior to 2014. The highest ever monthly anomaly was in July of 1998 when it reached 0.526. This is also prior to 2014. The anomaly in 2013 was 0.376 and it is ranked 6th.
The slope is flat since September 2004 or 9 years, 11 months. (goes to July)
For GISS: There is no statistically significant warming since October 1997: CI from -0.002 to 1.249.
The GISS average anomaly so far for 2014 is 0.64. This would rank it as third place if it stayed this way. 2010 was the warmest at 0.66. The highest ever monthly anomaly was in January of 2007 when it reached 0.93. The anomaly in 2013 was 0.60 and it is ranked 6th.
There is a large divergence between HadSST3 and RSS in 2014. Why?