Guest Post by Werner Brozek, Edited by Just The Facts:
In the above graphic, the zero line from February 2000 has been offset to make it visible. It actually falls right on top of the zero trend line from December 1996.
The title may seem odd since RSS shows no trend for 18 years and 3 months now. The title was triggered by an exchange several years ago in which we were challenged to show there was no warming for 15 years. I promptly showed that to be the case with RSS, but was accused of cherry picking since I went on the other side of the 1998 El Nino. Some one else started on this side of the 1998 El Nino and was accused of not going 15 years. We could not win then. But now we can.
Fifteen years is important because of the following quote by NOAA found on page 23:
”The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate.”
Later, NOAA talks about El Ninos and the bottom line seemed to be that if any trend goes on the other side of the 1998 El Nino, then the simulations are not invalidated. I have always said that the La Ninas on either side of the 1998 El Nino cancel out the affects of the 1998 El Nino, but that did not seem to matter. People focus on and see what they want to see.
Note also that the 15 years is a time for a slope of zero. So to get no warming at the 95% level, one could easily add about 4 years unless anomalies really fell off a cliff prior to February 2000. So whichever way we look at it, RSS shows a discrepancy with the simulations.
At this point, some may ask about UAH, which only shows no warming since April 2009. However both Dr. McKitrick and Nick Stokes agree the time for no statistically significant warming is over 15 years for UAH. For further details, see section 2 or rows 8, 9 and 10 from the table in section 3.
In other news, the GISS anomaly in 2014 was 0.68 and it set a new record. However it dropped to 0.67 with the February numbers. And due to other changes, there is now less than a 38% certainty that 2014 was the new record hot year. For further details, please ask.
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 some data sets. At the moment, only the satellite data have flat periods of longer than a year. 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 2015 so far compares with 2014 and the warmest years and months on record so far. For three of the data sets, 2014 also happens to be the warmest year. 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 on at least one calculation. 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.
1. For GISS, the slope is not flat for any period that is worth mentioning.
2. For Hadcrut4, the slope is not flat for any period that is worth mentioning. Note that WFT has not updated Hadcrut4 since July and it is only Hadcrut4.2 that is shown.
3. For Hadsst3, the slope is not flat for any period that is worth mentioning.
4. For UAH, the slope is flat since April 2009 or 5 years and 11 months. (goes to February using version 5.6)
5. For RSS, the slope is flat since December 1996 or 18 years and 3 months. (goes to February)
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 blue line at the top 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 the two slopes are essentially zero. 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 18 years, the temperatures have been flat for varying periods on the two sets.
For this analysis, data was retrieved from Nick Stokes’ Trendviewer available on his website. 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 14 and 22 years according to Nick’s criteria. Cl stands for the confidence limits at the 95% level.
Dr. Ross McKitrick has also commented on these parts and has slightly different numbers for the three data sets that he analyzed. I will also give his times.
The details for several sets are below.
For UAH: Since July 1996: Cl from -0.002 to 2.218
This is 18 years and 8 months.
(Dr. McKitrick says the warming is not significant for 16 years on UAH.)
For RSS: Since January 1993: Cl from -0.016 to 1.711
This is 22 years and 2 months.
(Dr. McKitrick says the warming is not significant for 26 years on RSS.)
For Hadcrut4.3: Since July 1997: Cl from 0.000 to 1.163
This is 17 years and 7 months.
(Dr. McKitrick said the warming was not significant for 19 years on Hadcrut4.2 going to April. Hadcrut4.3 would be slightly shorter however I do not know what difference it would make to the nearest year.)
For Hadsst3: Since May 1995: Cl from -0.011 to 1.694
This is 19 years and 10 months.
For GISS: Since August 2000: Cl from -0.005 to 1.419
This is 14 years and 7 months.
Note that all of the above times, regardless of the source, with the exception of GISS are larger than 15 years which NOAA deemed necessary to “create a discrepancy with the expected present-day warming rate”.
This section shows data about January 2015 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. 14ra: This is the final ranking for 2014 on each data set.
2. 14a: Here I give the average anomaly for 2014.
3. year: This indicates the warmest year on record so far for that particular data set. Note that the satellite data sets have 1998 as the warmest year and the others have 2014 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.
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. Periods of under a year are not counted and are shown as “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. sy/m: This is the years and months for row 8. Depending on when the update was last done, the months may be off by one month.
10. McK: These are Dr. Ross McKitrick’s number of years for three of the data sets.
11. Jan: This is the January 2015 anomaly for that particular data set.
12. Feb: This is the February 2015 anomaly for that particular data set.
13. ave: This is the average anomaly of all months to date taken by adding all numbers and dividing by the number of months.
14. rnk: This is the rank that each particular data set would have for 2015 without regards to error bars and assuming no changes. Think of it as an update 10 minutes into a game.
If you wish to verify all of the latest anomalies, go to the following:
For UAH, version 5.6 was used. Note that WFT uses version 5.5 however this version was last updated for December 2014 and it looks like it will no longer be given.
For Hadsst3, see: http://www.cru.uea.ac.uk/cru/data/temperature/HadSST3-gl.dat
To see all points since January 2014 in the form of a graph, see the WFT graph below. Note that Hadcrut4 is the old version that has been discontinued. WFT does not show Hadcrut4.3 yet. As well, only UAH version 5.5 is shown which stopped in December. WFT does not show version 5.6 yet.
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 December, 1996 or 18 years, 3 months. (goes to February)
For RSS: There is no statistically significant warming since January 1993: Cl from -0.016 to 1.711.
The RSS average anomaly so far for 2015 is 0.348. This would rank it as 3rd place. 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 2014 was 0.255 and it was ranked 6th.
The slope is flat since April 2009 or 5 years and 11 months. (goes to February using version 5.6)
For UAH: There is no statistically significant warming since July 1996: Cl from -0.002 to 2.218. (This is using version 5.6 according to Nick’s program.)
The UAH average anomaly so far for 2015 is 0.324. This would rank it as 3rd place. 1998 was the warmest at 0.42. The highest ever monthly anomaly was in April of 1998 when it reached 0.663. The anomaly in 2014 was 0.27 and it was ranked 3rd.
The slope is not flat for any period that is worth mentioning.
For Hadcrut4: There is no statistically significant warming since July 1997: Cl from 0.000 to 1.163.
The Hadcrut4 average anomaly so far for 2015 is 0.675. This would set a new record if it stayed this way. The highest ever monthly anomaly was in January of 2007 when it reached 0.835. The anomaly in 2014 was 0.564 and this set a new record.
For Hadsst3, the slope is not flat for any period that is worth mentioning. For Hadsst3: There is no statistically significant warming since May 1995: Cl from -0.011 to 1.694.
The Hadsst3 average anomaly so far for 2015 is 0.429. This would rank 2nd if it stayed this way. The highest ever monthly anomaly was in August of 2014 when it reached 0.644. The anomaly in 2014 was 0.479 and this set a new record.
The slope is not flat for any period that is worth mentioning.
For GISS: There is no statistically significant warming since August 2000: Cl from -0.005 to 1.419.
The GISS average anomaly so far for 2015 is 0.77. This would set a new record if it stayed this way. The highest ever monthly anomaly was in January of 2007 when it reached 0.93. The anomaly in 2014 was 0.68 and it set a new record. However it dropped to 0.67 with the February numbers. And due to other changes, there is now less than a 38% certainty that 2014 was the new record hot year. For further details, please ask.
It is no longer necessary to go earlier than 1998 to prove no warming for 15 years as per NOAA’s statement. At least that is the case for RSS.
The other data sets, with the exception of GISS, show no statistically significant warming going longer than 1998. However as I have shown, the La Ninas on either side of 1998 cancel the effect of the 1998 El Nino, so that is not a big deal either.
With the March anomaly coming in at 0.255, the average drops to 0.316 and this would rank 5th if it stayed this way. The length of time for a zero slope increases to 18 years and 4 months. (It is also 15 years and 2 months.)