Guest Post by Werner Brozek, Excerpts from Barry and Edited by Just The Facts
At Dr. Roy Spencer’s site, regular commenter Barry posted seven very interesting comments, begining here, with respect to the requirements for the UAH pause to resume. He has graciously allowed me to use whatever I wished in this blog post. Everything that appears below is from him until you see the statement “Written by Barry.” below:
Since the el Nino rose last year there have been many predictions here that a la Nina would form shortly afterwards and once again return the trend since 1998 to a flat line or cooling. I decided to check the change in trend from 1998 to each month past the el Nino peak (determined by warmest month last year in UAHv6 data).
My prediction is that for each month added past the el Nino peak the trend will be ever so slightly warmer, also when including December and January values in UAHv6 TLT data.
The warmest month of last year was February in the UAH dataset. I’ll start with that as the benchmark and see how the trend evolved from 1998 to then, with each successive month of cooler temps.
Feb 2016: 0.011 /decade
Mar 2016: 0.020 /decade
Apr 2016: 0.028 /decade
May 2016: 0.034 /decade
Jun 2016: 0.036 /decade
Jul 2016: 0.038 /decade
Aug 2016: 0.041 /decade
Sep 2016: 0.045 /decade
Oct 2016: 0.047 /decade
Nov 2016: 0.050 /decade
Dec 2016: 0.050 /decade (higher to 4 decimal places than Nov)
Jan 2017: 0.054 /decade
Even with la Nina conditions over the last few months, the trend has increased slightly month by month since the peak in Feb last year.
Testing to see how cool Feb would need to be to make the trend flatline….
You read right – not -0.5, but -5C.
What would the trend since 1998 be if 2017 annual was the same as January 2017 (0.30)?
0.063C /decade – warmer than current trend.
What would the annual anomaly of 2017 need to be to get a flatline trend since 1998?
How likely is it that 2017 would have an annual anomaly of -0.16C?
Coolest years post 1998:
Before 1998 there were 8 years of average annual anomaly less than -0.16. Starting from the most recent year where this was so:
ENSO conditions relevant to the above were:
2008 – nina
2000 – nina
1993 – neutral
1992 – nino
1989 – nina
1986 – nino
1985 – nina
1984 – nina
1982 – nino
1989 – nina
With predictions of a ENSO-neutral or Nino 2017, that would make it unlikely that the annual anomaly would go as low as -0.16C, and thus unlikely that the trend since 1998 would flatten.
I tested another line of inquiry.
For 30-year averages, every year where this can be achieved in the UAH 6.0 data, each year added (and one dropped off the beginning to keep the averages 30-year only), the 30-year average has gone up.
For this to fail to happen due to the 2017, the annual anomaly for that year would have to be < 0.05C.
Just possible, but very unlikely, I think.
Written by Barry
In the sections below, we will present you with the latest facts. The information will be presented in two sections and an appendix. The first section will show for how long there has been no statistically significant warming on several data sets. The second section will show how 2017 compares with 2016, the warmest year so far, and the warmest 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.
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 0 and 23 years according to Nick’s criteria. Cl stands for the confidence limits at the 95% level.
The details for several sets are below.
For UAH6.0: Since November 1993: Cl from -0.009 to 1.784
This is 23 years and 2 months.
For RSS: Since July 1994: Cl from -0.005 to 1.768 This is 22 years and 6 months.
For Hadcrut4.5: The warming is statistically significant for all periods above four years.
For Hadsst3: Since March 1997: Cl from -0.003 to 2.102 This is 19 years and 9 months.
For GISS: The warming is statistically significant for all periods above three years.
This section shows data about 2017 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. 16ra: This is the final ranking for 2016 on each data set. On all data sets, 2016 set a new record. How statistically significant the records were was covered in an earlier post here: https://wattsupwiththat.com/2017/01/26/warmest-ten-years-on-record-now-includes-all-december-data/
2. 16a: Here I give the average anomaly for 2016.
3. 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.
4. ano: This is the anomaly of the month just above.
5. 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.
6. sy/m: This is the years and months for row 5.
7. Jan: This is the January 2017 anomaly for that particular data set if available.
8. rnk: This is the 2017 rank for each particular data set assuming the January anomaly stays that way all year. Since the January GISS and HadCRUT4.5 are not out yet, I ranked the December anomaly in ( ).
If you wish to verify all of the latest anomalies, go to the following:
For UAH, version 6.0beta5 was used.
For RSS, see: ftp://ftp.ssmi.com/msu/monthly_time_series/rss_monthly_msu_amsu_channel_tlt_anomalies_land_and_ocean_v03_3.txt
For Hadcrut4, see: http://www.metoffice.gov.uk/hadobs/hadcrut4/data/current/time_series/HadCRUT.126.96.36.199.monthly_ns_avg.txt
For Hadsst3, see: https://crudata.uea.ac.uk/cru/data/temperature/HadSST3-gl.dat
For GISS, see:
To see all points since January 2016 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 2016. This makes it easy to compare January 2016 with the latest anomaly.
The thick double line is the WTI which shows the average of RSS, UAH, HadCRUT4.5 and GISS.
In this part, we are summarizing data for each set separately.
For UAH: There is no statistically significant warming since November 1993: Cl from -0.009 to 1.784. (This is using version 6.0 according to Nick’s program.)
The UAH January anomaly is 0.300. This would rank in fourth place if it stayed this way. 2016 was the warmest year at 0.504. The highest ever monthly anomaly was in February of 2016 when it reached 0.830.
For RSS: There is no statistically significant warming since July 1994: Cl from -0.005 to 1.768.
The RSS January anomaly is 0.409. This would rank in fourth place if it stayed this way. 2016 was the warmest year at 0.574. The highest ever monthly anomaly was in February of 2016 when it reached 0.996.
For Hadcrut4.5: The warming is significant for all periods above four years.
The Hadcrut4.5 average anomaly for 2016 was 0.773. This set a new record. The highest ever monthly anomaly was in February of 2016 when it reached 1.070.
For Hadsst3: There is no statistically significant warming since March 1997: Cl from -0.003 to 2.102.
The Hadsst3 January anomaly is 0.488. This would rank third if it stayed this way. The highest ever monthly anomaly was in January of 2016 when it reached 0.732.
For GISS: The warming is significant for all periods above three years.
The GISS average anomaly for 2016 is 0.99. This set a new record. The highest ever monthly anomaly was in February of 2016 when it reached 1.35.
Do you think UAH will ever have a pause of over 18 years again? Why or why not?