Guest Post by Werner Brozek, Edited by Just The Facts
As can be seen from the above graphic, the slope is positive from January 1998 to December 2016, however with the error bars, we cannot be 95% certain that warming has in fact taken place since January 1998. The high and low slope lines reflect the margin of error at the 95% confidence limits. If my math is correct, there is about a 30% chance that cooling has taken place since 1998 and about a 70% chance that warming has taken place. The 95% confidence limits for both UAH6.0beta5 and RSS are very similar. Here are the relevant numbers from Nick Stokes’ Trendviever site for both UAH and RSS:
Temperature Anomaly trend
Jan 1998 to Dec 2016
CI from -0.750 to 1.649;
Temp range 0.230°C to 0.315°C
Temperature Anomaly trend
Jan 1998 to Dec 2016
CI from -0.813 to 1.765;
Temp range 0.113°C to 0.203°C
If you wish to see where warming first becomes statistically significant, see Section 1 below. In addition to the slopes showing statistically insignificant warming, the new records for 2016 over 1998 are also statistically insignificant for both satellite data sets.
In 2016, RSS beat 1998 by 0.573 – 0.550 = 0.023 or by 0.02 to the nearest 1/100 of a degree. Since this is less than the error margin of 0.1 C, we can say that 2016 and 1998 are statistically tied for first place. However there is still over a 50% chance that 2016 did indeed set a record, but the probability for that is far less than 95% that climate science requires so the 2016 record is statistically insignificant.
If anyone has an exact percentage here, please let us know, however it should be around a 60% chance that a record was indeed set for RSS. In 2016, UAH6.0beta5 beat 1998 by 0.505 – 0.484 = 0.021 or also by 0.02 to the nearest 1/100 of a degree. What was said above for RSS applies here as well. My predictions after the June data came in were therefore not correct as I expected 2016 to come in under 1998.
What about GISS and HadSST3 and HadCRUT4.5? The December numbers are not in yet, but GISS will set a statistically significant record for 2016 over its previous record of 2015 since the new average will be more than 0.1 above the 2015 mark. HadSST3 will set a new record in 2016, but it will only be by a few hundredths of a degree so it will not be statistically significant. HadCRUT4.5 is still up in the air. The present average after 11 months is 0.790. The 2015 average was 0.760. As a result, December needs to come in at 0.438 to tie 2015. The November anomaly was 0.524, so only a further drop of 0.086 is required. This cannot be ruled out, especially since this Nicks site shows December 0.089 lower than November:
Also worth noting are that UAH dropped by 0.209 from November to December and RSS dropped by 0.162. Whatever happens with HadCRUT4.5, 2016 and 2015 will be in a statistical tie with a possible difference in the thousandths of a degree. The difference will be more important from a psychological perspective than a scientific perspective as it will be well within the margin of error.
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 2016 so far compares with 2015 and the warmest years and months on record so far. For three of the data sets, 2015 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. Only the satellite data go to December.
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 2016 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. 15ra: This is the final ranking for 2015 on each data set.
2. 15a: Here I give the average anomaly for 2015.
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 2015 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 prior to 2016. 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. 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.
8. sy/m: This is the years and months for row 7.
9. Jan: This is the January 2016 anomaly for that particular data set.
10. Feb: This is the February 2016 anomaly for that particular data set, etc.
21. ave: This is the average anomaly of all months to date.
22. rnk: This is the rank that each particular data set would have for 2016 without regards to error bars and assuming no changes to the current average anomaly. Think of it as an update 55 minutes into a game. However the satellite data are complete for the year.
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, UAH6.0beta5, 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 average anomaly for 2016 is 0.505. This sets a new record. 1998 was previously the warmest at 0.484. Prior to 2016, the highest ever monthly anomaly was in April of 1998 when it reached 0.743. The average anomaly in 2015 was 0.261 and it was ranked third but will now be in fourth place.
Presently, for RSS: There is no statistically significant warming since July 1994: Cl from -0.005 to 1.768.
The RSS average anomaly for 2016 is 0.573. This sets a new record. 1998 was previously the warmest at 0.550. Prior to 2016, the highest ever monthly anomaly was in April of 1998 when it reached 0.857. The average anomaly in 2015 was 0.381 and it was ranked third but will now be in fourth place.
For Hadcrut4.5: The warming is significant for all periods above four years.
The Hadcrut4.5 average anomaly so far is 0.790. This would set a record if it stayed this way. Prior to 2016, the highest ever monthly anomaly was in December of 2015 when it reached 1.024. The average anomaly in 2015 was 0.760 and this set a new record.
For Hadsst3: There is no statistically significant warming since March 1997: Cl from -0.003 to 2.102.
The Hadsst3 average anomaly so far for 2016 is 0.629. This would set a record if it stayed this way. Prior to 2016, the highest ever monthly anomaly was in September of 2015 when it reached 0.725. The average anomaly in 2015 was 0.592 and this set a new record.
For GISS: The warming is significant for all periods above three years.
The GISS average anomaly so far for 2016 is 1.01. This would set a record if it stayed this way. Prior to 2016, the highest ever monthly anomaly was in December of 2015 when it reached 1.11. The average anomaly in 2015 was 0.86 and it set a new record.
Does it seem odd that only GISS will probably set a statistically significant record in 2016?