Huge Divergence Between Latest UAH & HadCRUT4 Temperature Datasets (Now Includes April Data)

Guest Post by Werner Brozek, Edited by Just The Facts:

Some of you may have wondered why the title and the above plot are comparing different data sets. The reasons are that GISS and HadCRUT4.3 are very similar. As well, UAH6.0 is now very similar to RSS. However WFT does not have the latest UAH nor Hadcrut. So when you plot UAH on WFT, you actually are plotting version 5.5 and not even 5.6. Version 5.5 has not been updated since December 2014, however HadCRUT 4.2 has not been updated since July 2014, so those slopes are really off by a huge amount due to the fact that HadCRUT had record levels over the last year. But GISS and RSS are up to date on WFT.

The times of 58 months and 162 months were chosen to give a symmetric picture of shorter and longer terms where the slopes diverge between the satellites and ground based data sets.

In the next four paragraphs, I will give information for HadCRUT4.2 in July 2014, HadCRUT4.3 in April 2015, UAH5.6 in March 2015 and UAH6.0 in April 2015. The information will be

1. For how long the slope is flat;

2. Since when the warming is not statistically significant according to Nick Stokes’s calculation;

3. Since when the warming is not statistically significant according to Dr. McKitrick’s calculation where applicable;

4. The previous hot record year; and

5. Where each data set would rank after the given number of months.

For HadCRUT4.2 in July 2014, the slope was flat for 13 years and 6 months. There was no statistically significant warming since November 1996 according to Nick Stokes. Dr. McKitrick said there was no statistically significant warming for 19 years. The previous record warm year was 2010. As of July 2014, HadCRUT4.2 was on pace to be the third warmest year on record.

For HadCRUT4.3 in April 2015, the slope is not negative for any period worth mentioning. There is no statistically significant warming since June 2000 according to Nick Stokes. The previous record warm year was 2014. As of April, HadCRUT4.3 is on pace to set a new record. Note that on all criteria, HadCRUT4.3 is warmer than HadCRUT4.2.

For UAH5.6 as of March 2015, the slope was flat for an even 6 years. There was no statistically significant warming since August 1996 according to Nick Stokes. Dr. McKitrick said there was no statistically significant warming for 19 years, however this would be from about April 2014. The previous record warm year was 1998. As of March 2015, UAH5.6 was on pace to be the third warmest year on record.

For UAH6.0 as of April 2015, the slope is negative for 18 years and 4 months. There is no statistically significant warming since October 1992 according to Nick Stokes. The previous record warm year was 1998 as well. As of April, UAH6.0 is on pace to be the 8th warmest year. Note that unlike the HadCRUT comparison, UAH6.0 is colder than UAH5.6.

A year ago, Dr. McKitrick used HadCRUT4.2 and UAH5.6 to come up with times for no statistically significant warming on each of these data sets. In the meantime, HadCRUT4.2 has been replaced by HadCRUT4.3 which has been setting hot records over the past year. However UAH5.6 has been replaced with UAH6.0 which is much cooler than the UAH5.6 version. As a result, his times are no longer valid for these two data sets so I will not give them any more.

For RSS, Dr. McKitrick had a time of 26 years. From Nick Stokes’s time of November 1992 for last April to the present time of January 1993, there is very little change in the starting time, however we are now a year later. Therefore I would predict that if Dr. McKitrick ran the numbers again, he would get a time of 27 years without statistically significant warming.

For UAH5.6, Dr. McKitrick had a time of 16 years. However, Nick Stokes’s new time for UAH6.0 is from October 1992. Since this is three months earlier than the RSS time, I would predict that if Dr. McKitrick ran the numbers again, he would also get a time of 27 years without statistically significant warming for the new UAH6.0.

For Hadcrut4.2, Dr. McKitrick had a time of 19 years. At that time, Nick Stokes’s had a time since October 1996. However Nick Stokes’s new time for Hadcrut4.3 is from June 2000. It would be reasonable to assume that Dr. McKitrick would get 15 years if he did the calculation today.

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.

Section 1

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 January 1997 or 18 years and 4 months. (goes to April using version 6.0)

5. For RSS, the slope is flat since December 1996 or 18 years and 5 months. (goes to April)

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.

Section 2

For this analysis, data was retrieved from Nick Stokes’s 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.

The details for several sets are below.

For UAH6.0: Since October 1992: Cl from -0.042 to 1.759

This is 22 years and 7 months.

For RSS: Since January 1993: Cl from -0.023 to 1.682

This is 22 years and 4 months.

For Hadcrut4.3: Since June 2000: Cl from -0.015 to 1.387

This is 14 years and 10 months.

For Hadsst3: Since June 1995: Cl from -0.013 to 1.706

This is 19 years and 11 months.

For GISS: Since November 2000: Cl from -0.041 to 1.354

This is 14 years and 5 months.

Section 3

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. Jan: This is the January 2015 anomaly for that particular data set.

11. Feb: This is the February 2015 anomaly for that particular data set, etc.

14. ave: This is the average anomaly of all months to date taken by adding all numbers and dividing by the number of months.

15. 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 20 minutes into a game.

If you wish to verify all of the latest anomalies, go to the following:

For UAH, version 6.0 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.

http://vortex.nsstc.uah.edu/data/msu/v6.0beta/tlt/tltglhmam_6.0beta2

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.4.3.0.0.monthly_ns_avg.txt

For Hadsst3, see: http://www.cru.uea.ac.uk/cru/data/temperature/HadSST3-gl.dat

For GISS, see:

http://data.giss.nasa.gov/gistemp/tabledata_v3/GLB.Ts+dSST.txt

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 6.0 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.

Appendix

In this part, we are summarizing data for each set separately.

RSS

The slope is flat since December, 1996 or 18 years, 5 months. (goes to April)

For RSS: There is no statistically significant warming since January 1993: Cl from -0.023 to 1.682.

The RSS average anomaly so far for 2015 is 0.281. This would rank it as 6th 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.

UAH6.0

The slope is flat since January 1997 or 18 years and 4 months. (goes to April using version 6.0)

For UAH: There is no statistically significant warming since October 1992: Cl from -0.042 to 1.759. (This is using version 6.0 according to Nick’s program.)

The UAH average anomaly so far for 2015 is 0.156. This would rank it as 8th place. 1998 was the warmest at 0.483. The highest ever monthly anomaly was in April of 1998 when it reached 0.742. The anomaly in 2014 was 0.170 and it was ranked 6th.

Hadcrut4.3

The slope is not flat for any period that is worth mentioning.

For Hadcrut4: There is no statistically significant warming since June 2000: Cl from -0.015 to 1.387.

The Hadcrut4 average anomaly so far for 2015 is 0.671. 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.

Hadsst3

For Hadsst3, the slope is not flat for any period that is worth mentioning. For Hadsst3: There is no statistically significant warming since June 1995: Cl from -0.013 to 1.706.

The Hadsst3 average anomaly so far for 2015 is 0.457. 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.

GISS

The slope is not flat for any period that is worth mentioning.

For GISS: There is no statistically significant warming since November 2000: Cl from -0.041 to 1.354.

The GISS average anomaly so far for 2015 is 0.78. 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.

Conclusion

Why are the new satellite and ground data sets going in opposite directions? Is there any reason that you can think of where both could simultaneously be correct? Lubos Motl has an interesting article in which it looks as if satellites can “see” things the ground data sets miss. Do you think there could be something to this for at least a partial explanation?

Updates:

RSS May: With the May anomaly at 0.310, the 5 month average is 0.287 and RSS would remain in 6th place if it stayed this way. The time for a slope of zero increases to 18 years and 6 months from December 1996 to May 2015.

WFT Update: A few days ago, WFT has been updated and now shows HadCRUT4.3 to date.

UAH5.5 has also been updated but it shows UAH5.6 and not UAH6.0, so it cannot be used

to verify the 18 year and 4 month pause for UAH6.0.