Image Credit: WoodForTrees.org
Guest Post By Werner Brozek, Edited By Just The Facts
*At least April data was my intention. However as of June 8, HadCRUT3 for April is still not up! Could it be because as of the end of March, the slope of 0 lasted 16 years and 1 month and they do not want to add another month or two? What do you think? WoodForTrees (WFT) is up to date however, thank you very much Paul!
The graph above shows a few different things for three data sets where there has been no warming for at least 16 years. WFT only allows one to draw straight lines between two points, however climate does not go in straight lines. Often, temperatures vary in a sinusoidal fashion which cannot yet be shown using WFT. However we can do the next best thing and show what is happening over the first half of the 16 years and what is happening over the last half. As shown, the first half shows a small rise and the last half shows a small decline. Note that neither the rise in the first half nor the drop in the last half is statistically significant. However the lines do suggest that we are just continuing a 60 year sine wave that was started in 1880 according to the following graphic:
Do you agree? What are your views on the question in the title? Do you think we are presently in a pause or in a decline or neither?
In the sections below, we will present you with the latest facts. The information will be presented in three sections and an appendix. The first section will show the period that there has been no warming for various data sets. The second section will show the period that there has been no “significant” warming on several data sets. The third section will show how 2013 to date compares with 2012 and the warmest years and months on record. The appendix illustrate sections 1 and 2 in a different format. 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. 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 8 years and 5 months to 16 years and 6 months.
1. For GISS, the slope is flat since January 2001 or 12 years, 4 months. (goes to April)
2. For Hadcrut3, the slope is flat since March 1, 1997 or 16 years, 1 month. (goes to March 31, 2013)
3. For a combination of GISS, Hadcrut3, UAH and RSS, the slope is flat since December 2000 or 12 years, 6 months. (This goes to May. I realize that Hadcrut3 is not up to date, but on the basis of its present slope and the latest numbers that I do have from the other three sets. I am confident that I can make this prediction.)
4. For Hadcrut4, the slope is flat since November 2000 or 12 years, 6 months. (goes to April)
5. For Hadsst2, the slope is flat from March 1, 1997 to April 30, 2013, or 16 years, 2 months.
6. For UAH, the slope is flat since January 2005 or 8 years, 5 months. (goes to May)
7. For RSS, the slope is flat since December 1996 or 16 years and 6 months. (goes to May) RSS is 198/204 or 97% of the way to Ben Santer’s 17 years. This 97% is real!
The next graph shows just the lines to illustrate the above for what can be shown. 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 sloped wiggly line shows how CO2 has increased over this period.
When two things are plotted as I have done, the left only shows a temperature anomaly. It goes from 0.1 C to 0.6 C. A change of 0.5 C over 16 years is about 3.0 C over 100 years. And 3.0 C is about the average of what the IPCC says may be the temperature increase by 2100.
So for this to be the case, the slope for all of the data sets would have to be as steep as the CO2 slope. Hopefully the graphs show that this is totally untenable.
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.
Section 2
For this analysis, data was retrieved from SkepticalScience.com. This analysis indicates for how long there has not been significant warming according to their criteria. The numbers below start from January of the year indicated. Data go to their latest update for each set. In every case, note that the magnitude of the second number is larger than the first number so a slope of 0 cannot be ruled out. (To the best of my knowledge, SkS uses the same criteria that Phil Jones uses to determine significance.)
The situation with GISS, which used to have no statistically significant warming for 17 years, has now been changed with new data. GISS now has over 18 years of no statistically significant warming. As a result, we can now say the following: On six different data sets, there has been no statistically significant warming for between 18 and 23 years.
The details are below and are based on the SkS site:
For RSS the warming is not significant for over 23 years.
For RSS: +0.123 +/-0.131 C/decade at the two sigma level from 1990
For UAH the warming is not significant for over 19 years.
For UAH: 0.142 +/- 0.166 C/decade at the two sigma level from 1994
For Hadcrut3 the warming is not significant for over 19 years.
For Hadcrut3: 0.092 +/- 0.112 C/decade at the two sigma level from 1994
For Hadcrut4 the warming is not significant for over 18 years.
For Hadcrut4: 0.093 +/- 0.108 C/decade at the two sigma level from 1995
For GISS the warming is not significant for over 18 years.
For GISS: 0.103 +/- 0.111 C/decade at the two sigma level from 1995
For NOAA the warming is not significant for over 18 years.
For NOAA: 0.085 +/- 0.104 C/decade at the two sigma level from 1995
If you want to know the times to the nearest month that the warming is not significant for each set to their latest update, they are as follows:
RSS since August 1989;
UAH since June 1993;
Hadcrut3 since July 1993;
Hadcrut4 since July 1994;
GISS since October 1994 and
NOAA since May 1994.
Section 3
This section shows data about 2013 and other information in the form of a table. The table shows the six data sources along the top and bottom, namely UAH, RSS, Hadcrut4, Hadcrut3, Hadsst2, and GISS. Down the column, are the following:
1. 12ra: This is the final ranking for 2012 on each data set.
2. 12an: Here I give the average anomaly for 2012.
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 four 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 two 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.
8. sig: This is the whole number of years for which warming is not significant according to the SkS criteria. The additional months are not added here, however for more details, see Section 2.
9. Jan: This is the January, 2013, anomaly for that particular data set.
10. Feb: This is the February, 2013, anomaly for that particular data set.
11. Mar: This is the March, 2013, anomaly for that particular data set.
12. Apr: This is the April, 2013, anomaly for that particular data set.
13. May: This is the May, 2013, anomaly for that particular data set.
21. 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 use their number. Sometimes the number in the third decimal place differs by one, presumably due to all months not having the same number of days.
22. 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. Of course it won’t, but think of it as an update 20 or 25 minutes into a game. Expect wild swings from month to month at the start of the year. As well, expect huge variations between data sets at the start. Due to different base periods, the rank may be more meaningful than the average anomaly.
| Source | UAH | RSS | Had4 | Had3 | Sst2 | GISS |
|---|---|---|---|---|---|---|
| 1. 12ra | 9th | 11th | 9th | 10th | 8th | 9th |
| 2. 12an | 0.161 | 0.192 | 0.448 | 0.405 | 0.342 | 0.56 |
| 3. year | 1998 | 1998 | 2010 | 1998 | 1998 | 2010 |
| 4. ano | 0.419 | 0.55 | 0.547 | 0.548 | 0.451 | 0.66 |
| 5. mon | Ap98 | Ap98 | Ja07 | Fe98 | Au98 | Ja07 |
| 6. ano | 0.66 | 0.857 | 0.829 | 0.756 | 0.555 | 0.93 |
| 7. y/m | 8/5 | 16/6 | 12/6 | 16/1 | 16/2 | 12/4 |
| 8. sig | 19 | 23 | 18 | 19 | 18 | |
| 9. Jan | 0.504 | 0.441 | 0.450 | 0.390 | 0.283 | 0.61 |
| 10.Feb | 0.175 | 0.194 | 0.479 | 0.424 | 0.308 | 0.52 |
| 11.Mar | 0.183 | 0.204 | 0.411 | 0.387 | 0.278 | 0.58 |
| 12.Apr | 0.103 | 0.219 | 0.425 | 0.353 | 0.50 | |
| 13.May | 0.074 | 0.139 | ||||
| 21.ave | 0.208 | 0.239 | 0.440 | 0.401 | 0.306 | 0.553 |
| 22.rnk | 6th | 8th | 11th | 12th | 11th | 10th |
| Source | UAH | RSS | Had4 | Had3 | Sst2 | GISS |
If you wish to verify all of the latest anomalies, go to the following links, UAH,
For RSS, Hadcrut4, Hadcrut3, Hadsst2,and GISS.
To see all points since January 2012 in the form of a graph, see the WFT graph below:
I wish to make a comment about this graph from WFT. It is right up to date. The only reason that both HadCRUT3 and WTI only go to March is because WTI uses 4 data sets, one of which is HadCRUT3, so if HadCRUT3 is not there for April, WTI cannot be there for April as well.
Appendix
In this part, we are summarizing data for each set separately.
RSS
The slope is flat since December 1996 or 16 years and 6 months. (goes to May) RSS is 198/204 or 97% of the way to Ben Santer’s 17 years.
For RSS the warming is not significant for over 23 years.
For RSS: +0.123 +/-0.131 C/decade at the two sigma level from 1990.
The RSS average anomaly so far for 2013 is 0.239. This would rank 8th 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 2012 was 0.192 and it came in 11th.
Following are two graphs via WFT. Both show all plotted points for RSS since 1990. Then two lines are shown on the first graph. The first upward sloping line is the line from where warming is not significant according to the SkS site criteria. The second straight line shows the point from where the slope is flat.
The second graph shows the above, but in addition, there are two extra lines. These show the upper and lower lines using the SkS site criteria. Note that the lower line is almost horizontal but slopes slightly downward. This indicates that there is a slight chance that cooling has occurred since 1990 according to RSS
UAH
The slope is flat since January 2005 or 8 years, 5 months. (goes to May)
For UAH, the warming is not significant for over 19 years.
For UAH: 0.142 +/- 0.166 C/decade at the two sigma level from 1994
The UAH average anomaly so far for 2013 is 0.208. This would rank 6th 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 0.66. The anomaly in 2012 was 0.161 and it came in 9th.
Following are two graphs via WFT. Everything is identical as with RSS except the lines apply to UAH.
Hadcrut4
The slope is flat since November 2000 or 12 years, 6 months. (goes to April.)
For Hadcrut4, the warming is not significant for over 18 years.
For Hadcrut4: 0.093 +/- 0.108 C/decade at the two sigma level from 1995
The Hadcrut4 average anomaly so far for 2013 is 0.440. This would rank 11th 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 2012 was 0.448 and it came in 9th.
Following are two graphs via WFT. Everything is identical as with RSS except the lines apply to Hadcrut4.
Hadcrut3
The slope is flat since March 1 1997 or 16 years, 1 month (goes to March 31, 2013)
For Hadcrut3, the warming is not significant for over 19 years.
For Hadcrut3: 0.092 +/- 0.112 C/decade at the two sigma level from 1994
The Hadcrut3 average anomaly so far for 2013 is 0.401. This would rank 12th if it stayed this way. 1998 was the warmest at 0.548. The highest ever monthly anomaly was in February of 1998 when it reached 0.756. One has to go back to the 1940s to find the previous time that a Hadcrut3 record was not beaten in 10 years or less. The anomaly in 2012 was 0.405 and it came in 10th.
Following are two graphs via WFT. Everything is identical as with RSS except the lines apply to Hadcrut3.
Hadsst2
For Hadsst2, the slope is flat since March 1, 1997 or 16 years, 2 months. (goes to April 30, 2013).
The Hadsst2 average anomaly for the first four months for 2013 is 0.306. This would rank 11th if it stayed this way. 1998 was the warmest at 0.451. The highest ever monthly anomaly was in August of 1998 when it reached 0.555. The anomaly in 2012 was 0.342 and it came in 8th.
Sorry! The only graph available for Hadsst2 is the following
this.
GISS
The slope is flat since January 2001 or 12 years, 4 months. (goes to April)
For GISS, the warming is not significant for over 18 years.
For GISS: 0.103 +/- 0.111 C/decade at the two sigma level from 1995
The GISS average anomaly so far for 2013 is 0.553. This would rank 10th 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 2012 was 0.56 and it came in 9th.
Following are two graphs via WFT. Everything is identical as with RSS except the lines apply to GISS.
Conclusion
Above, various facts have been presented along with sources from where all facts were obtained. Keep in mind that no one is entitled to their own facts. It is only in the interpretation of the facts for which legitimate discussions can take place. After looking at the above facts, do you think that we should spend billions to prevent the claimed catastrophic anthropogenic global warming? Or do you think we should take a “wait and see” attitude for a few years to be sure that future warming will be as catastrophic as some claim it will be? Keep in mind that even the MET office felt the need to revise its forecasts. Look at the following and keep in mind that the MET office believes that the 1998 mark will be beaten by 2017. Do you agree?
By the way, here is an earlier prediction by the MET office:
“(H)alf of the years after 2009 are predicted to be hotter than the current record hot year, 1998.”
When this prediction was made, they had Hadcrut3 and so far, the 1998 mark has not been broken on Hadcrut3. 2013 is not starting well if they want a new record in 2013. Here are some relevant facts today: The sun is extremely quiet; ENSO has been between 0 and -0.5 since the start of the year; it takes at least 3 months for ENSO effects to kick in and the Hadcrut3 average anomaly after March was 0.401 which would rank it in 12th place. Granted, it is only 3 months, but you are not going to set any records starting the race in 12th place after three months. So even if a 1998 type El Nino started to set in tomorrow, it would be at least 4 or 5 months for the maximum ENSO reading to be reached. Then it would take at least 3 more months for the high ENSO to be reflected in Earth’s temperature. How hot would November and December then have to be to set a new record? In my opinion, the odds of setting a new record in 2013 are extremely remote.
Barry Elledge says:
June 10, 2013 at 10:13 pm
Four data sets (RSS, UAH, HADCRUT3 and SST) record highs in 1998, and thus haven’t set new records for 14 years. The 2 data sets which did set new records in 2010 (HADCRUT4 and GISS) went 12 years before the new highs.
Your first sentence is correct, but not the second. Here are the top 4 years in HadCRUT4 and GISS. Note that 1998 is not in second place in either.
For NEW HadCrut4,
1 {2010, 0.547},
2 {2005, 0.539},
3 {1998, 0.531},
4 {2003, 0.503},
GISS
1. 66 2010
2. 65 2005
3. 62 2007
4. 61 1998
Ooops! My apologies! I am out of date! Since the last time I checked, not too long ago, 1998 was 4th. It has now slipped to 5th. Here are the latest top 5 now.
GISS
1. 66 2010
2. 66 2005
3. 62 2007
4. 62 2002
5. 61 1998
Barry E,
Gavin points out that GISS broke the record within 8 years, and HadCRUt had not – this was his “ambiguous” result within 8 years. His unambiguous result is 4 years out.
He also makes this point:
Just rediscovered some blogposts hiding in my bookmarks that rely on maths to determine minimum periods for getting reliable trends from global temperature data (based on the surface records). Included in the list is one I’ve already linked.
24 years: http://tamino.wordpress.com/2012/07/06/how-long/
20 – 30 years: http://moregrumbinescience.blogspot.com.au/2009/01/results-on-deciding-trends.html
30 (or 45) years: http://www.bartonpaullevenson.com/30Years.html
I would prefer to have included blog posts from ‘skeptical’ bloggers, but I’ve not found any that look for a general principle as above. Does anyone know of such?
As the subject of short-term trends generates such interest, it would be good to nail down what is a good minimum time period, not just for statistical significance, but to establish a real change in the momentum of climate.
barry says:
June 11, 2013 at 6:22 pm
Gavin points out that GISS broke the record within 8 years
However as my latest numbers above show, 2002 beat 1998 but only by 0.01 C. The largest difference between 1998 and any higher year on either GISS or HadCRUT4 is only 0.05 and I believe I read that any difference of less than 0.1 can be considered a virtual tie. If that is the case, then we cannot be certain that 1998 was beaten by any data set at any time.
Werner, I think the 8-year record-breaker is overinterpreted by others. Gavin seems to dismiss it in favour of a less ambiguous result, which is the 18-year posit.
There is some ambiguity in his language, but I think he means a 0.1C record breaker in one data set (GISS?) would mean that the other data sets would all then have broken their records, which would seem, superficially, to accord with the behaviour of the various records (see 2010, the highest temp for GISS).
http://www.woodfortrees.org/plot/gistemp/from:1979/offset:-0.35/mean:12/from:1979/plot/hadcrut3vgl/from:1979/offset:-0.26/mean:12/from:1979/plot/rss/offset:-0.10/mean:12/from:1979/plot/uah/mean:12/from:1979
A strong el Nino year should determine this. We’re due for one in the next few years, and as said above, we have 4 years to go to see how Gavin’s analysis pans out. At the same time, it seems clear to me that the extended flat trend is unusual, if not impossible under a warming scenario, and worthy of current interest. I think it has been overinterpreted is all.
wbrozek at 3:39 pm on 6/11 points out that 2 of 6 data sets (HADCRUT4 and GISS) recorded new high T values before 2010, thereby salvaging the 8-year time interval for new high T values according to Gavin Schmidt’s analysis of the AR4 climate models.
So, Werner … thanks for scuzzing up the face of the Truth with new data. The story was a lot simpler before.
The GISS data first. Many people including me are mystified by the phenomenon of quantum entanglement, with its spooky simultaneous-action-at-a-distance implication. But GISS may be even spookier, because it implies action-on-the-past. Notably, the year 2002 heated up miraculously more than a decade after it was over. I don’t know how this can be accomplished physically, but it seems to pose deep philosophical challenges for time-series evaluations: if T is undead and is constantly stirring in its grave, how can we conclude anything about the restless past? In fact, were we to evaluate Gavin’s postulate in 2008 using GISS, we would conclude it had been violated (1998 to 2007 is 9 years). But now in 2013, his postulate is miraculously intact. The New Old Data are as tedious as the New Old Christine.
As for HADCRUT4, it shows a new high T in 2005 by a whopping 0.008 deg C.
How do we deal with this discrepancy among data sets? The original goal of the AR4 projections was to show probable actual future Ts; the projections were not supposed to emulate any particular data set. Therefore the most honest basis for evaluation should be an average of them all.
On that basis the interval of greater than 8 years without a new high T was surpassed, and the interval of 18 years without a new high of at least 0.1 deg C is still in play.
barry says:
June 11, 2013 at 8:31 pm
a record that is at least 0.1ºC warmer than the previous one (so that it would be clear in all observational data sets)
So he seems to want every data set to exceed their 1998 mark by at least 0.1 C within 18 years is how I interpret it. That seemed extremely remote for HadCRUT3 with its huge gap between first and second. (Here are the top 11. Note the position of 2007 which is in 11th place, yet GISS has it above 1998!!)
1 {1998, 0.548},
2 {2005, 0.482},
3 {2010, 0.478},
4 {2003, 0.475},
5 {2002, 0.465},
6 {2004, 0.447},
7 {2009, 0.443},
8 {2006, 0.425},
9 {2001, 0.408},
10 2012 0.406
11 {2007, 0.402}
Then there was speculation that HadCRUT3 would be discontinued. I have no clue. I just know the April anomaly is still not up. Furthermore, Hadsst2 was used for HadCRUT3 so that could go too if HadCRUT3 goes. Of course they cannot very well beat their 1998 mark if they are no longer kept up.
Barry Elledge says:
June 11, 2013 at 8:57 pm
Therefore the most honest basis for evaluation should be an average of them all.
If that includes GISS, then I do not agree. Here is why. GISS had 2007 above 1998 by 0.01, however HadCRUT3 had 2007 lower than 1998 by 0.146. That gives a net difference of 0.156. Presumably this is because the polar regions are warming faster and GISS accounts for this better. Also, we are talking about the north polar region and not the south since it is in the north where some extra warming is occurring. (I do not deny some extra warming in the north.) Let us assume we are talking about north of latitude 82.5 degrees which is where RSS can “see”. The area north of latitude 82.5 is 1/230 of the whole area of the earth. So if an area that is 1/230 of the total made the overall temperature go up by 0.156 C, then that area must have been 0.156 x 230 = 36 C warmer in 2007 that 1998!
barry says:
June 10, 2013 at 10:44 pm
2001 IPCC defines climate change thus:
Climate change refers to a statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period (typically decades or longer).
+++++++++++++++++++
If you read more than this one sentence, the IPCC does not define climate change as you suggest. After all, they are all about climate and have produced thousands of pages of fodder. They define climate change as something that would be pretty stable without Anthropogenic forcing. Did you know that?
Sounds likely. The language is a little ambiguos, though.
Barry E,
The data for all stations do not arrive simultaneously, many are recovered after a few years. There may be other processes that attempt to refine the record (I don’t know). As the adjustments are minimal – hundredths of a degree – then the significance of this in terms of the ‘clear record-breaker’ is not terribly much.
Mario,
how does IPCC define climate change – in terms of periodicity, which is the point addressing the conjecture in the top post – if not as I quoted them on it?
A glance at their paleoclimate section (ice ages, for example), shows how wrong this is.
barry says:
June 11, 2013 at 11:51 pm
Mario,
how does IPCC define climate change – in terms of periodicity, which is the point addressing the conjecture in the top post – if not as I quoted them on it?
They define climate change as something that would be pretty stable without Anthropogenic forcing.
A glance at their paleoclimate section (ice ages, for example), shows how wrong this is.
+++++++++++++++++++++
Barry I referenced their Summary for Policy Makers. There, they do not speak of what we all know that climate changes. They point to Anthropegenic causes, without which, the climate would be pretty stable over the period where they we/ I am talking about (in their summary for policy makers.) I’m sure you believe that the IPCC are credible Barry. You are taking what I said, and twisting it to somehow distract from the truth. That is, they use the most extreme models to make their summary stick it to us. No one would make policy on models which don’t show catastrophic warming, so your pointing to the one that shows nothing catastrophic and saying they had it covered is dishonest Barry. Their I fixed it for you, again.
Mario,
You said:
How have I twisted what you said? Do you now wish to limit the IPCC documents to the SPM? Then I will quote from there.
The reference 6.4 in the SPM points to the sections on ice age changes.
Your assertion:
is indefensible. If you had said that (1) IPCC have a strong focus on anthropogenic climate change, or that (2) they attribute most of the warming of the last 50 years to anthropogenic CO2, that would have been more accurate.
Barry says:
“How have I twisted what you said? Do you now wish to limit the IPCC documents to the SPM? Then I will quote from there.”
It’s simple Barry: I made a true statement about the IPCC Summary for Policy Makers. You twisted what I said by pointing to some “other document” that was not in the Summary for Policy Makers. You then transcended into telling me that what I said was untrue. It was and is not untrue.
If you cannot understand, I can no longer tutor you. If you want to make a claim about what I’ve said, you need to be honest, or be called out. If you have a point, make it. If you don’t have enough respect to be truthful, you can continue blathering on.
There I fixed it for you again. Apology anticipated.
counting 1…2….3….?
Barry: pardon the following metaphors… By the way, you’re on a sinking ship, so I do not expect you to be reasonable. You’ve thrown out all sorts of conjecture to distract during this argument. You did not like the truth that I stated, so you chose to go to battle instead of understand what I’d written.
IPCC states that man caused almost all of the warming in the 20th Century and that man will continue to warm the planet. There is and has never been any factual evidence of that –none. You’ve stood with those claims and now as everyone can see that you were misled and that you misled others, you go down fighting. You seem educated enough to be capable of taking a deep breath, reading a little bit and trying to understand what went wrong with your hypothesis. I suggest you open your mind and grow. You’ll be welcomed with open arms by the folks who know better.
The longer you stick with your ilk, the worse it will get. You’ll grow to be an angry old person wondering why nature through you a curve ball.
barry says:
June 11, 2013 at 7:32 am
Richard,
BTW, I’m still waiting for someone to provide a reference to a model run with over 15 years of flat temps and no volcanic eruption.
You missed it.
Well, I checked your reference and the only periods with long flat periods were cherry picked situations going from a high value to a low value (like going from an El Niño to a La Niña. They were clearly not a true period of non-increasing temperatures. Admittedly, some skeptics had been using this method to claim non-warming at the time of that paper. I guess I should have added non-cherry picking to my criteria.
Now, things have changed. We can see non-warming from ENSO neutral to ENSO neutral periods. In fact 1996 was slightly negative at the start of the current 16.5 year period of no warming.
So, your examples are without merit. Try again.
tumetuestumefaisdubien1 says:
June 13, 2013 at 3:48 pm
http://wattsupwiththat.com/2013/06/09/are-we-in-a-pause-or-a-decline-now-includes-at-least-april-data/#comment-1335347
almost all the links in the looooong comment are dead ends.Try proof reading next time.
Some argue that climate is too chaotic to detect genuine cycles or even pseudocycles with any real meaning. Too many variables must be summed to produce lower troposphere temperatures, which in any case can’t be easily averaged or measured.
That said, if for the sake of argument, you try to fit curves to the admittedly inadequate estimates of average global near-surface temperature, then ~half of the 50 to 70-year PDO cycle works fairly well, starting from c. 1850 as the end of the LIA:
1998-2013: Flat to Cooling (& counting)
1977-1998: Warming
1945-1977: Cooling (with rising CO2)
1915-1945: Warming
1880-1915: Cooling
1850-1880: Warming
http://myweb.wwu.edu/dbunny/pdfs/CO2_past-century.pdf
You can quibble about start & end dates. For instance in at least one data set, there has been no statistically significant warming since 1995. And of course the climate books have been cooked (the real but fictitious “global warming”), so that no one really knows anymore what the surface record, such as it is, should show. But even with these caveats, the pseudo-sinusoidal cyclical trends within the secular warming during recovery from the LIA look robust.