Guest Post By Werner Brozek, Edited By Just The Facts
In order to answer the question in the title, we need to know what time period is a reasonable period to take into consideration. As well, we need to know exactly what we mean by “stalled”. For example, do we mean that the slope of the temperature-time graph must be 0 in order to be able to claim that global warming has stalled? Or do we mean that there has to be a lack of “significant” warming over a given period? With regards to what a suitable time period is, NOAA says the following:
”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.” To verify this for yourself, see page 23 here
Below, we will present you with just the facts and then you can decide whether or not global warming has stalled in a statistically significant manner.
The information will be presented in three sections and an appendix. Section 1 will show for how long there has been no warming on several data sets. Section 2 will show for how long there has been no significant warming on several data sets. Section 3 will show how January 2013 compares with 2012 and the warmest years and 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.
Section 1
This analysis uses the latest month for which data is available on WoodForTrees.com (WFT). However WFT has not been updated for GISS, Hadcrut3 and WTI past November so I had to use the SkS site for GISS and Hadcrut3. 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 4 years and 7 months to 16 years and 1 month.
1. For GISS, the slope is flat since May 2001 or 11 years, 9 months. (goes to January)
2. For Hadcrut3, the slope is flat since March 1997 or 15 years, 11 months. (goes to January)
3. For a combination of GISS, Hadcrut3, UAH and RSS, the slope is flat since December 2000 or an even 12 years. (goes to November)
4. For Hadcrut4, the slope is flat since November 2000 or 12 years, 3 months. (goes to January)
5. For Hadsst2, the slope is flat since March 1997 or 15 years, 11 months. (goes to January)
6. For UAH, the slope is flat since July 2008 or 4 years, 7 months. (goes to January)
7. For RSS, the slope is flat since January 1997 or 16 years and 1 month. (goes to January) RSS is 193/204 or 94.6% of the way to Ben Santer’s 17 years.
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 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 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 have now been updated either to the end of December 2012 or January 2013. 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.)
For RSS the warming is not significant for over 23 years.
For RSS: +0.127 +/-0.134 C/decade at the two sigma level from 1990
For UAH the warming is not significant for over 19 years.
For UAH: 0.146 +/- 0.170 C/decade at the two sigma level from 1994
For Hadcrut3 the warming is not significant for over 19 years.
For Hadcrut3: 0.095 +/- 0.115 C/decade at the two sigma level from 1994
For Hadcrut4 the warming is not significant for over 18 years.
For Hadcrut4: 0.095 +/- 0.110 C/decade at the two sigma level from 1995
For GISS the warming is not significant for over 17 years.
For GISS: 0.111 +/- 0.122 C/decade at the two sigma level from 1996
If you want to know the times to the nearest month that the warming is not significant for each set, they are as follows: RSS since September 1989; UAH since June 1993; Hadcrut3 since August 1993; Hadcrut4 since July 1994; GISS since August 1995 and NOAA since June 1994.
Section 3
This section shows data about 2013 and other information in the form of a table. Each table shows the six data sources along the top, namely UAH, RSS, Hadcrut4, Hadcrut3, Hadsst2, and GISS. Down the column, are the following:
1. 2012 rank: This is the final ranking for 2012 on each data set.
2. 2012 anomaly: Here I give the average anomaly for 2012.
3. warmest 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. anomaly of above: This is the average of the monthly anomalies of the warmest year just above.
5. warmest month: 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. anomaly of above: This is the anomaly of the month just above.
7. year/month no warm: This is the longest period of time where the slope is not positive. So 15/11 means that for 15 years and 11 months the slope is 0 or slightly negative.
8. This is the January, 2013, anomaly for that particular data set.
20. This is the average anomaly of all months to date taken by adding all numbers and dividing by the number of months. (Of course, for this time, it would simply be the January anomaly.)
21. 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 5 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. For UAH, the 0.506 was ranked first. That is because 0.506 is above the highest yearly average of 0.419 in 1998. It is not the hottest month ever. That happens to be April of 1998 when the anomaly was 0.66.
| Source | UAH | RSS | Had4 | Had3 | HADSST2 | GISS |
|---|---|---|---|---|---|---|
1. 2012 Rank |
9th | 11th | 10th | 10th | 8th | 9th |
| 2. 2012 Anomaly | 0.161 | 0.192 | 0.433 | 0.406 | 0.342 | 0.56 |
| 3. Warmest Year | 1998 | 1998 | 2010 | 1998 | 1998 | 2010 |
| 4. Anomaly Of Above | 0.419 | 0.55 | 0.540 | 0.548 | 0.451 | 0.66 |
| 5. warmest month | Ap98 | Ap98 | Ja07 | Fe98 | Au98 | Ja07 |
| 6. Anomaly Of Above | 0.66 | 0.857 | 0.818 | 0.756 | 0.555 | 0.93 |
| 7. Years / Months With No Warming | 4/7 | 16/1 | 12/3 | 15/11 | 15/11 | 11/9 |
| 8. Jan. 2013 Anomaly | 0.506 | 0.442 | 0.433 | 0.388 | 0.283 | 0.61 |
| 20. 2013 Average So Far | 0.506 | 0.442 | 0.433 | 0.388 | 0.283 | 0.61 |
| 21. 2013 Rank So Far | 1st | 3rd | 10th | 12th | 12th | 4th |
If you wish to verify all 2012 rankings, go to the following:
For UAH, see here, for RSS see here and for Hadcrut4, see here. Note the number opposite the 2012 at the bottom. Then going up to 1998, you will find that there are 9 numbers above this number. That confirms that 2012 is in 10th place.
For Hadcrut3, see here. Here you have to do something similar to Hadcrut4, but look at the numbers at the far right. 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.
For Hadsst2, see here. View as for Hadcrut3. It came in 8th place with an average anomaly of 0.342, narrowly beating 2006 by 2/1000 of a degree as that came in at 0.340. In my ranking, I did not consider error bars, however 2006 and 2012 would statistically be a tie for all intents and purposes.
For GISS, see here. Check the J-D (January to December) average and then check to see how often that number is exceeded back to 1998.
To see all points since January 2012 in the form of a graph, see the WFT graph below:
Relative to December, the January anomalies have changed as follows: UAH up 0.30, RSS up 0.34, Hadcrut4 up 0.17, Hadcrut3 up 0.13, Hadsst2 down 0.06, and GISS up 0.17.
Dr. Spencer explains why the satellite anomalies are up but the sea surface anomaly is down here.
Appendix
In this part, we are summarizing data for each set separately.
RSS
The slope is flat since January 1997 or 16 years and 1 month. (goes to January) RSS is 193/204 or 94.6% of the way to Ben Santer’s 17 years.
For RSS the warming is not significant for over 23 years.
For RSS: +0.127 +/-0.134 C/decade at the two sigma level from 1990.
The RSS average anomaly so far for 2013 is 0.442. This would rank 3rd 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 per graph 1 and graph 2.
UAH
The slope is flat since July 2008 or 4 years, 7 months. (goes to January)
For UAH, the warming is not significant for over 19 years.
For UAH: 0.146 +/- 0.170 C/decade at the two sigma level from 1994
The UAH average anomaly so far for 2013 is 0.506. This would rank 1st 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, 3 months. (goes to January.)
For Hadcrut4, the warming is not significant for over 18 years.
For Hadcrut4: 0.095 +/- 0.110 C/decade at the two sigma level from 1995
The Hadcrut4 average anomaly so far for 2013 is 0.433. This would rank 10th if it stayed this way. 2010 was the warmest at 0.540. The highest ever monthly anomaly was in January of 2007 when it reached 0.818. The anomaly in 2012 was 0.433 and it came in 10th.
Following are two graphs via WFT. Everything is identical as with RSS except the lines apply to Hadcrut4.Graph 1 and graph 2.
Hadcrut3
The slope is flat since March 1997 or 15 years, 11 months (goes to January)
For Hadcrut3, the warming is not significant for over 19 years.
For Hadcrut3: 0.095 +/- 0.115 C/decade at the two sigma level from 1994
The Hadcrut3 average anomaly so far for 2013 is 0.388. 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 0.406 and it came in 10th.
Following are two graphs via WFT. Everything is identical as with RSS except the lines apply to Hadcrut3. Graph 1 and graph 2.
Hadsst2
The slope is flat since March 1997 or 15 years, 11 months. (goes to January)
The Hadsst2 average anomaly so far for 2013 is 0.283. This would rank 12th 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 May 2001 or 11 years, 9 months. (goes to January)
For GISS, the warming is not significant for over 17 years.
For GISS: 0.111 +/- 0.122 C/decade at the two sigma level from 1996
The GISS average anomaly so far for 2013 is 0.61. This would rank 4th if it stayed this way and would tie it with 1998. 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. Graph 1 and graph 2.
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 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 feel that we should spend billions to prevent catastrophic warming? Or do you feel 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?
“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?”
A technical analyst or “chartist” coming from the stock market might say that each of the last four peaks has been higher than its predecessor and all the troughs have been higher than their predecessors, so there is evidence that supports the Met Office’s contention. Perhaps not by 2017 but somewhat later.
The difference is that stock market prices are directly and immediately affected by human behaviour whereas even climatologists do not claim that human behaviour has such a direct and immediate affect on global temperatures. So forecasting future medium term (let alone long term) global temperatures from such charts is a waste of effort.
What the charts do tend to show is that the models which, in the late nineties, forecast continued global warming have been getting it wrong for the last fifteen years or so. This is a long enough period to lead any open-minded scientist to query the accuracy of his/her model and, in the absence of a good scientific explanation for its failure, to admit that the model was unsound. At this point, were it not for the grant money involved, the climatogist might reason that, perhaps, CO2 was not leading to the destruction of the world as we know it.
On the other hand thinking of all the money that the renewables industry might lose should politicians change their minds, the rational climatologist might consider it too dangerous to admit that he/she had been in error. Rather than do this he/she will continue to make arbitrary adjustments to the raw data to remove the impact of known factors on short-term temperature variations (El Niño/southern oscillation, volcanic aerosols and solar variability). If these do not suffice he/she wil,l no doubt, make further adjustments to the raw data to allow, say, for the year’s exceptional snowfall as it affected albedo or for a change in the level of the jet stream or even, who knows, meteor strikes and other acts of nature. After all making such adjustments so as to remove all natural impacts – especially those which serve to increase global temperatures – can always be done in such a manner as to leave a series of increased temperature readings.
A more interesting question is how many more years of non-significant growth will it take before the first member of the hockey team admits that the evidence points to his/her theory that the CO2 component of AGW global warming having been disastrously exaggerated and that the principal driver of climate change is natural?
My guess is not in this century.
2 Sigma is thin proof of anything at all. In High-Energy Physics, 5 sigma is required to be considered for publication but they prefer 6 Sigma. If “Climate Science” even required 2 Sigma we never would have had the Hockey Stick. At 5 Sigma there would be NO “Climate Science,” as there is no proof at this level that we can predict anything about the weather at all, other than that the Sun will rise in the East tomorrow morning, and summers tend to be warmer than winters. A lot of “pin-head angels” on here, Much Ado About Nothing….
Philip Shehan says:
March 6, 2013 at 12:30 am
No problem!
Philip Shehan says:
March 6, 2013 at 1:06 am
But at the risk of drawing the wrath of those who have expressed distaste for this graph, the record for the past century and a half is non-linear.
I agree. As Girma showed at 4:38 A.M., (Thanks!) we have a 60 year sine wave superimposed on a slightly rising linear line. At the moment, we seem to be heading down the sine wave. This seems to have gone on for the last 10 years so we may have another 20 years to go before we bottom out.
Wait, there are data after 2005??
Someone needs to advise Michael Mann of this development.
Why not apply Craig Loehle’s method out to 2013?
http://icecap.us/images/uploads/05-loehleNEW.pdf
Its going to be fun watching the CAGW bletheren as global temperatures start to drop over the next few years.
We have already seen Marcott’s little piece of statistical chicanery, there will be more to come as they get more and more desperate not to be shown up as total fools.
I have come to the conclusion that we all have a little blame global warming and its consequences and guilt even more politicians who do not slow down.
http://www.globalwarmingweb.com/