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?
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As an antidote to the ‘warming stalled’ euphoria, I would opine that the only sensible way to look at a supposed rising temperature with cyclical variability is peak-to-peak or trough-to-trough. That means 0.404 degrees (HADCRUT3) in 52.5 years from 1945 to 1998. The recent hiatus makes no difference to this. Still, I can look at a rate of rise of less than 0.8 degrees C per century and go back to sleep: it really doesn’t matter, provided those nuclear fusion bunnies eventually get their act together…
wbrozek says:
March 5, 2013 at 1:48 pm
=======
Werner, the first line is a typo for JTF……..it needs a “go” in there..
Here’s the whole line makes it easier for JTF to find it….
“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………………………. back to the 1940s to find the previous time that a Hadcrut3 record was not beaten in 10 years or less.”
Philip Bradley says:
March 5, 2013 at 2:28 pm
What’s disturbing is that agencies and many climate scientists seem to think the statement above has scientific validity, when it has no scientific validity at all.
Does catastrophic anthropogenic global warming have any scientific validity at all?
I just saw this new documentary called CHASING ICE which shows the physical evidence of melting glaciers. Opinions and facts can be disputed but visual evidence cannot. See it to believe it. The film was so beautiful yet terrifying at the same time. A must see.
Of course, more corrections and adjustments will be done to make this data fall in line. I’ve watched many-a-datasets buck the expected trend, then be later corrected. Certain years in my home town, in the 1800s, are 2 degrees cooler than those same years were before new corrections were applied. The Argo floats data showed cooling, until corrected. Etc.
Philip Shehan says:
March 5, 2013 at 2:39 pm
People here declare that there has been no warming for the last 17 years of Hadcrut4 data
With respect to Hadcrut4, there has been no warming since November 2000 or 12 years and 3 months. There has been no statistically significant warming since July 1994 or 18 years and 7 months. So the “17 years” is somewhere in the middle. It should be noted that if warming is occurring at a half decent pace, then 16 years is enough to achieve statistical significance as shown below for 1995 to 2010:
Start of 1995 to end 2009: 0.133 +/- 0.144. Warming for 15 years is not significant.
Start of 1995 to end 2010: 0.137 +/- 0.129. Warming for 16 years is significant.
Start of 1995 to end 2011: 0.109 +/- 0.119. Warming for 17 years is not significant.
Start of 1995 to end 2012: 0.095 +/- 0.110. Warming for 18 years is not significant.
Yet all consideration of statistical significance is ignored when declaring that UAH data fro the last 4 years and 7 months shows a pause.
Trend: -0.006 ±1.441 °C/decade
Yes, that is short. My effort has been to show all the facts, even if they do not agree with the main thrust of my article. However I would also like to point out that UAH shows no significant warming for longer than GISS. For UAH, the period of no significant warming is from June 1993, but for GISS, it is from August 1995. Two cold months is all it would take for UAH to have no slope for 12 years.
Werner Brozek says: March 5, 2013 at 9:16 am
JTF, I just have a concern about the size of the graphs. When you click on them, they are good, but when viewed as they are, they are twice as big as they should be and just the left half appears. This applies to 4 out of the 5. Can this be fixed? Thanks!
Mike McMillan says: March 5, 2013 at 1:41 pm
This is a problem with WordPress.
PNG images sometimes get stretched this way, other times they present normally. The only way to prevent this is to use GIF or JPG images. GIF’s are best because JPG introduces artifacts in graphs and diagrams.
I’ve had this problem with my WP site, and one of these days I’ll get around to fixing it.
Mike, thanks for the input, I’ve been struggling with this, as it only seemed to impact WFT and was intermittent, hopefully the conversion to GIFs solves the problem.
Werner, apologies for the delay in addressing this, hopefully everything looks good now.
Latitude says: March 5, 2013 at 3:22 pm
Werner, the first line is a typo for JTF……..it needs a “go” in there..
Here’s the whole line makes it easier for JTF to find it….
“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………………………. back to the 1940s to find the previous time that a Hadcrut3 record was not beaten in 10 years or less.”
Corrected, thanks. JTF
This chart shows clearly why HadCRUT4 replaced HadCRUT3: HadCRUT4 shows more global warming.
Paloma says:
March 5, 2013 at 3:41 pm
I just saw this new documentary called CHASING ICE which shows the physical evidence of melting glaciers.
It is my understanding that many glaciers have been melting since 1880. However CO2 did not really increase since about 1945. Just because glaciers are melting does not necessarily mean that man has anything to do with it. For example, the ice page today shows the southern sea ice area is 0.614 million square km above normal, but the northern sea ice area is 0.422 million square km below normal, for a net positive amount of 0.192 million square km above normal.
@Werner Brozek
Speaking of glaciers, has anyone been able to access the Hubbard Glacier monitoring site?:
http://glacierresearch.com/ … I haven’t been able to for over a year.
This is the largest tidewater glacier in North America. It has been advancing and increasing in mass since the 1880s. Maybe cherry picking, but it IS the largest tidewater glacier.
Also the Taku Glacier recognized as the deepest and thickest glacier known in the world, the Taku Glacier is measured at 4,845 feet (1,477 m) thick. It is the largest glacier from the Juneau Icefield. in AK.and it too is advancing. Is that cherry picking, too?
Haven’t seen any info on Hubbard Glacier since 2007 or maybe a report from 2009..
@J. Philip Peterson
I was able to visit http://glacierresearch.com/ but only if I added security exceptions in browser. Seems it is hosted on a military server and the browser expects a security certificate. Couldn’t get past the issue in Firefox, but was able to in IE8 and in Chrome.
Do a “proceed anyway” in Chrome from this URL: http://rsgisias.crrel.usace.army.mil/hubbard/glaciers.html
here is Hubbard: http://rsgisias.crrel.usace.army.mil/hubbard/glaciers.html
The NOAA State of the Climate report you link to is discussing ENSO-adjusted data, both for observed and modeled temperatures. You, in this post, are _not_ – apples and oranges, an invalid comparison.
If you consider the observed temperature swings with ENSO (http://blog.chron.com/climateabyss/2013/01/global-temperature-anomaly-forecasts-january-2013/), we are right on track with the models.
Thanks Anthony!
Werner,
Certainly by luck of the draw, short term periods of 15 to 20 years will produce a “statistically significant” results on occasion. But no one should be the least surprised when they regularly fail to produce a statistically significant result.
The examples you show of significant/not significant warming are declared so by very slim margins. They are right on the cusp of significant/not significant. (In another comment I pointed out that this is a problem many scientists have with Fisherian measure of statistical significance, a result that can be declared with 95.1% confidence is declared “significant” while a result with 94.9% confidence is not.)
It is because for short term periods, the signal to noise ratio becomes small so that the noise, which is random dominates the signal.
In the example I gave of the Hadcrut4 data, the trends for 17 years and 68 years are the same. The peak to peak noise (the distance maximum distance vertical distance of the red temperature data from the trend line) varies from the downward spike at 1977 to the el nino peak of 1998. This covers a larger range than the peak to peak noise for the last 17 years, but the signal in the former case (the vertical temperature range covered by the trend line) is large enough so that the overall signal to noise ratio gives a statistically significant result. For the shorter term, it does not.
http://tinyurl.com/d4jxlth
The longer you go back the stronger the signal to noise and the more reliable the result.
1996 0.091 ± 0.120 °C/decade (blue line on plot)
1995: 0.098 ± 0.111
1994: 0.116 ± 0.102 point at which 2σ significance achieved
1990: 0.144 ± 0.080
1980: 0.158 ± 0.045
1970: 0.164 ± 0.031
1960: 0.132 ± 0.025
1945: 0.094 ± 0.019 (green line on plot)
I take your point that you only included the UAH data for 4 years and 7 months for completeness, but it nevertheless emphasises my point here.
That short term trends are too dependent on the noise level to tell you anything meaningful about the signal, and the shorter the period, the more likely the noise is to take over.
Trend: -0.006 ±1.441 °C/decade (2σ)
Trend: -0.156 ±0.682 °C/decade (2σ) Hadcrut4
RSS Update
RSS has just come out for February. The anomaly dropped from 0.442 to 0.194. As I said in the report, the 0.442 value ranked 3rd. The 0.194 value ranks 11th to put it into perspective. The average between these two is 0.318 and would rank 5th if it stayed this way.
As well, the longest time for a slope that is not positive goes up from 16 years and 1 month to 16 years and 2 months, going from January 1997 to February 2013. This is 194/204 = 95% of the way to Santer’s 17 years.
“This indicates that there is a slight chance that cooling has occurred since 1990 according to RSS per graph 1 and graph 2.”
No. The RSS trend since 1990 is 0.127 ±0.134 °C/decade.
That is there is a 95% chance that the true trend is between 0.261 and -0.007 °C/decade.
The probability of the true trend being in the negative (cooling) part of this range is very small.
Shehan still doesn’t get it. global warming has stalled, and all his wishful thinking won’t change that fact.
Philip Shehan says:
March 5, 2013 at 6:52 pm
I agree with everything you said. Personally, I think the period where the slope is 0 is more meaningful. However it appears that climate science has a certain set of rules as the following question and answer with Phil Jones shows:
“B – Do you agree that from 1995 to the present there has been no statistically-significant global warming
Yes, but only just. I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level.”
In that section, I merely reported what SkS showed. Can you confirm if Phil Jones uses the same sort of program that SkS uses to determine significance?
You like long term trends and point out that “1945: 0.094 ± 0.019 (green line on plot)” At this rate of 0.094/decade, it would take 128 years to increase the global temperature to 2 C from the present 0.8 C. It looks like we have nothing to worry about! Is that not good news?
Philip Shehan says:
March 5, 2013 at 7:43 pm
“This indicates that there is a slight chance that cooling has occurred since 1990 according to RSS per graph 1 and graph 2.”
No. The RSS trend since 1990 is 0.127 ±0.134 °C/decade.
That is there is a 95% chance that the true trend is between 0.261 and -0.007 °C/decade.
The probability of the true trend being in the negative (cooling) part of this range is very small.
It seems as if you are splitting hairs over my wording over what “a slight chance” means? Correct me if I am wrong here. 0.007 is 0.007/0.268 is 2.6% of the total in the 95% range, right? And there is a 2.5% chance the slope is less than -0.007, right? So if that is the case, then there is a 2.5 + 2.6 = 5.1% chance the slope is negative, correct? Is that not a “slight chance” that cooling has occurred?
Werner Brozek says:
March 5, 2013 at 3:33 pm
Philip Bradley says:
March 5, 2013 at 2:28 pm
Does catastrophic anthropogenic global warming have any scientific validity at all?
It does, to the extent it derives from a scientific theory with empirical support.
You may think it is alarmist hogwash, as I do. But from a scientific perspective, the main problem is lack of empirical support. The theory itself (which I have other issues with) does indeed predict warming that could be described as catastrophic.
Philip Bradley says:
“It does, to the extent it derives from a scientific theory with empirical support.”
I’m sorry, Philip, but that is not a scientific “theory”. It is not even a “hypothesis”, because it is not falsifiable or testable.
AGW [and the even more preposterous “catastrophic AGW”] is merely a “conjecture”. It is an opinion; an evidence-free assertion. Without verifiable, testable measurements, AGW [or CAGW] is simply speculation.
Wake me when the alarmist crowd comes up with verifiable measurements of “AGW”. Until then, AGW [and CAGW] just feeds their fevered imaginations.
Philip Bradley says:
March 5, 2013 at 8:24 pm
The theory itself (which I have other issues with) does indeed predict warming that could be described as catastrophic.
My understanding is that the theory says that a doubling of CO2 without any feedbacks increases warming by 1 C. It is only the presumed positive feedbacks due to extra water vapour that make warming catastrophic. In my opinion, both Dr. Spencer and planet Earth have proven that the feedbacks are negative and not positive so we will never have catastrophic global warming. Think of it like applying Le Chatelier’s Principle to planet earth. For more on this, see:
http://motls.blogspot.ca/2007/11/le-chateliers-principle-and-natures.html#more
KR says:
March 5, 2013 at 5:40 pm
If you consider the observed temperature swings with ENSO (http://blog.chron.com/climateabyss/2013/01/global-temperature-anomaly-forecasts-january-2013/), we are right on track with the models.
Here is what was said for Hadcrut4:
“My HadCRUTv4 forecast for 2013 is +0.59 +/- .08 C. This too would be the warmest global anomaly in this data set, breaking the record set in 2010 by +0.05 C. Again, the odds of setting a new record are about 2 in 3. My forecast for 2013 is 0.15 C warmer than the observed value for 2012.”
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 January anomaly was 0.433 which would rank it in 10th place. Granted, it is only 1 month, but you are not going to set any records starting the race in 10th place. 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 are more like 1 in a 1000.
Werner, Pardon me. I took your meaning to be that there was a slight chance that it was more likely that the trend would be for cooling rather than warming.
Werner. With regards to Phil Jones comments:
BBC: Do you agree that from 1995 to the present there has been no statistically-significant global warming
Phil Jones: Yes, but only just. I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods.
I assume he is using the same calculation for statistical significance as I am. It is after all a fairly standard formula.
http://www.skepticalscience.com/trend.php
I agree with Jones on that statement – that the period in question does not show warming to a 95% confidence level. But he appears to share my reservations on the limitations and usefuleness of Fisherian statistical significance for short term data sets.
With regard to the trend from 1945 showing a warming trend of “only” 0.094/decade, compared to say the statistically significant trend from 1960 of 0.132/decade, the assumption that you can extrapolate a linear trend to the end of the century is not supported by the IPCC (sorry can’t find a reference for that at the moment). 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.
http://www.skepticalscience.com/trend.php
http://www.woodfortrees.org/plot/hadcrut3vgl/compress:12/plot/gistemp/compress:12/offset:-0.08/detrend:0.04/plot/hadcrut4gl/compress:12/offset:-0.03/detrend:0.02/plot/hadcrut3vgl/mean:732/plot/hadcrut3vgl/mean:252/plot/hadcrut3vgl/mean:252/offset:0.2/plot/hadcrut3vgl/mean:252/offset:-0.2/plot/hadcrut3vgl/scale:0.000001/offset:4/plot/esrl-co2/scale:0.003/offset:-1.03/detrend:-0.22/from:1982/plot/hadcrut3vgl/mean:252/offset:0.015/plot/hadcrut3vgl/mean:732/offset:0.015/plot/esrl-co2/scale:0.003/offset:-1.03/detrend:-0.22/from:1982
The GMST has a secular (long-term non-periodic variation) component represented by the monotonic curve obtained from the 61-years moving average GMST.
The GMST has a cyclic component of 60-years period represented by the 21-years moving average GMST.
The cyclic GMST was at its peaks in 1880’s, 1940’s & 2000’s and at its trough in 1910 and 1970.
The amplitude of the Cyclic GMST decreases with increase in the moving average period and is zero for moving average period of 61 years. This means that a moving average period of 61 years smoothes out all of the transient GMST and in this case the GMST Trend becomes equal to the Equilibrium GMST.
The decrease in the magnitude of the cyclic GMST with increase in the moving average period shown above suggests changing the averaging period in the definition of climate from 30-years to 61-years.
All the oscillations relative to the secular GMST are transient and should be excluded when analyzing the climate. As a result, the whole climate of the 20th century may be completely defined by the Secular GMST curve (Purple curve). Note that there was no change in shape of the Secular GMST before and after mid-20th century, which indicates a single climate pattern existed in the whole of the 20th century.