Image Credit: WoodForTrees.org
Guest Post By Werner Brozek, Edited By Just The Facts
I will attempt to answer the question in the title from two different perspectives. First of all, can a super El Niño cause the present 1998 record in RSS to be broken in 2014? The next question is whether or not the slope of 0 will go under Santer’s 17 years. To answer the first part, we need to note that the average anomaly in 1998 was 0.550. The average anomaly for the first three months this year so far is 0.213. So a simple equation can be set up as follows to see what average would be required for the remaining 9 months to set a record. 12(0.550) = 3(0.213) + 9x. Solving for x gives 0.66. Naturally this is above 0.55, but more importantly is how this compares to the highest 9 month average during the 1998 super El Niño. According to the above plot of RSS with a mean of 9 months, that number is 0.63.
Since 0.66 is required, it may initially appear as if we need an El Niño that is stronger than the one in 1998. However the 9 month average before the 1998 El Niño started was around 0, whereas it is around 0.2 now. So the climb to potentially set a record is not as high. So it is possible for an El Niño that is almost as strong as the 1998 El Niño to set a record, however things have to move fast. The April anomaly for RSS does not necessarily have to be 0.66, but as a guess, I would say it should jump to at least 0.4 from the 0.214 March value and then it must make good jumps in the next months. According to the graph above, when the December number for RSS is in, the new 9 month height must be just above the 1998 nine month height in order for a new record to be set.
I would be very surprised if 2014 broke the 1998 record. In 1997, the El Niño started in May 1997 and the peak did not come until about March 1998. Right now, we are not above 0.5, so in my opinion, there is just not enough time to break the 1998 mark this year. As well, quoting Bob Tisdale:
“[T]he time lag between the major changes in the sea surface temperatures of the equatorial Pacific (NINO3.4 region) and the response in global surface temperatures is a few (3 to 4) months. For lower troposphere temperature anomalies, it’s about 5 to 6 months.”
Moving on to Santer’s 17 years, if we assume it takes a while for an El Niño to form and for it to affect RSS temperatures, I predict that at least to the end of 2014, RSS will still have over 17 years of pause. To verify this for yourself, note the area BELOW the green line in the top graph of this post between August 1996 and December 1997. If temperatures do spike, the August 1996 date has a bit of room to be moved forward until December 1997 is hit. Then, the new area ABOVE the green line at the far right needs to be more or less equal to the present area below and to the left of the 1997 spike. In light of what was just said in terms of how long it takes for temperatures to change, there just does not seem to be enough time for much to happen. I will concede that November and December could have very high anomalies, however it would not be for a long enough period to cause a huge area above the green line. Keep in mind that I am just talking about the case to the end of 2014. Anything can happen in 2015.
In the parts below, as in the 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 several data sets.
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 2014 to date compares with 2013 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.
(P.S. As of May 1, the Hadcrut3 data was not out. Since the March anomaly for Hadcrut4 was 0.034 above the January anomaly, I made the assumption that the March anomaly for Hadcrut3 would also be 0.034 above its January anomaly. Since March showed a huge spike from February in Hadcrut4, I thought it would be better to estimate the March value in Hadcrut3 rather than just leaving things as they were at the end of February.)
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 9 years and 7 months to 17 years and 8 months.
1. For GISS, the slope is flat since September 2001 or 12 years, 7 months. (goes to March)
2. For Hadcrut3, the slope is flat since June 1997 or 16 years, 10 months. (goes to March)
(This was estimated.)
3. For a combination of GISS, Hadcrut3, UAH and RSS, the slope is flat since December 2000 or 13 years, 4 months. (goes to March)
(This was estimated.)
4. For Hadcrut4, the slope is flat since December 2000 or 13 years, 4 months. (goes to March)
5. For Hadsst3, the slope is flat since November 2000 or 13 years, 5 months. (goes to March)
6. For UAH, the slope is flat since September 2004 or 9 years, 7 months. (goes to March using version 5.5)
7. For RSS, the slope is flat since August 1996 or 17 years, 8 months (goes to March).
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 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 all slopes are essentially zero. As well, I have offset them so they are evenly spaced. 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 17 years, the temperatures have been flat for varying periods on various data sets.
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 Nick Stokes’ Trendviewer. 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 16 and 21 years.
The details for several sets are below.
For UAH: Since February 1996: CI from -0.044 to 2.366
For RSS: Since November 1992: CI from -0.023 to 1.882
For Hadcrut4: Since August 1996: CI from -0.005 to 1.308
For Hadsst3: Since January 1993: CI from -0.016 to 1.812
For GISS: Since July 1997: CI from -0.004 to 1.246
Section 3
This section shows data about 2014 and other information in the form of a table. The table shows the six data sources along the top and other places so they should be visible at all times. The sources are UAH, RSS, Hadcrut4, Hadcrut3, Hadsst3 and GISS.
Down the column, are the following:
1. 13ra: This is the final ranking for 2013 on each data set.
2. 13a: Here I give the average anomaly for 2013.
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 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.
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. Jan: This is the January 2014 anomaly for that particular data set.
10.Feb: This is the February 2014 anomaly for that particular data set, etc.
12.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 may use their number. Sometimes the number in the third decimal place differs slightly, presumably due to all months not having the same number of days.
13.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. It will not, but think of it as an update 15 minutes into a game. Due to different base periods, the rank is more meaningful than the average anomaly.
| Source | UAH | RSS | Had4 | Had3 | Sst3 | GISS |
|---|---|---|---|---|---|---|
| 1. 13ra | 7th | 10th | 8th | 6th | 6th | 6th |
| 2. 13a | 0.197 | 0.218 | 0.486 | 0.459 | 0.376 | 0.60 |
| 3. year | 1998 | 1998 | 2010 | 1998 | 1998 | 2010 |
| 4. ano | 0.419 | 0.55 | 0.547 | 0.548 | 0.416 | 0.66 |
| 5.mon | Apr98 | Apr98 | Jan07 | Feb98 | Jul98 | Jan07 |
| 6. ano | 0.662 | 0.857 | 0.829 | 0.756 | 0.526 | 0.93 |
| 7. y/m | 9/7 | 17/8 | 13/4 | 16/10 | 13/5 | 12/7 |
| 8. sig | Feb96 | Nov92 | Aug96 | Jan93 | Jul97 | |
| Source | UAH | RSS | Had4 | Had3 | Sst3 | GISS |
| 9.Jan | 0.236 | 0.262 | 0.507 | 0.472 | 0.342 | 0.69 |
| 10.Feb | 0.127 | 0.162 | 0.304 | 0.263 | 0.314 | 0.45 |
| 11.Mar | 0.139 | 0.214 | 0.541 | 0.506 | 0.343 | 0.70 |
| Source | UAH | RSS | Had4 | Had3 | Sst3 | GISS |
| 12.ave | 0.167 | 0.213 | 0.450 | 0.414 | 0.333 | 0.613 |
| 13.rnk | 10th | 11th | 10th | 10th | 11th | 6th |
If you wish to verify all of the latest anomalies, go to the following:
For UAH, version 5.5 was used since that is what WFT used, see: http://vortex.nsstc.uah.edu/public/msu/t2lt/tltglhmam_5.5.txt
For RSS, see: http://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.4.2.0.0.monthly_ns_avg.txt
For Hadcrut3, see: http://www.cru.uea.ac.uk/cru/data/temperature/HadCRUT3-gl.dat
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 2013 in the form of a graph, see the WFT graph below:
As you can see, all lines have been offset so they all start at the same place in January 2013. This makes it easy to compare January 2013 with the latest anomaly.
Appendix
In this part, we are summarizing data for each set separately.
RSS
The slope is flat since August 1996 or 17 years, 8 months. (goes to March)
For RSS: There is no statistically significant warming since November 1992: CI from -0.023 to 1.882.
The RSS average anomaly so far for 2014 is 0.213. This would rank it as 11th place 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 2013 was 0.218 and it is ranked 10th.
UAH
The slope is flat since September 2004 or 9 years, 7 months. (goes to March using version 5.5)
For UAH: There is no statistically significant warming since February 1996: CI from -0.044 to 2.366.
The UAH average anomaly so far for 2014 is 0.167. This would rank it as 10th place 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 0.662. The anomaly in 2013 was 0.197 and it is ranked 7th.
Hadcrut4
The slope is flat since December 2000 or 13 years, 4 months. (goes to March)
For Hadcrut4: There is no statistically significant warming since August 1996: CI from -0.005 to 1.308.
The Hadcrut4 average anomaly so far for 2014 is 0.450. This would rank it as 10th place 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 2013 was 0.486 and it is ranked 8th.
Hadcrut3
(Since March was not out as of May 1, the numbers below assume Hadcrut3 made the same jump in March from January as Hadcrut4 did.)
The slope is flat since June 1997 or 16 years, 10 months. (goes to March)
The Hadcrut3 average anomaly so far for 2014 is 0.414. This would rank it as 10th place 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 2013 was 0.459 and it is ranked 6th.
Hadsst3
For Hadsst3, the slope is flat since November 2000 or 13 years and 5 months. (goes to March).
For Hadsst3: There is no statistically significant warming since January 1993: CI from -0.016 to 1.812.
The Hadsst3 average anomaly so far for 2014 is 0.333. This would rank it as 11th place if it stayed this way. 1998 was the warmest at 0.416. The highest ever monthly anomaly was in July of 1998 when it reached 0.526. The anomaly in 2013 was 0.376 and it is ranked 6th.
GISS
The slope is flat since September 2001 or 12 years, 7 months. (goes to March)
For GISS: There is no statistically significant warming since July 1997: CI from -0.004 to 1.246.
The GISS average anomaly so far for 2014 is 0.613. This would rank it as 6th place 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 2013 was 0.60 and it is ranked 6th.
Conclusion
We do not know if an El Niño will form in 2014, nor do we know how strong it will be if it does form. However, RSS is unlikely to set a new record or fall below Santer’s 17 years in 2014. As for other data sets, it is hard to say what will happen. However GISS has the unique distinction of having its January (0.69) and March (0.70) anomaly above its average record of 2010 (0.66). It could even set a record without an El Niño. Would that be what the doctor ordered? WUWT? ☺
Just The Facts says:
May 4, 2014 at 6:30 pm
Soon Phil Jones could be crowing that the statistically significant pause has ended and CAGW has returned.
If he’s lucky…
With the spike in March now on Nick’s site, the period of no statistically significant warming for Hadcrut4 jumps to October 1996 from August 1996. See the graph below and note the difference in slope from October 1996 and from July 1997.
http://www.woodfortrees.org/plot/hadcrut4gl/from:1996.75/plot/hadcrut4gl/from:1996.75/trend/plot/hadcrut4gl/from:1997.5/trend
Note how low the anomalies were in the 9 months from October 1996 to July 1997. This gives some idea how high the anomalies have to be over the next 9 months to merely maintain the period of no statistically significant warming for 17.5 years. Also, keep in mind that NOAA regards 15 years as significant, so I see no way that Phil Jones will be able to claim statistically significant warming for Hadcrut4 for 15 years any time soon.
Just the Facts asked: What basis do you have for calling the 1978-1998 warming “rapid”?
Good question. If warming in the 21st century continued at the 1978-1998 rate, total warming would be 2.5 degC. I would call that “rapid warming”. Both 1978-1998 and 1920-1940 were periods of rapid warming, but 1978-1998 change was somewhat larger (0.5-0.6 degC vs 0.3-0.4 degC). The early warming makes it unreasonable to say the later warming was unprecedented, but that doesn’t mean it shouldn’t be termed “rapid”.
The NASA Earth Observatory’s definition of global warming is inappropriate. Anthropogenic global warming is caused by burning of fossil fuels and other human activities. One can’t look at any period of rapid global warming and conclude that it was caused by human activity without some way of ruling out the possibility that some (or all) of it represents unforced natural variability.
Just the Facts says: “we can attribute the warming between 1978-1998 to the “chaotic nature of climate” and call off the CAGW alarm.”
Wrong. You can’t ARBITRARILY attribute anything – including the pause – to chaotic behavior or “unforced variability” (a clearer term). Unforced variability is what one observes when no external factors are perturbing the system. When one is observing a forced chaotic system, one must subtract the forced changes from the observed changes before attributing anything unforced variability. We know that natural variability (solar and volcanic forcing) and human forcing (mostly GHGs and aerosols) alter the radiative balance of our planet and therefore its temperature. However, we can’t convert these forcings (usually expressed in terms of W/m2) to temperature changes without knowing climate sensitivity. This problem dramatically limits our ability to attribute any fraction of any period of rapid OR paused warming to unforced variability. Lorenz wrote a very prophetic short paper on attribution in 1991 (before most of the hysteria) called “Chaos, Spontaneous Climatic Variations and Detection of the Greenhouse Effect”. He makes it clear that 20th-century warming can’t be attributed to GHGs by purely statistical methods. He believed that climate models can be used for attribution (of forced change), but only if they haven’t been tuned to fit the historical record. http://eaps4.mit.edu/research/Lorenz/Chaos_spontaneous_greenhouse_1991.pdf
Just the Facts said: [Phil Jones will be crowing about the end of the pause only] “If he is lucky”.
Before you bet on the pause continuing indefinitely, examine the odds of it continuing. Can it be ended by a strong El Nino? How about four years of 1980’s warming (+0.1 degC)? If you don’t like those odds, don’t give Phil Jones a chance to get lucky by focusing all of the attention on 15+ years of pause.
Splice says:
May 4, 2014 at 9:21 am
@Alan Robertson
Are you mentally challanged? RSS (and UAH) are lower troposphere’s temperatures, sea surface temperaturs are present in GISS and HadCRU but not in RSS and UAH.
________________________
How funny. It’s a pity that you don’t realize to what extent you betray yourself in public. You launch an ad hominem attack by insulting my intelligence, all while misspelling “challanged” (sic) and “temeraturs” (sic) and totally fumble HadCRUT. Oh yes, about those grammatical errors… Nice.
Your laughable talking point is that the oceans just haven’t had enough decades to manifest all the warming. Just think how many more decades they will need to indicate warming if the current positive global sea ice anomaly of >900,000 KM2 starts to melt.
By all means, continue, you anonymous troll. Dazzle us with your brilliance.
You certainly aren’t baffling us with your BS.
Ps to Splice
About your claim of 3C degrees increase per doubling of CO2… not even NASA claims more than 1.6C. There have been any number of papers which show that the increase can’t be shown to be greater than 1.4- 1.6C. The truth is out there, if you look for it.
@Alan Robertson
I assumed you are mentally challanged, as you entered the discussion about surface temperatures and presented something, that have nothing to do with surface temperatures.
And I see I was right, as you just did it again – we discussed about response to CO2 doubling and time of response (that is > 50 years on see surface) and you’ve entered the discussion and presented some claims about historical temperatures, which is again not related to the discussed topic.
Frank says:
May 4, 2014 at 10:07 pm
Both 1978-1998 and 1920-1940 were periods of rapid warming, but 1978-1998 change was somewhat larger (0.5-0.6 degC vs 0.3-0.4 degC).
Before you bet on the pause continuing indefinitely, examine the odds of it continuing.
When Phil Jones made those statements here:
http://news.bbc.co.uk/2/hi/science/nature/8511670.stm
the changes were based on Hadcrut3 and were virtually identical. It appears as if Hadcrut3 has now been discontinued since March is still not out. And Hadcrut4 does have a slightly larger slope for the later period.
As for the pause, that can be wiped out totally with a strong El Nino, but the period of time for statistically significant warming will take a long time before that reaches 15 years.
Splice says:
May 5, 2014 at 1:56 am
_________________________
You make my points so eloquently. You’ve also just demonstrated your lack of reading comprehension, or veracity (or both.)
Please, continue.
We’re all wondering when Trenberth’s missing heat will appear.
@Alan Robertson
What you’ve just did what is called “projection” http://en.wikipedia.org/wiki/Projection_%28psychology%29
You see your own lack of reading comprehension in other persons.
Let me remind you:
We were talking about surface temperatures – but you were unable to understand that we are talking about surface temeratures, so you entered our disussion and started talking about lower troposphere temperatures
Then were talking about response to CO2 doubling and time of this response, and again you were unable to understand what we are talking about, so you entered our discussion and started talking about historical temperatures.
@ur momisugly Splice
Do go on.
Frank says: May 4, 2014 at 10:07 pm
Good question. If warming in the 21st century continued at the 1978-1998 rate, total warming would be 2.5 degC. I would call that “rapid warming”.
So what you are saying is that the term “rapid” is arbitrary and you have no comparative basis to support its use?
Both 1978-1998 and 1920-1940 were periods of rapid warming, but 1978-1998 change was somewhat larger (0.5-0.6 degC vs 0.3-0.4 degC). The early warming makes it unreasonable to say the later warming was unprecedented, but that doesn’t mean it shouldn’t be termed “rapid”.
If it wasn’t for the bucket model adjustments;
http://wattsupwiththat.com/tag/the-bucket-model/
then the warming in the first half of the century would exceed the warming in the second half of the century. Can you identify a period of warming that wasn’t “rapid”?
The NASA Earth Observatory’s definition of global warming is inappropriate. Anthropogenic global warming is caused by burning of fossil fuels and other human activities. One can’t look at any period of rapid global warming and conclude that it was caused by human activity without some way of ruling out the possibility that some (or all) of it represents unforced natural variability.
Aside from the “rapid” part, I completely agree.
Wrong. You can’t ARBITRARILY attribute anything – including the pause – to chaotic behavior or “unforced variability” (a clearer term).
If the variation is less than the natural noise within the system, then the variation could be attributable to a multitude of variables. The point is that such variation cannot form a rational basis for alarm.
When one is observing a forced chaotic system, one must subtract the forced changes from the observed changes before attributing anything unforced variability.
But we aren’t even sure what all of the forcings are, our measurements of the known ones is poor and our historical record is laughably brief. We should be spending our resources measuring and studying the climate system, not on misguided efforts to “prevent climate change”:
http://en.cihan.com.tr/news/Concrete-action-should-be-taken-to-prevent-climate-change-UN-urges_3311-CHMTQxMzMxMS80
Before you bet on the pause continuing indefinitely, examine the odds of it continuing.
I am not betting on anything, again, I have no horse in this race. Earth’s temperature may go up, it my go down or it may stay the same. Regardless, I don’t see any evidence of Catastrophic Anthropogenic Global Warming. Do you?
Can it be ended by a strong El Nino? How about four years of 1980′s warming (+0.1 degC)? If you don’t like those odds, don’t give Phil Jones a chance to get lucky by focusing all of the attention on 15+ years of pause.
Earth’s climate will do what it will do and we will report on it. If Earth enters another period of warming, then we will try to understand the reasons for this warming. But for now, we are in an extended period of flat temperatures, while CO2 emissions are growing rapidly, thus the CAGW narrative is close to being falsified.
Just The Fact: Most of your answers seem quite reasonable.
It seems to me that others at WUWT (Lord Monckton, for example), but not you, may be over-invested in the length of the pause (a temporary phenomena). My original comment was meant as a “wake-up call”.
You may be overestimating the uncertainty in forcing for the satellite era or since 1950. Otto, Lewis and others gotten fairly tight estimates of TCR by dividing (warming +/- warming uncertainty) by (forcing +/- forcing uncertainty). Perhaps you are referring to carbon black of the indirect aerosol effect. (I don’t know much about them.)
I certainty don’t see CAGW now or for the next half century. In the center of the US, the mean annual temperature rises about 1 degC for every 100 miles you move south, so I like to convert warming to miles moved south. It’s hard to get too excited about climate change gradually moving me a few hundred miles south. I get a little more worried when I look at a polar projection showing Greenland. Why is the GIS still hanging around when everything else at a similar latitude melted long ago? The GIS survived the Holocene Climate Optimum, which was warmer than today. How much more warming can it take and how long will it take to go away? A good chunk of the GIS melted in the Eemian. If I lived in the Western US where most of the rainfall is already being used and a winter snowpack is helpful, I would be more worried. Hopefully some of the overall increased rainfall will fall there.
http://en.wikipedia.org/wiki/File:Iceage_north-intergl_glac_hg.png
Frank says:
May 5, 2014 at 8:59 pm
It seems to me that others at WUWT (Lord Monckton, for example), but not you, may be over-invested in the length of the pause (a temporary phenomena).
I would not say it that way regarding Lord Monckton. Going by my memory now, a few months ago, he said something to the effect that a strong El Nino could wipe out the pause but at the same time, this would not mean the warming became catastrophic.
I could say, for example that Hadcrut4 shows no warming at all for 13 years and 4 months. Or I could say the warming is not significant at the 95% level for 17 years and 6 months. Both are true and both show warming is not catastrophic.
However if we have a strong El Nino, it could be the case in a year from now that the pause will have a length of zero, however the lack of warming at the 95% level could still be for a period of 17 years and 6 months.
Both Lord Monckton and I are aware of this possibility, but we talk about the period of the pause with 0 slope because it is an easy concept to understand so why not use this particular argument as long as it applies?
I also know about others who will proclaim “no warming for 16 years” even if the warming is still slightly positive at 0.004/year, but that is another matter.
Werner: Thanks. Some people understand my point.
Personally I prefer to say there has been no statistically significant warming if a warming rate of 0 degC/decade is within the 95% confidence interval for the warming rate (slope of the least squares fit). (If you work with annual mean temperature anomalies, autocorrelation isn’t a big problem.) If the central estimate for warming is +0.05 degC/decade, you need a long interval for the 95% ci to not include zero. However, a long-term warming rate of 0.05 degC/decade isn’t going to cause much climate change. When expressed in these terms, lack of statistically significant warming is equivalent lack of meaningful warming. Other approaches are simpler and perhaps easier to understand.
I would like to thank all for their contributions.
UAH just came in for April. It was version5.6 and it went up from 0.170 in March to 0.190 in April. If I assume version5.5 will also go up by 0.02, then the 4 month average becomes 0.165. If it were to stay at 0.165, 2014 would rank 10th. The time for a slope of 0 would be at least 9 years and 8 months, but it could go back further.
(Hadcrut3 for March is still not out!)
Frank says: May 5, 2014 at 8:59 pm
Bill Illis – S12.postimg.org – Click the pic to view at source[/caption]
You may be overestimating the uncertainty in forcing for the satellite era or since 1950. Otto, Lewis and others gotten fairly tight estimates of TCR by dividing (warming +/- warming uncertainty) by (forcing +/- forcing uncertainty). Perhaps you are referring to carbon black of the indirect aerosol effect. (I don’t know much about them.)
Or you may be overestimating the certainty. The potential forcings associated with volcanic eruptions, cosmic rays and anthropogenic aerosols are highly uncertain, and variables such as clouds, ENSO and polar vorticity are poorly understood. Climate models are currently awful and we shouldn’t put any confidence in their predictions/guesses, e.g.:
“Many atmospheric general circulation models (GCMs) and chemistry–climate models (CCMs) are not able to reproduce the observed polar stratospheric winds in simulations of the late 20th century. Specifically, the polar vortices break down too late and peak wind speeds are higher than in the ERA-40 reanalysis. Insufficient planetary wave driving during the October–November period delays the breakup of the southern hemisphere (SH) polar vortex in versions 1 (V1) and 2 (V2) of the Goddard Earth Observing System (GEOS) chemistry–climate model, and is likely the cause of the delayed breakup in other CCMs with similarly weak October-November wave driving.”
“In the V1 model, the delayed breakup of the Antarctic vortex biases temperature, circulation and trace gas concentrations in the polar stratosphere in spring. The V2 model behaves similarly (despite major model upgrades from V1), though the magnitudes of the anomalous effects on springtime dynamics are smaller.”
“Clearly, if CCMs cannot duplicate the observed response of the polar stratosphere to late 20th century climate forcings, their ability to simulate the polar vortices in future may be poor.”
http://meetingorganizer.copernicus.org/EGU2009/EGU2009-651.pdf
http://adsabs.harvard.edu/abs/2010JGRD..11507105H
“It is unclear how much confidence can be put into the model projections of the vortices given that the models typically only have moderate resolution and that the climatological structure of the vortices in the models depends on the tuning of gravity wave parameterizations.
Given the above outstanding issues, there is need for continued research in the dynamics of the vortices and their representation in global models.”
http://www.columbia.edu/~lmp/paps/waugh+polvani-PlumbFestVolume-2010.pdf
I certainty don’t see CAGW now or for the next half century. In the center of the US, the mean annual temperature rises about 1 degC for every 100 miles you move south, so I like to convert warming to miles moved south. It’s hard to get too excited about climate change gradually moving me a few hundred miles south. I get a little more worried when I look at a polar projection showing Greenland. Why is the GIS still hanging around when everything else at a similar latitude melted long ago? The GIS survived the Holocene Climate Optimum, which was warmer than today. How much more warming can it take and how long will it take to go away?
I think the simple answer is a lot warmer than today and a lot longer than you think, i.e. it was much warmer during the prior interglacial;
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and recently “scientists were greatly surprised to discover an ancient tundra landscape preserved under the Greenland Ice Sheet, below two miles of ice.
“We found organic soil that has been frozen to the bottom of the ice sheet for 2.7 million years,” said University of Vermont geologist Paul Bierman — providing strong evidence that the Greenland Ice Sheet has persisted much longer than previously known, enduring through many past periods of global warming.
He led an international team of scientists that reported their discovery on April 17 in the journal Science.”
http://www.reportingclimatescience.com/news-stories/article/study-greenland-ice-sheet-much-older-than-thought.html