Thoughts on IPCC AR5 SPM – discussion thread

There’s so much to talk about in the IPCC AR5 report, and I have other obligations this weekend. So, it seems time for an open thread on the subject.

IPCC_AR5_OpenThread

A few starting thoughts:

1. It seems news coverage is rather muted. Google News says there are 1087 news media articles that use the phrase “IPCC AR5” as of this writing. That’s low. Typically a major story will get from 2000-4000 stories. Many of the 1087 are blog posts from new media outlets like Huffington Post. The typical outlets like NYT and the Guardian have their obligatory boilerplate coverage, but it doesn’t seem to have much trickle down. The phrase “It doesn’t play in Peoria” might be an apt description of the news coverage.

2. It seems the climate skeptics have landed and have obtained a beachhead. Many stories I’ve viewed contain skeptical opinions, far more so than in 2007 with AR4. Even the NYT in this story U.N. Climate Panel Endorses Ceiling on Global Emissions mentioned the Heartland Institute’s opinion about how many degrees of warming might be expected.

3. The science is apparently not settled at all. The failure of the IPCC to give a “best estimate” number for climate sensitivity, which breaks with tradition in the previous four reports, is remarkable. In a footnote at the bottom of page 11 of the SPM, it seems that there is dissension in the science, and in the ranks:

nobest-estimate-sensitivity[1]

So much for the much ballyhooed “consensus”.

Dr. Roy Spencer sums it up:

A best estimate for climate sensitivity — unarguably THE most important climate change variable — is no longer provided, due to mounting contradictory evidence on whether the climate system really cares very much about whether there are 2, or 3, or 4, parts of CO2 per 10,000 parts atmosphere.

YET…the IPCC claims their confidence has DOUBLED (uncertainty reduced from 10% that 5%) regarding their claim that humans are most of the cause behind the warming trend in the last 50 years or so:

“It is extremely likely that human influence on climate caused more than half of the observed increase in global average surface temperature from 1951-2010.”

4. The things that we saw with the leaked SPM draft that suggested a more moderate approach, seem to have been disappeared. For example, Bob Tisdale has done a before and after comparison here: Side-By-Side Comparison of Draft and Final IPCC AR5 SPM on Warming Plateau and Attribution and noted that “It appears the politicians agreed to delete the attribution discussion of the warming plateau.”

You can do your own comparisons with the two documents:

the final draft (7Jun2013) and the approved final version (27Sep2013)

5. Dr. Richard Lindzen has made a statement, via Climate Depot, that sums up what many of us think, and why AR5 SPM is a credibility train wreck:

I think that the latest IPCC report has truly sunk to level of hilarious incoherence.  They are proclaiming increased confidence in their models as the discrepancies between their models and observations increase.

Their excuse for the absence of warming over the past 17 years is that the heat is hiding in the deep ocean.  However, this is simply an admission that the models fail to simulate the exchanges of heat between the surface layers and the deeper oceans.  However, it is this heat transport that plays a major role in natural internal variability of climate, and the IPCC assertions that observed warming can be attributed to man depend crucially on their assertion that these models accurately simulate natural internal variability.  Thus, they now, somewhat obscurely, admit that their crucial assumption was totally unjustified.

Finally, in attributing warming to man, they fail to point out that the warming has been small, and totally consistent with there being nothing to be alarmed about.  It is quite amazing to see the contortions the IPCC has to go through in order to keep the international climate agenda going.

6. On the plus side, contrary to ongoing claims from that alarmist media mill side there are no mentions of tornadoes and hurricanes in the extreme weather events section. They give low confidence to tropical storm activity being connected to climate change, and don’t mention mesoscale events like tornadoes and thunderstorms at all. Similarly, they give low confidence to drought and flood attribution.

They’ve only talked about heat waves and precipitation events and being connected. From Page 4 of the SPM:

IPCC_AR5_SPM_Extreme

IPCC_AR5_SPM_Table1

This is consistent with what was reported last year in the IPCC SREX report ( IPCC Special Report on Extremes PDF)

From Chapter 4 of the SREX:

  • “There is medium evidence and high agreement that long-term trends in normalized losses have not been attributed to natural or anthropogenic climate change”
  • “The statement about the absence of trends in impacts attributable to natural or anthropogenic climate change holds for tropical and extratropical storms and tornados”
  • “The absence of an attributable climate change signal in losses also holds for flood losses”

Let’s hope this lack of attribution of severe storms to “man made climate change” in AR5 finally nails the lid shut on the claims of Hurricane Sandy, tornado outbreaks, and other favorite “lets not let a good crisis go to waste” media bleatings about climate change.

Now with two IPCC reports making no connection, and with Nature’s editorial last year dashing alarmist hopes of linking extreme weather events to global warming saying:

Better models are needed before exceptional events can be reliably linked to global warming.

…we can finally call it a dead issue.

There’s simply no connection between droughts, hurricanes, thunderstorms, flash floods, tornadoes and “climate change”. Note to Brad Johnson of “Forecast the Facts”, and Bill McKibben of 350.org, both of whom daily try to link weather events to climate change: IPCC says STFU.

There are many more things of interest to discuss, but this should provide a good primer. – Anthony

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Ian W


“There is medium evidence and high agreement that long-term trends in normalized losses have not been attributed to natural or anthropogenic climate change”
“The statement about the absence of trends in impacts attributable to natural or anthropogenic climate change holds for tropical and extratropical storms and tornados”
“The absence of an attributable climate change signal in losses also holds for flood losses”

Perhaps this should be drawn to the attention of the Executive Order issuing President and the EPA. It would seem that their actions are not supported by the science.

lucaturin

“Now this is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning.” Winston Churchill

RockyRoad

Is it “…blog posts from new media outlets like Huffington Post…” or should it be “…blog posts from news media outlets like Huffington Post…”?

gopal panicker

the whole ‘report’ is bullshit

Greg Goodman

One of the most notable statements is in the same paragraph says “most” is due to man , then the anthro contribution is the same as what has happened , which makes is “all due to man”.
A result of staying up all night before making key changes to wording I assume but makes a farce out of anything else they say.

Bill Illis

Hiding in the Oceans – Here is a chart showing the temperature changes in the Oceans (Surface, 0-700 metre and 0-2000 metre ocean) and then how much will they warm by 2100 at the current trends. The 0-2000 metre ocean will only increase to 0.22C by 2100 at the current rate. That’s not hiding, that’s basically nothing.
http://s18.postimg.org/d8222h8jt/Ocean_Temp_Change_Q2_2013_to_2100.png

Perry

Magnus Magnusson wrote about Iceland, “During these early Celtic and Viking settlements, the climate was significantly warmer, and about 25% of Iceland was covered with forest compared to 1% now.” The Vikings. (1980) Pages 188-191. ISBN 978-0-7524-2699-0
http://en.wikipedia.org/wiki/Magnus_Magnusson
It occurs to me that the CAGW gatekeepers at Wikipedia have either become lax or have realised that the gig is up & they cannot stand in the face of evidence about the Mediaeval Warm Period being warmer than the 21st century.

Greg Goodman

AR5: “It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human induced contribution to warming is similar tothe observed warming over this period.
I don’t see a lttle asterisk pointing us to a legally accountable definition of “similar to”.
Perhaps it means “more than half”. LOL

> YET…the IPCC claims their confidence has DOUBLED (uncertainty reduced from 10% that 5%)
Bah. The confidence has gone up 5/90 x 100%. The DOUBT has been cut in half. If you’re going to play games with percentages and ratios, let’s do it right. And no, there’s not 2X less doubt. Fie (in advance) to anyone who claims that! 🙂
Thanks, I feel better now.

RACookPE1978

But, the “standard excuse” keeps using volcanoes for some reason as a part of the “natural changes” that are the excuse for the “pause” in global warming: Yet there have been NO substantial eruptions since 1991!
So how can they continue to include as a cause for a 17 year pause in warming something that has NOT occurred measurably in the records? Unlike the three explicitly clear spikes (drops) in atmosphere transmissivity at Mauna Loa observatory in 1963, 1982, amd 1991 from volcanoes, there has been NO CHANGE since 1992. .
See the plot on the WUWT Solar Page:
http://www.esrl.noaa.gov/gmd/webdata/grad/mloapt/mlo_transmission.gif
However, even those three volcanoes only had a 1 to 1-1/2 year impact on global temperatures.
https://sfb574.geomar.de/74.html
And there have been no large volcanoes since Pinatubo in 1991-1992.

Uh, it looks like parts of the MSM are waking up:
“U.N. Climate Panel Endorses Ceiling on Global Emissions”
http://www.nytimes.com/2013/09/28/science/global-climate-change-report.html?_r=0
The first sentence:
“The world’s top climate scientists on Friday formally embraced an upper limit on greenhouse gases for the first time, establishing a target level at which humanity must stop spewing them into the atmosphere or face irreversible climatic changes.”
Yikes!

Leon0112

In previous reports, the IPCC asserted that it was settled science that increasing CO2 levels caused increasing surface temperatures. Now, the IPCC asserts that the heat is hiding in the ocean. This is an implicit admission that previous settled science was wrong.

peter

If you make a claim that Volcano’s offer a significant increase in CO2, you get shot down because everyone knows that Volcano’s only emit a faction of the CO2 as man. but suddenly they are responsible for causing a slow down in warming?
What I have been noticing on all the sites that support GW, is that they believe that this report offers total confirmation that man has caused increased warming this century. The only part of the report that they are remotely interested in is the statement that backs this up.
There is a large portion of the public that will simple never believe that man is not causing GW, and that it is dangerous. IF by chance ice levels in the arctic return to the levels of 1979, they will most likely say that this is the result of some other factor that has given us some breathing room and we must double down on preventive measures while we have the chance.
The most recent issue of Sceptic has lumped GW skeptics in with other Science deniers, as if there could be no doubt at all. I have always respected this publication, and have always been troubled by their stance on GW
It makes it very hard for someone like me, who really does not have the book learning to examine the facts properly and has to rely on other people for information to wonder if I am letting my bias against snake oil salesman blind me to the truth and GM really is happening.

Ian W

From the UK Guardian:
IPCC Report in Doubt: Are Climate Change Skeptics “Dumb”?
Governments have implemented fuel taxes on non-renewable energy sources and poured billions into constructing wind farms, and other “green” energy strategies, all in the name of reducing carbon emissions. If these scientists are eventually forced to admit that their climate change theories have been terribly mistaken, it will certainly be a very costly one; incalculable sums of money will have been wasted, and the reputation of the scientific community will be left in tatters. On this basis, what would be the incentive for the IPCC to ever confess they were wrong?
By: James Fenner (Op-Ed)

http://guardianlv.com/2013/09/ipcc-report-in-doubt-are-climate-change-skeptics-dumb/

Aethelbert of Kent, King

The missing hot air can be found apparently in the language of the report itself

Leon0112:
At September 28, 2013 at 7:08 am you say

In previous reports, the IPCC asserted that it was settled science that increasing CO2 levels caused increasing surface temperatures. Now, the IPCC asserts that the heat is hiding in the ocean. This is an implicit admission that previous settled science was wrong.

No. It is an EXPLICIT admission that previous settled science was wrong.
I have repeatedly explained this on WUWT recently, for example here
http://wattsupwiththat.com/2013/09/27/ipcc-fails-to-come-clean-over-global-temperature-standstill/#comment-1428640
Richard

Here in Israel it got a headline coverage with the usual yellow coverage, and a few hours later just disappeared altogether.
The coverage here too is in the hands of activists of the green shade, shallow and (very) inaccurate.
Sad.

Keitho

gopal panicker says:
September 28, 2013 at 6:50 am (Edit)
the whole ‘report’ is bullshit
—————————————————
I suspect, based on several years of watching this circus, that it is only the interpretation that is bullshit. The underlying science, such as it is, has always been open to varying levels of understanding and attribution. My internal metaphor is that of Rorschach Ink Blots. The science can be seen through different prisms depending on where one is at that particular time.
You can see how the kids over at SkS are interpreting this PR exercise, they think it supports them. The fact is the IPCC seem to have reeled in the gotterdammerung and that implies the big report will not support the “destroy the village to save the village” mindset. George Osborne, a giant among men, has already stated that he will no longer allow green initiatives to impoverish British citizens. All in all I feel encouraged by this little brain fart that was released into the world yesterday. It lacks confidence and a cause for action and so appears to be an empire in decline.
It isn’t over till the fat lady sings but that sloppy, slovenly, over fed pig is tuning up those vocal chords. This science by committee is already smelling like last week’s guests.

Greg Goodman

AR5 [my bold]” The reduced trend in radiative forcing is primarily due to volcanic eruptions and the timing of the downward phase of the 11-year solar cycle. However, there is low confidence in quantifying the role of changes in radiative forcing in causing the reduced warming trend.”
Well the reduced trend can hardly be due to the piddling volacism since 2000 compared to 1980-1997 warming period. This BS is simply padding out the solar attribution with _something_ (albeit anti-correlated) to make it sound like the are “lots” of factors at play.
So this para actually boils down to a statement that it’s due to a quiet sun. In comparison to 30 years of ridiculing such a suggestion this is quite an about face. It also requires a statement about how much this newly recognised affect accounted for the earlier warming. You can’t have your cake and eat it.
AR5: “There is medium confidence that internal decadal variability causes to a substantial degree the difference between observations and the simulations; the latter are not expected to reproduce the timing of internal variability. There may also be a contribution from forcing inadequacies and, in some models , an overestimate of the response to increasing greenhouse gas and other anthropogenic forcing (dominated by the effects of aerosols). ”
Well how many is “some” ? “Nearly all models” would be ‘consistent’ with this claim. IIRC there are only two of the CMIP5 model outputs that come remotely close to actual recorded temps. So I guess this is more legally accurate but misleading phrasing.
However, it is the first official IPCC admission “some” (read “nearly all”) models have ” forcing inadequacies”.

John West

I find Table SPM.1 particularly telling, note the fourth column is theLikelihood of further changes, Early 21st century fails to commit to any predictions/projections over that time frame. Oh, they’re virtually certain late 21st century (5th column) will be a hot mess though. LOL.

Henry

It seems the warminsts next move will be to shut down the IPCC and coem out with a series of smaller reports where they can better control the “scientists” and the science. It will be interesting to see if the UN and asociated govs let them get away with it.

john

Legal Analysis of EPA’s Proposed Carbon Pollution Standard
http://www.globalwarming.org/2013/09/27/legal-analysis-of-epas-proposed-carbon-pollution-standard/
The analysis below subjects EPA’s proposed Carbon Pollution Standard to the D.C. Circuit Court’s rigorous standard of review under Clean Air Act Section 111. Previously, I explained how EPA’s proposed standard, whose purpose is to reduce greenhouse gases, is likely to increase greenhouse gas emissions in practice.

Since AR4, instrumental biases in upper-ocean temperature records have been identified and reduced, enhancing confidence in the assessment of change.
If several instrumental errors have been found within a period of six years, how exactly is this supposed to enhance our confidence in them? Is my hunch right, that the corrections were all in the direction of more warming?

Sasha

Anyone want a laugh? Check this out :
The Gore Effect Strikes UN Global Warming Meeting: Just in time for the UN IPCC meeting: Unusual cold hits Stockholm
The cartoon of AG !
http://www.climatedepot.com/2013/09/25/the-gore-effect-strikes-un-global-warming-meeting-just-in-time-for-the-un-ipcc-meeting-unusual-cold-hits-stockholm/

John West

This part is absolutely hilarious:
[bolds mine]

Ocean acidification is quantified by decreases in pH13. The pH of ocean surface water has
decreased by 0.1 since the beginning of the industrial era (high confidence),
corresponding to
a 26% increase in hydrogen ion concentration (see Figure SPM.4). {3.8., Box 3.2}
[INSERT FIGURE SPM.4 HERE]
Figure SPM.4: Multiple observed indicators of a changing global carbon cycle: (a) atmospheric
concentrations of carbon dioxide (CO2) from Mauna Loa (19°32′N, 155°34′W – red) and South Pole
(89°59′S, 24°48′W – black) since 1958; (b) partial pressure of dissolved CO2 at the ocean surface (blue curves) and in situ pH (green curves), a measure of the acidity of ocean water. Measurements are from three stations from the Atlantic (29°10′N, 15°30′W – dark blue/dark green; 31°40′N, 64°10′W – blue/green) and the Pacific Oceans (22°45′N, 158°00′W − light blue/light green). Full details of the datasets shown here are provided in the underlying report and the Technical Summary Supplementary Material. {Figures 2.1 and 3.18; Figure TS.5}

So, we can say with high confidence the ocean has dropped a full 0.1 pH unit (pretty darn hard to measure) with a whopping 3 measurement locations worldwide? Yea, right.
Furthermore, the use of percentages with pH is extraordinarily inappropriate:
8.2 = 0.00000000630957 mol/L
8.1 = 0.00000000794328 mol/L
Increase = 0.00000000163371 mol/L
% Increase = 25.8925412
So, while technically correct (in a way) it’s misleading in that 26% is not 26 out of 100 but 26 out of 1X10^14 (if just taking 0-14 scale). Clear evidence of advocacy over the “whole truth” as being the IPCC’s priority.

Peter Miller

We must never forget the grim truth that the IPCC, like all quasi-government bureaucracies, is primarily interested in its own perpetuation. Everything else is a secondary consideration.
George Orwell would be proud of the IPCC and the way it portrays the ‘facts’ about climate.

Latitude

RACookPE1978 says:
September 28, 2013 at 6:59 am
But, the “standard excuse” keeps using volcanoes for some reason as a part of the “natural changes” that are the excuse for the “pause” in global warming: Yet there have been NO substantial eruptions since 1991!
=================
and interestingly enough…..if you remove the Pinatubo cooled years 1992-1994….you get this
….a pause in the warming of 22 years
http://stevengoddard.wordpress.com/2013/09/28/warming-pause-is-actually-22-years/

manicbeancounter

I have had a look at Figure SPM5 – Radiative forcing components – and compared to the equivalent Figure 2.4 in AR4. Some interesting things emerge.
1. The uncertainty bands for CO2, CH4 and NOx have all been doubled.
2. The forcing effect per unit of CO2 (potency) has been reduced by 10%, whilst that of CH4 has almost doubled.
3. Rather than these factors causing doubt in the minds of the scientists it has not changed their high confidence in the CH4 and NOx figures, and the confidence in the CO2 figures has gone from “high confidence” to “very high confidence”.
4. The forcing impact of halocarbons has been halved, the uncertainty range increased five-fold in absolute terms (ten-fold in percentage terms), yet confidence in the figures has risen from “high confidence” to “very high confidence”.
If I get figures wrong, I tend to lose confidence. But then I am not a climate scientist.
I have laid out my figures at http://wattsupwiththat.com/2013/09/28/thoughts-on-ipcc-ar5-spm-discussion-thread/

timspence10

The IPCC report seems to have bombed in the Spanish press. The Spanish national TV RTVE mentioned it on the Friday evening weather forecast and then proceeded to cast doubt on it before moving on sharply.

John West:
At September 28, 2013 at 8:13 am you say

This part is absolutely hilarious:
[bolds mine]

Ocean acidification is quantified by decreases in pH13. The pH of ocean surface water has decreased by 0.1 since the beginning of the industrial era (high confidence), corresponding to a 26% increase in hydrogen ion concentration (see Figure SPM.4). {3.8., Box 3.2}

Yes, it is “hilarious”. But I am certain the IPCC authors don’t know why.
If the IPCC is right that (n.b. I doubt they are right) the “pH of ocean surface water has decreased by 0.1 since the beginning of the industrial era” then that would explain ALL of the rise in atmospheric CO2 concentration over that time.
The pH change would have altered the equilibrium concentrations of atmospheric and ocean surface layer CO2 such as to have caused the observed rise in atmospheric CO2. And such a pH change may have resulted from submarine volcanism having released more sulphate ions into the thermohaline circulation centuries ago so they have recently reached the ocean surface layer. And the carbonate buffer would not prevent the injection of additional sulphate from inducing the pH change.
Simply, the IPCC statement could be interpreted to be an indication that the rise in atmospheric CO2 concentration “since the beginning of the industrial era” was NOT caused by emissions of CO2 from human activities.
Richard

Martin Lewitt

A chart has been making the rounds, I think created by wunderground.com, miss-representing this SPM statement by leaving off the highlighted, non-greenhouse part:
“It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations AND OTHER ANTHROPOGENIC FORCINGS TOGETHER” [emphasis mine]
Here is the image:
http://icons.wxug.com/hurricane/2013/IPCC_version95.png
Here is where it is posted:
http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2535&cm_ven=gp

Latitude

And the carbonate buffer would not prevent the injection of additional sulphate from inducing the pH change.
====
Biological processes release magnitudes more sulphate than that…..

Lyle

Thanks, IPCC. Now I understand what’s been happening.
All that heat created by human CO2 emmitters has sequestered itself in the deep dark oceans where it lurkes, ready to pounce (someday). But, on it’s way to the ocen depths it took time to launch hurricane Sandy, a couple of awful tornadoes, some forest fires in Colorado, floods in southern Alberta and, no doubt, caused Captain Schettino to stear his cruise ship onto the rocks. I now have new bedtime stories to scare my granchildren with.

As I said on jonova, I like how the Coyote Blog put it:
The IPCC claims more confidence that warming over the past 60 years is due to man. But this is odd given that the warming all came from 1978 to 1998.
So, only 20 out of the last 60+ years have been warming? And this is supposed to be runaway catastrophic warming?? Not even close.

Latitude:
Your post at says September 28, 2013 at 8:47 am

And the carbonate buffer would not prevent the injection of additional sulphate from inducing the pH change.

Biological processes release magnitudes more sulphate than that…..

“More” than what?
The DMS emission is great but does not go into solution. And the volcanic injection would be an addition to the sulphate from biological processes. Indeed, if the injection disturbs the “biological processes” then that could add to the effect. The pH change from sulphate emissions is not inhibited by the carbonate buffer.
The important point is that the IPCC asserts (without adequate evidence) that the pH change has happened. If so then that pH change could be responsible for ALL the observed rise in atmospheric CO2 concentration since 1750.
Richard

I’ve extended the analysis recently posted on WUWT to include the 1850-1900 time period. It shows
The results of the earlier analysis are confirmed
The rate of increase of the temperature slope has remained remarkably constant since 1850
The detection method is first order insensitive to amplitude variations in the natural variation
There is no detectable AGW contribution over the observation interval
An AGW contribution of the magnitude specified in the IPCC AR5 summary would be easily detectable by this method.
Details are available here

Stephana

I can live with the claim that Humans are causing most of the warming, since 90% of zero is still zero. Probably the only claim that they have made that hasn’t been debunked yet.

Latitude

Richard, too much coffee??
biological processes that make the ocean work produce more acids than CO2 or anything else…
and those same biological processes produce more sulphates than any volcanoes
they have to, or it don’t work

Morph

Can’t really comment on the report itself, but the comment about the coverage being lacking is interesting. Here in the UK the Guardian and of course Guardian TV (aka the BBC) gave it full on coverage with headlines on every news channel – which meant the mantra was repeated throughout the day every 20 minutes on BBC News 24 and BBC Radio 5 live – the Beeb’s (usually quite good) live news / sport radio channel.
This was of course quite annoying not helped by one presenter I quite like deciding to indulge in the D-word during his report / interview. Never mind, it is a feeding frenzy and anyone who disagrees is in the “flat earth society” – again.
In amongst this of course there were some positive signs – for a start whenever a “scientist” woudl appear they would be questioned about the pause and when they responded with the “the missing heat is in the oceans” argument at least a couple of tame BBC presenters pointed out the lack of evidence for this.
Added to this Bishop Hill (AW Montford) appeared a few times on the BBC outlets both nationally and in Scotland (where he and I are both based) and seemed reasonable, sensible and calm in pointing out the holes.This could be a positive sign or a sop to the idea that BBC needs to be “more impartial” on this subject. Maybe.
Another thing – BBC news runs in daily cycles – breakfast, mid-day, travelling home time, evening news and last thing at night news. Normally a story like this runs through them all but by the last of those Syria had pushed it off the top spot and the previous reports had been trimmed quite a lot.
Maybe we might get a balanced view from now on, but I doubt it.

Neil Jordan

The IPCC news is on the front page of the Los Angeles Times and ninth page of Wall Street Journal. Note that Roger Pielke Jr. was quoted. The LA Times article is at:
http://www.latimes.com/local/la-me-0928-climate-change-20130928,0,2765027.story
[begin quotes]
The world’s leading climate scientists have for the first time established a limit on the amount of greenhouse gases that can be released before the Earth reaches a tipping point and predicted that it will be surpassed within decades unless swift action is taken to curb the current pace of emissions.
[…]
The report also addressed the so-called hiatus, a slowdown in the rise of surface temperature that has been observed over the last 15 years. That slowing of the increase in temperatures has been seized on by skeptics to cast doubt on the science of climate change.
The report touches the subject only briefly, saying that temperatures fluctuate naturally in the short term and “do not in general reflect long-term climate trends.”
[…]
Roger Pielke Jr., a professor of environmental studies at the University of Colorado and a leading critic of the climate science establishment, praised the core science of the report, but said many of its conclusions, including the idea of a carbon dioxide limit, are neither new or surprising. He criticized the panel for not doing more to acknowledge uncertainty over how climate change will express itself in the near term.
“By not addressing the issues associated with the ‘hiatus’ in warming the IPCC missed an opportunity to clarify this issue, and also has guaranteed continuing allegations from its critics that is has dodged this issue,” Pielke said.
[…]

manicbeancounter

At the comment above, I gave the wrong link to my analysis of the radiative forcings in the report.
It should be http://manicbeancounter.com/2013/09/28/radiative-forcing-unipcc-ar5-undermines-ar4-but-scientists-have-unshaken-confidence-in-their-work/
Compared with 2007, the forcing components have change for the major greenhouse gases, and the uncertainty bands have increased. But the climate scientists are if anything more confident in their results.

Lance Wallace

I tried comparing the draft and final versions using the Word Compare function. (Never used it before–pretty neat!). Got through about half the document before giving up in disgust about the waste of my time. Their estimates of temperature increase are particularly frustrating–they managed to delete the reference period in a few cases, and in another case they replaced the 1850-1900 reference period with “preindustrial” but left the numerical increases the same!
I have about a dozen examples in Dropbox. Including of course the famous footnote, now gone, where they say they can’t give an estimate of climate sensitivity because of disagreement.
https://dl.dropboxusercontent.com/u/75831381/AR5%20revisions%20to%20draft%20summary.docx

Phil.

richardscourtney says:
September 28, 2013 at 8:33 am
John West:
At September 28, 2013 at 8:13 am you say
If the IPCC is right that (n.b. I doubt they are right) the “pH of ocean surface water has decreased by 0.1 since the beginning of the industrial era” then that would explain ALL of the rise in atmospheric CO2 concentration over that time.
The pH change would have altered the equilibrium concentrations of atmospheric and ocean surface layer CO2 such as to have caused the observed rise in atmospheric CO2. And such a pH change may have resulted from submarine volcanism having released more sulphate ions into the thermohaline circulation centuries ago so they have recently reached the ocean surface layer.

Except that this doesn’t happen, as I’ve pointed out in the other thread where you raised it!
Sulphate ion is one of the conserved species in the ocean, its concentration is constant relative to the other major ions such as Cl-
Submarine vents and volcanoes are observed to contribute no sulphate to the ocean. E.g. El Hierro: “The degassing of the volcano could be observed from the research vessel Cornide de Saavedra. The composition of these gases was fundamentally CO2 with complete absence of sulfur compounds.”
http://www.sciencedaily.com/releases/2012/04/120417080336.htm
“4. hydrothermal vents (Table 4-3 from Von Damm et al, 1985). These high-temperature waters differ from seawater in that Mg, SO4 and alkalinity have all been quantitatively removed.”
http://www.ocean.washington.edu/courses/oc400/Lecture_Notes/CHPT4.pdf

markx

Re Table SPM.1
“Increased incidence and/or magnitude of extreme high sea level.”
Only “likely” until late 21st century, when it becomes “very likely”?
Given the great certainly expressed on all other parameters, I thought they’d be a bit more sure of this one.

Latitude:
I am copying all your post at September 28, 2013 at 9:02 am

Richard, too much coffee??
biological processes that make the ocean work produce more acids than CO2 or anything else…
and those same biological processes produce more sulphates than any volcanoes
they have to, or it don’t work

I fail to understand why my drinking coffee would make you so obtuse.
Nature emits orders of magnitude more CO2 than human activities, but people claim the emissions of CO2 from human activities are causing the observed rise in atmospheric CO2.
The dynamics of the CO2 sequestration processes indicate those processes can easily sequester all the emitted CO2 (n.b. both natural and anthropogenic) each year. However, the sequestration processes do not sequester all of the emissions each year so the atmospheric CO2 has risen and is rising. This is explicable as being a result of a change to the equilibrium of the carbon cycle.
(ref. Rorsch A, Courtney RS & Thoenes D, ‘The Interaction of Climate Change and the Carbon Dioxide Cycle’ E&E v16no2 (2005) )
It is no more improbable to suggest that submarine volcanism could add sulphate to the ocean surface layer than that human emissions can add CO2 to the atmosphere. Indeed, it is less improbable because the sulphate addition could be enhanced by biota.
The IPCC says the ocean surface layer has altered its pH by 0.1. If that is true then the result would be a change to atmospheric CO2 concentration of the form and magnitude which is observed. This change to atmospheric CO2 would be caused by the alteration to the equilibrium concentrations of CO2 in the air and ocean surface layer. Indeed, this hypothesis would explain the peak in atmospheric CO2 concentration around 1940 which is indicated by the data Beck collated.
I do not know if the sulphate hypothesis is true or not, but it is more likely than the suggestion that emissions of from human activity are accumulating in the air: the observed dynamics refute that suggestion.
Richard

JimS

I think I get it now. Nature was responsible for the warming from 1979 to 1998, but humans were responsible for the warming from 1999 to 2013. But there was no warming from 1999 to 2013, you say? Well, I stand by my conclusion.

Latitude

I fail to understand why my drinking coffee would make you so obtuse.
=====
Because I’m agreeing with you….and you don’t understand why

Latitude:
At September 28, 2013 at 9:26 am you say you are agreeing with me.
Clearly I have misunderstood your posts addressed to me.
Please explain the meaning of your posts at September 28, 2013 at 8:47 am
http://wattsupwiththat.com/2013/09/28/thoughts-on-ipcc-ar5-spm-discussion-thread/#comment-1429756
and at September 28, 2013 at 9:02 am
http://wattsupwiththat.com/2013/09/28/thoughts-on-ipcc-ar5-spm-discussion-thread/#comment-1429775
I do not see the agreement and I would like to. Please explain.
Richard

Here is an eye opening article on the general poor quality of the released report, including inconsistencies it contains on the Antarctic ice cap and other defects:
“IPCC: Frist AR5 SPM Report Lousy!”
http://informthepundits.wordpress.com/2013/09/28/ipcc-first-ar5-spm-report-lousy/