New paper finds another amplification mechanism by which the Sun controls climate

A paper published today in Quaternary Science Reviews reconstructs climate of the central Alps over the past 10,000 years and finds precipitation and floods were driven by changes in solar activity. The authors propose variations in solar activity and insolation cause widening and shrinking of the Hadley cell, and influence on the North Atlantic Oscillation [NAO] and Intertropical Convergence Zone [ITCZ]. The paper adds to many other peer-reviewed publications finding solar amplification mechanisms by which small changes in solar activity have large effects on climate.



The authors also find floods and heavy precipitation were more common during cold periods such as the Little Ice Age than during warm periods such as the Medieval Warm Period, the opposite of claims that warming increases precipitation and floods from increased atmospheric water vapor.


According to the authors, "We found that flood frequency was higher during cool periods, coinciding with lows in solar activity. In addition, flood occurrence shows periodicities that are also observed in reconstructions of solar activity from 14C and 10Be records (2500–3000, 900–1200, as well as of about 710, 500, 350, 208 (Suess cycle), 150, 104 and 87 (Gleissberg cycle) years). As atmospheric mechanism, we propose an expansion/shrinking of the Hadley cell with increasing/decreasing air temperature, causing dry/wet conditions in Central Europe during phases of high/low solar activity. Furthermore, differences between the flood patterns from the Northern Alps and the Southern Alps indicate changes in North Atlantic circulation."

Fig. 6. Stacked flood records for the N- and S-Alps (100-year low-pass filtered) spanning (a) the past 10 kyr and (b) the past 2 kyr. Both representations show strong decadal- to millennial-scale fluctuations in flood activity. In a), gray areas and gray arrows mark periods with increased flood activity. In b), important historic and climatic periods characterized by rather high/low flood occurrence are marked with dark/light areas. LIA: Little Ice Age; MCA: Medieval Climate Anomaly; MP: Migration Period; RE: Roman Empire.

Fig. 8. Comparison of the Alpine flood reconstruction to records reflecting solar forcing, as well as to other climate proxy records and reconstructions: a) 30°N summer insolation (Berger and Loutre, 1991); Holocene cold events reported by (b) Wanner et al. (2011) (short gray bars) and (c) Bond et al. (1997) (with numbers 0–6); d) variations in TSI (Steinhilber et al., 2009) (50-year running mean with 100-year smooth); flood activity in the (e) N-Alps and (f) S-Alps (100-year low-pass filtered), on the right: arrow indicates state of the NAO based on S-Alpine flood frequency; g) global glacier advances (Denton and Karlén, 1973); h) NAO reconstruction from Greenland (Olsen et al., 2012); i) precipitation record from the Cariaco Basin (Haug et al., 2001); j) NAO reconstructions covering the past 1000 years (Trouet et al., 2009); k) ssNa concentrations from the GISP2 ice core (56 and 57) (100-year low-pass filtered); l) storminess (0–1) record from the NE United States (Noren et al., 2002). Gray shaded areas and gray arrows mark periods with enhanced flood activity in the Alpine realm. Blue arrows mark periods in the N-Alps that show an opposite flood activity than the S-Alps. Elevated flood activity in the S-Alps is an indicator for a more southerly positioned Atlantic circulation system and a tendency towards lower NAO indices.

Holocene flood frequency across the Central Alps – solar forcing and evidence for variations in North Atlantic atmospheric circulation

• Stefanie B. Wirth^{a, , 1, 2,} , 


• Lukas Glur^b, 2, 


• Adrian Gilli^a, 


• Flavio S. Anselmetti^b, c

• ^a Geological Institute, ETH Zurich, Zurich, Switzerland


• ^b Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland


• ^c Institute of Geological Sciences and Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland

Highlights

•

Lake sediments are a valuable terrestrial archive of past flood events.

•

High flood frequency in the Alps is driven by low solar activity.

•

Widening/shrinking of the Hadley cell brings dry/wet conditions to the Alps.

•

South-Alpine flood frequency indicates changes in a paleo-NAO pattern.

•

Frequent S-Alpine floods suggest a southerly position of the N-Atlantic circulation.

---

Abstract

The frequency of large-scale heavy precipitation events in the European Alps is expected to undergo substantial changes with current climate change. Hence, knowledge about the past natural variability of floods caused by heavy precipitation constitutes important input for climate projections. We present a comprehensive Holocene (10,000 years) reconstruction of the flood frequency in the Central European Alps combining 15 lacustrine sediment records. These records provide an extensive catalog of flood deposits, which were generated by flood-induced underflows delivering terrestrial material to the lake floors. The multi-archive approach allows suppressing local weather patterns, such as thunderstorms, from the obtained climate signal. We reconstructed mainly late spring to fall events since ice cover and precipitation in form of snow in winter at high-altitude study sites do inhibit the generation of flood layers. We found that flood frequency was higher during cool periods, coinciding with lows in solar activity. In addition, flood occurrence shows periodicities that are also observed in reconstructions of solar activity from ¹⁴C and ¹⁰Be records (2500–3000, 900–1200, as well as of about 710, 500, 350, 208 (Suess cycle), 150, 104 and 87 (Gleissberg cycle) years). As atmospheric mechanism, we propose an expansion/shrinking of the Hadley cell with increasing/decreasing air temperature, causing dry/wet conditions in Central Europe during phases of high/low solar activity. Furthermore, differences between the flood patterns from the Northern Alps and the Southern Alps indicate changes in North Atlantic circulation. Enhanced flood occurrence in the South compared to the North suggests a pronounced southward position of the Westerlies and/or blocking over the northern North Atlantic, hence resembling a negative NAO state (most distinct from 4.2 to 2.4 kyr BP and during the Little Ice Age). South-Alpine flood activity therefore provides a qualitative record of variations in a paleo-NAO pattern during the Holocene. Additionally, increased South Alpine flood activity contrasts to low precipitation in tropical Central America (Cariaco Basin) on the Holocene and centennial time scale. This observation is consistent with a Holocene southward migration of the Atlantic circulation system, and hence of the ITCZ [Intertropical Convergence Zone], driven by decreasing summer insolation in the Northern hemisphere, as well as with shorter-term fluctuations probably driven by solar activity.

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Helping the IPCC with decadal trend graphs

The IPCC AR5 has a new "decadal average" graph designed to hide the statistically insignificant global warming over the past 20 years. Since nobody wants to be accused of cherry-picking starting dates and using a decadal average instead of a decadal trend line, let's graph the decadal linear trends for each starting year since 1988. This paints a quite different picture than the IPCC decadal average graph, showing a clear halt in "decadal average" and "decadal trend" global warming starting at the beginning of the 21st century.

The decadal mean temperature graph 

October 1, 2013 Reblogged from The IPCC Report

Perhaps the most ridiculous graph in the IPCC AR5 SPM is this one showing “decadal mean” temperature.





A few points about this graph: 

As far as I know, such a graph has not been used in any peer reviewed publication
The graph was not in the draft version of the SPM subjected to expert review
No such graph has been used in any of the previous IPCC reports.
I’m not aware of any such graph being used in any other field of science – any examples?

So why is the graph so bad? It’s hard to see why it is necessary to point this out. Firstly, it takes a graph with about 160 data points on it, and reduces this to just 16, effectively throwing away most of the data. Secondly, the appearance of the graph depends very much on how you choose to do the 10-year cuts. They seem to have chosen either 0-9 or 1-10 bins (it’s not clear which) so that the last two or three years aren’t included at all. But if we chose 5-4 bins, the picture would probably look quite different (has anybody done this?). The introduction of this graph into AR5, with no such graph in the previous reports, leaves the IPCC open to accusations of trying to “hide the decline” in warming this decade, though of course the levelling off is clear in the graph above, so the graph seems quite pointless.

In the draft version of the SPM reviewed by scientists, this graph was not there, perhaps because the authors were aware that it might be criticised. This illustrates the point about the authors having carte blanche to insert whatever they like into the final version after the review. The decadally averaged graph was there in the main section of the report, in chapter 2, Fig 2.20 (In the final draft version, it is Fig 2.19). In my review comments, I was very critical of this graph (“Fig 2.20 – I am surprised to see this absurd figure still in the SOD. No such figure appears in the cited paper Morice et al, or in any other published paper I am aware of , or in previous IPCC reports. Such a figure would be widely and rightly ridiculed as an attempt disguise the recent slow-down of warming.”)

The IPCC responded to my criticism by putting the graph in the SPM.

I have not seen much comment on this graph. But Reiner Grundmann tweeted “Summary for policymakers dodges issue of ‘pause’ in global warming. New fig.1 makes problem invisible” and “So SPM replaced the ‘dodgy sandwich’ graph with an ‘elevator’ graph of decadal temp rise. Good PR, but is it sustainable?” on the day the SPM was published.

This type of graph seems to have originated in a Met Office press release from 2009, although the IPCC version seems to be based on this one from 2012 from the EEA.

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New paper finds E. Antarctic ice shelf gaining more ice mass than previously believed

A paper published today in the Journal of Geophysical Research - Atmospheres finds the East Antarctica Fimbul ice shelf has accumulated significantly more ice mass over the past 26 years than previously believed. According to the authors, "the 26-year mean [surface ice mass balance] on the Fimbul ice shelf varies between 170 and 620 [kilograms per meter squared per year] giving a regional average value of 310 ±70 kg  [per meter squared per year]. Our measurements indicate higher long-term accumulation over large parts of the ice shelf compared to the [prior] large-scale studies."


Surface mass balance on Fimbul ice shelf, East Antarctica: comparison of field measurements and large-scale studies

Abstract:

Many challenges remain for estimating the Antarctic ice sheet surface mass balance (SMB), which represents a major uncertainty in predictions of future sea-level rise. Validating continental scale studies is hampered by the sparse distribution of in-situ data. Here we present a 26-year mean SMB of the Fimbul ice shelf in East Antarctica between 1983–2009, and recent interannual variability since 2010. We compare these data to results of large-scale SMB studies for similar time periods, obtained from regional atmospheric modeling and remote sensing. Our in-situ data include ground penetrating radar, firn cores and mass balance stakes, and provide information on both temporal and spatial scales. The 26-year mean SMB on the Fimbul ice shelf varies between 170 and 620 kg m^-2 a^-1 giving a regional average value of 310 ±70 kg m^-2 a^-1. Our measurements indicate higher long-term accumulation over large parts of the ice shelf compared to the large-scale studies. We also show that the variability of the mean annual SMB, which can be up to 90 %, can be a dominant factor in short-term estimates. The results emphasize the importance of using a combination of ground based validation data, regional climate models and remote sensing over a relevant time period in order to achieve a reliable SMB for Antarctica.

Related: 

ICESAT Data Shows Mass Gains of the Antarctic Ice Sheet Exceed Losses

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WSJ: One lesson of the IPCC report is it's time for policy caution; the climate models may need remodeling

Climate of Uncertainty

A U.N. report can't explain the hiatus in global warming.

WSJ.COM 9/30/13: Between 1998 and 2012 the global economy more than doubled in size—to some $71 trillion in GDP from $30 trillion. That's the good news. Over the same period the world pumped more than 100 billion tons of carbon dioxide into the atmosphere. That is supposedly the bad news. Yet global surface temperatures have remained essentially flat. That's the mystery: If emitting CO2 into the atmosphere causes global warming, why hasn't the globe been warming?

That's the question we would have liked to see answered by the U.N. Intergovernmental Panel on Climate Change (IPCC), which Friday published the summary of its fifth report on what co-chairman Thomas Stocker calls "the greatest challenge of our times." It would have also been nice to see some humility from the IPCC, which since its last report in 2007 has seen some of its leading scientists exposed as bullies, and some of its most eye-catching predictions debunked. (Remember the vanishing Himalayan glaciers?)

No such luck. "Warming of the climate system is unequivocal," insists the report in its first bold-face conclusion, followed by the claim that "each of the last three decades has been successively warmer at the Earth's surface than any preceding decade since 1850." What follows are warnings of shrinking ice sheets, rapidly rising sea levels and other scary events.

So what about the warming that hasn't been happening since 1998? Here's the key paragraph, buried on page 10: "The observed reduction in surface warming trend over the period 1998-2012 as compared to the period 1951-2012, is due in roughly equal measure to a reduced trend in radiative forcing and a cooling contribution from internal variability, which includes a possible redistribution of heat within the ocean."

Corbis

After noting that scientists have only low or medium confidence in various theories for this reduced warming trend, the report adds that "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." (Our emphasis.)

Translation: Temperatures have been flat for 15 years, nobody can properly explain it (though there are some theories), and the IPCC doesn't want to spend much time doing so because it is politically inconvenient and shows that the computer models on which all climate-change predictions depend remain unreliable.

Though the IPCC doesn't admit it, the real lesson of its report is uncertainty. Droughts and hurricanes? Contrary to Al Gore's hype, the report acknowledges there's little evidence to suggest that climate change caused by man has had much to do with the duration of droughts or the intensity of hurricanes, although it might in the far future.

Unbearable heat? The IPCC predicts that temperatures are "likely" to rise by somewhat more than 1.5 degrees Celsius throughout the rest of the century. But in 2007 the IPCC said they were "likely" to increase by more than 2 degrees, and "very unlikely" to increase by less than 1.5 degrees.

It's also hard to take any of this as gospel when the IPCC's climate models haven't been able to predict past warming. As Canadian economist and longtime climate student Ross McKitrick points out, IPCC models based on CO2 emissions predicted that temperatures should have risen between 0.2 and 0.9 degrees Celsius since 1990. Instead they have increased by about 0.1 degrees.

One lesson of the IPCC report is that now is the time for policy caution. Let's see if the nonwarming trend continues, in which case the climate models will need remodeling. But that's far less costly than trying to undo grand global redistribution schemes like carbon cap and trade.

The other lesson is that amid such uncertainty the best insurance against adverse climate risks is robust economic growth. The wealthier the world is in 50 or 100 years, the more resources and technology it will have to cope if the worst predictions come true. But that requires free-market, pro-growth policies that are the opposite of the statist fixes pushed by the climate alarmists.

They use the flimsy intellectual scaffolding of the IPCC report to justify killing the U.S. coal industry and the Keystone XL pipeline, banning natural gas drilling, imposing costly efficiency requirements for automobiles, light bulbs, washing machines and refrigerators, and using scarce resources to subsidize technologies that even after decades can't compete on their own in the marketplace.

All of these involve giving more economic control to political actors whose interventions make the world poorer than it would otherwise be. When even the climate-change lobbyists at the IPCC concede that the world is warming at a slower pace than they once thought, it's no time for panicky rearranging of the global economy.

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The Economist: All of the warming we're not having is 'still our fault'

If you can't explain the pause, you can't explain the cause...



Article published in The Economist, with added [clarifications & corrections]



It's still our fault -- the IPCC climate-change report

by J. P., Stockholm, The Economist, September 27, 2013

It has been a long time coming. But then the fifth assessment of the state of the global climate by the Intergovernmental Panel on Climate Change (IPCC), a United Nations body, was a behemoth of an undertaking. It runs to thousands of pages, involved hundreds of scientists and was exhaustively checked and triple-checked by hundredds [sic] of other boffins and government officials to whom they report—and whose policies are often based on what they read. The first tranche of the multi-volume report—an executive summary of the physical science—was released in Stockholm on September 27th. And it is categorical in its conclusion: climate change has not stopped and man is the main cause.

It may be the last report of its kind: a growing chorus of experts thinks a more frequent, less bally-hooed and more up-to-date assessments would be more useful. It is certainly the first since negotiations for a global treaty reining in carbon emissions collapsed in Copenhagen in 2009; the first since questions were raised about the integrity of the IPCC itself following mistaken claims about the speed of glacier melt in the Himalayas and, most important, the first since evidence became incontrovertible that global surface air temperatures have risen much less quickly in the past 15 years than the IPCC had expected. A lot is riding on its findings, from the public credibility of climate science to the chances of a new global treaty.

The report is more definitive than in the past about the role of people in causing climate change. It say that it is "extremely likely"—IPCC speak for having a probability of over 95%—that man is responsible. This contrasts with the tentative tone of the early IPCC reports. “The observed increase [in surface air temperatures] could be largely due to this natural variability,” said the first one, in 1990. The next report in 1995 merely suggested a link between rising temperatures and human activity. That link was deemed “likely” (which means probability of 66%) in 2001, and “very likely” (90%) in 2007.

The latest iteration identifies radiative forcing, the difference between the amount of heat coming into the climate and the amount reflected back, as the immediate cause of warming. Radiative forcing is expressed in watts per square metre (W/m2), a unit of energy. A rise indicates that heat is building up in the system.

Total radiative forcing from man-made sources since 1750 (i.e., before industrialisation) has risen from 0.29-0.85 W/m2 in 1950 to 0.64-1.86 W/m2 in 1980 to 1.13-3.33 W/m2 in 2011. The average has jumped from 0.57 to 1.25 to 2.29, respectively—a four-fold increase in 60 years. [Note: all of these numbers are entirely based upon falsified, theoretical assumptions in climate models, models which have been falsified at confidence levels of 90-98% over the past 15-20 years] The big change recently, the report points out, is that the cooling effect of aerosols seems to have been less strong than it used to be. [This was formerly the excuse du jour why the Earth wasn't warming] But there is no sign that the [theoretical modelled] rise in radiative forcing has slowed during the past 15 years of flat surface temperatures. The best estimate for total man-made radiative forcing in 2011 is 43% above 2005 levels.

Of course, more heat does not necessarily equal perceptible climate change. The IPCC admits the pause in the rise of surface air temperatures is real. “The rate of warming over the past 15 years,” it says, “[is] 0.05 ºC per decade...smaller than the rate calculated since 1951.” In its 2007 report the panel had said the rate of warming was 0.2ºC per decade in 1990-2005 (four times the current rate). It predicted that this would continue for the next two decades. [i.e. the IPCC admits warming has slowed to only 25% of the former rate]

But it plays down the long-term significance of the shift, saying that “due to natural variability, trends based on short records are very sensitive to the beginning and end dates and do not in general reflect long-term climate trends.” The start of the recent 15-year trend, in 1998, was a year of a strong worldwide fluctuation in the climate known as El Niño. This produced a temperature spike.

Still, all the [theoretical, "missing"] extra heat implied by higher radiative forcing has to go somewhere.[or never existed in the first place] It isn’t going into the air. It is possible that not all that much is going into the surface waters of the oceans, either. The report says that “it is about as likely as not that ocean heat content from 0-700 metres increased more slowly during 2003-2010 than during 1993-2002.” That only leaves one other heat sink: the deep oceans below 700 metres [where we have no observations], where it could be locked up in the deep oceans without affecting other parts of the climate.

And indeed, most of the [theoretical] extra heat does go into the oceans, which is not surprising given that they cover two thirds of Earth’s surface and have a much greater capacity to absorb heat than the air does. “Ocean warming,” the report says, “is largest near the surface and the upper 75 metres warmed by 0.11 ºC per decade over the period 1971-2010.” It adds that more than 60% of the net energy increase in the climate system is stored in the upper ocean (0-700 metres)...and about 30% is stored in the ocean below 700 metres. [Note the upper 2000m of the oceans has warmed only 0.09C over the past 55 years, and even this is statistically insignificant & unmeasureable]

In fact, vast deeps are a plausible candidate to explain the pause in surface air temperatures. The trouble is that measurements deep down, while improving, remain patchy. The IPCC says that it is likely [>66% probability in IPCC-speak] that the ocean warmed from 3,000 metres to the bottom in 1992-2005 and that heat will penetrate from the surface down.[no measurements at all there & heat rises]  Moreover, in a report earlier this month in Nature (published too late to make it into the IPCC report), Yu Kosaka and Shang-Ping Xie of the Scripps Institute of Oceanography, in San Diego, suggests that a cooling trend in an area of the eastern equatorial Pacific ocean may be “the cause of the pause.” But at the moment, this conclusion remains tentative.

Global warming is, then, continuing unabated in the watery world. It is not clear whether the trend itself has changed dramatically since 1990 or whether the rise is due to improved measurements, which have enabled scientists to gauge more exactly what has been going on. Probably the latter.[they can't "improve" measurements that were not done in the past] The new assessment says that, since the fourth report in 2007, "instrumental biases in upper-ocean temperature records have been identified and reduced, enhancing confidence in the assessment of change."

Either way, the trend is worrying. Since water, like almost everything else, expands as it gets hotter, its rising temperature causes sea levels to rise. It is "very likely," the report adds, “that the mean rate of global averaged sea level rise was 1.7 mm a year between 1901 and 2010, 2.0 mm a year between 1971 and 2010 and 3. 2mm a year between 1993 and 2010.” The rate of sea-level rise all but doubled between the start of the 20th century and its end.[false] That is a significant change and one that the first IPCC assessment report in 1990 had little inkling of. That report reckoned that “the average rate of rise over the last 100 years has been 1.0-2.0 mm a year. There is no firm evidence of acceleration in sea level rise during this century.” The rate is now thought to be higher—and growing.[false]

New instruments are providing better information about the rate at which ice sheets and glaciers are melting, too. In particular, the launch of the twin GRACE satellites has provided more detail about how much ice there actually is. GRACE, which stands for Gravity Recovery and Climate Experiment, enables the mass of objects on Earth to be worked out more precisely by measuring tiny changes in their gravitation pull. The report says that “the average rate of ice loss from glaciers around the world, excluding glaciers on the periphery of the ice sheets, was very likely 226 Gt [trillion tonnes] a year over the period 1971-2009 and very likely 275 Gt a year over the period 1993-2009.” [GRACE shows sea levels are only rising less than 4 inches per century]

In other words, it has speeded up. The Greenland ice sheet, the Antarctic sea ice and the Arctic sea ice have all lost mass (got thinner). The extent of the Arctic sea ice has shrunk by 3.5-4.1% a decade in 1979-2012, more than was estimated in 2007, and the summer sea-ice minimum is shrinking by about 10% a decade, though this year’s summer ice melt was smaller than last year’s.

What does that mean for the future? The report uses four new sets of scenarios for greenhouse-gas concentrations to claim that “global surface temperature change for the end of the 21st century is projected to be likely to exceed 1.5 ºC relative to 1850 to 1900 in all but the lowest scenario considered, and likely to exceed 2 ºC for the two high scenarios.” The 2 ºC mark is widely considered to be the dividing line between warming which is just about tolerable and that which is dangerous.

For the first time, the IPCC gives some credence to the possibility that Earth’s climate may not be responding to higher concentrations of greenhouse gases quite as sharply as was once thought. The response is referred to as “equilibrium climate sensitivity” and defined as the rise in surface temperatures in the long term which accompanies a doubling of the concentration of CO2 in the atmosphere. In its previous report, the IPCC put this at between 2ºC and 4.5 ºC, with a most likely figure of 3ºC. But recent work, partly influenced by the pause in temperatures, has suggested sensitivity might be somewhat lower. The IPCC’s new range of 1.5-4.5 ºC (the same as in its first report) reflects the new consensus (though some new research puts the upper bound of sensitivity below 4.5 ºC).

The IPCC also decided to scrap its central “best guess.” Perhaps this is meant to reflect uncertainty in the science. If so, some scientists argue, then perhaps it should not have increased its confidence that man is the main cause of global warming.

In theory, a lower climate sensitivity means temperatures would rise more slowly for any given amount of extra radiative forcing. Earth might hence have a little more time to adjust to a changing climate. But whether such breathing space actually exists depends on how many tonnes of greenhouse gases people are putting into the atmosphere. So, for the first time, the IPCC has set what is usually called a carbon budget. To have a two-thirds chance of keeping global warming below 2 ºC, it says, “will require cumulative CO2 emissions from all anthropogenic sources to stay between 0 and about 1,000 [trillion tonnes].”

The world has already blown through just over half that amount (531 trillion tonnes) by 2011. At current rates of greenhouse-gas emission, the rest of the budget will have been spent before 2040. The odds of keeping the eventual rise in global temperatures to below 2 ºC will lengthen—even if climate sensitivity is lower than was thought and even if the pause in surface air temperatures persists for a while. As Thomas Stocker, the co-chair of the report depressingly put it: “we are committed to climate change…for many centuries even if emissions of CO2 stop.”

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WSJ Op-Ed: The U.N. IPCC is unreformable and its latest political science report should be its last

The Political Science of Global Warming

The U.N.'s latest climate-change report should be its last.

By 

• RUPERT DARWALL

WSJ.COM 9/30/13: "Human influence extremely likely to be the dominant cause of observed warming since the middle of the last century," was the headline from Friday's release of the first instalment of the Intergovernmental Panel on Climate Change's fifth assessment report. "Extremely likely"—indicating a 95%-100% likelihood—was ratcheted up one notch from the 2007 fourth assessment report's "very likely." Yet compared to 2007, the IPCC widened its estimate of the responsiveness of the climate system to carbon dioxide by reducing the lower band to a 1.5°C increase from 2°C, qualifying the new estimate as only "likely."

This is a glaring discrepancy. How can the IPCC be more confident that more than half the temperature rise since the mid-20th century is caused by greenhouse-gas emissions when it is less sure of the climatic impact of carbon dioxide? The explanation is that IPCC reports, especially the summaries for policymakers, are primarily designed for political consumption. And as if on cue, British Prime Minister David Cameron commented on the IPCC report, "If someone said there is a 95% chance that your house might burn down, even if you are in the 5% that doesn't agree with it, you still take out the insurance."

But poke beneath the surface of the IPCC's latest offering and the confection is revealed for what it is. The IPCC's quantification of the separate components of the warming since 1951 (greenhouse gases, cooling from aerosols, internal variability) is deemed only "likely" (66%-100% likelihood). Only at the IPCC could the sum of these components be given a greater likelihood than the individual building blocks. Perhaps the most revealing aspect is that none of the climate scientists involved seems embarrassed at this nonsense or protests at the manipulation of science for political ends.

This time around, the greatest difficulty faced by the IPCC was explaining the ongoing 15-year pause in atmospheric temperature increases. The body estimates that between 2011 and 2005, there has been a 43% rise in human-induced radiative forcing—the difference between solar radiation entering the atmosphere and infrared radiation leaving the atmosphere, whose balance is supposedly greatly disturbed by heat-trapping man-made emissions. But there has been little warming for 15 years.

© Dave Reede/First Light/Corbis

Other than saying that short periods do not reflect long-term trends, the IPCC ducked out of a dilemma of its own making. One lead author, Jochem Marotzke, explained to reporters that the issue had come a bit late in the process. There was a tendency for each of the 14 teams to think someone else was working on it. Thomas Stocker, the working-group co-chair, said that the IPCC relies on peer-reviewed journal articles. "I'm afraid to say there is not a lot of published literature that allows us to delve deeper into the required depth of this emerging scientific question," Mr. Stocker said, as quoted by the Christian Science Monitor. Is it plausible to believe that if the story had been temperatures rising faster than expected, the IPCC and climate journals would have remained silent? Evidently nature has embarrassed the climate-science consensus.

If climate scientists are really as confident in their understanding of the climate as the IPCC's 95% confidence headline figure is meant to suggest, they would put a firm date by when the pause must end and temperatures bounce back to what the IPCC claims is the long-term upward trend. All too predictably, the IPCC avoids such a hard-edged test. It merely projects a likely temperature rise of 0.3°-0.7°C for 2012-2035 compared to 1986-2005, offered with "medium confidence."

A better indicator of the evolution of what climate scientists really think can be found elsewhere. In the IPCC's first assessment report of 1990, there was discussion of scientists' then-inability to reliably detect predicted signals of global warming. The second report, in 1995, said the "signal" was still emerging from the noise of background variability. Have climate scientists at last unambiguously detected the greenhouse signal? The word is not mentioned once in the summary of the 2013 report.

Ever since the second assessment, controversy has surrounded these reports. It first erupted on these pages in 1996, when Frederick Seitz charged that he had "never witnessed a more disturbing corruption of the peer-review process." An official in the U.S. State Department had ordered text to be amended "in an appropriate manner." Justifying the intervention, Stephen Schneider, a leading IPCC climate scientist, argued that the Second Assessment Report was "fraught with political significance" as the Clinton administration was on the verge of announcing its acceptance of binding emissions cuts.

Politicization is thus an ingrained feature of IPCC reports. After the fiasco of the 2007 assessment, the U.N. secretary general asked the InterAcademy Council to review IPCC processes and practices. The committee, chaired by Princeton economist Harold Shapiro, observed that government representatives and scientists meet to agree the final wording of the summary for policymakers line by line "for clarity of message" and to get government "buy-in." Perhaps that's being polite. The real question is who is buying whom.

The committee recommended changes in IPCC governance, which were mostly ignored, and specifically recommended that the IPCC not use the quantitative probability scale that it re-used last week, as in the IPCC's 95% probability headline. The body's flagrant disregard for the InterAcademy Council's findings and its reluctance to address the 15-year warming pause are symptomatic of a failure of leadership. The conclusion is unavoidable: The IPCC is unreformable and the Fifth Assessment Report should be the IPCC's last.

Mr. Darwall is the author of "The Age of Global Warming: A History," (Quartet, 2013).

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Mathematical & observational proof that CO2 has no significant effect on climate

A recent comment at WUWT sets out the mathematical and observational proof that the effect of CO2 on climate is effectively nil. 



The comment is a succinct summary of many recent posts here on the Hockey Schtick. 

Bart says:

September 28, 2013 at 11:09 am

‘As Monk would say, “Here’s what happened”.’

That Monk is a smart guy. It’s been pretty obvious, actually, for a long time that the climate modelers had conflated the natural cyclical upswing with a sudden anthropogenic rise. But, the fact that the rise from approximately 1970-2000 was almost precisely the same as the rise from 1910-1940 gave the game away.

“This analysis shows that the real AGW effect is benign and much more likely to be less than 1 °C/century than the 3+ °C/century given as the IPCC’s best guess for the business-as-usual scenario.”

It’s actually pretty obvious from other data that it must be even less than that, and effectively zero. If we look at the relationship between CO2 and temperatures, it is apparent that to a very high degree of fidelity that

dCO2/dt = k*(T – Teq)

CO2 = atmospheric concentration
k = sensitivity factor
T = global temperature anomaly
Teq = equilibrium temperature

k and Teq are parameters for a 1st order fit. They may change over time, but are well represented by constants for the modern era since 1958 when precise measurements of CO2 became available.

This is a positive gain system – an increase in temperatures produces an increase in CO2 concentration. If we now presume that there is a positive feedback between CO2 and temperature, we get a positive feedback loop, which would be unstable.

There are other negative feedbacks, e.g., the T^4 radiation of heat. But, to maintain stability, these would have to be dominant, in which case the overall effect of CO2 on temperature would be negligible anyway. All roads lead to Rome –whatever the overall system response is, it must be such that the effect of CO2 on temperatures is effectively nil.

Now, a note on how the relationship above comes about. Atmospheric CO2 obeys a partial differential diffusion equation. The interface with the oceans sets boundary conditions. The boundary condition can be considered to obey something akin to Henry’s law (buffering processes complicate the actual relationship)

CO2(boundary) = Kh*CO2_Oceans(boundary)

The derivative of this is

dCO2(boundary)/dt = dKh/dt*CO2_Oceans(boundary) + Kh*dCO2_Oceans(boundary)/dt

Kh is a function of temperature, and thus can be expanded to first order as

Kh = Kh_eq + Kh_partial*(T – Teq)

where Kh_partial is the partial derivative of Kh to temperature. The oceans have been a net source of CO2 to the atmosphere. Assuming these are dominant, then

dCO2(boundary)/dt := (Kh_partial*dCO2_Oceans(boundary)/dt) * (T – Teq)

which is the form of the equation above with

k = Kh_partial*dCO2_Oceans(boundary)

In words, the influx of CO2 from the oceans produces a temperature dependent pumping action into the atmosphere.

The full dynamics are an atmospheric diffusion equation, with ocean boundary conditions as above, as well as a boundary condition with the land, which establishes a flow from the atmosphere into the miinerals and biota of the land, and an outflow from anthropogenic release of latent CO2. This is vastly simplified, of course, as the oceans contain their own biota and other CO2 absorbing processes. So, rather than division strictly into oceans and land, there is some overlap between the two reservoirs. In any case, though I have not yet worked out the details, it is clear where all this is heading. A very simplified ODE system model is

dCO2/dt = (CO2eq – CO2)/tau + H
dCO2_eq/dt = k*(T – Teq)

CO2 = atmospheric CO2
CO2eq = equilibrium CO2 established by the oceanic boundary condition
H = human inputs
tau = a time “constant”

The equilibrium CO2 is established by the interface with the oceans, and is relentlessly driven upward by temperatures above the equilibrium level. These feed into the atmospheric diffusion equation, which is being driven by human inputs, but is also being depleted by natural sinks which react in proportion to the CO2 level above equilibrium.

If “tau” is short, then H will be dramatically attenuated, and have little overall effect, and CO2 will track CO2eq. The actual dynamics are undoubtedly much more complicated, and “tau” would be more precisely modeled as an operator theoretic value which smooths the CO2 differential, leading to a “long tail” response, though not too long in the most significant components, as the data show that human inputs are being fairly rapidly sequestered.

But, this is effectively what the data show is happening. There really is no doubt about it. And, because of the positive feedback effect noted above, CO2 concentration cannot have a significant effect on temperature, because otherwise, we already would have maxxed out at some enormous level of CO2 and exceedingly high temperatures eons ago.

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