August 22, 2008

More Hurricane Reality

A new paper published in GRL gives a 1000-year perspective on Hurricane activity in Boston, USA. The paper is entitled: 'A 1,000-year, annually-resolved record of hurricane activity from Boston, Massachusetts,' by Besonen et al.

The Abstract states:

The annually-laminated (i.e., varved) sediment record from the Lower Mystic Lake (near Boston, MA), contains a series of anomalous graded beds deposited by strong flooding events that have affected the basin over the last millennium. From the historic portion of the record, 10 out of 11 of the most prominent graded beds correspond with years in which category 2–3 hurricanes are known to have struck the Boston area. Thus, we conclude that the graded beds represent deposition related to intense hurricane precipitation combined with wind-driven vegetation disturbance that exposes fresh, loose sediment. The hurricane signal shows strong, centennial-scale variations in frequency with a period of increased activity between the 12th–16th centuries, and decreased activity during the 11th and 17th–19th centuries. These frequency changes are consistent with other paleoclimate indicators from the tropical North Atlantic, in particular, sea surface temperature variations.

The paper concludes:

The LML sedimentary record provides a well-controlled and annually-resolved record of category 2–3 hurricane activity in the Boston area over the last millennium. The hurricane signal shows centennial-scale variations in frequency with a period of increased activity between the 12th–16th centuries, and decreased activity during the 11th and 17th–19th centuries. We recognize that the LML record is a single point source record representative for the greater Boston area, and hurricanes that passed a few hundred km to the east or west may not have produced the very heavy rainfall amounts and vegetation disturbance in the lake watershed necessary to produce a strong signal within the LML sediments. Nevertheless, we also note that clear evidence of a secular change in hurricane frequency identified in the LML record is consistent with other lines of evidence that conditions for the development of hurricanes have changed on centennial timescales. Hence, it appears that hurricane activity was more frequent in the first half of the last millennium when tropical Atlantic SSTs were warmer and eastern equatorial Pacific SSTs were cooler than in subsequent centuries.

Also, a NOAA climate realist speaks out:

Excerpt: “I did not say if there is global warming, it would be man-made,” Mr. Goldenberg emphasized. “Not all scientists agree that the warming we’ve seen is necessarily anthropogenic. It is a blatant lie put forth in the media that makes it seem there is only a fringe of scientists who don’t buy into anthropogenic global warming.” According to Stanley Goldenberg, meteorologist with the Hurricane Research Division of NOAA, based in Miami, “Numerous hurricane meteorologists agree that the historical data has not produced any evidence of changes [due to climate change] in the number or intensity of hurricanes, particularly in the Atlantic Basin, and even globally. “There are some who have done studies that do claim a link, [but] virtually all those studies have been heavily rebutted by others in the hurricane community,” he noted. “In my opinion, the flaw in those studies is an improper utilization of historical databases. I have been a specialist in hurricane climate data for close to three decades, and others who know the databases well agree with what I am saying.” Mr. Goldenberg pointed to a number of confounding problems in such studies, including the time frame chosen, the techniques available now and in the past to measure hurricane activity, the ways in which such activity was recorded, and the availability of satellite data—or lack thereof. “The biggest fallacy is that people think that a hurricane feeds off a warm ocean, and if the ocean gets warmer, we will have more intense hurricanes,” he explained. “But there are other factors involved, such as vertical wind shear, which is the difference between the upper and lower layers of the atmosphere. You could also have drier air. These are far more critical factors than the ocean being warmer. “Everything else being equal, if you warm the ocean under a storm, you might get a stronger storm—but everything else is not equal,” said Mr. Goldenberg. “Warming may increase vertical shear and therefore inhibit storms. The ocean itself warming is such a little effect.” […] Mr. Goldenberg of NOAA added, “There are those who want to attribute any perceived increase in natural disasters to anthropomorphic global warming. I predict that if we have an active hurricane season, someone will attribute it to AGW. They’re not really looking at the science; they’re looking at the disaster.

Global Warming Not Linked To Increased Hurricane Activity

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August 21, 2008

A Spot of Controversy

The current cycle of the sun is taking a long time to start, triggering different explanations, writes Mark Lawson in an article entitled: 'Scientists disagree over lack of sunspots,' published in the Australian Financial Review (subscription required).

Excerpt: Despite being dismissed by a number of scientists as of little consequence to the present discussion of climate change, the issue of the sun's activity - or apparent lack of it - has been the subject of considerable debate in recent months. Scientists who concern themselves with the fledgling subject of space weather (changes in the sun's emissions) have been wondering where all the sunspots have gone, when they might come back and what effect this will have on climate.....

Another scientist who says he has identified a link between the sun's activity and climate - in particular between rainfall in Australia and sunspots - is Robert Baker, an associate professor at the University of New England's School of Human and Environmental Studies. Baker tells the AFR he has identified a strong correlation between sunspots, the sun's magnetic activity and the Southern Oscillation Index (SOI). He says variations in the earth's magnetic field account for about half of the variation in the SOI, and that changes in sunspot activity as an indicator of magnetic activity can be correlated with rainfall patterns in south-east Australia . The Bureau of Meteorology has rejected Baker's reasoning and a paper by him was not accepted by the Australian Meterological Magazine. But Baker says his analysis has been accepted by the peer-reviewed journal Solar Terrestrial Physics for publication in December.

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August 20, 2008

Sea Surface Temperatures of the Oceans Surrounding Australia - A Note from Bob Tisdale

The extended title of the post is "Sea Surface Temperatures of the Oceans Surrounding Australia and the Magnitude of ENSO Events, " because the following illustrations of Sea Surface Temperatures (SSTs) of Australian waters present an interesting effect, the impact of the magnitude of El Nino-Southern Oscillation (ENSO) events on SST. While I've seen it before in other data sets, I haven't yet singled it out for discussion.

(Note: To economize words, throughout the rest of the post, I'll use "Australian waters" in place of "oceans surrounding Australia" or the "combined Southwest South Pacific and Southeast South Indian Ocean data set.")

First, to determine the area to evaluate, I downloaded data for two geographical areas from the NOAA NOMADS system. They're identified by the red and blue boxes in Figure 1. The coordinates used are 10-45S, 105-165E for the red area and 0-55S, 95-175E for the blue.

Figure 1

Figure 2 illustrates the SST anomalies from January 1854 to June 2008 for the two ocean areas surrounding Australia. Both data sets have been smoothed with a 37-month filter. Picking the start date in the trough at 1905 and the end date at a peak in 2000 (There must be an alarmist side to me.), both data sets show rises in SST that are on the order of 1.0 to 1.2 deg C. The two signals are similar, with the smaller area having the greater variations. For the remainder of this post, I'll use the data from the smaller area, the red curve.

Figure 2

Figure 3 shows the raw long-term data for the SST anomalies of Australian waters. Also illustrated is data that's been smoothed with a 12-month running-average filter. Typical of many other oceanic data sets, there is an overall decline in SSTs from the late 1800s to 1910 and a rebound in SSTs until 1940. Then, though there are underlying oscillations, SSTs rise almost continuously from 1940 to present. El Nino events appear to stand out.

Note: The step change (temperature drop) at 1945 has been identified as an error in a recent Thompson et al letter to "Nature" with the title "A Large Discontinuity in the Mid-Twentieth Century in Observed Global-Mean Surface Temperature".
http://www.nature.com/nature/journal/v453/n7195/abs/nature06982.html

Figure 3

But there's something that seems to be missing from the data in later years. Refer to Figure 4, which illustrates short-term (January 1978 to June 2008) SST anomalies for Australian waters. The delayed responses to the 82/83, the 86/87/88, and the 97/98 El Nino events are again easy to find with the sudden rises in SST, but…

Where are the effects of the La Ninas?

The 97/98 El Nino is so much larger than the subsequent multiyear La Nina that it gives the impression that it supplied enough heat to create a step change in the SSTs of Australian waters and that the heat then dissipated over a ten year period. But that impression is only partly correct. The effects of the La Ninas are there, but they are overwhelmed by the magnitudes of those major El Ninos.

Figure 4

In Figure 5, I've added NINO3.4 SST anomaly data to the graph of short-term SST anomalies for Australian waters. A scaling factor of 0.3 has been applied to the NINO3.4 data. I've also noted the timing of the two major volcanic eruptions in case someone feels they're relevant.

The time lags between an ENSO event and the response of SST for Australian waters appear to be on the order of a few months to a year. And with the scaling factor used (0.3), the magnitude of the NINO3.4 SSTs during the 82/83, the 86/87/88, and the 97/98 events appear to generate similarly sized reactions in the SSTs of Australian waters.

Then, starting at 1998, it would appear that the entire drop in NINO3.4 SST should result in a similarly sized response in SST, but the response of the Australian waters falls far short. The logic behind the "Would-Should" statement is wrong.

In simple terms, ENSO events supply heat to sea surfaces when the NINO3.4 SST anomalies are greater than zero and remove heat when they're less than zero. So the reference point for the NINO3.4 data is zero when comparing it to other anomaly data. Looking at the data again and using zero as the reference for the multiyear La Nina episode after the 97/98 El Nino, the reaction by the SSTs of Australian waters is in the proper scale. There are minor differences in the cause and effect and in the time lags in prior ENSO events, but all in all, there are no surprises.

Figure 5

The effects of ENSO events on SST trends are obvious once we're reminded of them. Keep in mind that it is not only the frequency of El Nino and La Nina events but also the magnitude of those events that must be considered during discussions of their impacts on global or local climate.

In "The Evolution of ENSO and Global Atmospheric Temperatures", Trenberth et al identify the linear trend in global temperatures that result from ENSO events: "For 1950-98, ENSO linearly accounts for 0.06 deg C of global warming." http://www.cgd.ucar.edu/cas/papers/jgr2001b/jgr2.html

The effects of ENSO events appear much greater on regional levels.

Closing Note: The additional problems with measuring and calculating global mean sea surface temperature are discussed at length in numerous posts at ClimateAudit and in the papers that are the subjects of or the references used for those posts. For further information, refer to the following ClimateAudit posts:
http://www.climateaudit.org/?p=3114
http://www.climateaudit.org/?p=1272

SOURCE

Sea Surface Temperature Data is Smith and Reynolds Extended Reconstructed SST (ERSST.v2) available through the NOAA National Operational Model Archive & Distribution System (NOMADS).
http://nomads.ncdc.noaa.gov/#climatencdc

Bob Tisdale

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7000 Year Climate Record Shows Century-Long Droughts in North America and 1500 Year Solar Cycle

A stalagmite in a West Virginia cave has yielded the most detailed geological record to date on climate cycles in eastern North America over the past 7,000 years. The new study confirms that during periods when Earth received less solar radiation, the Atlantic Ocean cooled, icebergs increased and precipitation fell, creating a series of century-long droughts.

A research team led by Ohio University geologist Gregory Springer examined the trace metal strontium and carbon and oxygen isotopes in the stalagmite, which preserved climate conditions averaged over periods as brief as a few years. The scientists found evidence of at least seven major drought periods during the Holocene era, according to an article published online in the journal Geophysical Research Letters.

“This really nails down the idea of solar influence on continental drought,” said Springer, an assistant professor of geological sciences.

Geologist Gerald Bond suggested that every 1,500 years, weak solar activity caused by fluctuations in the sun’s magnetic fields cools the North Atlantic Ocean and creates more icebergs and ice rafting, or the movement of sediment to ocean floors. Other scientists have sought more evidence of these so-called “Bond events” and have studied their possible impact on droughts and precipitation. But studies to date have been hampered by incomplete, less detailed records, Springer said.

The stalagmites from the Buckeye Creek Cave provide an excellent record of climate cycles, he said, because West Virginia is affected by the jet streams and moisture from the Gulf of Mexico and the Pacific Ocean.

Other studies have gleaned climate cycle data from lakes, but fish and other critters tend to churn the sediment, muddying the geological record there, said study co-author Harold Rowe, an assistant professor of geological sciences at the University of Texas at Arlington.

“(The caves) haven’t been disturbed by anything. We can see what happened on the scale of a few decades. In lakes of the Appalachian region, you’re looking more at the scale of a millennium,” Rowe said.

Strontium occurs naturally in the soil, and rain washes the element through the limestone. During dry periods, it is concentrated in stalagmites, making them good markers of drought, Rowe explained. Carbon isotopes also record drought, Springer added, because drier soils slow biological activity. This causes the soil to “breathe less, changing the mix of light and heavy carbon atoms in it,” he said.

In the recent study, the scientists cut and polished the stalagmite, examined the growth layers and then used a drill to take 200 samples along the growth axis. They weighed and analyzed the metals and isotopes to determine their concentrations over time.

The data are consistent with the Bond events, which showed the connection between weak solar activity and ice rafting, the researchers said. But the study also confirmed that this climate cycle triggers droughts, including some that were particularly pronounced during the mid-Holocene period, about 6,300 to 4,200 years ago. These droughts lasted for decades or even entire centuries.

Though modern records show that a cooling North Atlantic Ocean actually increases moisture and precipitation, the historic climate events were different, Springer said. In the past, the tropical regions of the Atlantic Ocean also grew colder, creating a drier climate and prompting the series of droughts, he explained.

Unfortunately, at this point the media release replaces data with computer modelled global warming alarmism:

The climate record suggests that North America could face a major drought event again in 500 to 1,000 years, though Springer said that manmade global warming could offset the cycle.

“Global warming will leave things like this in the dust. The natural oscillations here are nothing like what we would expect to see with global warming,” he said.

Though some climate and drought records exist for the Western and Midwest areas of North America, the eastern Appalachian region hasn’t been studied much to date, Rowe said. The research team plans to examine additional stalagmite records from West Virginia and Tennessee to paint a better picture of North American climate cycles.

Collaborators on the study also included Lawrence Edwards, Ben Hardt and Hai Cheng of the University of Minnesota.

Ohio University Research News - ATHENS, Ohio (Aug. 19, 2008): New climate record shows century-long droughts in eastern North America

Weak sun created cool oceans, lowered rainfall seven times in 7,000 years

Geophysical Research Letters

Solar Forcing of Holocene Droughts in a Stalagmite Record from West Virginia in East- Central North America

Abstract:

Elevated Sr/Ca ratios and δ13C values in Holocene-age stalagmite BCC-002 from eastcentral North America record six centennial-scale droughts during the last five North Atlantic Ocean ice-rafted debris (IRD) episodes, previously ascribed to solar irradiance minima. Spectral and cross-spectral analyses of the multi-decadal resolution Sr/Ca and δ13C time series yield coherent ~200 and ~500 years periodicities. The former is consistent with the de Vries solar irradiance cycle. Cross-spectral analysis of the Sr/Ca and IRD time series yields coherent periodicities of 715- and 455-years, which are harmonics of the 1,450±500 year IRD periodicity. These coherencies corroborate strong visual correlations and provide convincing evidence for solar forcing of east-central North American droughts and strengthen the case for solar modulation of mid-continent climates. Moisture transport across North America may have lessened during droughts because of weakened north-south temperature and pressure gradients caused by cooling of the tropical Pacific and Atlantic Oceans. across the region throughout much of the year. As such, hydroclimates of eastern NA are dually sensitive to the climate state of the North AO and mid-latitude transcontinental teleconnections linking the Pacific and North Atlantic oceans [McCabe et al., 2004; Seager, 2007]. Herein, we demonstrate that this dual dependency allowed an east-central NA paleoclimate archive (speleothem) to directly record solar-forcing of Mid- to Late Holocene droughts that were caused by weakening of moisture transport over east-central NA in response to cooling of the Pacific and Atlantic Oceans.

Conclusions:

Seven significant Mid- to Late Holocene droughts are recorded in West Virginia stalagmite BCC-002 as elevated Sr/Ca ratios and δ13C values. Six droughts correlate with cooling of the Atlantic and Pacific Oceans as part of the North Atlantic Ocean ice-rafted debris cycle, which has been linked to the solar irradiance cycle. The Sr/Ca and δ13C time series display periodicities of ~200 and ~500 years and are coherent in those frequency bands. The ~200-year periodicity is consistent with the de Vries (Suess) solar irradiance cycle. We interpret the ~500- year periodicity to be a harmonic of the IRD oscillations. Visually, the Sr/Ca and IRD time series show strong correlations and cross-spectral analysis of the Sr/Ca and IRD time series yields statistically significant coherencies at periodicities of 455 and 715 years. These latter values are very similar to the second (725-years) and third (480-years) harmonics of the 1450±500-years IRD periodicity [Bond et al., 2001]. Collectively, these findings and a 1,200-year periodicity in the Sr/Ca time series, demonstrates solar forcing of droughts in east-central North America on multiple time scales. Droughts typically occur during solar minima when SST in the Atlantic and Pacific Oceans are comparatively cool. These SST anomalies cause migration of the jet stream away from east-central NA, yielding decreased meridional moisture transport and reduced convergence over east-central NA. Our findings appear to corroborate works indicating that millennial-scale solar-forcing is responsible for droughts and ecosystem changes in central and eastern North America [Viau et al., 2002; Willard et al., 2005; Dennison et al., 2007], but our high-resolution time series provide much stronger evidence in favor of solar-forcing of North American drought by yielding unambiguous spectral analysis results.

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August 19, 2008

Climate Skepticism now Mainstream, But Australian PM Hides behind White Coats?

Popular Australian television current affairs program 60 Minutes ran the skeptical line on climate change on Sunday night.

To be sure, there were only two skeptics on the segement Professor Richard Lindzen and Dr David Evans, but they did get a fair hearing.

The Prime Minister was even asked to justify his claim that "the 12 hottest years in human history have occurred in the last 13 years."

Indeed Tara Brown responded, "It's not my position to correct you Prime Minister but Ive been told that in fact during the middle ages the global temperatures were two to three degrees warmer than now. Certainly we've had the hottest 12 years in recent history but the planet's been a lot hotter."

Instead of replying in a considered way, the PM said he stood by what the IPCC had to say. [And since the 'hockey stick debacle', what exactly is the IPCC position on the medieval warm period? ]

Early in the segment the PM had this to say about the IPCC: "There's a group of scientists called the International Panel on Climate Change - 4000 of them. Guys in white coats who run around and don't have a sense of humour. They just measure things."

The PM really has no idea!

You can read the transcript here.
The segment was entitled 'Crunch Time', it was shown on Sunday, August 17, 2008 and the reporter was Tara Brown and producer Stephen Taylor.

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August 17, 2008

Gordon Robertson on a Molten Core

I have become curious about something. The core of the Earth is alleged to be molten. It's also a fact that the deeper you dig into the Earth, the warmer it gets. Where is that heat coming from... surely not from the Sun. What's the possibility that the Earth generates some of it's own heat from geothermal processes?

When I studied a bit of geology, we learned that the Earth is actually oblate, like a pumpkin. That shape apparently comes from the stress of the gravitational pull of the Sun the Moon. As the Earth moves in its orbit about the Sun, it is flexing due to those stresses, and cracks in the Earth heat up as they rub against one another.

There are estimates that the Earth's core may be in the vicinity of 5,000 to 6,000°C. That heat has to go somewhere. There is also a theory that the core may be turning at a differnt rate than the rest. There would be immense friction in that case, and immense heat generated.

Posted by: Gordon Robertson at August 17, 2008 08:18 AM

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William Kininmonth on the Radiation of Energy and Global Warming

Could ‘the greenhouse effect’ be one of those things that everybody claims to understand because it is apparently so important, but in reality it is not supported by a credible scientific literature?

That's the view of Bill Kininmonth, meteorologist and head of Australia's National Climate Centre from 1986 to 1998.

Furthermore, Mr Kininmonth is of the view that, "the role of greenhouse gases is to cool the atmosphere and this, with the surface warming from solar radiation, generates convective instability. It is the temperature lapse rate required for deep convection that leads to the ‘greenhouse effect’"

Confused?

Well in the following note, Mr Kininmonth explains in more detail:

The closest you will come to an explanation of carbon dioxide and the green house effect is in the 'Frequently Asked Questions' of the on-line IPCC Fourth Assessment Report.

My critique on them follows.

“The IPCC’s most recent assessment attempts to be helpful to the casual enquirer by having a series of explanations for ‘frequently asked questions’, or FAQs. The first FAQ is ‘What factors determine earth’s climate’? We are informed that, on average, the earth emits 240 w m-2 of radiation to space and that this equates to an emission temperature of -19oC. The earth’s temperature, however, is about 14oC and the -19oC temperature is found at a height of about 5 km above the surface. To quote the IPCC: “The reason the earth’s surface is this warm is the presence of greenhouse gases, which act as a partial blanket for the longwave radiation coming from the earth’s surface. This blanketing is known as the natural greenhouse effect”.

This explanation by the IPCC is clearly misleading, if not wrong. The inference that the greenhouse gases are acting like a blanket suggests that they are increasing the insulating properties of the atmosphere. However, the main gases of the atmosphere are oxygen and nitrogen, non-greenhouse gases, and they are also excellent insulators against the conduction of heat (like a blanket); adding additional trace amounts of carbon dioxide will have no appreciable impact on the insulating properties of the atmosphere.

In its third FAQ, ‘What is the greenhouse effect?’ the IPCC comes to the nub of the issue but provides a different and equally misleading explanation. “Much of the thermal radiation emitted by the land and the ocean is absorbed by the atmosphere, including clouds, and reradiated back to earth. This is called the greenhouse effect”. According to the IPCC’s global energy budget, the surface emits 390 W m-2 of radiation and the energy radiated back to the surface is 324 W m-2. It is difficult to see how an ongoing net loss of longwave radiation energy from the surface of 66 W m-2 can lead to warming! Indeed, we are all aware that between dusk and dawn the earth’s surface cools.

The IPCC has not explained in a scientifically sound and coherent way, how the ‘greenhouse effect’ is maintained. The greenhouse gases do not increase the insulating properties of the atmosphere and the back radiation does not warm the surface. The IPCC explanation of the greenhouse effect is obfuscation and, even to the mildly scientific literate, reflects ignorance of basic processes of the climate system.”

I am of the view that ‘the greenhouse effect’ is one of those things that is accepted because it is there, everybody claims to understand it because it is so important, but in reality few know how it comes about. My explanation follows (and you will not find this in IPCC publications):

“A credible explanation has no need for smoke and mirrors. The energy flow through the climate system is predominantly by way of four stages: 1) absorption of solar radiation at the surface; 2) conduction of heat and evaporation of latent energy from the surface to the atmospheric boundary layer; 3) convective overturning that distributes heat and latent energy through the troposphere; and 4) radiation of energy from the atmosphere to space. We will see that it is the characteristics of convective overturning that keep the surface warmer than it would otherwise be.

The Kiehl and Trenberth (1997) global average energy budget of the earth (see figure, where the units are W m-2) is used by the IPCC and is a useful starting point for explanation of the establishment and maintenance of the greenhouse effect.

Of the 340 units of solar radiation entering the earth’s atmosphere, 67 are absorbed by the atmosphere and 168 are absorbed at the surface. There is thus an ongoing source of solar energy available to the atmosphere and the surface.

At the surface there is a net accumulation of radiation energy because the incoming solar radiation (168 units) exceeds the net loss of longwave radiation (66 units).

In the atmospheric layer there is absorption of 417 units (390 of emission from the surface, less 40 that go directly to space, plus absorption of 67 of solar radiation) and an emission of 519 units (324 back to the surface and 195 direct emission to space). The net effect of the interaction between the greenhouse gases and radiation is a tendency to cool the atmosphere because it is continually losing energy.

Overall there is a dichotomy, with radiation processes firstly tending to warm the earth’s surface and secondly tending to cool the atmosphere. Air is an excellent insulator against conduction of heat and will not transfer heat through the atmosphere, as is necessary for energy balance. Also, the thermodynamic properties of air (potential temperature increases with height) ensure that turbulent motions of the atmosphere will mix energy downward, not upward as required.

The process for transferring energy from the surface to the atmosphere, necessary to achieve overall energy balance of the climate system, was explained by Herbert Riehl and Joanne Malkus (the latter better known as Joanne Simpson) in a 1958 paper, On the heat balance of the equatorial trough zone (Geophysica). Riehl and Malkus noted that boundary layer air, rising buoyantly in the protected updraughts of deep tropical convection clouds, converts heat and latent energy to potential energy. Away from the convection, compensating subsidence converts potential energy to heat.

What is implied in the Riehl and Malkus model is that deep tropical convection, and the transfer of energy from the surface to the atmosphere, will not take place without buoyant updraughts within deep convection clouds. That is, there is a need for the temperature of the atmosphere to decrease with altitude and that the rate of decrease of temperature must be sufficient to allow buoyancy of the air ascending in the updraughts. From well-known thermodynamic laws, the rate of decrease of temperature must be at least 6.5oC/km to allow the buoyancy forces of convection to overcome the natural stratification of the atmosphere.

The climate system will come into energy equilibrium when temperatures are such that the net solar radiation absorbed is balanced by the longwave radiation to space. At equilibrium, the greenhouse effect (ie, that the average surface temperature of 14oC is greater than the -19oC blackbody emission temperature of earth) is an outcome from the need for convective overturning of the atmosphere.”

Essentially, the role of greenhouse gases is to cool the atmosphere and this, with the surface warming from solar radiation, generates convective instability. It is the temperature lapse rate required for deep convection that leads to the ‘greenhouse effect’. But this takes the wind from the sails of the AGW folk.

William Kininmonth
Melbourne

Mr Kininmonth is the author of Climate Change: A Natural Hazard available from Amazons.

---------------

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August 16, 2008

Arctic Sea Ice Refuses to Melt

"Just a few weeks ago, predictions of Arctic ice collapse were buzzing all over the internet. Some scientists were predicting that the 'North Pole may be ice-free for first time this summer'. Others predicted that the entire 'polar ice cap would disappear this summer'," writes Steven Goddard in yesterday's UK Register.

The article continues, "The Arctic melt season is nearly done for this year. The sun is now very low above the horizon and will set for the winter at the North Pole in five weeks. And none of these dire predictions have come to pass. Yet there is, however, something odd going on with the ice data...

Read more by clicking here.

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Alan Siddons on Radiative Equilibrium

Radiative equilibrium is one of the foundation stones of radiative forcing theory. But it is not a law of physics, only a rather archaic and untested supposition found in climatology textbooks alone.

"For the Earth to neither warm or cool, the incoming radiation must balance the outgoing."

Not really.

It’s best to regard radiant energy simply as a finite power source — indeed, that power is expressed as watts per square meter. An object is said to "cool" by radiating, yet this would seem to imply that restricting its radiation will make it get hotter and hotter. That’s the very premise of greenhouse theory, of course, that by disturbing outgoing radiance any magnitude of temperature gain is possible. But this is easy to test.

Confine a lightbulb inside an infrared barrier (like a globular mirror) and electrically feed one watt to it. After a while, will it be generating the heat of a thousand watt bulb? No.

When its temperature is consistent with the input, further heating stops.

It’s like water seeking its own level. Lacking any means to radiate to its surroundings, the lightbulb merely gets as hot as a watt of power can make it, which is not much hotter than what it would be in the open. If not, we’d be able to generate incredible temperatures very cheaply. Just confine, wait, and release.

Conservation of energy: it’s not just a phrase. The theory of radiative equilibrium arose early in the 19th century, before the laws of thermodynamics were understood.

From The Analytical Theory of Heat:
The radiation of the sun in which the planet is incessantly plunged, penetrates the air, the earth, and the waters; its elements are divided, change direction in every way, and, penetrating the mass of the globe, would raise its temperature more and more, if the heat acquired were not exactly balanced by that which escapes in rays from all points of the surface and expands through the sky. — Joseph Fourier (1768-1830)

Alan Siddons
Holden, Massachusetts

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August 13, 2008

Global Warming and Some Maths: A Note from William Kininmonth

Dear Jennifer,

A couple of weeks ago I became quite agitated after reading an article in The Australian’s Higher Education section by Roger Jones of CSIRO. Jones questioned the sceptics drawing attention to flaws in the computer models and then went on to explain what the models were supposed to do, not what they actually do!

I responded to The Australian with the following submission:

Global Warming: Solving an Environmental Problem or Creating a Social Crisis?

Prevention of dangerous climate change, particularly through implementation of a national carbon pollution reduction scheme, has emerged as a primary policy objective of the Rudd government. The rationale for the policy is the scientific assessment of the Intergovernmental Panel on Climate Change (IPCC) and its computer-based projections of global warming. We are told by the IPCC ‘consensus of scientists’ that continued burning of fossil fuels, and a range of other industry activities that increase the concentration of ‘greenhouse gases’ in the atmosphere, will lead to dangerous climate change, possibly passing a ‘tipping point’ causing ‘runaway global warming’.

What does this all mean, really?

The IPCC’s most recent assessment attempts to be helpful to the casual enquirer by having a series of explanations for ‘frequently asked questions’, or FAQs. The first FAQ is ‘What factors determine earth’s climate’? We are informed that, on average, the earth emits 240 w m-2 of radiation to space and that this equates to an emission temperature of -19oC. The earth’s temperature, however, is about 14oC and the -19oC temperature is found at a height of about 5 km above the surface. To quote the IPCC: “The reason the earth’s surface is this warm is the presence of greenhouse gases, which act as a partial blanket for the longwave radiation coming from the earth’s surface. This blanketing is known as the natural greenhouse effect”.

This explanation by the IPCC is clearly misleading, if not wrong. The inference that the greenhouse gases are acting like a blanket suggests that they are increasing the insulating properties of the atmosphere. However, the main gases of the atmosphere are oxygen and nitrogen, non-greenhouse gases, and they are also excellent insulators against the conduction of heat (like a blanket); adding additional trace amounts of carbon dioxide will have no appreciable impact on the insulating properties of the atmosphere.

In its third FAQ, ‘What is the greenhouse effect?’ the IPCC comes to the nub of the issue but provides a different and equally misleading explanation. “Much of the thermal radiation emitted by the land and the ocean is absorbed by the atmosphere, including clouds, and reradiated back to earth. This is called the greenhouse effect”. According to the IPCC’s global energy budget, the surface emits 390 W m-2 of radiation and the energy radiated back to the surface is 324 W m-2. It is difficult to see how an ongoing net loss of longwave radiation energy from the surface of 66 W m-2 can lead to warming! Indeed, we are all aware that between dusk and dawn the earth’s surface cools.

The IPCC has not explained in a scientifically sound and coherent way, how the ‘greenhouse effect’ is maintained. The greenhouse gases do not increase the insulating properties of the atmosphere and the back radiation does not warm the surface. The IPCC explanation of the greenhouse effect is obfuscation and, even to the mildly scientific literate, reflects ignorance of basic processes of the climate system.

How then do we explain to people who are going to be affected by reactionary government policies what are the greenhouse effect and its enhancement by additional carbon dioxide?

A credible explanation has no need for smoke and mirrors. The energy flow through the climate system is predominantly by way of four stages: 1) absorption of solar radiation at the surface; 2) conduction of heat and evaporation of latent energy from the surface to the atmospheric boundary layer; 3) convective overturning that distributes heat and latent energy through the troposphere; and 4) radiation of energy from the atmosphere to space. We will see that it is the characteristics of convective overturning that keep the surface warmer than it would otherwise be.

The Kiehl and Trenberth (1997) global average energy budget of the earth is used by the IPCC and is a useful starting point for explanation of the establishment and maintenance of the greenhouse effect.

Of the 340 units of solar radiation entering the earth’s atmosphere, 67 are absorbed by the atmosphere and 168 are absorbed at the surface. There is thus an ongoing source of solar energy available to the atmosphere and the surface.

At the surface there is a net accumulation of radiation energy because the incoming solar radiation (168 units) exceeds the net loss of longwave radiation (66 units).

In the atmospheric layer there is absorption of 417 units (390 of emission from the surface, less 40 that go directly to space, plus absorption of 67 of solar radiation) and an emission of 519 units (324 back to the surface and 195 direct emission to space). The net effect of the interaction between the greenhouse gases and radiation is a tendency to cool the atmosphere because it is continually losing energy.

Overall there is a dichotomy, with radiation processes firstly tending to warm the earth’s surface and secondly tending to cool the atmosphere. Air is an excellent insulator against conduction of heat and will not transfer heat through the atmosphere, as is necessary for energy balance. Also, the thermodynamic properties of air (potential temperature increases with height) ensure that turbulent motions of the atmosphere will mix energy downward, not upward as required.

The process for transferring energy from the surface to the atmosphere, necessary to achieve overall energy balance of the climate system, was explained by Herbert Riehl and Joanne Malkus (the latter better known as Joanne Simpson) in a 1958 paper, On the heat balance of the equatorial trough zone (Geophysica). Riehl and Malkus noted that boundary layer air, rising buoyantly in the protected updraughts of deep tropical convection clouds, converts heat and latent energy to potential energy. Away from the convection, compensating subsidence converts potential energy to heat.

What is implied in the Riehl and Malkus model is that deep tropical convection, and the transfer of energy from the surface to the atmosphere, will not take place without buoyant updraughts within deep convection clouds. That is, there is a need for the temperature of the atmosphere to decrease with altitude and that the rate of decrease of temperature must be sufficient to allow buoyancy of the air ascending in the updraughts. From well-known thermodynamic laws, the rate of decrease of temperature must be at least 6.5oC/km to allow the buoyancy forces of convection to overcome the natural stratification of the atmosphere.

The climate system will come into energy equilibrium when temperatures are such that the net solar radiation absorbed is balanced by the longwave radiation to space. At equilibrium, the greenhouse effect (ie, that the average surface temperature of 14oC is greater than the -19oC blackbody emission temperature of earth) is an outcome from the need for convective overturning of the atmosphere.

Additional warming of the surface will come about when the greenhouse effect is enhanced. The fundamental question is how much warming will additional greenhouse gas concentrations cause and will it be dangerous?

An increase in the atmospheric carbon dioxide concentration reduces the emission of longwave radiation to space and increases the back radiation at the surface. An increase in back radiation adds energy to the surface, which will further warm the surface. However there is a constraint on the surface temperature rise because of the commensurate increase in rate of energy loss from the surface: both the rate of infrared emission and the rate of evaporation of latent heat increase with temperature.

The increase in radiation emission from the surface can be calculated from the well-known Boltzmann equation and is 5.4 units/oC at 15oC. The earth’s surface is mainly ocean or freely transpiring vegetation and evaporation will increase near exponentially with temperature according to the Claussius-Clapeyron relationship and is 6.0 units/oC at 15oC. According to the IPCC, the radiative forcing from doubling of carbon dioxide concentration is 3.7 units.

The actual surface temperature increase is derived from the ratio of the radiation forcing (3.7) to the natural rate of increase in surface energy loss with temperature (5.4 + 6.0). The direct surface temperature rise from a doubling of carbon dioxide is therefore 3.7/(5.4 + 6.0) = 0.3oC.

A 0.3oC global temperature increase towards the end of the 21st century from a doubling of current carbon dioxide concentration is not obviously dangerous. However, what also needs to be taken into account is the positive feedback. A warming of the surface temperature will cause a warming of the overlying atmosphere, an increase in the water vapour concentration (another naturally occurring greenhouse gas), a further increase in back radiation, and an incremental increase in surface temperature. Each successive incremental surface temperature increase will cause another incremental temperature increase through the positive feedback amplification.

The amplification follows standard mathematical treatment and, as long as the ratio r is less than unity, the gain is given by [1 / (1 – r)]. Here r is the ratio of natural increase in back radiation with temperature (4.8 units/oC – estimated from a standard radiation transfer model) to the natural increase of surface energy loss with temperature (as previously, 11.4 units/oC). The natural gain is 1.7 and increases the surface temperature rise from a doubling of carbon dioxide concentration from 0.3oC to 0.5oC.

A 0.5oC increase in global temperature over the coming century is within recent short-term temperature variability and is less than the apparent global temperature rise of the past century. Moreover, both the direct forcing of surface temperature and the amplification gain are tightly constrained by the magnitude of the natural increase of surface energy loss with temperature increase. It is not immediately apparent how ‘runaway global warming’ could come about with such a constraint.

A fundamental question arises as to why the IPCC global temperature projections for doubling carbon dioxide concentration, based on computer models of the climate system, lead to estimates of about 3oC, or about six times the above estimate.

A clue to the conundrum can be found in published descriptions of the performance of the computer models used in the IPCC fourth assessment. Isaac Held and Brian Soden, writing in the Journal of Climate (2006) note that the rate of increase of evaporation in the computer models, on average, only increases at about one-third of the rate expected from the Claussius Clapeyron relationship. Additionally, Frank Wentz and colleagues, writing in the journal Science (2007), have confirmed the under-specification of evaporation increase with temperature and, from satellite based observations, have determined that global evaporation does indeed comply with the Claussius Clapeyron relationship.

It is clear from the above formulation of the surface temperature rise and the associated amplification gain that each is sensitive to the specification of evaporation increase with temperature. Substitution of the average evaporation specification of computer models into the formulation will boost the projected temperature rise from the above expected value of 0.5oC to 1.5oC, the lower end of IPCC projections. When the specification of evaporation increase with temperature is very low, as in the more extreme models, then the feedback amplification gain increases to a value of about ten; the temperature sensitivity of the computer model becomes highly exaggerated and model would likely simulate the behaviour of runaway global warming. The behaviour, of course, is false and arises only because of the significant under-specification of evaporation.

Despite the many claims that the IPCC projections of human-caused global warming are sound, the consensus of climate scientists and that the science is settled, there are disturbing shortcomings to both the essential explanations and to the computer modelling. The shortcomings are disturbing because the projections and their associated predictions of diabolical impacts on environmental systems are the only rational justification given for wholesale government restructuring of our industrial base and lifestyles.

This is the first time in human history that there has been a conscious move at the national level to discard the tools that have underpinned security, wellbeing and comfort. We are deliberately abrogating energy usage from proven and widely available sources on the basis of a perceived environmental threat which is poorly articulated and substantiated only by recourse to obviously deficient computer modelling.

Why am I reminded of Charles MacKay’s 1841 tome, “Extraordinary popular delusions and the madness of crowds’?

William Kininmonth
Melbourne, Australia.

William Kininmonth is a former head of Australia’s National Climate Centre; a consultant to the World Meteorological Organization; and author of Climate Change: A Natural Hazard (2004, Multi-Science Publishing)

P.S. The four important papers underpinning my analysis are:

Riehl, H and J. Malkus, 1958. On the heat balance of the equatorial trough zone. Geophysica, v6, Nos 3-4 pp503-538 (This paper describes how heat and moisture from the tropical boundary layer is distributed through the troposphere by way of deep buoyant convection, thus offsetting net radiation loss of energy of the troposphere. Buoyant convection requires a decrease of temperature with altitude, thus the surface must be warmer than the effective emission temperature of the troposphere – the greenhouse effect!)

Priestley, C.H.B., 1966. The limitation of temperature by evaporation in hot climates. Agricultural Meteorology, 3 pp241-246 (This paper explains, supported by data, why deserts are hotter than vegetated lands. Essentially, the earth’s surface loses energy by way of conduction, evaporation and emission of infrared radiation; for dry surfaces there is a shift in energy loss to conduction and radiation at higher temperatures whereas for wet surfaces there is a shift to evaporation of latent heat at a lower temperature. This analysis clearly makes a nonsense of the IPCC claim of a linear relationship between surface temperature increase ΔTs and radiation forcing ΔF, that is, (ΔTs/ΔF = λ). From surface energy balance (or conservation of energy), ΔTs = ΔF*[4*σ*Ts4 + A*L*(dqs/dT)]. Here (dqs/dT) is the rate of increase of water vapour saturation specific humidity with temperature (the Claussius Clapeyron relationship); the first term in the brackets on the right hand side is the rate of increase of surface infrared emission with temperature; and the second term is the rate of increase of latent heat exchange with temperature. For a dry surface, the rate of increase of infrared emission with temperature is approximately linear over short temperature ranges – earth’s surface happens to be approximately 70 percent water and a large part of the remainder is transpiring vegetation.)

Held, I.M. and B.J. Soden, 2006. Robust response of the hydrological cycle to global warming. J of Climate, v19 pp5686-5699 (The paper identifies that, in the GCM used in the IPCC fourth assessment, the rate of increase of surface evaporation is on average only one third the Claussius Clapeyron relationship (dqs/dT). The authors use this deficiency to explain why the rate of convective overturning of the models decreases as temperature increases. The important point is that the GCM apparently significantly under-estimate surface evaporation and latent heat exchange with temperature increase.)

Wentz, F.J., L. Ricciardulli, K. Hilburn and C. Mears, 2007 How much more rain will global warming bring? ScienceExpress 31 May (published later in Science, 13 July 2007). (This paper confirms, from satellite data over recent decades, that global precipitation (and hence evaporation and latent heat exchange) increases with temperature according to the Claussius Clapeyron relationship. Thus the under-estimation of evaporation in GCM also implies an underestimation of precipitation increase with warming. The authors do not recognise that under-estimation of evaporation and latent heat exchange will also lead to overestimation of surface temperature rise! I have quantified the over-estimation of global temperature rise in the analysis that follows.)

Posted by jennifer at 10:02 PM | Comments (146) | TrackBack

The Story of the Caspar Amman Affair and the IPCC AR4 Paleoclimate Chapter

Bishop Hill blog has put together the story of the Amman and Wahl paper that purported to support the 'hockey stick' reconstruction of paleoclimate, cited in IPCC AR4:

There has been the most extraordinary series of postings at Climate Audit over the last week. As is usual at CA, there is a heavy mathematics burden for the casual reader, which, with a bit of research I think I can now just about follow. The story is a remarkable indictment of the corruption and cyncism that is rife among climate scientists, and I'm going to try to tell it in layman's language so that the average blog reader can understand it. As far as I know it's the first time the whole story has been set out in a single posting. It's a long tale - and the longest posting I think I've ever written and piecing it together from the individual CA postings has been a long, hard but fascinating struggle. You may want to get a long drink before starting, and those who suffer from heart disorders may wish to take their beta blockers first.

Read the entire blog post entitled: 'Caspar and the Jesus paper'

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August 12, 2008

Two New Papers Examining the Hurricane-Climate Link

Two new papers examining the link between Hurricanes and climate have been published in the Journal of Climate.

In the July edition, Gabriel A. Vecchi and Thomas R. Knutson have a paper entitled: 'On Estimates of Historical North Atlantic Tropical Cyclone Activity'

The Abstract states:

In this study, an estimate of the expected number of Atlantic tropical cyclones (TCs) that were missed by the observing system in the presatellite era (between 1878 and 1965) is developed. The significance of trends in both number and duration since 1878 is assessed and these results are related to estimated changes in sea surface temperature (SST) over the “main development region” (“MDR”). The sensitivity of the estimate of missed TCs to underlying assumptions is examined. According to the base case adjustment used in this study, the annual number of TCs has exhibited multidecadal variability that has strongly covaried with multidecadal variations in MDR SST, as has been noted previously. However, the linear trend in TC counts (1878–2006) is notably smaller than the linear trend in MDR SST, when both time series are normalized to have the same variance in their 5-yr running mean series. Using the base case adjustment for missed TCs leads to an 1878–2006 trend in the number of TCs that is weakly positive, though not statistically significant, with p 0.2. The estimated trend for 1900–2006 is highly significant (+4.2 storms century−1) according to the results of this study. The 1900–2006 trend is strongly influenced by a minimum in 1910–30, perhaps artificially enhancing significance, whereas the 1878–2006 trend depends critically on high values in the late 1800s, where uncertainties are larger than during the 1900s. The trend in average TC duration (1878–2006) is negative and highly significant. Thus, the evidence for a significant increase in Atlantic storm activity over the most recent 125 yr is mixed, even though MDR SST has warmed significantly. The decreasing duration result is unexpected and merits additional exploration; duration statistics are more uncertain than those of storm counts. As TC formation, development, and track depend on a number of environmental factors, of which regional SST is only one, much work remains to be done to clarify the relationship between anthropogenic climate warming, the large-scale tropical environment, and Atlantic TC activity.

The paper concludes:

Overall, our findings suggest that it is possible that Atlantic TC counts may have significantly increased since the late nineteenth century, although the evidence is decidedly mixed, with some other activity measures showing either no change or a decrease with time. Total storms per year and U.S. landfalling activity show no increasing trend, and average TC duration shows a significant decrease over time. Further, attribution of an increase in tropical storm counts to any particular mechanism (including increasing greenhouse gasses or natural decadal variations) would require further dynamical analysis to complement any observational results. It is noteworthy that in our adjusted record of TCs the sensitivity of basin-wide storm counts to local SST is smaller for the longest time scales (e.g., trend since 1878) than for the pronounced multidecadal variability, although the current observational “best estimate” would be that this sensitivity is positive. Additional study is needed to reconcile these findings with climate simulations of past and future Atlantic storm activity. Future work should also focus on including more ship-track information where possible and examining assumptions about landfall detection in earlier years, and historical tropical cyclone database reconstructions should be extended to include other basins.

See also Discovery Channel News: Warming Won't Drive More Hurricanes, Study Says

In the August edition of the Journal of Climate, Philip J. Klotzbach and William M. Gray have a paper entitled: 'Multidecadal Variability in North Atlantic Tropical Cyclone Activity'

The Abstract states:

Recent increases in Atlantic basin tropical cyclone activity since 1995 and the associated destructive U.S. landfall events in 2004 and 2005 have generated considerable interest into why there has been such a sharp upturn. Natural variability, human-induced global warming, or a combination of both factors, have been suggested. Several previous studies have discussed observed multidecadal variability in the North Atlantic over 25–40-yr time scales. This study, using data from 1878 to the present, creates a metric based on far North Atlantic sea surface temperature anomalies and basinwide North Atlantic sea level pressure anomalies that shows remarkable agreement with observed multidecadal variability in both Atlantic basin tropical cyclone activity and in U.S. landfall frequency.

The paper concludes:

This paper expounds upon previous research by highlighting Atlantic basin multidecadal variability in both large-scale atmospheric–oceanic fields as well as Atlantic basin TC (tropical cyclone) activity. Using an index of basinwide SLP (sea level pressure) and far North Atlantic SSTs (sea surface temperatures), positive and negative periods for the AMO (Atlantic multi-decadal oscillation) can be clearly delineated. When the AMO is in its positive phase, TC activity in the Atlantic basin is heightened, especially for MH (major hurricane) activity. Landfalling hurricanes along the U.S. coastline also become more frequent, with the most dramatic increases in a positive AMO phase being seen for the U.S. East Coast and the Florida Peninsula. Additional research involving potential physical drivers of the AMO should be conducted.

Posted by Paul at 11:44 PM | Comments (2) | TrackBack

Causal Linkage between Carbon Dioxide and Global Warming (Part 3): Causal Criteria Still Wanting

The Australian government is planning to introduce an emission’s trading scheme, also described as a carbon pollution reduction scheme, on the basis that that carbon dioxide from the burning of fossil fuels is contributing to dangerous global warming.

Many people assume that such a drastic action is premised on good evidence establishing a proven causal link between anthropogenic carbon dioxide and global warming.

For example, when establishing causality between an environmental pollutant and an effect on an animal species, scientists would be expect to establish not only a correlation between the presence of the pollutant and an effect (for example an illness in the population), but be also able to demonstrate a dose-response relationship and describe a credible toxicological basis for the proposed mechanism linking the proposed cause and effect.

Interestingly while anthropogenic carbon dioxide is now considered to be one of the worst pollutants,
there does not appear to be a body of work establishing the basic criteria for a claimed causal relationship between the purported pollutant, anthropogenic carbon dioxide, and the claimed effect, global warming; atleast not outside of the United Nations Intergovernmental Panel on Climate Change reports. In particular there does not appear to be a body of work published in reputable scientific journals.

Furthermore, much of the science underpinning the need for a proposed carbon pollution reduction scheme in Australia appears to be based on the claim of a scientific consensus and the observation that there have been increasing levels of atmospheric carbon dioxide over the last 150 years and over this period temperatures have also been generally increasing.

I posted a note on my blog and John Quiggin’s blog on Sunday evening suggesting this deficiency and requesting “research results that have been published in reputable scientific journals that: 1. examine the causal link between anthropogenic carbon dioxide and warming, and 2. quantify the extent of the warming from anthropogenic carbon dioxide.”

Several papers were suggested to me, I believe in good faith, as fulfilling this criteria including a paper entitled ‘Causes of Climate Change Over the Past 1,000 Years’ by Thomas Crowley (14 July 2000, Vol 289, Science).

I was disappointed with the paper when I read it this afternoon. The paper essentially compares output from a reconstruction of past climate with output from an energy balance climate model. In other words, the paper looks at the fit between output from two models. So the paper is about correlation not causation.

But most disappointing, the reconstruction of past climate in the Crowley paper is based on the work of Michael Mann and colleagues which has been the source of much controversy and many believe completely discredited by a report from a team of statisticians led by Edward Wegman, chair of the National Academy of Sciences’ (NAS) Committee on Applied and Theoretical Statistics, assembled at the request of U.S. Rep. Joe Barton and U.S. Rep. Ed Whitfield .

Indeed what has become known as the hockey stick controversy is illustrative of the nature of climate science in what Aynsley Kellow, Professor and Head, School of Government, University of Tasmania, has described as post-normal science with an extensive reliance upon models and the potential for significant manipulation of their source data.

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Part 1, Causal Linkage between Carbon Dioxide and Global Warming:
Part 2, Causal Linkage between Carbon Dioxide and Global Warming (Part 2): Still Searching for Evidence

Posted by jennifer at 10:29 PM | Comments (222) | TrackBack

August 11, 2008

Causal Linkage between Carbon Dioxide and Global Warming (Part 2): Still Searching for Evidence

On Sunday a colleague and I discussed the general issue of correlation versus causation in science. He suggested that 1. There must be a body of work establishing a causal link between anthropogenic carbon dioxide and warming, and also 2. Some work that quantifies the extent of the warming from the anthropogenic carbon dioxide. He assumed as much because our government, the Australian government, is planning major perturbation to our economic system on the basis that carbon dioxide from the burning of fossil fuels is contributing to dangerous global warming. He assumed that the Australian government would not undertake such an action lightly, indeed that such an action would be premised on good evidence establishing a proven causal link between anthropogenic carbon dioxide and global warming. I replied that I was not so sure.

He said he would do a search of the scientific literature on Monday. I said it would be interesting to compare what he turned up from this systematic search of library databases with a few random requests on the internet.

So, Sunday evening I posted a note at my blog, at John Quiggin’s blog and at a yahoo climate science group of mostly so-called climate change skeptics.

Perhaps not surprisingly one of the first to claim that a body of work existed was John Quiggin; a well known climate alarmist. Professor Quiggin went as far as to claim that there are “hundreds of papers on both the causal link and the question of sensitivity” but could only cite a few papers which dabble with the issue of sensitivity later in that blog thread.

By early Monday evening (when I started writing this blog post) the thread at Professor Quiggin’s blog had thrown up only three papers that I thought could potentially provide a causal link and a quantification of the extent of warming. Interestingly one of them was published as long ago as 1938. I had listed the papers earlier in the day at the threads at both Professor Quiggin’s and my blogs to see if other papers were put forward in preference to these, but they weren’t. The papers are:
1. Callendar, G.S., 1938. The artificial production of carbon dioxide and its influence on temperature. Q. J. R. Meteorol. Soc., Vol 64, 223–237.
2. Hofmann, D.J., J. H. Butler, E. J . Dlugokencky, J . W. Elkins, K. Masarie, S. A. Montzka and P. Tans, 2006. The role of carbon dioxide in climate forcing from 1979 to 2004: Introduction of the Annual Greenhouse Gas Index, Tellus B, Vol 58, 614-619.
3. Crowley, T. 2000. Causes of Climate Change Over the Past 1000 Years. Science Vol 289: 270-277.

The Hofmann et al. paper initially looked the most promising to me, is available on the internet (click here) and is the first that I shall consider. (I plan to post comment on the Crowley or Callendar paper tomorrow.)

While the title of the Hofmann et al paper does suggest a “role” is established for carbon dioxide as a forcing/warming agent, in fact it is just assumed in the body of the paper.

The authors simply taken a set of gases (including carbon dioxide) and ascribed an effect: climate forcing. They do not demonstrate a mechanism, or even shown a correlation, between levels of anthropogenic carbon dioxide and global warming.

So, I shall have to conclude that this paper fails the criteria (1. There must be a body of work establishing a causal link between anthropogenic carbon dioxide and warming, and also 2. Some work that quantifies the extent of the warming from the anthropogenic carbon dioxide).

Reading the paper I was struck by the extent to which the authors assume that the increase in atmospheric levels of carbon dioxide since 1750 is primarily a result of “anthropogenic emissions” without explaining why.

There is an extensive scientific literature discussing the notion of causation and how this might be established, for example between environmental stressors and observed effects in natural systems. This literature emphasises that where there are potential alternative explanations for an observed correlation these should be considered.

In the case of carbon dioxide and global warming, Lance Endersbee (former Dean of Engineering and Pro-Vice Chancellor of Monash University) has suggested a direct physical relation between increasingly levels of atmospheric carbon dioxide and increasingly average global sea surface temperatures over the last few decades (click here) suggesting the carbon dioxide is being released from the warming oceans.

Thanks to everyone who has posted and/or emailed papers and comment following my three random requests on the internet last night.

I intend this to be just the second in the series. I shall endeavour to consider the submissions beginning with those that appear the most promising and as a series of blog posts. Of course guest posts, and with alternative opinions, are welcome.

Posted by jennifer at 10:33 PM | Comments (125) | TrackBack

We Aren’t Responsible for Rising Atmospheric Carbon Dioxide: A Note from Alan Siddons

The following chart is largely self-explanatory:

Red: The actual rise of atmospheric CO2 from 1966 to 2006
Pink: The actual rise of human emissions within that 40 year timeframe (starting point at 321 ppm for comparison)
Blue: Human emissions multiplied by 24.41 to parallel atmospheric CO2 growth
Black: The human emissions slope as it would be if CO2 had stagnated in the atmosphere
Gray line: Accumulating atmospheric human emissions with a yearly retention rate of 0.56 -- meaning that 44% is absorbed yearly, which contradicts the assertion that CO2 remains in the atmosphere for hundreds or thousands of years.

Alan Siddons
Holden, Massachusetts

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Data sources are from the US government’s Carbon Dioxide Information Analysis Center (CDIAC):
http://cdiac.ornl.gov/ftp/trends/co2/maunaloa.co2
http://cdiac.ornl.gov/ftp/ndp030/global.1751_2004.ems

But here’s the trick: How do you convert gigatons of carbon into ppm so you can compare the human and atmospheric trend? Well, CDIAC informs you: Divide gigatons by 2.13.
http://cdiac.ornl.gov/faq.html#Q6

Posted by jennifer at 12:38 AM | Comments (92) | TrackBack

August 10, 2008

Causal Linkage between Carbon Dioxide and Global Warming

I've been having some discussions with a colleague who has never thought too hard about anthropogenic global warming.

Anyway, he says there must be some work/some research results that have been published in reputable scientific journals that:

1. examine the causal link between anthropogenic carbon dioxide and warming, and

2. quantify the extent of the warming from anthropogenic carbon dioxide.

What he really want is links to research papers or citations to research papers.

Posted by jennifer at 10:14 PM | Comments (99) | TrackBack

August 09, 2008

Bloggers Fail to Negate Broader Global Warming Argument: Cameron Stewart

Cameron Stewart writing in today's The Australian makes reference to the influence of internet bloggers in succeeding in highlighting that measuring climate change is an evolving science. But, goes on to suggest that "their success has been at the margins only" because we have apparently failed to "prove that these discrepancies negate the broader core arguments about the trends of global warming."

The article is entitled 'Key degrees of difference' and it begins:

"Has global warming stopped? The question alone is enough to provoke scorn from the mainstream scientific community and from the Government, which says the earth has never been hotter. But tell that to a new army of sceptics who have mushroomed on internet blog sites and elsewhere in recent months to challenge some of the most basic assumptions and claims of climate change science...

Read more here: http://www.theaustralian.news.com.au/story/0,25197,24148862-11949,00.html

This is at least the second time in the last two weeks that internet bloggers have been identified by the mainstream Australian media as relevant to the debate on climate change. The earlier story was on ABC Lateline, you can watch the video clip: http://www.abc.net.au/news/video/2008/07/29/2318074.htm . I comment on the Lateline report in an associated blog post here: http://www.jennifermarohasy.com/blog/archives/003290.html.

Posted by jennifer at 09:05 AM | Comments (70) | TrackBack

August 08, 2008

Guest Weblog by Bob Tisdale: Part 2 - Natural Variability of SSTs has NOT been Accounted for by the US CCSP

Natural Variability of SSTs has NOT been Accounted for by the US CCSP.

In my first post at jennifermarohasy.com/blog, I noted a magnificent 0.9 deg C drop and rebound in North Pacific SSTs (sea surface temperatures). The anomaly occurs there between the late 19th to the early 20th centuries. Its impact is reflected in global SST anomaly data illustrated on the same graph:

http://i25.tinypic.com/2cyg07k.jpg

The largest of the late 19th century explosive volcanic eruptions, Krakatau in 1883, was approximately the same magnitude as Mount Pinatubo, and the Mount Pinatubo eruption did not duplicate the effect on SSTs. Assuming that TSI (total solar irradiance) variations are not responsible, and since there have been no discussions in any scientific papers that I could find of an anthropogenic cause for the drop in SST during that period, that leaves Thermohaline Circulation (THC) or Meridional Overturning Circulation (MOC) as the driver.

A similar but lesser drop in SST occurs in the North Atlantic. This data set is the basis for the much studied Atlantic Multidecadal Oscillation (AMO):

http://i27.tinypic.com/212s789.jpg

Referring to the first two illustrations, Global SST anomalies dropped 0.45 deg C from 1878 to 1910, then rebounded that amount plus 0.1 deg C from 1910 to 1941. I acknowledge that I cherry-picked the 1878 start date, but it's used simply for illustration purposes. The AGW skeptical part of me looks at those graphs of Global SST anomalies and concludes that if a 0.45 decrease in SST is within the bounds of natural variability, a 0.45 deg C increase could also be natural, yet global SSTs haven't come close to climbing 0.45 deg C above that 1878 starting temperature.

These THC/MOC oscillations are found in other SST data sets. The drop in SST during that period can also been seen in the data sets of THC upwelling points in both hemispheres of the Atlantic and Pacific Oceans:

http://i27.tinypic.com/29c27v5.jpg

The placid South Pacific appears at first glance to contain more subtle SST oscillations, and it's easy to see the influence of the North Pacific. However, as illustrated, the eastern half of the South Pacific also contains substantial oscillations that are independent of the North:

http://i25.tinypic.com/25allw2.jpg

If we divide the east-central mid-latitude South Pacific by 10 degree longitudinal bands and plot those data sets, those oscillations become much more pronounced:

http://i35.tinypic.com/250s2t2.jpg

THC/MOC MISSING FROM THE NEW CCSP REPORT

The effects of North Atlantic and North Pacific THC/MOC on global SST anomalies are illustrated in the preceding. In the recently released draft of "Global Climate Change Impacts in the United States", the U.S. Climate Change Science Program briefly discusses the impacts of the El Nino-Southern Oscillation and the Pacific Decadal Oscillation on SALMON PRODUCTION. Salmon production? I believe they missed the greater effects of those two natural variables, their influences on climate. I searched the CCSP document for "Atlantic Multidecadal Oscillation ", for "thermohaline", for "meridional", for "overturning", but the search feature of Adobe Reader returned the same message: "No matches were found." I have to conclude from these oversights that the CCSP are either misinformed, or they have been misdirected, or they are attempting to mislead the public.

SOURCES

The graphs are from my series on Smith and Reynolds SST data:

http://bobtisdale.blogspot.com/2008/06/smith-and-reynolds-sst-posts.html

Sea Surface Temperature Data is Smith and Reynolds Extended Reconstructed SST (ERSST.v2) available through the NOAA National Operational Model Archive & Distribution System (NOMADS):

http://nomads.ncdc.noaa.gov/#climatencdc

Bob Tisdale

Posted by Paul at 04:44 PM | Comments (35) | TrackBack

August 07, 2008

Guest Weblog by Bob Tisdale: Part 1

The PDO is NOT a Simple Residual Like the AMO.

People understand the Atlantic Multidecadal Oscillation (AMO). It's calculated very simply; subtract Global SST (sea surface temperature) anomalies from the North Atlantic SST anomalies. This simple process has been said to remove the global warming signal from the AMO. Many people believe the Pacific Decadal Oscillation (PDO) is calculated using the same basic equation, but it's not. According to Nathan Mantua of JISAO, the details of how the PDO is calculated are found in this paper:

ENSO-like Interdecadal Variability: 1900–93

Calculating the PDO is a multistep process. It includes creating an SST anomaly time series for each 5 degree grid of the North Pacific (North of 20N), calculating the residual for each grid, and computing the EOFs ( empirical
orthogonal function) of these North Pacific residual SST anomaly fields. The PDO index is the leading PC (principal component) of that analysis. It's far from a simple process.

The PDO has been found to be a function of ENSO. In "ENSO-Forced Variability of the Pacific Decadal Oscillation", Newman et al state in the conclusions, "The PDO is dependent upon ENSO on all timescales."

A few months ago, I discovered the instructions for retrieving Smith and Reynolds ERSST.v2 data (extended reconstructed SST) from the NOAA NOMADS system based on user selected dates and global coordinates:

http://www.ncdc.noaa.gov/oa/climate/research/sst/ERSST-ts.txt

One of the first data sets I downloaded was the time series of SST anomalies for the North Pacific, 20 to 65N, what I called the Mid-Latitude North Pacific SST Anomaly in the following graph. Note the 0.9 deg C drop then rebound in temperature from the late 19th to the mid-20th centuries. It's tough to miss. It certainly appears to be related to Meridional Overturning Circulation (MOC), not ENSO.

http://i25.tinypic.com/2cyg07k.jpg

Using the same simple process employed to calculate the AMO, that is, subtracting the Global SST Anomaly from the Mid-Latitude North Pacific Anomaly, provides a data set that I've dubbed the North Pacific Residual.

http://i28.tinypic.com/jrwjk6.jpg

The North Pacific Residual bears no resemblance to the PDO. In fact, note that I had to scale the PDO to bring it back into line with the data set from which it is extracted. (The PDO data illustrated is from the ERSST.v2 data set, not the JISAO version. The curves of the two PDO data sets are similar, but the ERSST.v2 data extends further back in time.)

http://i27.tinypic.com/2n1sv49.jpg

When compared to the AMO, the two Northern Hemisphere SST oscillations complement one another from the 1920s to present. Prior to that, they were out of synch, offsetting their individual impacts on global temperature. It is no coincidence that Northern Hemisphere and global temperatures follow the rises and falls of these two residual anomalies.

http://i30.tinypic.com/11kv7r5.jpg

CLOSING
Past studies have estimated the contribution of the AMO to the rises and falls of Northern Hemisphere and Global temperatures over the 20th century. I would think that the North Pacific Residual would contribute similarly. Shouldn't climatologists and climate change bloggers have another index of North Pacific temperature anomalies, one that could be used to determine the effect of the North Pacific SST oscillation on Northern Hemisphere and Global temperatures?

SOURCES

The links and graphs are from my series on Smith and Reynolds SST data:

http://bobtisdale.blogspot.com/2008/06/smith-and-reynolds-sst-posts.html

Sea Surface Temperature Data is Smith and Reynolds Extended Reconstructed SST (ERSST.v2) available through the NOAA National Operational Model Archive & Distribution System (NOMADS):

http://nomads.ncdc.noaa.gov/#climatencdc

Bob Tisdale

Posted by Paul at 09:32 PM | Comments (19) | TrackBack

CSIRO & BoM Drought Report Analysed by David Stockwell

David Stockwell has analysed the CSIRO/BoM Drought Report using data reluctantly released by CSIRO in response to public pressure. His report is entitled: 'Tests of Regional Climate Model Validity in the Drought Exceptional Circumstances Report'

The Abstract states:

In a statistical re-analysis of the data from the Drought Exceptional Circumstances Report, all climate models failed standard internal validation tests for regional droughted area in Australia over the last century. The most worrying failure was that simulations showed increases in droughted area over the last century in all regions, while the observed trends in drought decreased in five of the seven regions identified in the CSIRO/Bureau of Meteorology report. Therefore there is no credible basis for the claims of increasing frequency of Exceptional Circumstances declarations made in the report. These results are consistent with other studies finding lack of adequate validation in global warming effects modeling, and lack of skill of climate models at the regional scale.

Read David's own blog here.

Climate Audit:

Stockwell on CSIRO Drought Report

Some Quick Thoughts on CSIRO Drought Info

CSIRO: A Limited Hang out??

CSIRO and Stock Promotions

CSIRO adopts Phil Jones’ Stonewall Tactic

Posted by Paul at 04:43 PM | Comments (16) | TrackBack

August 05, 2008

Cooling: The Human Climate Signal? A Note from 'Cohenite'

Malcolm Hill alerted me to Cohenite's comments that are worthy of a new thread:

I'm just a middle man connecting the points first raised by John McLean and Thomas Quirk in their paper, ' Australian Temperature Variations - An Alternative View:'

http://mclean.ch/climate/Aust_temps_alt_view.pdf

And Bob Tisdales work with Pacific Decadal Oscillation (PDO)

I agree with Malcolm that this is a crucial issue because if there has been no temperature increase then AGW is shot to bits.

A starting point would be a graph of PDO phase shifts over the 20th Century;

http://wattsupwiththat.files.wordpress.com/2008/04/pdo_monthly.png

There were 3 PDO's during the 20thC; a warm and dry +ve PDO from 1905-46; a cool and wet -ve PDO from 1946-76; and another +ve PDO from 1976-2006.

A typical temperature chart of the 20th Century is as follows;

http://i32.tinypic.com/2s01m5y.jpg

The 2 upward trends at the beginning and end of the 20th Century are typical because they are similar +ve PDO's with similar temperature regimes; if one looks at the slope and amplitude for the temperature increase at the beginning, it is identical to the one from 1977 onwards; the only difference is that the one at the beginning of the 20th Century starts from a lower base. The reason for this is not because the temperatures were lower, but because of base period bias. HadCrut uses a base period of 1961-90. This period covers the end of the middle -ve PDO and the beginning of the 2nd +PDO; an average of the 30 years of this base will cause temperatures in the 2nd +PDO period to be anomalously higher because these temperatures will not have the impact of the cooler temperatures of the base period dragging them down as occurred in the averaging process; conversely, the temperatures in the -ve PDO from 1946 onwards will be anomalously cooler because they do not have the averaging benefit of the +ve PDO temperatures; there will be, therefore a step-up in temperature after 1977 and a step-down before 1946. The base period weighting for Hadcrut is 0.15C, which would drag the temperatures of the 2nd +ve PDO back down slightly; but the weighting doesn't prevent the step-up at 1977 or the step-down at 1946.

What Bob Tisdale has done is to remove the base period bias; he does this by the simple method of annual variance; Tn+1-Tn over the full range of the HadCrut data; the result is this;

http://i25.tinypic.com/e6zj0l.jpg

This shows only variance within the PDO climate; if there was a seperate anthropogenic signal based on increasing CO2 increases it would show as an increasing trend; there is no seperate upward temperature trend, so there is no CO2 caused temperature increase; a comparison between the 2 temperature histories is here;

http://i26.tinypic.com/2hmpw6r.jpg

It is interesting that Lucia has undertaken something similar, but from an opposite direction, when she removed the ENSO signal from all temperature indices in the post 2000 period;

http://rankexploits.com/musings/wp-content/uploads/2008/07/ipcc-falsifies-gavin.gif

That Lucia shows a cooling trend would tend to suggest that if there is an anthropogenic signal, it is a cooling one.

Posted by Paul at 09:19 PM | Comments (100) | TrackBack

Climate Report Plays Hockey with Photoshop

The new US Climate Change Science Program (CCSP) report has been criticised by the likes of Roger Pielke Senior and Junior because science comes a poor third to sloppiness and political advocacy. The report represents the biased and narrow opinions of the lead authors, rather like the UN IPCC reports.

Amongst the report's many and deliberate flaws are the use of the discredited 'Hockey Stick' figure from the Arctic Climate Assessment report (that splices paleoclimate temperature proxies and the modern instrument record, despite expert views that such splicing should not be done), and a image of a flooded house doctored using photoshop.

Maybe one day we will see an objective, scientific climate report that is actually of genuine use to policymakers. I fear global cooling will come to Hell first!

Roger Pielke Sr: Comments On The Draft CCSP Report “Global Climate Change Impacts in the United States”

Prometheus: Sloppy Work by the CCSP

Watts Up With That: NCDC: Photoshopping the climate change report for better impact

Climate Audit: Chucky and the U.S. CCSP

http://www.climateaudit.org/?p=3384#comment-284918

Posted by Paul at 04:46 PM | Comments (6) | TrackBack

Climate Enterprise: Captains' Logs

Britain's great seafaring tradition is to provide a unique insight into modern climate change, thanks to thousands of Royal Navy logbooks that have survived from the 17th century onwards.

A preliminary study of 6,000 logbooks has produced results that raise questions about climate change theories. There was a surge in the frequency of summer storms over Britain in the 1680s and 1690s. Many scientists believe storms are a consequence of global warming, but these were the coldest decades of the so-called Little Ice Age that hit Europe from about 1600 to 1850.

During the 1730s, Europe underwent a period of rapid warming similar to that recorded recently – and which must have had natural origins.

“Global warming is a reality, but what our data shows is that clima