Dr. Rienstra's Review of "Environmental Effects of Increased Atmospheric Carbon Dioxide"

by Arthur B. Robinson, Noah E. Robinson, and Willie Soon

While finality seems always to escape us in this Earthly existence, the debate about whether human activities contribute to current changes in climate is drawing to a close. Only questions of detail and mitigation remain.

Thus I was surprised to find an argument against the entire thesis of human influence on climate in a medical journal.1

The authors' argument seems to be that

The authors go on to note that annual human carbon dioxide emissions total about 8 gigatons, which in comparison to mid- and deep-ocean reservoirs of 38,000 gigatons is vanishingly small. The authors conclude by saying that there is "no experimental evidence" that hydrocarbon emissions influence earth's climate.

Careful attention to the authors' arguments and to the literature they cite reveal numerous faults with the case presented.

Because this paper appears in a medical journal, and presumably addresses a general audience, I respond not as a climate scientist but as a physician and climate science layman. No doubt I will make some errors in interpreting the literature.

Further, I will address only certain points in the authors' very lengthy thesis, and in the order in which they present it. To allow the reader to more quickly cover the important issues, most supporting information and discussion has been relegated to footnotes.

Major Climate Change Issues

Glacial length

The authors imply that mean global temperature is the only determinant of glacier length and cite several references. Reference 42 refutes that implication, noting that factors such as precipitation carry major influence as well.

The authors produce this graph based upon Oerlemans'3 paper

with the caption

"Figure 2: Average length of 169 glaciers from 1700 to 2000 (4). The principal source of melt energy is solar radiation. Variations in glacier mass and length are primarily due to temperature and precipitation (5,6). This melting trend lags the temperature increase by about 20 years, so it predates the 6-fold increase in hydrocarbon use (7) even more than shown in the figure. Hydrocarbon use could not have caused this shortening trend."

Oerlemans, however, the quoted authority, produces a graph of global mean temperature which differs from the authors', showing that global mean temperature does not leave the band of standard deviation until 1900 or later.

Further, glacier behavior in 2007 also contradicts the authors' thesis. Were glacier thinning dependent solely upon global mean temperature, and were global mean temperature trending upward in parallel with solar activity, we would not now be experiencing an acceleration4 of glacier retreat, because we are now at an eleven year solar minimum.5 Data and analysis from the Physikalisch-Meteorologisches Observatorium Davos World Radiation Center indicate that insolation6 in 2007 reached its lowest point since 1975.

Source: http://www.pmodwrc.ch/pmod.php?topic=tsi/composite/SolarConstant

Given this and other data,7 the authors' assertion that solar activity wholly governs earth's temperature loses its force. Sunspot activity does not mirror global insolation nor temperature.8,9 The climate literature shows that this view has been considered and found incomplete.10 As one scientist writes

"we should distinguish between internal influences (such as the deglacial carbon dioxide increase) and external influences (such as the anthropogenic carbon dioxide increase) on the climate system.... The radiative forcing due to carbon dioxide may serve as an amplifier of initial orbital forcing, which is then further amplified by fast atmospheric feedbacks that are also at work for the present-day and future climate."11

Aerosols

The authors' title promises only a discussion of carbon dioxide, but their conclusion that human energy generation is not only harmless but beneficial ignores other important factors such as aerosols. For example, volcanism is well recognized as having caused cooling periods. Human aerosol production as well has complex effects,12 probably mitigating global temperature increases. As we reduce our aerosol production, as we must for health reasons, we may well unmask greenhouse effects of greater magnitude than we now experience.13,14

Carbon dioxide feedback with temperature

The authors' write

"Ice-core records are reported to show seven extended periods during 650,000 years in which carbon dioxide, methane (CH4), and temperature increased and then decreased (63-65). Neither this new source [ human carbon production ] nor the older natural carbon dioxide sources are causing atmospheric temperature to change. The hypothesis that the carbon dioxide rise during the interglacials caused the temperature to rise requires an increase of about 6 °C per 30% rise in carbon dioxide as seen in the ice core record. If this hypothesis were correct, Earth temperatures would have risen about 6 °C between 1900 and 2006, rather than the rise of between 0.1 °C and 0.5 °C, which actually occurred."15

First, all the authors' citations do not support their estimate of temperature rise. They cite the National Climatic Data Center16 as authority for their "0.1 to 0.5 degree C" temperature rise. As I look at the data in the citation, the temperature deviation averaged -0.276 deg C from the first decade given in the reference (1880 through 1889) to 0.694 during the most recent decade (1997 through 2006), for a temperature increase of 0.97 deg C.17

Second, a careful reading of the literature indicates that historic data regarding the sequence and magnitude18 of carbon-cycle changes19 secondary to external and internal forcings is difficult to obtain and interpret. As the authors point out later in their paper, huge carbon sinks exist. Our knowledge of global carbon flows, while impressive, is still inexact, and does not allow us to reach conclusions such as quoted above.

Third, the authors fail to address current thinking about climate. Kemp, for example, writes20

"The pacemaker of Pleistocene climate change seems to be subtle changes in the Earth's orbit around the Sun (see the reviews in this issue by Rahmstorf , pages 207–214, and Lambeck et al., pages 199–206), but the climatic response clearly involves carbon dioxide."
"We need to look beyond the glacial record, though, if we want to be able to predict the future. The range of natural variability in atmospheric pCO2 over the past 400,000 years, from approximately 180 to 280 parts per million by volume (p.p.m.v.), does not even include the present-day human-perturbed value of 370 p.p.m.v. We thus have no analogue in the Pleistocene glacial record for climates of the future, with atmospheric pCO2 potentially reaching 2,000 p.p.m.v. upon complete utilization of the world's coal supplies."
"It is difficult to predict the extent of amplification or damping of the external forcings by internal feedbacks. Complex general circulation models of the climate system incorporate the current understanding of the nature of these feedbacks, and predict net warming well in excess of the direct effects of carbon dioxide for this century."

I do not include this quote as the final word on human influences on climate. Though it is representative,21 uncertainties remain and give some support to Robinson et al.22 Yet, Kemp's disagreement23 with the simplistic views of Robinson et al mirrors the language I find in most all the climate science literature. That is, climate scientists acknowledge many more influences on climate than do Robinson, et al. The referenced papers are replete with as many questions as answers. As a physician and curious human being, my experience has been that those with all the answers usually have something to sell. The ice-core record24 does not tell the simple story that Robinson, et al convey.

Oceanic carbon sink

The authors correctly state that deep ocean carbon dioxide amounts to 38 to 40 thousand gigatons. If, however, atmospheric carbon moved without hindrance into that deep ocean reservoir, atmospheric carbon dioxide would not be increasing. Knowledge about global carbon fluxes exists25 and indicates that there are several mechanisms of carbon flow in the ocean. Some, such as the continental shelf pump26 have limited capacities for carbon transfer into the deeper ocean reservoirs.

Let me pose a medical analogy to the readers of this article in a medical journal. Your doctor notes that you have hypokalemia, in fact being about 5 percent low. He correctly estimates that your total body potassium is about 3000 mEq and draws up a dose of 150 mEq. Are you ready for the injection?27

Other Factual Errors and Shortcomings of Article

In my view, the authors' primary claims critiqued above fatally undermine the major thrust and conclusion of their article. Let me now address other issues raised by the authors.

Unfounded Assumptions re Historical Climate Data

Conflation of Local with Global Phenomena

Medieval Climate Optimum

A major element of the authors' argument is that the globe was warmer around the year 1000 than it is now, which could not have been caused by human contributions to atmospheric carbon dioxide. The time period they refer to, the Medieval Climate Optimum, occurred in the North Atlantic Ocean and Europe, and is not considered by climate scientists a surrogate for global mean temperature.28

Sargasso Sea

The authors introduce temperatures in the Sargasso Sea as evidence that the globe was much warmer about 3000 years ago than it is now. One could easily lose a large ship in the Sargasso Sea, yet it constitutes a minute fraction of the earth's surface.

Robinson's figure 3

The authors figure 3 (reproduced here) summarizes data showing general congruence between arctic air temperature and solar activity; nonetheless climate scientists find such congruence only partially explains global mean temperature. Figure 3 further raises the question as to why arctic sea icing has fallen dramatically in recent years when arctic air temperatures were higher in 1939 than they are now.

Urban Heat Island

Similarly, the "urban heat island" is a well-known phenomenon. The authors present the idea as if new, with no acknowledgement that estimates of global temperature are adjusted to account for such effects.29

Global heat reservoirs include not just the sea surface and land surface, but various levels of the atmosphere, the oceans, and land masses. Climate studies show that local temperatures and global temperatures vary independently.30 The authors err to conflate the two.

Sea Level change

The authors' graph31 of sea level change does not conform with current thinking as to our ability to determine global mean sea levels, especially over time. Further, the authors do not acknowledge the uncertainties and magnitude of sea level changes relative to climate.32

Hurricane Data

In figure 10, the authors illustrate no change in hurricane frequency or severity over time, the caption reading

"Annual number of violent hurricanes and maximum attained wind speed during those hurricanes in the Atlantic Ocean between 1944 and 2006 (22,23). There is no upward trend in either of these records. During this period, world hydrocarbon use increased 6-fold."

Certainly, one can find observers33 who see no demonstrable change in hurricane frequency even though the same observers describe changes in other extreme weather events. Strangely enough, the authors cite a paper34 that concludes

"The years 1995 to 2000 experienced the highest level of North Atlantic hurricane activity in the reliable record. Compared with the generally low activity of the previous 24 years (1971 to 1994), the past 6 years have seen a doubling of overall activity for the whole basin, a 2.5-fold increase in major hurricanes (>/=50 meters per second), and a fivefold increase in hurricanes affecting the Caribbean. The greater activity results from simultaneous increases in North Atlantic sea-surface temperatures and decreases in vertical wind shear. Because these changes exhibit a multidecadal time scale, the present high level of hurricane activity is likely to persist for an additional approximately 10 to 40 years. The shift in climate calls for a reevaluation of preparedness and mitigation strategies."

In this instance, then, the authors' cited source adduces data in complete contradiction of figure 10 and the arguments based upon it.

References that do not support authors' contentions

Aside from the immediately preceding example, several of the author's references do not support the conclusions that the references purport to provide authority for.

Warming on Other Planets

Robinson et al postulate that warming trends on other planets confirm their theory that solar activity is the sole influence on Earth's climate. Their references, while informative, do not confirm this. For example, authors' reference 4135 indicates that, at least on Mars, solar influences are amplified by the atmosphere. On Pluto and Jupiter as well, the cited papers impute but partial importance to solar irradiation.36

Carbon Dioxide Not the only Human Influence on Climate

On page 83, the authors assert

"While major green house gas H2O substantially warms the Earth, minor green house gases such as CO2 have little effect, as shown in Figures 2 and 3."

However, an examination of figure 2 shows glacier length, not global temperature, and does not address minor greenhouse gases. Similarly, figure 3 graphs solar activity, arctic air temperature, and carbon fuel use. To evaluate the degree to which minor greenhouse gases affected arctic air temperature requires

The authors do not make such an analysis. Their references do not support this conclusion. Were their reasoning correct, there would be a great deal more sea ice in the Arctic, for solar insolation, as shown above, is at a several-decadal minimum. The authors' point to data that Antarctic ice may be increasing, but fail to mention the complexity of polar hydrologic cycles37 and data suggesting net Antarctic ice loss.38 They do refer to data indicating loss of Arctic sea ice, but do not mention more dire ramifications39 mentioned in the article cited.

More sober observers find aerosols to a more likely cause of current Arctic climatic change.40

Assertions not Based on Established Facts

On page 81, the authors state

"Figures 2, 3, 11, 12, and 13 show, however, that human use of hydrocarbons has not caused the observed increases in temperature."

Looking back at the referents for this statement, we find that Figure 2, reproduced at the beginning of this essay, incorporates assumptions that do not stand up to analysis. Figure 11 deals with temperature not at all. The statement does not stand up to examination.

Conclusion

The most successful predictions of climatic variations incorporate41

The authors' restrict their analysis to just two of these factors. This article should not have been published as it appears. While, thankfully, the authors do not raise the discredited "hockey stick controversy,"43 the arguments they raise do not stand up to examination.44

Since the authors have not demonstrated their primary thesis, their misleading discussion of agricultural45 benefits is moot as well. Their discussion of economic consequences46 of mitigation of climate change is moot. To make a medical analogy, the cost of the cure may be something to consider, but it cannot be adduced as an argument that the disease does not exist.

Current thought,47 as best this layman can determine it, is that while current conditions result from natural cycling as well as human activity, and while there are many buffering systems in the biosphere, we are subjecting them to changes at a rate and magnitude never before experienced. While earth has previously seen dramatic climatic changes, and while earth will no doubt remain in her orbit whatever we do to her, the most vulnerable of our six-billion member human family may not survive major climatic disruptions and their effect upon agriculture.

Robinson et al pay little attention to the many feed-forward phenomena that contribute to climate change. To make another medical analogy, it is one thing to dispute various approaches to treatment of an individual with recently-discovered cancer; it is entirely another to make such decisions while ignoring the irreversibility of certain outcomes.48

Further Information

Footnotes

1 "Environmental Effects of Increased Atmospheric Carbon Dioxide", Arthur B. Robinson, Noah E. Robinson, Willie Soon, Journal of American Physicians and Surgeons (2007) 12, 79-90.

2 "Extracting a Climate Signal from 169 Glacier Records" by J Oerlemans (Science; Apr 29, 2005; 308, 5722;675

3 Oerlemans also points out that the glacier record, especially in the earlier periods, is most heavily influenced by European observers. (Was nineteenth century European glacier behavior influenced by other industrial emissions such as particulates and aerosols?)

4 http://en.wikipedia.org/wiki/Image:Glacier_Mass_Balance.png

5 http://science.nasa.gov/headlines/y2006/10may_longrange.htm

6 http://en.wikipedia.org/wiki/Insolation

7 Lane LJ, Nichols MH, Osborn HB. Environ Pollut. 1994;83(1-2):63-8. USDA-ARS Southwest Watershed Research Center, 2000 E. Allen Road, Tucson, Arizona 85719, USA.
The hypothesis that statistical analyses of historical time series data can be used to separate the influences of natural variations from anthropogenic sources on global climate change is tested. Point, regional, national, and global temperature data are analyzed. Trend analyses for the period 1901-1987 suggest mean annual temperatures increased (in degrees C per century) globally at the rate of about 0.5, in the USA at about 0.3, in the south-western USA desert region at about 1.2, and at the Walnut Gulch Experimental Watershed in south-eastern Arizona at about 0.8. However, the rates of temperature change are not constant but vary within the 87-year period. Serial correlation and spectral density analysis of the temperature time series showed weak periodicities at various frequencies. The only common periodicity among the temperature series is an apparent cycle of about 43 years. The temperature time series were correlated with the Wolf sunspot index, atmospheric CO2 concentrations interpolated from the Siple ice core data, and atmospheric CO2 concentration data from Mauna Loa measurements. Correlation analysis of temperature data with concurrent data on atmospheric CO2 concentrations and the Wolf sunspot index support previously reported significant correlation over the 1901-1987 period. Correlation analysis between temperature, atmospheric CO2 concentration, and the Wolf sunspot index for the shorter period, 1958-1987, when continuous Mauna Loa CO2 data are available, suggest significant correlation between global warming and atmospheric CO2 concentrations but no significant correlation between global warming and the Wolf sunspot index. This may be because the Wolf sunspot index apparently increased from 1901 until about 1960 and then decreased thereafter, while global warming apparently continued to increase through 1987. Correlation of sunspot activity with global warming may be spurious but additional analyses are required to test this hypothesis. Given the inconclusive correlation between temperature and solar activity, the significant intercorrelation between time, temperature, and atmospheric CO2 concentrations, and the suggestion of weak periodicity in the temperature data, additional research is needed to separate the anthropogenic component from the natural variability in temperature when assessing local, regional, and global warming trends.

8 Lockwood and Frohlich at Stanford used ocean sediment debris and geologic samples to identify solar activity and concluded:

"Our results show that the observed rapid rise in global mean temperatures seen after 1985 cannot be ascribed to solar variability, whichever of the mechanisms is invoked and no matter how much the solar variation is amplified."

Proceedings of the Royal Society A doi:10.1098/rspa.2007.1880 at http://www.pubs.royalsoc.ac.uk/media/proceedings_a/rspa20071880.pdf

http://solar-center.stanford.edu/sun-on-earth/Climate_Change_Attribution.png

9 This graph tracks sunspot numbers since 1850, showing a strong correlation between CO2 and temperature, and less of a correlation with sunspot count.

Source http://solar-center.stanford.edu/sun-on-earth/600px-Temp-sunspot-co2.svg.png

10 This report from Stanford is merely representative

‘Solar irradiance changes have been measured reliably by satellites for only 30 years. These precise observations show changes of a few tenths of a percent that depend on the level of activity in the 11-year solar cycle. Changes over longer periods must be inferred from other sources. Estimates of earlier variations are important for calibrating the climate models. While a component of recent global warming may have been caused by the increased solar activity of the last solar cycle, that component was very small compared to the effects of additional greenhouse gases. According to a NASA Goddard Institute for Space Studies (GISS) press release, "...the solar increases do not have the ability to cause large global temperature increases...greenhouse gases are indeed playing the dominant role..."'
http://solar-center.stanford.edu/sun-on-earth/glob-warm.html

11 Timing of atmospheric CO2 and Antarctic temperature changes across Termination III
Nicolas Caillon; Jeffrey P Severinghaus; Jean Jouzel; Jean-Marc Barnola; et al
Science; Mar 14, 2003; 299, 5613; pg. 1728 CO2 increase lags temp increases by about 800 years. Author's analysis of reasons favors deep ocean equilibrium effects, and in conclusion author states "we should distinguish between internal influences (such as the deglacial CO2 increase) and external influences (such as the anthropogenic CO2 increase) on the climate system.... The radiative forcing due to CO2 may serve as an amplifier of initial orbital forcing, which is then further amplified by fast atmospheric feedbacks that are also at work for the present-day and future climate."

[ CO2 n temp 2.pdf ]

12 Is a Thinning Haze Unveiling the Real Global Warming?
Richard A Kerr. Science. Washington: Mar 16, 2007. Vol. 315, Iss. 5818; pg. 1480
Abstract (Summary)
The sunlight-reflecting haze that cools much of the planet seems to have thinned over the past decade or so, remote-sensing specialists report in this issue of Science. If real, the thinning might explain the unexpectedly strong global warming of late, the accelerating loss of glacial ice, and much of rising sea levels.

Long-Term Satellite Record Reveals Likely Recent Aerosol Trend
Michael I Mishchenko, Igor V Geogdzhayev, William B Rossow, Brian Cairns, et al. Science. Washington: Mar 16, 2007. Vol. 315, Iss. 5818; pg. 1543
Abstract (Summary)
Analysis of the long-term Global Aerosol Climatology Project data set reveals a likely decrease of the global optical thickness of tropospheric aerosols by as much as 0.03 during the period from 1991 to 2005. This recent trend mirrors the concurrent global increase in solar radiation fluxes at Earth's surface and may have contributed to recent changes in surface climate.

13 "Reducing uncertainty about carbon dioxide as a climate driver" Lee R. Kump
Department of Geosciences and NASA Astrobiology Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA Nature 2002 419: 188.

14 "A satellite view of aerosols in the climate system" Yoram J. Kaufman*, Didier Tanré† & Olivier Boucher† Nature 419; 215

*NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771, USA (e-mail: kaufman@climate.gsfc.nasa.gov)

†Laboratoire d'Optique Atmosphérique, Université de Lille/CNRS, Villeneuve d'Ascq, France

"Anthropogenic aerosols are intricately linked to the climate system and to the hydrologic cycle. The net effect of aerosols is to cool the climate system by reflecting sunlight. Depending on their composition, aerosols can also absorb sunlight in the atmosphere, further cooling the surface but warming the atmosphere in the process. These effects of aerosols on the temperature profile, along with the role of aerosols as cloud condensation nuclei, impact the hydrologic cycle, through changes in cloud cover, cloud properties and precipitation. Unravelling these feedbacks is particularly difficult because aerosols take a multitude of shapes and forms, ranging from desert dust to urban pollution, and because aerosol concentrations vary strongly over time and space. To accurately study aerosol distribution and composition therefore requires continuous observations from satellites, networks of ground-based instruments and dedicated field experiments. Increases in aerosol concentration and changes in their composition, driven by industrialization and an expanding population, may adversely affect the Earth's climate and water supply."

15 "Environmental Effects of Increased Atmospheric Carbon Dioxide", Arthur B. Robinson, Noah E. Robinson, Willie Soon, Journal of American Physicians and Surgeons (2007) 12, 85

16 http://data.giss.nasa.gov/gistemp/graphs/Fig.D.txt

17 That, of course, is US data, may be influenced by "heat island" effects, and contributes but little to our knowledge of global mean temperature. However, when the authors confidently list this as their authority one loses confidence in them as un-biased reporters and analysts.

18 Values given for CO2 vs temperature vary widely. Here are two example citations.

Stable Carbon Cycle-Climate Relationship During the Late Pleistocene
Urs Siegenthaler; Thomas F Stocker; Eric Monnin; Dieter Lüthi; et al
Science; Nov 25, 2005; 310, 5752; pg. 1313. Lists numerous efforts to measure for CO2 vs temperature relationships, thinks 1900 year temperature delay is a reasonable average over the period examined.
[ CO2 temp Pleistocene ]

Timing of atmospheric CO2 and Antarctic temperature changes across Termination III
Nicolas Caillon; Jeffrey P Severinghaus; Jean Jouzel; Jean-Marc Barnola; et al
Science; Mar 14, 2003; 299, 5613; pg. 1728 CO2 increase lags temp increases by about 800 years. Author's analysis of reasons favors deep ocean equilibrium effects, and in conclusion author states "we should distinguish between internal influences (such as the deglacial CO2 increase) and external influences (such as the anthropogenic CO2 increase) on the climate system.... The radiative forcing due to CO2 may serve as an amplifier of initial orbital forcing, which is then further amplified by fast atmospheric feedbacks that are also at work for the present-day and future climate."

19 Reducing uncertainty about carbon dioxide as a climate driver Lee R. Kump
Department of Geosciences and NASA Astrobiology Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA Nature 2002 419: 188.

"We need to look beyond the glacial record, though, if we want to be able to predict the future. The range of natural variability in atmospheric pCO2 over the past 400,000 years, from approximately 180 to 280 parts per million by volume (p.p.m.v.), does not even include the present-day human-perturbed value of 370 p.p.m.v. We thus have no analogue in the Pleistocene glacial record for climates of the future, with atmospheric pCO2 potentially reaching 2,000 p.p.m.v. upon complete utilization of the world's coal supplies."

20 Reducing uncertainty about carbon dioxide as a climate driver Lee R. Kump Nature 2002 419: 188.

21 Covariation of carbon dioxide and temperature from the Vostok ice core after deuterium-excess correction
Kurt M. Cuffey & Francoise Vimeux Nature 2001 412: 523.
Ice-core measurements of carbon dioxide1,2 and the deuterium palaeothermometer reveal significant covariation of temperature and atmospheric CO2 concentrations throughout the climate cycles of the past ice ages. This covariation provides compelling evidence that CO2 is an important forcing factor for climate

22 The authors report as fact that CO2 levels do not correlate with global temperature. Workers at Bell Labs conclude "The hypothesis that the increase in atmospheric carbon dioxide is related to observable changes in the climate is tested using modern methods of time-series analysis. The results confirm that average global temperature is increasing, and that temperature and atmospheric carbon dioxide are significantly correlated over the past thirty years. Changes in carbon dioxide content lag those in temperature by five months."
Coherence Established between Atmospheric Carbon Dioxide and Global Temperature
Kuo, Cynthia; Lindberg, Craig; Thomson, David J
Nature; Feb 22, 1990; 343, 6260; pg. 709 [ Current CO2 and temp.pdf ]

23 Reducing uncertainty about carbon dioxide as a climate driver Lee R. Kump Nature 2002 419: 188.

"[greenhouse gases] direct effects on global energy balance can be readily calculated, but the climate system they are disturbing is complex, with numerous feedback mechanisms (interdependent cause–effect relationships) that create indirect effects that are more difficult to predict."

Kump acknowledges that because water vapor is the major greenhouse gas, and because an initial warming 12Kyr ago led to a reglaciation (the Younger Dryas), that human climate influences can, at first blush, be discounted. Robinson, Robinson, and Soon raise just these points.
Kump continues

"To understand the answer to this question we must distinguish ‘external' versus ‘internal' influences on the climate system. External influences include variations in insolation on a wide range of timescales, inputs of greenhouse gases and reflective aerosols from anthropogenic activities and natural processes such as volcanism, and, on geologic (million-year) timescales, the uplift of mountain belts and the geographical distribution of the continents. These factors are external to the climate system in the sense that although they affect climate, climate has no apparent reciprocal effect on them. (However, it has been suggested that climate may indeed influence mountain uplift and thus that tectonics is not strictly ‘external' to the climate system; additionally, policy changes in response to climate change may ultimately affect human activities such as fossil-fuel burning.)"

These external forcings can cause complex atmospheric responses.

"For example, the cooling effect of sulphuric-acid aerosols produced by fossil-fuel combustion offsets some of the present warming resulting from fossil-fuel CO2 emissions, but once the burning stops, the aerosol cooling will disappear within years to decades whereas the warming from CO2 will last for millennia (and thus will affect other climatic factors such as the size of polar ice sheets).

Kemp reviews internal forcings, the feedbacks within the system that amplify or retard external forcings, "which cannot in themselves drive climate change."

This paper in Nature, then, in 2002, contradicts the straw man set up and ostensibly destroyed by Robinson et al.

Kemp notes

"The pacemaker of Pleistocene climate change seems to be subtle changes in the Earth's orbit around the Sun (see the reviews in this issue by Rahmstorf , pages 207–214, and Lambeck et al., pages 199–206), but the climatic response clearly involves CO2."

"We need to look beyond the glacial record, though, if we want to be able to predict the future. The range of natural variability in atmospheric pCO2 over the past 400,000 years, from approximately 180 to 280 parts per million by volume (p.p.m.v.), does not even include the present-day human-perturbed value of 370 p.p.m.v. We thus have no analogue in the Pleistocene glacial record for climates of the future, with atmospheric pCO2 potentially reaching 2,000 p.p.m.v. upon complete utilization of the world's coal supplies."

"It is difficult to predict the extent of amplification or damping of the external forcings by internal feedbacks. Complex general circulation models of the climate system incorporate the current understanding of the nature of these feedbacks, and predict net warming well in excess of the direct effects of CO2 for this century."

Kemp reviews CO2 climate relationships prior to the phanerozoic era (i.e. the more distant geologic past) pointing out difficulties in determining cause and effect. He concludes

"We have made the natural world our laboratory, but the experiment is inadvertent and thus not designed to yield easily decipherable results. Consequently, we will have difficulty isolating the effects of our manipulations from natural variations in climate until the signal has risen well above the noise (and the climate perhaps has been detrimentally altered). In looking into the past history of the planet for clues to the future, we find general support for the notion that an increase in atmospheric pCO2 will cause global warming. However, in detail the relationship is neither linear nor in phase on all timescales. Proxy indicators of global warmth do not always coincide with proxy indications of elevated pCO2 , and when they do, as in the Late Pleistocene, there is no lead–lag relationship from which one might hope to assign cause and effect. Fortunately, improved models evaluated against expanded high-fidelity palaeoclimate databases are on the horizon, and should be adequate to support policy decisions concerning the reduction of fossil-fuel CO2 emissions. In the meantime, there are unsettling indications that these models are underestimating rather than overestimating the climatic consequences of greenhouse gas build-up."

[ CO2 climate driver.pdf ]

24 The Ice-Core Record: Climate Sensitivity and Future Greenhouse Warming
Lorius, C; Jouzel, J; Raynaud, D; Hansen, J; Le Treut, H
Nature; Sep 13, 1990; 347, 6289; 139.
Authors point out the difficulty in reconciling different GCM (global circulation models) because of various uncertainties regarding cloud cover, time phenomena, etc. They point out that ice core studies confirm orbital variation as a driver of pre-industrial climate changes, but that magnitude of change depended historically on greenhouse gas amplification of changes in insolation. (While solar radiation refers to events on the sun, insolation refers to radiative heating of earth depending on orbital precession, obliquity, albedo, latitude in question, etc.) They go on to show that Vostok ice cores indicate that a doubling of atmospheric CO2 concentration results in about 3 to 4 degrees C increase in global temperature, though time sequence is unclear.

Further, there are rapid changes in temperature that cannot be explained by orbital changes, that may be due to alterations in ocean currents or other secondary effects. They note "changes in the CO2 and CH4 content have played a significant part in the glacial-interglacial climate changes by amplifying, together with the growth and decay of the Northern Hemisphere ice sheets, the relatively weak orbital forcing."

25 http://www.ess.uci.edu/~reeburgh/fig1.html

26 http://en.wikipedia.org/wiki/Continental_shelf_pump

27 Note to lay readers. This dose of potassium is lethal within seconds.

28 http://www.grida.no/climate/ipcc_tar/wg1/070.htm
See also http://en.wikipedia.org/wiki/Medieval_climate_optimum

29 http://www.epa.gov/hiri/about/index.html

30 A critique of Micheal Crichton's "State of Fear" at http://www.pewclimate.org/state_of_fear.cfm notes "data to demonstrate that not all locations of the world show warming trends. This is correct, and is acknowledged by the climate science community – as one moves to smaller geographic scales, local factors (e.g., terrain, altitude, land cover, wind patterns, etc.) become increasingly important in determining climate conditions. Hence, the importance of averaging temperature data over large areas, which yields an unambiguous warming trend. Crichton's cherry-picking of sites to show cooling is a common, yet irrelevant tactic. Crichton's second point is that warming appears to manifest only in urban areas, suggesting the effects of urban heat islands explain warming trends. This issue has been investigated repeatedly over the past decade (including a few papers just in the past 18 months), using a variety of methods. Although heat islands are known to occur around urban areas and affect local temperatures, the consistent conclusion is that their influence on global temperature trends is negligible. Furthermore, both satellite and surface observations indicate that the most rapid warming has occurred over land in the Arctic (e.g., northern Canada and northern Asia). Obviously, these are regions that are sparsely populated with low occurrences of dense development or urbanization that could influence temperature trends. Similarly, urban heat islands cannot account for the observed warming of the world's oceans."

31 Figure 11 shows a steady state of sea-level rise since 1850. Figure 12 and accompanying text use historical sea-level readings as evidence that global warming antedates massive CO2 emissions. The reference (Jevrejeva, S., A. Grinsted, J. C. Moore, and S. Holgate (2006), Nonlinear trends and multiyear cycles in sea level records, J. Geophys. Res., 111, C09012, doi:10.1029/2005JC003229) cited

  • gives several compelling reasons why sea level is extremely difficult to determine over the past few hundred years
  • details how it correlates with volcanic activity, not just global temperature
  • points out that natural variation is difficult to understand.

32 Links between climate and sea levels for the past three million years
Kurt Lambeck*†, Tezer M. Esat* & Emma-Kate Potter* Nature 2002 419:199

*Research School of Earth Sciences, Australian National University, Canberra 0200, Australia

†Swedish Research Council and Lund University, Tornavägen 13, S223 63, Sweden

The oscillations between glacial and interglacial climate conditions over the past three million years have been characterized by a transfer of immense amounts of water between two of its largest reservoirs on Earth — the ice sheets and the oceans. Since the latest of these oscillations, the Last Glacial Maximum (between about 30,000 and 19,000 years ago), ~50 million cubic kilometres of ice has melted from the land-based ice sheets, raising global sea level by ~130 metres. Such rapid changes in sea level are part of a complex pattern of interactions between the atmosphere, oceans, ice sheets and solid earth, all of which have different response timescales. The trigger for the sea-level fluctuations most probably lies with changes in insolation, caused by astronomical forcing, but internal feedback cycles complicate the simple model of causes and effects.

33 http://www.gcrio.org/ipcc/qa/08.html

34 Authors reference 23 "The recent increase in Atlantic hurricane activity: causes and implications" by Goldenberg SB et al published in Science. 2001 Jul 20;293(5529):474-9

35 Lori K. Fenton, Paul E. Geissler, Robert M. Haberle. Nature. London: Apr 5, 2007. Vol. 446, Iss. 7136; pg. 646

"For hundreds of years, scientists have tracked the changing appearance of Mars, first by hand drawings and later by photographs. Because of this historical record, many classical albedo patterns have long been known to shift in appearance over time. Decadal variations of the martian surface albedo are generally attributed to removal and deposition of small amounts of relatively bright dust on the surface. Large swaths of the surface (up to 56 million km2) have been observed to darken or brighten by 10 per cent or more. It is unknown, however, how these albedo changes affect wind circulation, dust transport and the feedback between these processes and the martian climate. Here we present predictions from a Mars general circulation model, indicating that the observed interannual albedo alterations strongly influence the martian environment. Results indicate enhanced wind stress in recently darkened areas and decreased wind stress in brightened areas, producing a positive feedback system in which the albedo changes strengthen the winds that generate the changes. The simulations also predict a net annual global warming of surface air temperatures by ~0.65 K, enhancing dust lifting by increasing the likelihood of dust devil generation. The increase in global dust lifting by both wind stress and dust devils may affect the mechanisms that trigger large dust storm initiation, a poorly understood phenomenon, unique to Mars. In addition, predicted increases in summertime air temperatures at high southern latitudes would contribute to the rapid and steady scarp retreat that has been observed in the south polar residual ice for the past four Mars years. Our results suggest that documented albedo changes affect recent climate change and large-scale weather patterns on Mars, and thus albedo variations are a necessary component of future atmospheric and climate studies.."

36 Prediction of a global climate change on Jupiter Philip S Marcus Nature; Apr 22, 2004; 428, 6985; pg. 828

Large changes in Pluto's atmosphere as revealed by recent stellar occultations B Sicardy; T Widemann; E Lellouch; C Veillet; et al Nature; Jul 10, 2003; 424, 6945; pg. 168

The recent expansion of Pluto's atmosphere J L Elliot; A Ates; B A Babcock; A S Bosh; et al
Nature; Jul 10, 2003; 424, 6945; pg. 165

37 An Active Subglacial Water System in West Antarctica Mapped from Space
Helen Amanda Fricker, Ted Scambos, Robert Bindschadler, Laurie Padman. Science. Washington: Mar 16, 2007. Vol. 315, Iss. 5818; pg. 1544
Abstract

Satellite laser altimeter elevation profiles from 2003 to 2006 collected over the lower parts of Whillans and Mercer ice streams, West Antarctica, reveal 14 regions of temporally varying elevation, which we interpret as the surface expression of subglacial water movement. Vertical motion and spatial extent of two of the largest regions are confirmed by satellite image differencing. A major, previously unknown subglacial lake near the grounding line of Whillans Ice Stream is observed to drain 2.0 cubic kilometers of water into the ocean over approximately 3 years, while elsewhere a similar volume of water is being stored subglacially. These observations reveal a wide spread, dynamic subglacial water system that may exert an important control on ice flow and mass balance.

Rethinking Ice Sheet Time Scales Martin Truffer, Mark Fahnestock. Science. Washington: Mar 16, 2007. Vol. 315, Iss. 5818; pg. 1508
Abstract
Information is presented on how satellite data show that ice sheets can change much faster than commonly appreciated, with potentially worrying implications for their stability.

Insignificant Change in Antarctic Snowfall Since the International Geophysical Year
Andrew J Monaghan, David H Bromwich, Ryan L Fogt, Sheng-Hung Wang, et al. Science. Washington: Aug 11, 2006. Vol. 313, Iss. 5788; pg. 827
Abstract

Antarctic snowfall exhibits substantial variability over a range of time scales, with consequent impacts on global sea level and the mass balance of the ice sheets. To assess how snowfall has affected the thickness of the ice sheets in Antarctica and to provide an extended perspective, we derived a 50-year time series of snowfall accumulation over the continent by combining model simulations and observations primarily from ice cores. There has been no statistically significant change in snowfall since the 1950s, indicating that Antarctic precipitation is not mitigating global sea level rise as expected, despite recent winter warming of the overlying atmosphere.

38 Recent Sea-Level Contributions of the Antarctic and Greenland Ice Sheets Andrew Shepherd, Duncan Wingham. Science. Washington: Mar 16, 2007. Vol. 315, Iss. 5818; pg. 1529
Abstract

After a century of polar exploration, the past decade of satellite measurements has painted an altogether new picture of how Earth's ice sheets are changing. As global temperatures have risen, so have rates of snowfall, ice melting, and glacier flow. Although the balance between these opposing processes has varied considerably on a regional scale, data show that Antarctica and Greenland are each losing mass overall. Our best estimate of their combined imbalance is about 125 gigatons per year of ice, enough to raise sea level by 0.35 millimeters per year. This is only a modest contribution to the present rate of sea-level rise of 3.0 millimeters per year. However, much of the loss from Antarctica and Greenland is the result of the flow of ice to the ocean from ice streams and glaciers, which has accelerated over the past decade. In both continents, there are suspected triggers for the accelerated ice discharge—surface and ocean warming, respectively—and, over the course of the 21st century, these processes could rapidly counteract the snowfall gains predicted by present coupled climate models.

39 Perspectives on the Arctic's Shrinking Sea-Ice Cover Mark C Serreze, Marika M Holland, Julienne Stroeve. Science. Washington: Mar 16, 2007. Vol. 315, Iss. 5818; pg. 1533
Abstract

Linear trends in arctic sea-ice extent over the period 1979 to 2006 are negative in every month. This ice loss is best viewed as a combination of strong natural variability in the coupled ice-ocean-atmosphere system and a growing radiative forcing associated with rising concentrations of atmospheric greenhouse gases, the latter supported by evidence of qualitative consistency between observed trends and those simulated by climate models over the same period. Although the large scatter between individual model simulations leads to much uncertainty as to when a seasonally ice-free Arctic Ocean might be realized, this transition to a new arctic state may be rapid once the ice thins to a more vulnerable state. Loss of the ice cover is expected to affect the Arctic's freshwater system and surface energy budget and could be manifested in middle latitudes as altered patterns of atmospheric circulation and precipitation.

40 Arctic Air Pollution: Origins and Impacts Kathy S Law, Andreas Stohl. Science. Washington: Mar 16, 2007. Vol. 315, Iss. 5818; pg. 1537
Abstract

Notable warming trends have been observed in the Arctic. Although increased human-induced emissions of long-lived greenhouse gases are certainly the main driving factor, air pollutants, such as aerosols and ozone, are also important. Air pollutants are transported to the Arctic, primarily from Eurasia, leading to high concentrations in winter and spring (Arctic haze). Local ship emissions and summertime boreal forest fires may also be important pollution sources. Aerosols and ozone could be perturbing the radiative budget of the Arctic through processes specific to the region: Absorption of solar radiation by aerosols is enhanced by highly reflective snow and ice surfaces; deposition of light-absorbing aerosols on snow or ice can decrease surface albedo; and tropospheric ozone forcing may also be contributing to warming in this region. Future increases in pollutant emissions locally or in mid-latitudes could further accelerate global warming in the Arctic.

41 http://www-das.uwyo.edu/~geerts/cwx/notes/chap06/clim_expl.html

42 A search for human influences on thermal structure of the atmosphere by B D Santer, et al ( Nature 1996 July 1; 382:39) discusses separation of human effects from natural variation by analysis of temperature in the troposphere and stratosphere, and concludes that "the trend is partially due to human activities, though many uncertainties remain, particularly relating to estimates of natural variability."

43 In 1999 Mann et al published "Northern Hemisphere temperatures during the past millennium: inferences, uncertainties, and limitations" in Geophysical Research Letters 26:759, the source of the famous "hockey stick controversy" discussed at http://en.wikipedia.org/wiki/Hockey_stick_controversy and more authoritatively reviewed by the National Academy of Sciences at http://books.nap.edu/openbook.php?record_id=11676&page=1 . Much of the "controversy" arose from failure of media figures to acknowledge the uncertainties expressed by the authors in their original report.

44 A full exploration of every claim in this article exceeds my time constraints, but careful attention finds many short-comings beyond those listed here. For example, Robinson et al argue that based upon recent observations, the atmospheric lifetime of CO2 is in the range of eight years. While some observers agree with this figure, the more pertinent question is the lifetime of additional atmospheric CO2. British workers estimate that at from twenty to forty years. (http://www.agu.org/pubs/crossref/1994/93GB03392.shtml) The EPA estimates that the atmospheric lifetime of carbon dioxide at 50 to 100 years. (http://www.epa.gov/nonco2/econ-inv/table.html) Carbon that leaves the atmosphere may return to the atmosphere (http://www.ess.uci.edu/~reeburgh/fig1.html); carbon fluxes can change and can have climatic effects.

On page 83, the authors write "an intermediate temperature ice trend, which led in the 1970's to fears of an impending ice age." If internet scuttlebutt (http://www.wmconnolley.org.uk/sci/iceage) is to be believed there are no peer-reviewed published papers in the 1970's expressing such concerns. While the popular media may have so stated, one cannot adduce such as impugnment of standard climate science.

45 Figure 22, illustrating increased timber resources, elides that US forest acreage has been increasing largely because land once cleared for farming has been left fallow, and become reforested.

The statement that "Amazonian rain forests are increasing their vegetation by about 900 pounds of carbon per acre per year" is misleading, because the cited research ("Carbon dioxide uptake by an undisturbed tropical rain forest in Southwest Amazon" Grace, John; Lloyd, Jon; McIntyre, John; Miranda, Antonio C; et al Science; Nov 3, 1995; 270, 5237; pg. 778 ) refers to "undisturbed" forest. Amazon basin biomass is in fact decreasing. ("Modeling conservation in the Amazon basin" Britaldo Silveira Soares-Filho et al Nature 23 March 2006, 440, 520-523 )

One would certainly hope that elevated atmospheric CO2 would lead to increased forest carbon sequestration but even that is not universally true. According to a report in Nature this year, CO2 uptake by forests in decreasing, not increasing, due to a change in timing of photosynthetic processes. (The original paper is not available to this writer. See report in the Guardian at http://www.guardian.co.uk/environment/2008/jan/03/climatechange.carbonemissions)

46 Commercial energy consultants report in the New York Times that "The United States could shave as much as 28 percent off the amount of greenhouse gases it emits at fairly modest cost and with only small technology innovations, according to a new report." (http://www.nytimes.com/2007/11/30/business/30green.html)

Analysts report that industrial efficiency can result in higher, not lower profits. (http://www.industrialefficiencyalliance.org/ )

Further, the authors' impassioned vision that unrestrained economic activity will benefit all mankind through movement of carbon from the earth's crust into the atmosphere omits the pulmonary consequences of fossil fuel, well known to citizens of nineteenth century London, twentieth century Los Angeles, and contemporary China.

47 Because the Robinson et al lean so heavily on solar effects on climate change, the fact that the Stanford Solar Center holds a contrary opinion is relevant. http://solar-center.stanford.edu/sun-on-earth/glob-warm.html As well, the United Nations Intergovernmental Panel on Climate Change has been studying global warming for years. Their most recent report, issued in February 2007, (see Climate Change 2007: The Physical Science Basis (summary for policymakers), U.N. Report Confirms Human Activity to Blame for Earth's Warming Climate (from Voice of America), and Intergovernmental Panel on Climate Change), concludes that

"The global increases in carbon dioxide concentration are due primarily to fossil fuel use and land-use change, while those of methane and nitrous exide are primarily due to agriculture." The report goes on to note that these findings come with a "very high confidence rate [words emphasized in italics in the report summary] that the globally averaged net effect of human activities since 1750 has been one of warming."

This more conventional explanation of the glacier shortening in 1850 is not addressed in the paper, nor is the analysis of other determinants of global temperature.

48 It must have seemed a good idea to bring some rabbits into Australia to provide sport and game. Every physician can easily recall several experiences of the law of unintended consequences.

NASA felt it was behaving responsibly to launch the Challenger because the engineers, after all, could not demonstrate conclusively that the seals on the booster rockets would fail at low temperatures. Human influences on earth's climate are similarly difficult to predict. As one futurist said "When considering future scenarios, the only real requirement is that your projection be plausible. Nature, of course, has no such restriction."