Guest Editorial by Gerald T. Westbrook
Volume 5, Number 8: 20 February 2002
Introduction
1. Recent Climate Change
There have been many reports and letters to newspapers and magazine editors by proponents(1) of the global warming issue that claim we are experiencing unprecedented climate change. Today, every major weather event receives almost unlimited media coverage. These reports frequently link the event to global warming. The charge is repeatedly made, or implied, that this climate change is due solely to society's activities. One writer, a Bill McKibben, argues these changes are not small at all. He has been most prolific(3) in this effort. His concerns include such items as:
* Spring coming a week earlier in the Northern Hemisphere. Nowhere does he offer any evidence that this event is caused by society. No mention is made that this could just as well be a product of natural climate variation. Nor does he go into any possible benefits of this development(4).
* 10% more vegetation above the 45th parallel since 1980. For those who understand photosynthesis this development would not come as a surprise(5). Again, he does not go into any possible benefits of this development.
* Now the world's climatologists say, with near unanimity, that the planet is heating up and that we are the cause. This statement by McKibben is probably the most outrageous of all he has made. This claim ignores(6a) the position of many key individual climatologists, meteorologists or other scientists that are concerned skeptics. It ignores the various declarations(6b) by climatologists, including the American Association of State Climatologists. And finally, it ignores the largest petition(6c) conducted of knowledgeable scientists and engineers on this subject.
2. ObjectivePerhaps the most egregious reports(2a,2b) about this unprecedented climate change is that for the hockey stick profile. This profile shows 950 years of temperature history as flat to slightly declining, followed by a dramatic rise over the past 50 years. More on this shortly.
The objective here will be a critique of the hockey stick profile and a defense of the prior view of a warm period followed by a cold period and now followed by another warm period. Our climate history is rich with stories of incredible climate change. This 1000-year period is long enough to show that such devastating climate change has occurred, completely independent of society's activities. This period is also recent enough to be relatively well covered by history and to have some familiarity with most readers.
Historian's Views on Recent Past Climates
1. BackgroundRather than listen to how prolific writers from the environmental movement discuss climate change, it is preferable to see what professional historians have had to say about this subject. The first historian is Barbara Tuchman(7), followed by some inputs from Hubert Lamb(8a). Historical inputs from the UN are also included.
Box 1 is a summary of Tuchman's writings on the 14th century. This material was written over 20 years ago. She notes that the 14th century was the start of the Little Ice Age (LIA). This LIA saw a rather dramatic cooling from a warmer era, known as the Medieval Warm Period (MWP). The MWP covered several hundred years up to the 14th century.
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Box 1 - Life in the 14th Century(7) A physical chill settled on the 14th century at its very start, initiating the miseries to come. The Baltic Sea froze over twice, in 1303 and 1306-07; years followed of unseasonable cold, storms and rains, and a rise in the level of the Caspian Sea. Contemporaries could not know it was the onset of what has since been recognized as the Little Ice Age. Nor were they yet aware that, owing to the climatic change, communications with Greenland were gradually being lost, that the Norse settlements there were being extinguished, that cultivation of grain was disappearing from Iceland and being severely reduced in Scandinavia. But they could feel the colder weather, and mark with fear its result: a shorter growing season. This meant disaster, for population in the last century had already reached a delicate balance with agriculture techniques. In 1315, after rains so incessant that they were compared to the Biblical flood, crops failed all over Europe, and famine, the dark horseman of the Apocalypse, became familiar to all. "No epoch was more mutually mad". The 14th was a time of ferocity and spiritual agony - a world plunged into chaos. These are the years when the Black Death struck in the great plague of 1348 - 1350, killing more than a third of the entire population between India and Iceland, and returned four times during the rest of the century .... when freebooting companies of brigands terrorized Europe with impunity .... when a "hundred years' war" seemed to have no beginning and no end, and, defying the belligerents' own efforts to end it, acquired a life of its own. In the next 50 years ... the Black Death disappeared, but ... depopulation reached its lowest point in a society already weakened both physically and morally. |
Perhaps no other writer has covered climate history in general, and the MWP and LIA in particular, more extensively than H. H. (Hubert) Lamb. His research(8a) is used extensively in this report. Among his many achievements was the founding and the initial directing of the Climatic Research Unit, University of East Anglia. Lamb passed away in 1997 as perhaps the greatest climatologist(8b) of his time. He might be viewed as the father of the study of climate change.
Finally, the 1990 and the 1995 Intergovernmental Panel on Climate Change (IPCC) determined that the mean air temperature of the globe most likely varied as shown in Figure 1(9). This temperature graph is deduced from weather records and a variety of proxy climate data. While the graph has the look of precision, there surely are major uncertainties incorporated in it. However, it is supported by, and consistent with, a very large number of anecdotal inputs. Yet today, the IPCC is walking away from this view without any explanation or debate. In contrast, Daly(10) argues if the IPCC today were more objective they would involve historians everywhere to research their resources to determine past climates as observed and experienced by human societies.
Figure 1
2. The Medieval Warm Period
The warmer conditions associated with the MWP are known to have had a largely beneficial impact on both animals and plants. These conditions were so favorable that this period is often referred to as the Little Climate Optimum. After 800 AD there was no doubt(8a) that the climate in Europe was warming. In Europe, temperatures are believed to have reached some of the warmest levels(8a) of the last 4000 years. The conditions during the MWP were such that:
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* More and more trips into the North Atlantic occurred. Records show that Irish monks settled on the Faeroe Islands around 700 AD, and visited Iceland in 790 AD. * A substantial part of the Arctic ice pack retreated north, allowing the settlement of Iceland and Greenland. The first recorded Viking trip to Iceland came in 860 AD. Cultivation of grain started immediately and continued into the 14th century. The first Viking settlement in Greenland was started about 980 AD. This warm phase reached it's peak in Greenland in the 12th century. * Exploration of the Labrador coastline occurred somewhere between 980 and 1000 AD. A modest settlement at L'Anse aux Meadows was established about 1000 AD. * Alpine passes, normally blocked year around with snow and ice, became functional. This development allowed trade between Italy and Germany to flourish. * Sufficient grape production was achieved to permit the emergence of a wine industry in England. Over the period from 1100 to 1300 AD, there seems to have been less threat from frost in the critical month of May. Although the warm phase extended over Europe into the 1300s, the end of the MWP was at hand. |
3. The Little Ice Age
The colder conditions associated with the LIA are known to have had a largely detrimental impact on both animals and plants. The 14th century was not the coldest of the years covered by the LIA, but this gave little comfort to those who were carving out an existence on the margin of sustainable development. The change that occurred was enough to begin to drive the inhabitants south, whether they were Eskimos or Iroquois or Vikings. And if they could not move south, many of them were destined to perish, primarily by starvation.
The coldest part of the LIA in Europe is believed to have occurred around 1695 AD. One of the more incredible reports about this period indicate that, from 1690 to 1728, Eskimos in Kayaks repeatedly visited the Orkney Islands and even northern Scotland.
Temperatures in Figure 1 show nearly a 1½ ºC (2¾ ºF) drop from the high during the MWP. Again, regional variations would exist. For example, for the interval from 1675 to 1705 AD, an area between Iceland and the Faeroe Islands was(9) about 5 ºC (9 ºF) colder than the modern average.
Conditions during the LIA were such that:
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* Sea ice returned to the coast of Iceland in 1203 AD. Between 1200 and 1240 AD the growing of oats on Iceland was abandoned and the production of barley grain was cut in half.
* Sea ice surrounded parts of Ireland. Many reports also indicate that Dutch canals and the Thames River in England froze over, both of which are now generally ice free year around. * Severe storms and flooding occurred in Europe repeatedly with unbelievable casualties. The numbers reported make the Galveston Hurricane look like a minor storm. The very cold North Atlantic created a strong thermal gradient between 50 º and 65 ºN latitudes, which led to occasional cyclonic wind storms exceeding the severity of the worst storms of modern times. Lamb(8a) reports at least four sea floods of the Dutch and German coasts in the 13th century where the death toll exceeded 100,000. These tragedies were repeated in storms of 1421, 1446 and 1570. In the storm of 1570, great cities were flooded and deaths were estimated at 400,000. * The period from 1690 through 1700 has been called the coldest decade in Europe's recorded history. The tragic story(11) of Queen Anne may be of interest in this context. Queen Anne was pregnant 18 times from 1683 to 1700, but only five children were born alive and only one of these survived to the age of eleven. Could this unfortunate string of events have been due to her own poor health? Could it have been a reflection of the state of medical services at that time? Or could it be testimony to the fact that it was impossible to keep the stone castles of that era warm and dry? * On March 6, 1716, the Aurora Borealis(12), also known as the Northern Lights, returned to England. Few, if any, had ever seen this phenomenon, as it had been absent from the skies for over 70 years, since 1645 AD. "Frightened servants thronged the street convinced that the day of judgement had arrived." Scientists now know this was the end of the Maunder Minimum, a period when sunspots virtually disappeared. Without these sunspots, and the magnetic activity and solar wind that came with them, the Northern Lights disappeared. |
4. What was the cause of the MWP/ LIA?
Three ideas are reviewed below. While listed separately, it is possible the three are interconnected. The hypotheses are:
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* Changes in atmospheric circulation. Part of the explanation(8a) of the MWP, in Europe and North America, must be that there was a persistent tilt of the circumpolar vortex(13) away from the Atlantic towards the Pacific. The Pacific was then impacted by frequent intrusions of polar air.
* Changes in oceanic circulation, specifically in the so-called thermohaline circulation(14) (THC). In a recent paper(15), Wallace Broecker, the guru who popularized the THC, noted that one of our tasks is to gain a better understanding of the Little Ice Age and its demise and to confirm or refute that it was due to changes in the THC. Do we understand why the THC has changed? Surely not in adequate detail. Although short term variability in Atlantic climate is thought to be relatively well understood(16) both the patterns and the mechanisms of variability on decadal to century scales are as yet poorly known. * Changes in solar output. It is well known that an 11-year sunspot cycle exists, but this period would seem to be too short for changes seen between the MWP and the LIA. It is also well known that many other solar cycles exist. For example, the 80 - 90 year Gleissberg cycle seems fairly clear in the sunspot record. Longer cycles, on the order of 150 to 300 years, are indicated in the geochemical record, and hinted at in the sun-spot record, with the Spoerer Minimum around 1500 AD, the Maunder Minimum at 1645 to 1715, and the Dalton Minimum at 1795 to 1825. These minima likely contributed to the Little Ice Age. They represent periods when the sunspot activity was at a very low level. Baliunas(17) believes these long-term lulls in activity could be the source of these longer-term climate cycles. Finally, the prospect of a 1500-year cycle has been raised(15). |
The Hockey Stick Analysis
As one might expect, the serious skeptics have been rather disturbed by Mann's reports in general, and the unquestioned acceptance of them by the mass media in particular. As this essay was in its final stages, the writer attended a debate in Houston, where the proponent included his version of Figure 2 in his evidence. There was zero discussion of its basis and its weaknesses. There was zero discussion of the very major uncertainties involved. It was presented as fact. How many other times and places has this graph been so used?
Figure 2
In a recent report(18), the author quotes Wallace Broecker, and notes that, since long-term temperature fluctuations are about 1 ºC, proxies must be accurate to 0.5 ºC to be useful over a 1000-year period. He also notes this rules out tree ring proxies as acceptable input.
Three boxes follow that either critique the hockey stick analysis directly or comment on the state of global warming science.
* The first critique is by John Daly - An Australian, Daly has been perhaps the critic that is the most outspoken. However, he still demands sound science. His arguments are listed in Box 2.
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Box 2 - Daly's Critique(10) of the Hockey Stick
While the developers of this hypothesis used a variety of temperature proxies, it is based almost entirely on tree ring data. Tree ring proxies are not sound indicators of the annual average temperature. They are proxies only for land based growth (~29 % of the planet), over daytime hours, during the growing season. Tree ring growth also depends on many other variables besides temperature: rainfall, sunlight, clouds, pests and nutrients. Conclusion: tree ring data provide a very weak base for temperature reconstructions. Greenhouse advocates argue that proxies are better inputs than historical anecdotes. However, Daly argues the wider academic community will grant much more credibility to well researched historical evidence. He argues it is inconceivable that the MWP/LIA could be observed so globally and yet be missed by Mann's study. He concludes that climate history bears no resemblance whatever to Mann's hockey stick. Daly asks why there was so little challenge to Mann's hypothesis? And why is there collective denial of the alternative hypothesis, e.g., the role of the sun? Daly cites the National Academy of Sciences booklet on the code of scientists. It extols the role of skeptics and the importance of skepticism. It treats them as virtues, but in the global warming field, skeptics are treated with great hostility. While Daly, and indeed this writer, are not opposed to the changing of conventional wisdom on any subject, it should be done with extensive, patient and wide-open debate. This has not been the case here. Rather, we are seeing change by omission, where the existing view is essentially ignored and the new view saluted over and over again by the environmental media and other proponents. Alternatively, the MWP/LIA is defined as only a local phenomenon and, hence, not relevant. Daly refutes this claim with extensive global examples. Ironically, the hockey stick research is based on N. Hemisphere data. |
* The Center for the Study of Carbon Dioxide and Global Change emphasizes the fact that CO2 is the primary raw material required for biomass. It has pioneered in the area of positive biospheric impacts due to increased CO2 production. The two original editors of this site -- Dr. Craig Idso and Dr. Keith Idso -- follow in the footsteps of their father, Dr. Sherwood Idso (who has just recently replaced Craig in this role). They have prepared a large number of editorials or summaries on topics of importance to this field. See Box 3 for several examples.
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Box 3 - Inputs from The Center for the Study of Carbon Dioxide and Global Change
+ Editorial 4-1-99: CO2 and Temperature: The Great Geophysical Waltz - So who leads who? It is definitely not CO2. Sometimes they are totally out of harmony. When they are in harmony, it is temperature that seems to take the lead. + Editorial 8-2-00: Temperature Reconstructions Based on Plant - Climate Interactions are Inaccurate if Atmospheric CO2 varied Over the Period of Reconstruction - QED. + Editorial 2-7-01: The Crux of the Climate Policy Debate - Claim this is a price/tax on carbon. + Editorial 2-14-01: Elitist Leaders Out of Step with Scientific Reality - The Idsos criticize David Gergen's editorial (U.S. News & World Report 2-5-01). Basis for this writing was the recent meeting of 3000 leaders in Davos, Switzerland. + Editorial 2-21-01: The Most Important Global Change - This is population growth along with the food, water and energy needs it will bring. The Idsos argue rather than reducing CO2, we need to let it rise to boost food production. |
* The third critique is based on the work of Fred Singer and his Science & Environmental Policy Project (SEPP). Singer is an atmospheric physicist, professor emeritus of environmental sciences at the University of Virginia and the first director of the U. S. Weather Satellite Service.
Like the Idsos, Singer has a web site and prepares and presents many essays each month. See Box 4. Singer concludes each weekly newsletter with the following quote by Thomas H. Huxley:
| "The improver of natural knowledge absolutely refuses to acknowledge authority as such. For him skepticism is the highest of duties: blind faith the one unpardonable sin." |
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Box 4 Inputs from SEPP - the Science & Environmental Policy Project
+ Science 5-20-98: Anthropogenic climate warming in the 20th century? Reports on three temperature reconstructions that show very different climate profiles since 1400 AD. The most significant differences are in the last 150 years. + EOS 4-20-99: Human Contribution to Climate Change Remains Questionable - Reviews evidence. Notes "the observational evidence suggests that any warming from the growth of greenhouse gases is likely to be minor, difficult to detect above the natural fluctuations of the climate, and therefore inconsequential". + The Christian Science Monitor, 8-24-00. (See also TWTW@sepp.org, 11-23-00): Some Lessons from a Major Climate Change in Our Own Era - Reports on the MWP/LIA with events from North America (Greenland, Ellsemere Island, Vinland, Alaska, and the Rocky Mountains), Europe (England, Iceland, Scotland, and mountain glaciers) and China. |
Conclusions
Several conclusions can be drawn from this excursion into 1300 years of recent history:
(1) Simplistic explanations in the field of climatic phenomena should be avoided as the science is incredibly complex, evolving, and full of areas of either very high uncertainty or of outright propaganda. To truly understand this field, one needs many inputs from a variety of sources.
(2) It is not axiomatic that the higher up the governmental chain one travels, the better the inputs one gets. In particular, readers are reminded that the IPCC is a UN organization, and inputs from it may come wrapped in the UN agenda. While there is very good science inside many UN reports, what frequently gets the headlines are politically driven executive summaries and fancy news releases.
(3) Tree-ring data, while useful for many applications, are not sound proxies for temperature reconstructions, such as the hockey stick profile. At the very best, tree-ring data represent less than 5 % of the temperature coverage needed for a global average (29 % of the world's area as land times about half the hours in a day times about a third of the months in a year). Hence, the existence of the MWP/LIA has not been disproven by this analysis, and the rush to shove the MWP/LIA aside should be halted.
(4) Far more research is needed to better understand the astrophysics, the biogeochemical aspects, the meteorology, and the oceanography that interact with our climate.
(5) Very real, natural, climate-variation phenomena are involved that have nothing to do with the emission of greenhouse gases in the 20th century.
(6) While the existence of strong, natural, climate-variation forces surely does not disprove the conventional greenhouse warming theory, it provieds plenty of food for thought.
(7) While it would be presumptuous to claim that all problems encountered over the past 1300 years were due to cooling, and all positive developments were due to warming, there seem to be some lessons here. The teaching of history just might be that if one had to choose between global cooling and global warming, a warming climate would be the one to choose.
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Gerald T. Westbrook Guest Editor |
References and Notes
(1) In this essay, the word proponents refers to those who believe that serious consequences are imminent unless mankind reduces its emissions of greenhouse gases immediately. Skeptics believe that the case for this scenario has yet to be made.
(2a) Mann, M., et al, Global-scale temperature patterns and climate forcing over the past six centuries, Nature, 392: 779-787, 1998. Mann's paper provides a temperature assessment, over the past millennium, that is primarily based on tree-ring data. This reconstruction, sometimes referred to as the hockey stick profile, shows the decade of the 1990's as the warmest of the Northern Hemisphere this millennium. However the authors of this work indicate their reluctance to compare this analysis with the MWP, by limiting it to the time period after 1400 AD.
(2b) Mann, M., et al, Northern Hemisphere Temperatures During the Past Millennium: Inferences, Uncertainties and Limitations, Geophysical Research Letters, 26, 6, 3-15-99.
(3) As an example of the writings of the omni present Bill McKibben, the following letters are cited. Not only does he write letters to the Editor, but he appears to do it all across the country. Or perhaps he gets it done for him by a hired public relations firm. For example, in spring of 1997, this writer noticed very similar letters by McKibben in the:
+ New York Times, The Earth Does a Slow Burn, 3-7-97,
+ Houston Chronicle, Not the same planet Earth on which we were born, 6-19-97, and
+ Dallas Morning News, U. S. abandons promise to cut greenhouse gas emissions, 6-26-97.
+ Further, one editorial - The Salt Lake Tribune, Global Warming May Be Causing Wild Weather, 5-18-97 - appeared to extract some of it's inputs from McKibben's writings.
It is a safe assumption that similar letters/editorials appeared in other newspapers across the USA.
(4) As one who grew up in the northern plains well knows, what farmers have generally most worried about is not spring coming early, but coming late, or alternatively, the fall frost coming early. Tuchman, in Box 1, notes the same concern, namely, a shorter growing season.
(5) One area that proponents and skeptics agree on is the increased level of carbon dioxide (CO2) in the atmosphere. Since CO2 is the raw material of photosynthesis, it should not be a surprise that increased agricultural yields and forest growth have been widely reported. Why that is a negative is hard to comprehend.
(6a) Gray, W., Viewpoint: Get Off the Global Warming Bandwagon, BBC News, 11-16-00. Dr. Gray is professor of Atmospheric Sciences at Colorado State University and the director of the foremost hurricane forecasting team in the world.
(6b) Cleary, P. (media contact), Survey of State Climate Experts Casts Doubt on Link Between Human Activity and Global Warming, Citizens for a Sound Economy, 10-7-97
(6c) Singer, F., Kyoto Accord Protest Quickening, Washington Times, 4-22-98. This reference notes that 15000 scientists and engineers, with at least 10,000 with advanced degrees signed this petition that urged the U. S. Government to reject the Kyoto Agreement. This petition, known as The Oregon Petition, is now believed to have over 20,000 signatures.
(7) Tuchman, B., A Distant Mirror - The Calamitous 14th Century, Alfred A. Knepf, 1978. Part of this description is from Chapter 2, and part is taken from the inside book cover.
(8a) Lamb, H., Climate, Change and the Modern World, 2nd ed., Routledge, London, New York, 1995.
(8b) Lamb, H., Through all the Changing Scenes of Life - A Meteorologist's Tale, Taverner Publ., 1997
(9) Earth's Climatic History: The Last 1000 Years, Center for the Study of Carbon Dioxide and Global Change, www.co2science.org/subject/other/clim_hist_1thousand.
(10) Daly, J., The 'Hockey Stick': A New Low in Climate Science, 11-12-00. See web site www.microtech.com/au/daly/hockey/hockey.
(11) Sagan, C., The Demon Haunted World - Science as a Candle in the Dark, Ballantine Books, New York, NY, 1996.
(12) Fara, P., Learning from the Past. See the Global Warming Debate - The Report of the European Science and Environment Forum, edited by J. Emsley, Bourne Press Ltd, Bournemouth, Dorset, 1996.
(13) The circumpolar vortex is the major flow of the atmosphere from west to east around the Earth, mainly over the mid-latitudes. The flow is never strictly circular around the pole, but exhibits wave-like movements with ridges and troughs in the pattern.
(14) The thermohaline circulation moves warm surface water from the tropics (via, for example, the Gulf Stream) to the North Atlantic. As this water cools, and as the salt concentration gradually increases, it ultimately sinks and returns south as a deep current. The term conveyor belt has been used to describe it, but this is an overly simplified analogy.
(15) Broecker, W., et al, Possible 20th-Century Slowdown of Southern Ocean Deep Water Formation, Science, 286, 11-5-99.
(16) Black, D., et al, Eight Centuries of North Atlantic Ocean Atmosphere Variability, Science, 286, 11-26-99.
(17) Baliunas, S., et al, The Sun Also Warms, presented at the GCMI/CEI Cooler Heads Coalition meeting, 3-24-00. This George C. Marshall paper is also available at www.marshall.org/sunalsowarms.
(18) World Climate Report, A High-Stick 100-Year Forecast, 3-5-01. See web site: www.greeningearthsociety.org/climate/v6n12/hot1.
(19) Additional references are incorporated into Box 3 and Box 4.
GERALD T. WESTBROOK is a chemical engineer and an energy economist by education. He retired in 1994 from Dow Hydrocarbons and Resources, Inc., after 34 years of service. Prior to that he worked for Imperial Oil in Canada for four years. His goal on retirement was to remain active in the many areas of interest to him. This has included activities in consulting, primarily in the petrochemical and petroleum refining fields, in educational support activities, in issues analysis, primarily on climate change, and on a retailing venture. Mr. Westbrook received his B.S. in Chemical Engineering from the University of Saskatchewan at Saskatoon, his M.S. in Chemical Engineering from the University of Minnesota, and his M.A. in Economics, also from the University of Minnesota at Minneapolis.
Among his duties at Dow was the preparation of three issues analysis on global warming, starting in 1988. In retirement, Westbrook has continued to research, write and speak on this issue. He is actively involved in various efforts to communicate the status of this issue and the rather embryonic nature of the sciences involved. Mr. Westbrook has published several dozen papers, essays, editorials and letters on the general status of the sciences, the inadequacy of computer models for policy formulation, on data quality, on the overall debate and on the politics involved. He has spoken at many professional organizations and conducted seminars at the University of Houston and Rice University, both in Houston. He is also a senior associate at the Energy Institute, University of Houston.
Mr. Westbrook is a member of the American Institute of Chemical Engineers, the International Association for Energy Economics, and the Southwest Chemical Association. He is a past member of the American Association for the Advancement of Science, American Geophysical Union and the National Association of Business Economists.