Customer Reviews

The Great Warming: Climate Change and the Rise and Fall of Civilizations

5 star:		(11)
4 star:		(11)
3 star:		(4)
2 star:		(8)
1 star:		(1)

 

 

Brian Fagan, a popular anthropoogist, has again written a well researched, clearly written book on climate and human anthropology. The Great Warming details how climate in the past affected different civilizations. From the Mayan Culture to Medieval Europe, Fagan investigates the period known as The Medieval Warm Period (800AD to 1350AD). Unlike other his other well regarded book, the Little Ice Age, Fagan expands his research into Asia, the Saraha, China, India, the Artic, and South America. As the result of his research, he believes that the Medieval Warm Period should be re-named the Medieval Dry Period, as much of the globe saw periods of devastating droughts, with Europe being the exception.

What Brian Fagan does best is to get down to the micro level of human existence during these periods. He uses his forensic skills in illustrating how individuals from the peasant to the nobility coped with sudden changes in thier local climate. He ties in history, anthropoligy and just enough climate science to render a very detailed easy to read narrative. The reader does not have to be a professional climate scientist or anthropoligst to understand his essays. Techinical language is kept to a minimum. His chapters that cover Gengis Khan, the Intuits, as well the Moors Gold Trade are quite fascinating.

There are a few technical defects I see in this book. One, is his use of the now famed Hockey Stick graph authored by Dr. Michael Mann. The reader should be warned that many of Fagan's climate graphs are derived from this flawed temperature reconstruction. The Hockey Stick essientially writes off the Medieval Warm Period as well as the Little Ice Age. Michael Mann believes they were both regional (European) events, and not global in reach. Subsequent audits done by McKitrick and McIntyre, as well as by Von Storch raised serious questions as to the validity of the Hockey Stick. I get the feeling, Dr Fagan had to answer to the Hockey Stick, as his previous book on the Little Ice Age pretty much concluded that the Little Ice Age was a global and not a regional climate event. Fagan, to his credit, stays out of the political catfights that now surround the whole question of Climate Change, and focuses mainly on the human implications. Fagan relies mainly on human records, fossils, and archeology, and not on esoteric proxy temperature reconstructions or global circulation models. The other defect I found concerns the Pacific Decadal Oscillation. Dr Fagan only visited this oscillation briefly when he discussed the climate of Western North America. The Pacific Decadal Oscillation (PDO) clearly enhances the strength of the El Nino Southern Oscillation (ENSO). Dr Fagan also gives no mention of the Atlantic Mutlidecadal Oscialltion (AMO). Together, the AMO and PDO drive about 60% of our global weather patterns. The study of these 2 oscillations are in thier infancy. Depsite what Dr Fagan says, the science is far from settled.

The power of this book lies in the evidence that Dr Fagan presents. That evidence is that as far as human civilizations are concerned, in the long run it is not temperature but precipitation that we should be worried about. Through out history , the majority of humans have lived not in the temperate mid latitudes, but in the tropics and subtropics. For this reason, atmospheric oscillations such as the Walker Circulation and ENSO drive the rise and fall of many civilzations through aburpt changes in precipitation patterns.

I suggest the reader purchase both the Great Warming and the Little Ice, and read them back-to-back. Brian Fagen offers a powerfull narrative on the implications of Climate Change. It matters not if the reader is a proponent of Anthropgenic Global Warming or a skeptic. The Great Warming both serves to enlighten and to warn. It is written by an excellent scientist and fantastic writer who obviously loves the field that he studies.

Most people who have heard the term "Medieval Warming Period" tend to think of it as a period of good weather in Western Europe which led to population growth, the construction of Gothic Cathedrals, and the beginning of the rise of centralized nation-states. Brian Fagan, in another work as intriguing as his earlier "The Little Ice Age, "The Long Summer," and "Floods, Famines, and Emperors," now examines the world wide evidence that this particular warming period not only affected Western Europe but Asia, Africa, Polynesia, and the Americas as well.

I find Fagan's work fascinating on many levels. His clear, succinct explanations of the science behind tree ring, glacial ice core, and sedimentation analyses are approachable but not insultingly simple for non-scientists. His ability to draw parallels is impressive, helping us to recognize that what benefited or at least did not harm one culture was damaging or even catastrophic to others. This is quite important when we study the El Nino-Southern Oscillation, or ENSO, which can cause simultaneous floods in the Americas and droughts in India. I especially like his short vignettes of life in various cultures during the Warming Period, which place the climate changes they had to deal with in human context.

This is an important book which helps us better understand the role climate change has played in the past and its potential role in our own future.

Climate change is a regular item in the news. Most articles and books look at the future - few address the past. While the human condition is a large consideration, real effects are not often dwelt on. Brian Fagan makes up for both these lacks in this finely researched and comprehensive study. In a framework centred on a millennium in the past, he takes us on a global tour of what is known as The Medieval Warm Period. Lasting for half a millennium, about 850 C.E. to 1300 C.E, Fagan shows us the importance of understanding the global nature of climate and its interconnected elements.

In Europe, the era was later named the High Middle Ages. Flourishing trade, wine grown in the British Isles and shipped to France [!] and the mighty cathedrals erected typified the period. Elsewhere, conditions weren't as salubrious. In the North American Southwest, drought brought to a close the civilisation of Chaco Canyon and toppled the great Mayan Empire. In Asia, the great Ankor Wat, built to symbolise a vast and rich realm, was abandoned to the jungle. China's peasant population, always at the edge of survival, was driven from their lands in many places by alternating extended droughts and torrential rainfalls stripping the soil. Even the Mongol Horde was prompted to move in what proved nearly catastrophic for Europe, driven by the need for grazing lands.

Enduring climate change has been a human consideration from the beginning. Even our evolutionary roots lie in the drying of Africa and the subsequent emergence of the savannah. In one sense, climate is what brought us the role of the one bipedal ape. The development of agriculture made us yet more vulnerable to shifts in climate, Fagan reminds us. Dependence on rainfall is the foundation of raising crops, alleviated only a little by irrigation canals. Irrigated farming plays a major role in this book, with the South American and other civilisations struggling with problems of water management. Those lacking such amenities, such as California Indians, suffered drastically when the severest droughts in thousands of years killed off natural food supplies.

Fagan's talent as a writer is equalled by his feeling for the human condition. In each region he describes, it's more than weather changes that he's concerned with. It's what that meant to the local population and how it reacted. The author uses a deft ploy to capture the reader's interest at the beginning of each section. He sets up a local scene with imaginary, but carefully defined, participants. The situation reflects the weather and social conditions, indicating how those interact to produce behaviours and adjustments.

At first glance, this book may seem merely a "history" with little meaning for today's conditions or those of the future. However, it is far from that - being instead a diagnosis for what is to come. Fagan concludes by reminding us of past population dislocations resulting from the great droughts. That pressure is certain to emerge again, and he asks how ready we are to deal with it. Although climate change is "normal", as the events of the Medieval Warm Period demonstrate, the population today is vastly larger than it was then. With the human contribution to warming accelerating the process, it will be billions of people affected by what is to come. In the earlier time, some people, such as the Chaco Canyon residents, had the ability to adjust, our capacity to follow their example is curtailed by our high density centres. This book is an overdue warning of what we, or our grandchildren, will be facing. [stephen a. haines - Ottawa, Canada]

My mother in law bought me three Brian Fagan books for Christmas last year because they were on my Amazon Wish List. I read the first one The Little Ice Age: How Climate Made History, 1300-1850 right away and enjoyed it. I gave it four stars. Feel free to follow the link and see what I said - my review is dated December 31, 2008.

I was saving this one, hoping to enjoy it just as much. Now, I am worried that I'll never muster enough interest to read the third one.

"The Great Warming" seems rushed - a poorly edited and a poor man's version of Jared Diamond's Collapse: How Societies Choose to Fail or Succeed with some global warming hype thrown in for good measure. Many of the cultures covered by Fagan were covered in Diamond's more detailed book.

Fagan looks at the time of the Medieval Warming Period, approximately from 800 AD to 1300 AD, and the effects of this slightly warmer time on numerous societies, including Western Europe, the Mongols, the Inuit, the Pueblos, the peoples of California, China, Easter Island and the Khmer of Southeast Asia. This is not a long book so there is just a snapshot of each civilization. Fagan notes that the data suggests that the Medieval Warm Period was a time of frequent droughts for nearly everyone but Central Asia and Europe. He points to research that suggests El Nino events caused or contributed greatly to the Medieval Warming Period.

Fagan theorizes that the Warming Period destroyed multiple civilizations and that we may suffer the same fate (pages 238-242). But, Fagan fails to note what he himself has written throughout the book - we do not understand climate systems. We think that some of these things may (might, probably, the data suggests - you pick the euphamism) be related but in reality we are unsure. Yes, we are warmer now than we were in 1860, at the end of the Little Ice Age. But, our warming may or may not have a thing to do with the warming of the past. They may be caused by different things. Fagan goes with the theory of man-made global warming which means his dire warnings from the past ("Today, we are experiencing sustained warming of a kind unknown since the Ice Age. And this warming is certain to bring drought..." - p. 239) are probably pointless since they were not caused by man-made global warming. Fagan points out the droughts during the Medieval Warming Period were caused by El Nino events that lasted for years. Were those events caused by the heat or did they create the heat? I suggest Fagan has fallen victim to the old causation/correllation trap. Certainly there is not enough hard data to suggest that the weather patterns of the Medieval Warming Period will be repeated in the 21st Century.

Fagan's thesis of man-made global warming (and the near-constant nagging throughout the book) is weakened by his own charts on pages 17 & 19 which clearly show a cooler period ending about 800 AD, a warmer period from 800-1300, a cooler period from 1350-1860 and a warmer period from 1860 to the present. The pattern is cool-warm-cool-warm. All of the comments about how we don't understand climate and the cool-warm-cool-warm pattern negate a good portion of the book.

There are other niggling details, such as the self-contradictory paragraph on page 123 that notes that NO ONE in the history of the entire world depended on acorns as much as the California Indians. Except, of course, for the Syrians that depended on them for their ENTIRE diet 14,000 years ago that he mentioned earlier in the same paragraph. His explanation of why the Pueblos were abandoned by a Anasazi flies in the face of more recent scholarship. Fagan makes it sound orderly ("Fortunately, the ancient traditions kicked in and people adjusted by moving away, household by household." - page 136) even though there is evidence some Pueblos were burned and were hastily abandoned (their belongings were left behind and scattered about) and there may have been widespread cannibalism (he poo-poos it as a bit of "ritual cannibalism"). To me that sounds like chaos, civil war or possibly invasion, not a gradual decline and walking away from a civilization.

For me, the final straw was the offhand comment on page 153 that maybe the Mayans could have stopped Cortes from invading Central Mexico and defeating the Aztecs if they hadn't have collapsed due to the Warm Period. Cortes landed in Vercruz. Veracruz was not a Mayan area. They were influenced by trade with Mayans but they were not Mayan.

I am hardly an expert, but if I spot these problems how many more are there?

So, my final assessment in a word: Disappointed.

Since I read two of Brian Fagan's books, "The Little Ice Age" and "The Great Warming" together, I'll review them together too.

Fagan's expertise is at digesting the latest voluminous and obscure scientific and archaeologic research results, then boiling them down and portraying them in plain (and sometimes even poetic) English for the non-professional readers. You won't be sidetracked by academic debates, by data that's been stale for decades, by researchers that don't know when to quit writing, or by pesky boundaries between different academic disciplines.

Fagan is very careful not to go beyond the actual research results (in fact he's almost sqeamish about it). There aren't a lot of all-encompassing grand theories here. And there isn't much that couldn't be footnoted to a specific paper. In these books Fagan forgoes footnotes for other reasons, but you sense that if he wanted to he could footnote almost every sentence without ticking off the original researchers.

Fagan must be a serious sailor - there are occasional bits of small boat jargon nobody else would know (or use correctly). This is a plus that's neither common nor obtrusive; unless you have some familiarity with sailing yourself, you'll probably never even notice it. And the insight into and descriptions of things like Norse and Polynesian voyages are much deeper than you'd expect. This is the one area where Fagan seems to fill out and even extend his sources, confidently (and correctly in my view).

Fagan is very good at presenting to the layman abstruse research from seemingly disparate fields. If that's what you're looking for, this is the place to get it.

Now the bad news - I have some serious quibbles. First is that impressing a narrative structure on material while at the same time being ultra-careful not to over-interpret the original leaves too many holes. Second, although it may be true that nobody fully understands the broad strokes of how our climate machine works, that's no excuse for bewildering the reader with too many non-obvious relationships. And third, the inadequate illustrations are a dreadful missed opportunity.

Way back in my school days teachers drilled into my head the idea that once you located the "topic sentence" in a pargraph, everything else supported it. But that's unfortunately not true here. Sometimes part of a paragraph will be about one subject and the rest about a subject that's only distantly related. Sometimes one sentence seems to lead to an implied "because" then the second supporting sentence, except the second sentence actually says the opposite. Sometimes what must have been an interesting tidbit from a research paper is thrust into the middle of a paragraph with no clear connection to any of the other material on either side.

Often there are "word pictures" of hunting or fishing expeditions. But they seldom connect clearly to the surrounding material. It's as though an archaeologist found a couple arrowheads, then fleshed them out into a plausible narrative. I'd hope that these mini-narratives would be a part of a larger narrative (or at least connected to the following material), but most of them are not. The mini-narratives are presented quite well, but most of them would make just as much sense (maybe more) if they were presented in sidebars.

Fagan starts at the beginning, with a lesson in directions: a westerly wind is air coming "from" the west, but a westerly current is water flowing "to" the west. But then the progression to full-blown climate discussions is so quick that a non-expert like me can easily get lost. Is salty water warmer or cooler? Does upwelling bring more or less food? Does upwelling lead to more or less sediment? Do winds emphasize currents, oppose them, or some of both? Does surface water move, or deep water, or both, or neither?

One description is of the consequences of increased upwelling in the Santa Barbara channel off California. I found it very confusing trying to get my mind around the idea this brought "more fish" and "less rain" at the same time, that it may have been a boon to island dwellers at the same time it was a disaster to mainland dwellers. I was left floundering, like a blindfolded person trying to pin "good" and "bad" labels on a donkey, but not even being in the right room.

Almost all of the illustrations are maps, whose only purpose seems to be to roughly locate archaeological sites. The names of a few large (or formerly large) cities are given, current political state boundaries are usually shown, and a very basic key of compass direction and scale in miles/kilometers is included. But that's all. There's no clue to either elevation or roughness of terrain, no latitude or longitude, and very little connection to the text. Although one doesn't necessarily need to go as far as Scientific American --whose goal is for a careful studier of graphics and legends to understand the entire gist of an article without actually reading the text-- graphics should at least be used for more than one purpose.

The text is full of references to particular years, often either the beginning or ending of a drought: Just in one section I found 550, 750, 760, 820, 860, 910, 1000BC, 300BC, 250, 292, 869, 1100, and 1519. This cries out for "time line" style graphics. In fact if each chapter had a drought time line graphic at the same scale, they could easily be lined up and compared. There'd be no need for hand-waving about some climate changes being "global", or about the connections between one region and another. The case for global climate change could be greatly strengthened and the text shortened at the same time by paying a little more attention to graphics and a little less to words alone.

The discussion of the tailing off of Mayan civilization refers to "highlands" and "lowlands". But which area is what on the map? No clue. The Yucatan peninsula has been carved up by the modern states of Mexico, Belize, and Guatemala. But how is it positioned in relation to continents or seas? No clue because there's no map at the other scale. How many watersheds are there and how to they relate? No clue. How long did it take to travel from one site to another? No clue, because distances are given only in "miles" and "kilometers", but we all know the same distance is very different at 60mph on a good highway than at 0.2mph on a bad trail.

For many kinds of information, well chosen graphics can convey a huge number of facts very quickly. (Edward Tufte, you're needed here!) Graphics should be more than an afterthought stuck into the book just to break up the text so it's clearer that laymen are the intended audience. They should be more than just place name identifiers copied from the original sources. And it should be possible to place a callout to each one in the text; if it's not clear where the callout should go, the connection between the graphic and the text is too weak.

Brian Fagan does an excellent job, with the knowledge we have today, of illustrating what lights paleoclimatology may be able to shine on today's global warming, with sufficient warnings for the humans that are causing it.

Specifically, the flight to the Sunbelt, especially the Desert Southwest, with its low-density sprawl and little mass transit, on the one hand, and demand for air conditioning, on the other, continuing to fuel anthropogenic global warming, Fagan would be excused if he didn't serve up a whole plateful of Schadenfreude crow for the largely conservative denizens of this part of the U.S. to digest.

He didn't, but he could. Why?

Based on paleoclimatology, it appears likely that this part of the country will experience the same long-term drought that wracked the Anasazi at Chaco Canyon, then later at Mesa Verde. Of course, the nearly 20 million of Southern California's Southland, the almost 5 million of the blot called Phoenix and the moving toward 1.5 million inexplicably in the Las Vegas area are a lot more thirsty for water than the Anasazi were.

But, move beyond the U.S. The droughts of sub-Saharan Africa that started in the early 1980s are also likely to get worse in the 21st century. So, too, are problems in China, especially north China.

Beyond this, Fagan documents the variety of ways in which civilizations of this time, from 900-1300 AD or so, called the Medieval Warm Period by British paleoclimatology pioneer Hubert Lamb, tried to deal with climate change of their era, or fell apart when they were able to deal no longer.

With excellent explanatory sidebars on climatic patterns, chapter-by-chapter maps of civilizations under discussion and more, Fagan details the power of climatic change, with a sobering bit of reality for our times.

From about 20,000 B.C. to modern times, this book spans most of human history and development. Very easy to read with very accessible science and archaeology. This book explains the effects of climate change on human development (both achievements and catastrophe).

History has a way of repeating itself. While small scale farming communities can easily adapt to severe climatic events large, complex societies will usually collapse in face of these events. The reason for this collapse, whether Old Kingdom Egypt or Tiwanaku in Bolivia, is because these large complex societies, which have large populations, are completely depended on complex agricultural technologies, these technologies completely depend on water. Once the water is gone, say by extreme drought, the society is too overly complex to successfully adapt and inevitably falls. This is a cautionary tale for our current global warming crisis, how will our globalized society react to extreme climate change?

I thought one of the most interesting parts was the effect the Younger Dryas Event (a 1000 year drought from 11,000 to 10,000 B.C.) had on the development of the first agriculture in the Near East. Although I would have enjoyed a chapter on the effects of climate change on Chinese civilization. I found this book fascinating, a must read.

Archeologist Brian Fagan has been in the forefront of studying how climate affects civilization for more than two decades. This important study suggests that in recorded history there is evidence of fundamental shifts in climate; he emphasizes here the manner in which the early Middle Ages were influenced by these changes. Based on a variety of sources ranging from historical documents to analysis of tree rings and deep ice cores, the period from the tenth to fifteenth centuries was marked by a warming trend around the world.

This caused a radical reorientation of climate patterns worldwide, sometime to the good but often quite debilitating to human populations. In terms of positive results, the Norse was able to settle parts of Greenland and engage in similar agriculture to what they had engaged in while living in Scandinavia. Equally important, in many parts of Europe longer summers, and growing seasons with bountiful harvests, as well as milder winters led to a rise of population, the development of more urban areas, and the development of more sophisticated culture.

More common was the changes in drought and rainfall patterns on many continents and resultant famine. These droughts led to the collapse of society in the American Southwest, which had enjoyed a high culture previously, decimated civilizations in the Mayan Yucatan and Central America, and restricted the impressive Polynesian society of the Pacific, including the settlers of Easter Island. In the steppes of Central Asia, prolonged drought forced Genghis Kahn and the Mongol Hordes to the West in search of water, food, and the necessities of its nomadic existence. Brian Fagan makes the case that Kahn and his followers were driven to conquest more by radical climate change than any other single factor. This is a fascinating and important observation.

Brian Fagan's last chapter suggests lessons for the future from this "Great Warming" of the early Medieval period. He concludes: "Whether the Medieval Warm Period was warmer than today, and why, is still a matter of much debate. Our current warming has not lasted nearly as long as the period studied in this book. It is, however, a steady and well-documented trend, with no downward curve in sight. And unlike the situation a millennium ago, humans are numerous enough, and our outputs profuse enough, to push the trend further and faster. What is not debatable is that if we reenact the climate history of a millennium ago--let along see the earth get even warmer--we will see how vulnerable humans are to the forces of their environments" (p. 232).

Fagan notes that we are already starting to see catastrophic repercussions from the current warming trend. Droughts are more common every year, populations are being displaced, natural phenomena such as hurricanes, cyclones, tornadoes, and tsunamis are more devastating than we have seen in recorded history. He comments that "we not confront a future in which most of us live in large and rapidly growing cities, many of them adjacent to rising oceans and waters where Category 5 hurricanes or massive El Niños can cause billions of dollars of damage within a few hours. We're at a point where there are too many of us to evacuate, where the costs of vulnerability are almost beyond the capacity of even the wealthiest governments to handle. The sheer scale of industrialized societies renders them far more vulnerable to such long-term changes as climbing temperatures and rising sea levels" (p. 240).

Fagan insists that we must take action, not just for the immediate future but for the long term. He believes that drought is the most far-reaching of the negative climatological effects we will experience in the twenty-first century. "The experience of the Medieval Warm Period shows hoe drought can destabilize a society and lead to its collapse," he writes. Today, destabilizing forces can jump local boundaries. It we look at how the chance to earn a better living has drawn millions from Latin America across U.S. borders, imagine how many people might uproot themselves if the choice were between famine and food" (p. 241). Water, Fagan believes, is what will precipitate future wars far more than most are willing to acknowledge. Genghis Kahn and the Mongol Hordes swarmed into Europe during the Medieval Warm Period to escape drought and find food and water. What armies will might do the same in the future? As Fagan concludes, "The people of a thousand years ago remind us that our greatest asset is our opportunism and endless capacity to adapt to our circumstances. Let us think of ourselves as partners with rather than potential masters of the changing natural world around us" (p. 242).

Of the many causes that have resulted in the collapse of most ancient cultures and civilizations, Brian Fagan in THE GREAT WARMING points a finger of blame at the fickleness of climate. It is quite true, he adds, that these prior cultures ended because of military conquest, disease, famine, and the like, but the driving force behind all of them was climate change. It has been only in the last few decades that climatologists like Fagan have had access to modern means to ascertain why past civilizations went under. Thanks to radio carbon dating, ice core sampling, and silt analysis, he has been able to draw a reasonably accurate map of world weather stretching back many thousands of years. His conclusions are many. First, climate change is a still imperfectly understood mixture of wind patterns, ice flow growth, volcanic eruptions, galloping desertification, and human intervention. Second, over the last few thousand years, the major culprit has been drought caused mostly by inadequate rain. We have not experienced any serious general global cooling for a dozen millenia. Third, human beings are capable of the most amazing blends of sheer lunacy with regard to self-destructive tampering with nature combined with an almost infinite capacity to adjust to the short term rhythms of a volatile climate.

Fagan cites numerous cultures as examples of those that thrived for centuries--like the Maya, the Aztecs, and the Pueblo--but then in a seeming geological blink of an eye collapsed, mostly due to prolong drought. Along the way, Fagan notes what seems to be a consistent pattern of human beings that cuts across all cultures and ages. When a culture just gets going, it tends to do so when it encounters favorable conditions for growth. There is ample rain, ample vegetation, and ample space to grow crops. The population grows quickly--too quickly. It reaches a tipping point when the previous subsistence level of water and food are now no longer adequate to feed this burgeoning population. Sometimes if the drought is severe and lengthy, the civil authorities do not have time to adjust and their civilization goes under. Other times, when the drought is less severe and less lengthy, these authorities possess enough acumen and foresight to prepare even haltingly a way to preserve water and horde food stuffs to wait out the drought. Fagan notes that even under the best of circumstance, human beings have showed only a limited capacity to withstand a fickle nature. The lessons that he draws for humanity in the twentieth century are cause for the deepest of concern. The potential for catastrophic famine and culture collapse is higher now than in the past if for no other reason than the same conditions which destroyed populations of much fewer numbers than today are still here, only our populations are much higher than those of the past. He is not optimistic that humanity in this century can avoid the same unhappy fates of our ancestors. The best that he can hope for is for all cultures today to look to the past so that we can view ourselves as partners with the earth rather than its master.

Brian Fagan has written an interesting, very readable book. Those who are concerned about global climate change will love it. Those who are unconcerned will hate it. Those who are looking for a well-reasoned scientific argument will come away disappointed.

In 1992, Al Gore published a political treatise on global warming called Earth in the Balance: Ecology and the Human Spirit. Gore's argument was much the same as the Prophet Jonah's argument to the Assyrians: change your evil ways or perish. Gore supported his argument with statistics and with examples of earlier civilizations that outstripped their resources and perished. Although Gore did not claim to be writing a book of science, his book was highly acclaimed in its time.

Sixteen years later, the debate has moved on and the Great Warming adds very little to it. Fagan claims to be conducting a scientific inquiry, yet his conclusions are based more on politics and less on science than Gore's political treatise. If footnotes water the garden of knowledge, this book is an arid desert. Fagan's poor choice of where to irrigate does not help.

Here is one example: "Violence was a fact of life in medieval Europe and an integral part of politics." (P. 23.) It seems rather obvious that in a society where rent and taxes are paid by providing military service to an overlord, there will be violence. Fagan overstates his case here though. He does footnote that but not his sweeping statement that the Medieval Warm Period was less warm than today. (P. 16-17.) It does not help his credibility when he later contradicts himself, admitting that this question "is still a matter of much debate." (P. 232.) If medieval agriculture was possible during the Medieval Warm Period in places that are too cold to support crops today, such as the Swiss Alps, Trondheim (which is well north of Oslo in Norway), and even Greenland, as he notes, then why is global warming necessarily harmful? He cites numerous contrary examples from other parts of the world, but one is tempted to recall an old adage: it is an ill wind that blows no good. Whatever the change in climate, it seems to help some and hurt others. His book is full of examples.

Fagan has a tendency to make sweeping statements without proof. Some of them are clearly wrong. His lack of footnotes hurts him seriously because it causes one to question other facts within his realm of expertise that might be correct. For example, he claims that the "Capetian kings (of France), whose dynasty began in 987. . . created an ideology that proclaimed they were chosen by God." (P. 24.) This is a ridiculous statement and it is easily disproved. Hugh Capet did indeed found the Capetian dynasty when he became king in 987 but he and his heirs hardly invented the concept of the divine right of kings to rule. The preceding dynasty, the Carolingians, were named for Charlemagne, who had been crowned by the Pope in 800 as the first Holy Roman Emperor. That is as good as it gets for divine right in medieval Christendom. The Carolingians' predecessors, the Merovingian kings of the Franks, also claimed divine right. It took papal sanction for the first Carolingian king to depose the last Merovingian king. In many cultures of the ancient world as far back as the Pharaohs and perhaps even before them, rulers often claimed either to be gods or to have been descended from the gods.

Fagan speaks glowingly of expanding trade in the ninth century and how Charlemagne controlled important trade routes across the North Sea. This claim no doubt would come as news to the Vikings, who sacked Paris twice in the ninth century before unsuccessfully laying siege to it in 885-886. In the ninth century, the Vikings sacked coastal cities all over the North Sea, in the Irish Sea, and even as far south as Spain. They were strong enough to settle in many of the places they attacked, such as England, Scotland, and Ireland (and later, Normandy). Dublin was actually founded by the Norsemen in the middle of the ninth century. There was little trade across the North Sea in the ninth century. If anyone controlled such trade as there was, it was the Norsemen and not Charlemagne or his successors.

Fagan's French geography is questionable: "Some parts of France, such as Brittany, were in shambles. . . . Only the western, Celtic-speaking regions escaped invasion. . ." (P. 24.) Brittany is of course both the westernmost part of France. In the ninth and tenth centuries, it was perhaps the most Celtic part.

Fagan also gets into trouble by overemphasizing climate in English history after the Medieval Warm Period: "the greatest fear of England's Tudor monarchs was urban unrest caused by grain shortages." (P. 32.) Henry VII founded the Tudor dynasty by defeating his predecessor in battle and thereby ending the Wars of the Roses. His greatest fear appears to have been a renewal of civil war after his death. That may have been true also for his son and successor, Henry VIII, who left detailed instructions in his will about the succession. Henry VIII is well-known for founding the Protestant Church of England and for his many marriages. Although he concerned himself deeply in all the affairs of his realm, grain shortages do not seem to have been his biggest concern. His son, Edward VI, was a boy king with a brief reign. Mary, who attempted to restore the Catholic Church, was certainly more afraid of the Protestants than she was of grain shortages. Elizabeth was concerned about plots by Catholics within her realm, by her cousin Mary Queen of Scots, and by Philip, King of Spain. Most of Fagan's readers will have heard of the Spanish Armada, sent by Philip. That completes the Tudor dynasty so one has to wonder which Tudor monarchs Fagan meant, and where he got his information.

Fagan might be on firmer ground in discussing geological and archaeological evidence of drought in the American southwest, in the Yucatan peninsula, in Peru, in Cambodia, and in China. He seems much more comfortable here than in dealing with reported history. Even in discussing China, which has had a bureaucratic tradition for two thousand years, he relies almost solely upon archaeology and geology. He suggests that the Chinese histories tend to focus on matters other than climate. Maybe he is right, although neighboring Korea and Japan have kept records dating back more than a thousand years showing the dates when the cherry trees blossomed in the spring.

His discussion of the influence of climate on Pacific trade winds and on the monsoon is interesting, and he makes a good case for how changes in the monsoon and the trade winds led to the settlement of the Pacific islands and to the downfall of the Pueblo, the Mayans, and the Khmer (although the last one occurred after the end of the Medieval Warm Period). His argument that climate change led to the depredations of the Mongols is interesting but speculative. Since other invaders such as the Khitan, the Seljuk Turks, and the Magyars had invaded civilized lands from the Eurasian steppes over a period of several hundred years before the election of Chinggis Khan as Great Khan in 1206, and the Arabs had expanded out of Arabia in the seventh century, well before the Medieval Warm Period, his conclusion is certainly an oversimplification.

All in all this is a "good read" and perhaps even useful for its discussion of the complex relationship among the monsoon, trade winds, ENSO, La Nina, and the ITCZ. However, I cannot call it a good book.