The Long Thaw: How Humans Are Changing the Next 100,000 Years of Earth’s Climate

by David Archer

Why a warmer climate may be humanity’s longest-lasting legacyThe human impact on Earth's climate is often treated as a hundred-year issue lasting as far into the future as 2100, the year in which most climate projections cease. In The Long Thaw, David Archer, one of the world’s leading climatologists, reveals the hard truth that these changes in climate will be "locked in," essentially forever.If you think that global warming means slightly hotter weather and a modest rise in sea levels that will persist only so long as fossil fuels hold out (or until we decide to stop burning them), think again. In The Long Thaw, David Archer predicts that if we continue to emit carbon dioxide we may eventually cancel the next ice age and raise the oceans by 50 meters. A human-driven, planet-wide thaw has already begun, and will continue to impact Earth’s climate and sea level for hundreds of thousands of years. The great ice sheets in Antarctica and Greenland may take more than a century to melt, and the overall change in sea level will be one hundred times what is forecast for 2100. By comparing the global warming projection for the next century to natural climate changes of the distant past, and then looking into the future far beyond the usual scientific and political horizon of the year 2100, Archer reveals the hard truths of the long-term climate forecast.Archer shows how just a few centuries of fossil-fuel use will cause not only a climate storm that will last a few hundred years, but dramatic climate changes that will last thousands. Carbon dioxide emitted today will be a problem for millennia. For the first time, humans have become major players in shaping the long-term climate. In fact, a planetwide thaw driven by humans has already begun. But despite the seriousness of the situation, Archer argues that it is still not too late to avert dangerous climate change--if humans can find a way to cooperate as never before.Revealing why carbon dioxide may be an even worse gamble in the long run than in the short, this compelling and critically important book brings the best long-term climate science to a general audience for the first time.With a new preface that discusses recent advances in climate science, and the impact on global warming and climate change, The Long Thaw shows that it is still not too late to avert dangerous climate change—if we can find a way to cooperate as never before.

Genres: Science, Nonfiction, Climate Change, Environment, Nature, Earth Sciences

187 pages, Kindle Edition

First published January 1, 2008

About the author

Librarian Note: There is more than one author in the Goodreads database with this name.

David Edward Archer is a computational ocean chemist, and has been a professor at the Geophysical Sciences department at the University of Chicago since 1993

Reviews

[Richard · Rating 5 out of 5]

Update, Summer 2021 — wow, wildfires in the North America’s west causing dank air in the cities over on the east coast. Hurricanes coming in unspeakably early. Flooding killing folks, even in places outside of the global “south”!

Do you think this is as bad as it’s gonna get. Maybe read up a bit?

If you’re curious about how scientists actually study climate change, David Archer is an excellent go-to guy. Every year brings new developments, so a book isn’t the best resource for up-to-date understanding of all of the details of what is known about what is happening, but a book is a good way of learning how the science gets done.

Another of his books is even more on-point for just understanding that, though. Check out The Climate Crisis: An Introductory Guide to Climate Change if that’s really what you want.

This book, The Long Thaw: How Humans Are Changing the Next 100,000 Years of Earth's Climate, instead delves into climate science across the vast spans of geological time. In this short book, you’ll learn that what our generations do (or, more precisely, don’t do) will change the climate for hundreds of thousands of years. Frankly, it’s fascinating.

The science really is the point here. We can’t predict what humanity will be going through in another hundred years, much less after thousands or tens of thousands, so the presentation of all of these details is to enlarge our understanding of the magnitude of what we are doing right now, in the hope that we’ll change our ways as soon as possible. Because it’s scary, and getting scarier as we discover more.

Although this is a book about science, you won’t be tasked with dealing with too much nitty-gritty. There isn’t a single equation, for example, and the endnotes are to guide further reading, so even those aren’t laden with impenetrable jargon.

In most of the analysis, all the reader has to do is concentrate a bit. There are a lot of phenomena that are examined, since the way science double-checks itself is for people in disparate fields to see if they come to similar conclusions, and “disparate fields” goes from oceanography, plant paleobiology, geologic chemistry and many more.

The toughest for most people will probably be in understanding how isotopes are used. I’m pretty science savvy, but it was still engrossing to learn how isotopes are central to some of these analyses.

I’ll try to boil down my favorite narrative:

➤  An isotope is an atom — an elementary particle — with varying numbers of neutrons. Even the “normal” variation is an isotope; it’s just going to be the most common variation. Thus hydrogen comes naturally in three varieties (with ¹H being that “normal” version), and four additional human-made varieties. Since neutrons aren’t charged, this affects the element’s chemistry only in subtle ways.

➤  One important isotope is that of oxygen, because it can start off in H₂O, and have subsequent effects seen in CaCO₃ and CO₂. “Normal” oxygen has eight neutrons, and since it also has eight protons, it is known as O-16 (or “¹⁶O”). The heavier O-17 (one extra neutron) and O-18 (two extra neutrons) isotopes are also stable.

➤  The extra neutron(s) also makes any water containing the heavier isotope heavier, which has the critical result that it evaporates with a little more difficulty than “normal” water (for more information, see the Wikipedia article on kinetic fractionation).

➤  This is crucial: because heavy water is more reluctant to evaporate, seaborne clouds will have fewer of the heavier oxygen isotopes, while the remaining seawater has relatively more.

➤  Since all the precipitation that eventually ends up on land originally comes from those clouds, that precipitation is isotopically lighter. Which means that snow has that relatively “lighter” attribute, too, and so do glaciers, and those huge ice sheets created during ice ages.

➤  So the amount of the planet’s water that ends up “stored” as ice or snow on land is therefore directly correlated with the varying ratio of oxygen isotopes left in the ocean. Woo-hoo!

➤  How do scientists discover that difference? That (slightly isotopically heavier) oxygen is taken up by billions and billions of microscopic sea creatures (the Foraminifera) to create their shells, commonly out of calcium carbonate. That’s CaCO₃, with three oxygen atoms and thus a few dozen chances of having one of those slightly-more-likely-to-be-heavy oxygen isotopes.

➤  As those microorganisms die, their shells remain and accumulate. When the layer of sediment they accumulate in is compressed into rock over geological time, we end up with limestone, such as the stuff the pyramids in Egypt are made out of. But for our purposes —

➤  When scientist dig up core samples of the sediments deep in the ocean, they can analyze the variation in the isotopic ratio of oxygen, and thus determine the varying ratio of water still in the oceans versus ice that was present in that era on land.

➤  The correlation can be validated by comparing the results to ice that has been stuck in ice sheets or glaciers for hundreds of thousands of years. See the Wikipedia page on ice cores for more information. Both the water (H₂O) and air (O₂ and CO₂) in tiny bubbles in the ice has oxygen than can be compared, as well as dust, pollen, etc., that lets us determine age in multiple ways, which are examined for consistency.

➤  Once the scientific community has debated and refined that methodology, it has been validated. Then results from the sediment samples which are far older than any of the extant ice cores can be considered used in further analysis.

This is one of the multiple ways that we can gaze back into the distant past and determine what the climate used to be like. The results of different methods can be compared to make sure they are being used properly. For example, some of the ice cores have been cut out of the Antarctic go back 800,000 years (there are places where ice may have been accumulating for 1.5 million years). The amount of carbon dioxide in the air bubbles found embedded in those cores is cross-checked with other factors, including various isotopic measurement.

Progress continues: fairly recently, ancient graffiti in a Chinese cave recorded the impact of droughts more than 500 years ago, including dates which correlate with Chinese historical records. That same cave provided minerals, which steadily accumulate in stalactites or stalagmites, etc., which show a change in oxygen isotopes consistent with other climate models.

Isotopic analysis is only one of the many “proxies” that are used to gauge climate history. Tree rings have been dated back almost 14,000 years; evolutionary changes in the pores on leaves (stomata), which relate to the concentration of carbon dioxide and humidity, are examined in the fossil record.

Scientists compete to build computerized models of the climate which incorporate those factors they’re guessing are most important, and which work over different time and geographic scales. These can be tested: a model which uses one set of historical data, and is then able to accurately predict what changes were taking place in another domain means the models is increasing its trustworthiness. When two models which use different input datasets yield predictions that are consistent with one another, that’s also a good sign.

But Archer notes many times in the book that models still can’t account for nearly enough for us know what is happening to our satisfaction. It is important to point out that this doesn’t mean that climate change isn’t happening — the question is how fast, and how bad, and what changes will take place in what part of the globe. For example, the recent drought in California is at least partially due to normal variations in weather, similar to other droughts in memory. But climatologists are increasingly worried that the the propensity towards more drought isn’t weather, but climate, and is an early sign of California’s “new normal”.

This isn’t the correct book for information about recent discoveries in climate modeling — books aren’t the right medium for that. But if your reading diet (or podcast listening!) includes enough science, you’ll spot the steady accumulation of data. For example, “a newly discovered strain of bacteria found in Arctic permafrost harvests methane from the air — meaning it could help mitigate the effects of warming” is good news I learned from Scientific American here, but “tree growth lags below normal for several years following droughts, a detail about carbon sequestration that climate models currently overlook”, from here, which is bad both for the climate and for California’s forests in the 2011–17 drought.
­

Even readers who are barely aware of what an isotope is will be able to keep up. This is especially true since a quick trip to Wikipedia or a Google query can help you brush up on the toughest stuff, although I found most of my complimentary online research was driven by voracious curiosity.

At one point I wanted to remind myself of the details of the surprising Larsen B Ice Shelf collapse in 2002 (which had been stable for maybe 12000 years). That then led me to examine the current status of the Ross Ice Shelf, and then the West Antarctic Ice Sheet, at which point I found myself looking up the differences between “ice shelfs” and “ice sheets”, for example, and then back to the Filchner-Ronne Ice Shelf, and then finally to the East Antarctic Ice Sheet.

Personally, I think the relatively near-term climate effects of agriculture will be so devastating that it might cause an economic collapse leading to the collapse of our global civilization. If it doesn’t, then maybe this reminder of what the longer-term threat will be (p. 138):

Yeah, the amount of carbon dioxide and methane we’re pumping into our atmosphere could easily mean that eventually the sea levels will be fifty meters higher. It’ll [probably] take a long, long time for all that ice to melt; hundreds of years, or maybe over a thousand. Still: this is what we’re doing to our home.

Curiously, while our addition of large amounts of carbon will be catastrophic for many species on our planet, and seriously detrimental to future humans’ ability to thrive on a biologically impoverished planet, it might stave off the return of an ice age, which normally would start closing in after another few tens of thousands of years. Given that our planet happily functions in both ice ages and ice-free ages, that probably doesn’t matter except to some specific species, including ours.

If you understood this stuff the to the same depth as the scientists, you wouldn’t need to read books like this. The point is to read enough that you are comfortable with how the science works, that there aren’t glaring omissions, and build your faith that the scientific enterprise actually does provide reliable guidance for us when we try to solve difficult policy questions. It’s also just a drop-dead fascinating lesson.

                        ☠☠☠

Related 2015 update: If We Burned All the Fossil Fuel in the World in the New Yorker.

[Larry Bassett · Rating 3 out of 5]

The bottom line for our forecast of the future is that the Earth has the ability to look after its own climate, but only if we are willing to wait a few hundred thousand years. It takes that long for the imbalance of CO₂ release and uptake back into the Earth to affect the CO₂ concentration of the atmosphere and ocean. The slow response time of Earth’s thermostat is the reason why our own climate experiment from releasing fossil fuel CO₂ will persist for hundreds of thousands of years into the future.

The Long Thaw: How Humans Are Changing the Next 100 000 Years of Earth’s Climate will guide you through the science of how even our short term degradation of our atmosphere will have a long term impact. And even if the science is a bit much for you, the Prologue and Chapter Seven alone will give you the information you need to be environmentally aware and to know that something has to be done about our current energy habits.

Where does this book come down on global warming?

A climate change of the magnitude of the deglaciation of 5-6⁰C, would be catastrophic to human civilization. The forecast for future warming, 3-5⁰C, is less than that for deglaciation, but the warming would take the planet to a climate unlike any in millions of years. A climate shift of this magnitude would rearrange the landscape and societies of the Earth.

This is a book in the Science Essentials series. Books in the series

bring cutting-edge science to a general audience. The series provides the foundation for a better understanding of the scientific and technical advances changing our world. In each volume, a prominent scientist – chosen by an advisory board of the National Academy of Sciences members – conveys in clear prose the fundamental knowledge underlying a rapidly evolving field of scientific endeavor.

I learned a lot about global warming and how it fits in with the Earth’s natural temperature regulation. It is a short book but filled with mostly accessible information. But you don’t have to understand it all to benefit from the content.

Requiring automobiles to get better fuel economy is just the tip of the iceberg. And we don’t seem to be able to even do that in a timely manner. This relatively short book does not deal with the politics of the issue, just the science.

And now even energy efficient light bulbs come under Congressional attack since it is an American right to waste energy.

The environmentalists on the political left (the people who brought you 1.6 gallon toilets) have recently succeeded in getting ordinary light bulbs banned in the United States. The federal ban on incandescent bulbs is a clear violation of the Tenth Amendment to the U.S. Constitution, but unfortunately there are few people in Washington (or anywhere else) who give that technicality a second thought. Source: http://www.akdart.com/cfl.html

Read it and weep.

[Jose Moa · Rating 5 out of 5]

This is a bok written by a prestigious professional scientist expert in the subject.

There are many books on global warming and climate change,but i think this is mainly foccused on the physics,climatic,paleoclimatic,glaciations and long term consecuences of the massive release by us of carbon dioxide to the atmosphere.

The book yet is a popular science book is more rigurous that the average in its explanations.
Makes a serious exposition of the greenhouse effect,of the orbital and axis of earth inclination features in explain the trigger og glacial ages and the interglacials.
Explains with detail the interchanges of carbon dioxide between oceans and atmosphere and the capacity of the oceans for absorb it,exposes also detailed the acidificacion process of the oceans and its consecuences.
Makes the prediction that in the busines as usual case in the next 100 years or more,the long term consecuences,is to say in milennia,will be a rising in planetary average temperatures of till 5ºC degrees for long time (thouands of years) and that in a period of centuries the melt of Greenland and Antartica ice sheets will give way to till 70 meters in ocean level rise with the obvious effect of substatially reduction of emerged land and displazament of at least a 10% of worlds population.

Undelines the danger of unexpected catastrophic effects ,as the massive release of methane by the permafrost and bottom of oceans specially the Artic driving the planet to disastrous ancient massive extintions event, as for example the Paleocene-Eocene thermal maximun event,55 million years ago.

the book gives a lot of data and graphics,says that the speed of rise in the carbon dioxide concentration has not known precedents,that from 1750 we have released to the atmosphere the eqivalent of extra 300 Gigatons of equvalent carbon(300000 millions of tons),that we are releasing 10000 millions of tons every year to day and growing exponentially,surely disrupting the normal climate cicles for 100000 to 500000 years accordig to scenario.

The book al says that for avoid trespass the 2ºC consensus we will ought stabilice the concentration in 420 ppm(October of 2016 is 402 ppm,the highest in recent several million years) a very difficult task that will make neccesary a strong and serious international ,very unlakely, cooperation.

A serious ,rigurous,with clear explanations of the consecuences of our actions book.

[Kaela · Rating 3 out of 5]

Does a great job of bringing urgency to the climate problem. It is a little too sciencey at times and includes a lot of graphs that I didn’t take the time to look at. It also used (perhaps overused at times) some great analogies. There were also a few pages that became so technical with CO2 emissions that I skimmed them, as the book could have done without them. But overall a great book.

This is a book where you must read the epilogue and if you only wanted to read a small portion of the book I would recommend reading the epilogue. The book is a real downer, explaining all the ways we are destroying ourselves and making changes that will take a few millenniums to naturally be undone. Essentially you finish the book without any hope for our future. You realize how optimistic and frankly unrealistic the forecast of a 3 degree Celsius increase in temperature with a rising sea level of a few meters is. But then hope is returned in the epilogue, which explains some ways to avoid increasing climate change. You’re left to wonder why we aren’t implementing these methods right now, especially since we don’t have the time to waste. This little bit of hope made the book end on a great note.

This book was not necessarily my favorite to read, but it is a book that every person should read. For anyone who is doubting climate change please pick up this book. Even if you believe in climate change, this book brings a new urgency to the topic. So I strongly recommend this book. It truly is a book everyone should read, as being aware of the issue is the first step to solving it.

[Jamie · Rating 3 out of 5]

I'm gonna finally admit that I won't finish this book and return it to the library. I've been hogging it since January, and have only read half. It's not bad. In fact, it's very interesting, and I took notes as I read it. It's just that there are so many much more fun books I'd rather be reading right now. It's the too many books, too little time problem...

In any case, I feel I'm pretty decently prepared to counter any acquaintance's argument against global warming thanks to this book, and I will definitely recommend it to any college student writing a paper on the subject. It's not hard to read, but it's not easy either, and in this day and age, I would say the text is difficult enough that most people won't read past the first couple of chapters. There are lots of charts and graphs, but the main information is repeated often enough (and astounding enough) that you absorb it even if you don't understand every detail of the science behind it.

[Abigail · Rating 5 out of 5]

This book is perfect for anyone who has wondered (1) could humans really be affecting the whole climate, and (2) even if we are, hasn't it changed like this before? (1. yes, 2. sort-of)

It's a short book with great explanations that non-scientists can follow. He delves into past climate on the scale of centuries, millennia, and glaciers, so that we can compare the past to what's happening today and anticipate what will happen.

I really appreciated that the author was open about the limitations of models and climate proxies—what we can and can't know about the past or predict about the future. He uses analogies and illustrations for relevant concepts from molecular chemistry to continental plate tectonics (although you will have to remember his definitions of some terms) so that we can have confidence in the values he uses. There were maybe 12 charts and graphs and I kept referring back to them because they were so interesting.

Most of it doesn't dive into the effects of the thaw on humans; there are plenty of other books and articles about that. He explains how the climate itself will be fine and eventually regulate, but it's on a much longer time-scale than humans are used to thinking about. Only the last chapter has recommendations for what to do. Unfortunately, the bad news has gotten worse since 2007 (when the book was written), but the good news is that addressing climate change is definitely a "better late than never" and "every little bit helps" situation.

[Thor · Rating 1 out of 5]

SOO poorly written and honestly close to making me a climate skeptic

[Bent Andreassen · Rating 2 out of 5]

Archer's argument seems inconsistent. He has not proved his case that almost all (or all) global warming is anthropogenic.

I bought this book because for years I have been wondering whether global warming is anthropogenic or not (to the extent there has been global warming). All the time we hear both views opinioned by scientists, although media and the organized environmental industry try to sell the propaganda that "we know with certainty" that ALL global warming is human caused. Has the hypothesis regarding anthropogenic global (AGW) warming been sufficiently verified by empirical findings? I had read that Archer's book The Long Thaw was balanced, and since it is reasonable short, I bought this book along with two other books (Chris Mooney's "Storm World" and Farmer and Cook's "Climate Change Science: A Modern Synthesis").

The book turned out to be a disappointment. Instead of being thoroughly and scientifically written and balanced, it is marred with alarmist tendencies, inconsistent inferences, including the claim that AGW is the only plausible explanation. The text does not consistently back up that this assertion. The representation of adjoining subjects and statements are not contiguous; does not move logically from 'a' to 'b' to 'c', etc., but are spread around in different parts of the book, making "connecting the dots" a "detective job" that should have been entirely unnecessary. Having read other reviews on Amazon.com and Amazon.uk I discovered that I am not the only one to experience this. Reading ‘The Long Thaw’ will not get you closer to the "truth". On me, it had an almost opposite effect. Not only am I not closer to be able to make a sound conclusion. I am now a little more skeptical.

One ‘short cut’ commonsense way of evaluating a book is this: If you have a strong view about a topic such that X causes Y, and you want to argue your case, what would you do? Naturally you would show the necessary number of graphs that makes it very difficult to deny a strong and consistent correlation between X and Y. Then you would add scientific explanations connecting cause and effect to these graphs. All along, you would make sure that every claim, every graph, and every scientific explanation (or plausible explanation or reasonable conjecture) is backed up by solid scientific references, so that the reader in principle can check ‘everything’ the author claims. Following this commonsense way of evaluating Archer's book, this is impossible, because of a fundamental lack of references. Only in a few instances does Archer offer references to back up his claims and inferences. One would believe that since it is Archer's aim to show that CO2 essentially drives climate changes, he would publish the necessary number of data or graphs (based on established empirical findings) that would confirm his beliefs to the extent that is becomes strongly implausible (given one is honest and reasonably intelligent) to deny a strong and consistent correlation between atmospheric CO2-concentration and global temperature (GT), in such a way that every time atmospheric CO2-concentration increases, there is an increase in GT, and every time there in a decrease in atmospheric CO2-concentration, there is a decrease in GT (given a minimum span of time). Also, the faster the increase in CO2-concentration, the faster a rise in GT.

Naturally, there are other causes for GT to increase and decrease. That is what makes climate change science very complex and difficult. Archer explains several of the different kinds of climate forcing agents, like the Milankovitch cycles (eccentricity, axial tilt, and precession), changes in the Earth's albedo, etc. So all proxy climate data must be adjusted for all the different climate forcing agents, and the resulting graph should then confirm a consistent and strong correlation between GT and CO2-concentration. But Archer is unable to reproduce as much as a single graph that correlates GT and CO2-concentration this way. Why not, if that would confirm his hypotheses? That is really a mystery to me! The only related graph Archer reproduces is one based on the famous Antarctic Vostok ice core data. However, the graph in Archer's book does not show correlation between GT and atmospheric CO2-concentration (page 76), but between sea-surface temperature levels and CO2-concentration. Why choose this one when other graphs are available, namely precisely the one we ought to see - a correlation between GT and atmospheric CO2-concentration from the time same period? The problem here is that since it takes a long time for ice to melt (hundreds if not thousands of years according to the author), it takes a long time for the sea-surface to rise. That means that correlating sea-surface levels with CO2-contration will not automatically confirm Archer's hypotheses (that atmospheric CO2-concentration forces GT) - unless increased CO2-concentration precede a rise in sea-level by "several centuries, if not thousands of years" (a quote from Archer). It turns out that this is not the case. On the contrary, the Antarctic Vostok ice core data converted to showing atmospheric CO2-concentration correlated with GT that I have seen reproduced in other periodicals shows GT rising before a rise in CO2-concentration, actually by several centuries. So a correlation surely exists, but a conclusion based on this graph, would be that GT forces atmospheric CO2-concentration because an effect cannot in time happen before its cause. Now, on first thought, that might sound absurd. How can GT force CO2-concentration in the atmosphere? However, it is common knowledge (accepted science) that the warmer the oceans, the less CO2 it can contain. And since CO2 is easily dissolvable in sea-water - in enormous amounts over thousands of years - CO2 will naturally be forced out of the ocean and into the atmosphere when ocean temperature naturally increase as a consequence of increasing GT.

Now, other climate change scientists claims that feedback mechanisms can cause problems so that graphs can be misinterpreted in the sense that what seems to be cause and effect is not so. E.g., an increase in atmospheric CO2-concentration can force GT up, even if GT started to rise first. In other words, the CO2-release from the ocean can then cause a further increase in GT. Now it is unclear how such feedback plausible can cause the kind of "perfect curves" we see in e.g. a graph like the Antarctic Vostok ice core data. Nowhere have I found a plausible explanation for this. However, and that is the point, Archer completely bypasses any such discussion. He does not even mention it. Therefore, one can only conclude at on this particular subject, reading Archer's book is a waste of time.

On page 42, the author argues: "But the natural world is a complicated and subtle place... For the sake of argument, suppose a phenomenon undreamed-of exists that causes the observed buildup of heat." However, instead of discussing such possibilities, he counters, "But we already have a satisfactory explanation" etc... The problem here is the author's failure to mention and discuss existing alternatives, like Danish scientist Henrik Svenmark's hypothesis that the sun's magnetic field diverts cosmic rays away from the Earth's atmosphere, causing changes in the Earth's cloud cover, and thus its albedo. This rather famous hypothesis has been known for a long time. It seems to offer a reasonable alternative explanation, and therefore Archer cannot just disregard this hypothesis. Not when he actually, in writing, asks if not other explanations might exist. How can readers draw reasonable sound conclusions when other hypotheses are not discussed?

What might be a very serious inconsistency in Archer's book are statements that add up to the claim that the Sun might not have been stable in the past, but that the Sun is stable now. Archer page 40: "Solar variations are the smallest of all, typically in the order of 0.1 Watts/m2." Farmer and Cook's above mentioned book shows a graphic representation of the Earth's energy balance on page 92: the Earth's surface receives in average 168 Watts/m2 from direct solar radiation. This confirms what we often hear: The Suns output of ‘sun-rays’ is very stable (variation less than two percent). What makes Archer believe it could be otherwise in the past, like during the Maunder Minimum (less radiation) and during The Medieval Climate Optimum (more radiation)? Here is what Archer writes on page 41: "The intensity of the Sun further back in time can be estimated by measuring the products of cosmic rays, depositing in ice cores. When the Sun is brightest, it has a strong magnetic field which shields the earth from cosmic rays. The cosmic rays, when they reach the atmosphere, produce radioactive elements like beryllium-10 and carbon-14. A brighter Sun means less cosmic rays reaching the atmosphere and thus less carbon-14 and beryllium-10 in the ice core." Then Archer on page 61: "If the year 1000 A.D. was as warm as the year 2000 A.D., then one might argue that our warming is natural, not an indication of global warming at all. But the Medieval Optimum warmth was probably the result of a warmer sun, according to the solar proxies. In our time, the Sun has not been getting warmer since 1970."

Here Archer seems to be confused since he mixes together solar radiation and the mentioned solar proxy data. These proxy data, according to Archer himself (as page 41 shows), was not caused by solar radiation but by the Sun's magnetic field. The proxy data is a measure of the Sun's magnetic field, not of the Sun's radiation (sun-rays). The fact that sun radiation is stable does not mean that the Sun's magnetic field must be stable also. To spell it out: The proxy data is a measure of how strong the Sun's magnetic field was during the Medieval Climate Optimum. That means it is irrelevant that solar radiation is stable, because the Sun's magnetic field is not stable! According to information found on the Internet, like NASA's web-pages, the Sun's magnetic field, since measurements started after World War 2, has shown a variation by a factor of at least two. Indeed, on Wikipedia [...] we find a graph showing what Archer's is writing about. This graph shows that during the Medieval Climate Optimum, the Sun's magnetic field was not stronger than it is today, while it was considerably weaker during the Maunder Minimum. In fact, according to this graph, there has been a dramatic increase in the Sun's magnetic field the last 80-90 years. It has even been given its own name: "The Modern Maximum".

Of course, there does not have to be a connection between the Sun's magnetic field and GT. But given that it apparently is false to base an inference on the causes of temperature maximums at earlier historic times on solar radiation, and given that there actually does exist a hypothesis connecting not solar radiation, but the strength of the Sun's magnetic field to changes in global temperature, one cannot plausibly just exclude such a possibility. However, that is precisely what Archer does. Therefore, obviously, Archer has not shown his case to be true. It even stands out - possibly - as fundamentally inconsistent.

So, I conclude: If you want to find out whether global warming is anthropogenic or not, it is a waste of time to read Archer's book. Because you will be unable to reach such a conclusion, given that you read the book carefully. Archer has not proved his case! That does not mean there is nothing of interest in Archer's book. Interesting stuff is revealed about earlier climate changes that are fascinating to read about. However, that is another matter.

[Yolanda · Rating 3 out of 5]

This book was great in terms of its content. I appreciated that Archer covered the different aspects of the climate system in its present state, its deep past, and its deep future. However, I was under the impression that this book would be appropriate to reach a general audience. I would say that especially in the first part (there are three parts), this was true. This was also true of the epilogue. In between though, I, an atmospheric science PhD, often got bored. If you want an accurate, comprehensive explanation how how Earth's climate has changed, how it is likely to change, and why, Yes, The Long Thaw is a fine read. But just know that it's good to approach it as an accessible textbook at times, rather than a comfortable read for a wide variety of audiences. Especially as a scientist, I know we can do a better job of making climate science interesting and accessible to the general public, so they can have the intellectual tools available to try to make sense out of the many news stories they hear about our climate.

[Anastasia · Rating 2 out of 5]

I guess this was worth reading, but I don't think it's actually as easy for a layperson to read and understand as the book reviews claim. Also, it's pretty dry, and for me, few of his analogies worked in helping me better understand climate issues. But parts of it were really readable and simple, and because it's so dry and it's really focused on climate changes, it's not at all scary or alarming. He doesn't really talk much about how the expected weather instability might affect humans or humans' lifestyles.

[Gary Reger · Rating 4 out of 5]

The great contribution of The Long Thaw is that David Archer lays out the evidence for the long-term changes in our climate already "baked in" to the atmosphere, which will grind on even if we were to get to zero emissions tomorrow. Especially now that last year was the hottest ever in human history, this year's tracking to surpass it, and billions of us are frying under temperatures rarely or never seen, climate change has become even more salient and tomorrow's effects palpable. But as Archer shows, that's barely the tip of the melting iceberg. What we have done to the planet will play out over thousands of years, and we better start thinking long-term.

That said, Archer's prose isn't always the most transparent. There are sections that are hard to follow, concepts crying out for more detailed explanation. Archer was aiming for a non-specialist audience and so may have been encouraged to keep the details to a minimum, but if so the cost is passages that, for me anyway, provoked a bit of puzzlement.

Never mind, though. The warnings are timely and needed. Naturally, of course, those who wield real power are almost all disinclined to do anything. Even Biden's trumpeted environmental legislation is far, far less than we must have right now. He is about to direct one trillion dollars to a 10-year project to upgrade our nukes. A truly human, necessary use of all that money would be toward climate accommodation. But even for Biden, guns come first.

[David Larrabee · Rating 4 out of 5]

The content of the book is first rate, well and clearly written, by an expert in the field. If that was the only basis for the rating it would unhesitatingly give it 5 stars.

The reason I have only given the book 4 starts is because the level at which it is written is probably mismatched to many who would like (and benefit from) reading this book. I would not hesitate to use this in one of my physics classes at the University, for science majors. I would hesitate to use it in a physics class for "liberal arts" majors. It is understandable by the non-science major, but with perhaps more effort than would be desirable. I would encourage the non-science major to make the effort, you will be rewarded for your trouble.

This book contains an important message about timescales. In my work I have occasion to talk to a number of climate change activists, many of whom do not have a strong science background. This book nicely addresses many of their misconceptions about the timing of events. They need to read this book. So I wish this book (or perhaps a companion piece) was aimed at an audience with a lower level of scientific understanding.

I do recommend the book.

[Joseph · Rating 5 out of 5]

In a nutshell; what we do to the Earth today will be around for much longer than we could ever imagine. Though we may stop polluting the Atmosphere, it will still get worse before it begins to get better because the ball has already been set in motion and because Geologic time is so slow, think of radioactive half-life. If it's say 10000 years, total breakdown is in 20ooo; well our affect upon the Earth will be similar, for the Earth to take time to correct itself back to what it was before we began pumping CO2 into the Atmosphere at an unprecedented rate. It's going to take a long time.
David Archer explains this very clearly in this book. It is not a long book, 174pgs; but enough information to give you pause.

[Shannan · Rating 3 out of 5]

Some great foundational explanations and predictions. What was startling was how far things have changed since 2009. But I jolt myself out of the illusion using the last century- 1909 vs 1925? That is a difference in time that is visceral.
The book mentions compact fluorescent bulbs. When was the last time you thought about those innovations? How long was their era? Surely around tens years?

Strange to think that almost right up until this moment people were afraid of the return of the glaciers - “Two centuries ago, climatologists were more concerned about the next ice age than they were about global warming.”

[Janne Sinkkonen · Rating 4 out of 5]

This is an excellent little book on past and future climate change, starting roughly from Eocene and discussing the current situation without artificially limiting to the first century. Well written, light style, mostly understandable but for me requires some concentration when ocean carbon chemistry is discussed.

The book is refreshingly free of politics. Economical dynamics are only discussed in the epilogue.

To get a glimpse, see http://assets.press.princeton.edu/cha...

[Fernleaf · Rating 3 out of 5]

This was a tough one to make it through. Although it is written for the curious layman, and the author does a good job of laying out the science in as simple of terms as are possible (also using analogies, and reminds of where information is covered) the science is over such large timescales (past and future) that it is just hard to wrap your head around. The chapters are concise, and organized well, but this is a book about science on timescales that humans just have a hard time with.

[Alayne · Rating 3 out of 5]

A very interesting book, written in some ways for the layperson, but with a lot of scientific jargon that I found hard to follow. It also had a lot of textual errors in sentence structure. I felt that as it was published in 2007, it was out of date, and I wondered what the author would think of the massive bushfires, droughts, floods (not to mention pandemic) that have happened worldwide in the last few years.

[B & A & F · Rating 3 out of 5]

The epilogue reduces one star from my rating because some of the solutions seem reckless without considering the unintended consequences, and its analysis of economic shock of climate crisis is very simple minded

[Ietrio · Rating 1 out of 5]

This witch doctor can't tell what is going to happen in the next decade, but 100,000 years comes easy to him. After all, he won't be alive 50 years from now. And anyway, he isn't responsible for anything generated by his fear mongering.

[IvanD · Rating 5 out of 5]

This is my favourite kind of books, written by people who know what they are writing about and who do not care whether their book comes across as too hard.

[Lee Hampton · Rating 4 out of 5]

One of the best i’ve read on glacial cycles. Super informative.

[Mckinley · Rating 4 out of 5]

Earth has been through a lot of climate changes. Happening very quickly this time around.

[Aron · Rating 4 out of 5]

I picked this one up primarily because it's so new (2009) and also because David Archer is a well respected climatologist and not just a journalist interested in the issue. I think it's a pretty good introductory book to the whole climate change topic, but it doesn't exactly flow well at points. Archer also tends to repeat things...and while this is somewhat excusable given the format he chose (present, past, future), it can be annoying. If those two things don't bother you, then by all means make this your go-to book for beginners. You won't need a science degree to digest everything here, so don't let that stop you. What little math/science is required, he explains quite well. He's also extremely up-front about what we do and do not know for sure, which is a nice change of pace.

I thought the book started out very strong. There's a great explanation of the greenhouse effect and how the basic science behind climate change has been understood since the end of the 19th century (solar intensity, feedbacks from ice albedo, water vapor,etc.). He touches on the urban heat island effect and the impact of sulfur and aerosols on the atmosphere. He also puts to rest any doubt about whether CO2 is responsible for the warming of the past couple decades. He talks a bit about the ice sheets and mentions that we really have close to no idea how to model their quirky behavior. Slow growth or melting we have down, but sudden collapses are where we're in the dark, and those are what we're most worried about. Later on he basically says the same thing about climate models - they capture the vast majority of any given era, but the very quick flips between glacial extremes and hothouses are problematic. He suggests (and it's fairly obvious) that this is due to unknown or misunderstood feedback systems.

In the second section of the book, he explains a number of the current techniques used to build temperature profiles for most of history where we don't have thermometer-based records. There's a great explanation of the Earth's orbit and its effect on climate forcing. The third section focuses on the Earth's natural ability to absorb CO2 and moderate the climate, and how we have the potential to throw everything out of whack for the first time in the planet's history.

In the epilogue, which is as long as any other chapter, he goes into the economics and ethics involved in this issue. He criticizes limiting our scope to the year 2100, and not caring about beyond then, because that gives us the sense of having additional breathing room that really isn't there. He talks briefly about Socolow's wedges, which is sort of a must-have in these books.

Overall, I'm giving it a 4 because I think it's a solid, if very brief (180 page) reference for the basics on the topic. I was tempted to give it a 3, because the writing was fairly dry at times, but sometimes that's to be expected. So consider it a 3.5. There's plenty to the book that I haven't mentioned here, in case you read this and wondered why topic "X" wasn't covered - it probably was.

[Jessica · Rating 4 out of 5]

The Long Thaw: How Humans Are Changing the Next 100,000 Years of Earth's Climate

David Archer argues in his book that it is not too late to make a change and help the planet revert back to conditions that are somewhat similar to how they were in the past, but that this is only possible if humans can find a way to make changes to their lifestyles in a way they’ve never know or experienced before. Archer makes it easy to see that he is arguing that all of us are up against something, but we can spark a change by doing the smallest things. He is presenting a “call to action” for anyone who reads his book to take a step and be a person that helps in the environmentalism movement. He brings ethics into the picture when saying that the countries/nations that have found and experienced the most use of fossil fuels, and thusly created the extreme dependency on fossil fuels, need to take the responsibility and try to make the first move in order to begin fixing the problem.
The book is packed with great information and a background that is relatively easy to understand, but not as easy as I originally expected. There were times while reading the book that I felt as though Archer just skipped over explaining the things that he was going over. While it is easy to see that the book was written for the general audience, some of the topics discussed, even if they were only mentioned briefly, weren’t always common knowledge. In the book, Archer moves right past the views that only present short-term consequences and goes into talking about the majority of impacts for the future. There were plenty of spelling and grammatical errors that I wouldn’t expect to see from an author that has written multiple books. The fluidity of the book was great, but sometimes I felt like he jumped around a little too much. He would be on one subject in one paragraph and then completely change course in the next paragraph.
David Archer uses the right mix of ominousness, seen in the undertone suggesting that there is next to no way that humans will survive the extreme changes in the atmosphere and changes in the environment, and positivity for human action that makes this book a great, easy, and more importantly, interesting read. Other than the sometimes inadequate definitions of scientific terms, The Long Thaw is a fantastic source of information for even those who have just begun their search for top-notch information on the subject of global warming. Archer is an author who shows that he is not afraid to speak the truth no matter what kind of response is going to go his way. In the end, the information that he presents gives a glimpse of exactly what is to come for human life. The language that David Archer uses provides exactly the right push that is needed for people to see that they are definitely playing a part in the warming of the planet; even if they don’t want to see it.

Overall, the book was a good read.

[Claire · Rating 4 out of 5]

‘The Long Thaw’, overall, is a compact book stuffed with many concepts, theories, and predictions that initiate understanding to the broad topic of climate change. Archer’s scientific writing was easy to follow and provided many metaphors like kitchen sinks to help explain CO2 in the atmosphere and heat energy budget (Archer, 83). Archer makes many colloquial comparisons to climate change that make the book, as depressing of a topic as it is, light and interesting. While the book is short, every word holds importance to the understanding of cycles, feedback loops, chemistry, etc. It is obvious that Archer is an expert in his field, but still allows non-science minded readers an easy roadmap and in depth knowledge of climate change beyond the change in temperature. His writing includes many of his opinions and an obvious bias to the upcoming disasters associated with climate change. He rarely mentions other scientists, opinions, or even sources within the text. While his credibility can be proven through his source list in the back of the book, it would be helpful to know where his information derived from when reading and where he received his statistics given the absence of footnotes. Despite these flaws, I can conclude that I admire his writing style for allowing a simple read (in scientific writing standards) and his large in depth range of implications including plant life, glacial cycles, agriculture, sea levels and economics. Archer’s epilogue is extremely admirable because unlike other scientific readings, he puts climate change in the perspective of economics and ethics. Most often, initiatives to decrease the effects of climate change revolve around ethics and monetary costs. His data is persuasive because it targets the most common questions in climate change initiatives. The book is impeccable in making a fulfilling argument based on data that is impelling and interests readers. The book is an overall enlightening experience that gives readers a call for change at the close of the book.

[Justin · Rating 4 out of 5]

Excellent, well-flowing and compelling discussion of the Earth's past climate, the function and complexities of climatic changes we are driving today, and the long-term impacts of those changes. Archer makes clear that a time horizon of only 2100 may be convenient for current generations but masks the ongoing result of our GHG emissions for tens to hundreds of millennia. One striking conclusion is that it doesn't even matter if we sequester CO2 in the deep oceans or saline aquifers -- on those timescales any storage will leak away and the natural carbon cycle will ensure that about 1/4 of total original emissions remain in the atmosphere until they are finally removed by rock weathering.

Burning fossil fuels makes CO2 and that CO2 will drive up Earth's global temperature over many centuries, fullstop. The only way to avoid that is not to burn them.

The only negative is Archer's frankly extremely weak discussion of energy options; obviously not an area he's overly well informed in. Building large solar arrays on the moon to transmit the energy back to earth via microwave relay is just fantasy. We have the technologies to provide our energy needs from renewables, with the necessary collective will and drive to expand their production and refine knowledge by actually doing it.

[Joseph · Rating 4 out of 5]

A fascinating and refreshingly non-sugarcoated look at the deep history of climate on the earth, and what it can tell us about what we might be in store with future climate change. I learned a ton of amazing things about the science and history of the earth/atmosphere/ocean system, and the writing tone is directly from a scientist working "in the trenches" who is clearly expert in his field and also clearly dismayed that the public climate debate is so light on real scientific information. So while it's a bit "unpolished" at times, to me it made the writing much more compelling and authentic and entertaining. Highly recommended for anyone that's trying to become better educated about how our amazingly complex and surprisingly fragile planet works and how we're affecting it.

[Sally · Rating 4 out of 5]

An expert on the carbon cycle and paleoclimate, the author describes in this short book the causes and consequences of past climate changes and what the consequences of humanity's ongoing massive release of CO2 into the atmosphere has been to date and is likely to be in the centuries and millennia to come. His explanations of the science involved are clear and accompanied by many graphs. His writing style is extremely straight forward, and he points out not only what data is known but what is still unknown. This is not an hysterical or propagandistic work where the author is seeking to manipulate the reader's emotions or ideology, one way or another. He is setting out what is known about the interaction of climate and atmospheric carbon, with an emphasis on long-term consequences.

[Bradley Jarvis · Rating 5 out of 5]

As advertised on realclimate.org, where I learned about it, this book is an excellent overview of the science of global climate change. The author honestly describes what we know, what we think we know, and what we can only guess about.

I learned several things, most importantly that the greatest impact of our large-scale release of carbon on the climate will be over many millennia following this century. An interesting fact: a gallon of gas will result in 40 million times the amount of energy we use being trapped as heat in the atmosphere.

This subject is very complex, and I expect to use this book as a valuable reference in attempting to understand it.

[Jeff · Rating 5 out of 5]

This was a re-read, just to refresh.
It's a very readable technological read that will give you the basic science of Climate Change. It's highly recommended for those who need to know about this most important issue of our time.