A Biblical Ice Age: Part One

A friend sent me a link to the following article, “Why The ‘Biblical’ Ice Age is a Creationist Myth”, and I felt challenged to provide a creationist response.  At first glance, the author (unknown) is clearly hostile towards young earth creation science, ridiculing the Institute for Creation Research and Answers in Genesis directly. He accused them of being arbitrary, cherry picking Biblical texts, fabrication, abandoning their own models, intellectual dishonesty, and being anti-science. Wonderful.

Based on such an emotional response, I suspected that once I researched the subject I’d find the author guilty of the very accusations he hurled at these creationist organizations, and I hope to demonstrate that that’s clearly the case over the course of several posts.

The article is fairly technical, delving into a geologic phenomenon known as isostatic rebound, specifically in relation to the Ice Age. Isostasy refers to the way the earth’s crust can be compressed by surface mass and then elevated once pressure is released. So post-glacial isostatic rebound occurred when large sheets of ice covering the land and compressing the surface began to melt, allowing the land to readjust.

It’s interesting that once the author explains how isostasy works, he asks why- if Noah’s Flood were really global- shouldn’t we find isostatic rebound everywhere on earth? He insists that a one-year long flood wouldn’t constitute a long enough duration for the earth’s surface to be compressed. So he ends up answering his own question: if a one-year global flood isn’t long enough to cause isostatic rebound, then that explains why we don’t find isostatic rebound everywhere on earth. So far we’re on the same page.

I think the point he was trying to make is, therefore, if the creationist model is correct, then we shouldn’t have satellite images showing isostatic rebound in places where continental ice sheets advanced during the last glacial maximum. By his reasoning, an ice age lasting a few centuries isn’t long enough to cause those satellite effects. However, he claims, we actually do observe isostatic rebound precisely predicted by the conventional secular model.

To answer these objections, there are a number important points to consider: first we need to understand what the creationist model is. Second, we need to understand the secular model he adheres to. And a third point is to note there’s no real consensus with either model. This isn’t an argument about settled science, as the author seems to imply. Both models are being reshaped as new evidence comes to light; that’s the nature of science. Paradigms change with better solutions and interpretations of the data.

The secular model, for example, recognized only four Ice Ages until the 1970’s; after that they abandoned their own model and began to recognize anywhere from 30 to 58 different ice ages (separated by interglacials). The creationist model, on the other hand, hasn’t changed much and basically recognizes only one Ice Age, which occurred during the Pleistocene- a geological period characterized by widespread glaciation- and lasting about 700 years.

Scientists (both secular and creationist) estimate that about 30% of the land on earth was covered by ice during the most recent Ice Age, including almost all of Canada and the northern United States. The end of the ice age is considered the period when world temperatures began to rise, triggering the retreat of the ice. Evidence used to identify the Ice Age includes geologic features, such as sediment deposits and moraines.

Creationists contend that secular scientists have misinterpreted the data in order to come up with many ice ages. In fact, the evidence for only one Ice Age is very strong, while evidence for multiple Ice Ages is weak. We know, for example, the earth was fairly warm prior to the Ice Age; there’s sedimentary evidence suggesting there were no cold-weather environments or glaciation prior to the Ice Age, with the exception of Antarctica and some high mountain ranges.

Secular science doesn’t have a definitive number of ice ages that have occurred in the past, and they can’t provide a satisfactory answer as to what causes ice ages. There are over 60 different theories to choose from. But of course there are popular models to explain a trigger mechanism, including an increase in volcanic activity.

As for how many ice ages have occurred in the past, remember that secular scientists abandoned a verified number of four ice ages in the 1970’s in favor of many ice ages. They rejected worldwide evidence from glaciology for a complicated and assumption-ridden astronomical model in relation to oxygen isotope ratios from sediment on the ocean floor and coiling in sea shells.

The astronomical model they rely on uses the Milankovitch mechanism, which is based on “cyclical past changes in the geometry of the earth’s orbit.” Supposedly, what causes repeated ice ages is a decrease in solar radiation as a result of changes in the earth’s orbit every 100,000 to 40,000 years. Scientists take deep-sea cores and match wiggles in variables, which they believe to represent an ice age. But one problem with this model is that the decrease in sunshine is too small for these deep sea cores. According to Didier Paillard, “there is [sic] no significant orbitally induced changes in the radiative [sunshine] forcing of the Earth in this frequency range (the “100-kyr Problem”)” In addition, based on current observation rates, the secular model is unable to satisfactorily explain recent ice ages; their explanations contain serious flaws, including the fact that there would need to be a cooling of more than 50 degrees in summer temperatures in the northern United States along with a massive rise of snow for thousands of years. David Alt of the University of Montana admits, “Although theories abound, no one really knows what causes ice ages.” The belief in multiple ice ages is merely based on assumptions and circular reasoning, such as the ability to make the evidence fit the paradigm through manual calibration, not any kind of objective truth that is self-evident or plain to all. Without such circular reasoning, the Milankovitch mechanism wouldn’t work.

In reality there’s no good reason to believe in in multiple ice ages. Instead the physical evidence can be interpreted as deposits from a single ice sheet advancing and retreating over a short time. Today we know ice sheets are very dynamic, so we don’t need hundreds of thousands or millions of years for multiple ice ages over long periods of time. According to Gravenor and Bayrock, for example, “Although it is generally recognized that Alberta has been glaciated more than once, no buried soils or other evidence of any long period between glacial deposits have been found.” In other words, the evidence in Alberta points to one ice age.

So the author of this article demonstrates a lot of arrogance, tossing around accusations when the model he adheres to contain significant flaws. Does he wish to dogmatically tell us exactly how many ice ages he believes in, and how and why he’s accepted this arbitrary number along with the duration of each one? Or can he tell us with certainty that the dynamic advancing and retreating of a single ice sheet over time produces complex sedimentation that can be differentiated from a completely separate ice age thousands of years apart without circular reasoning or bias? Does he understand the astronomical model well enough to explain how the coils in sea shells provide irrefutable evidence of many ice ages in spite of the criticism offered by other secular scientists?  And when the evidence shifts, will he admit that his previously held belief was wrong? And if he was wrong about many of his beliefs, is he willing to accept that, just maybe, the creationist model could be correct?

I’ll end Part One here and respond to some of the other criticisms in Part Two, where I’ll get into some of the Creationist mechanisms triggering an ice age.

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26 thoughts on “A Biblical Ice Age: Part One

  1. Hi Jonathan, I’m glad you came across my post, though I’m disappointed you found the tone to be such. 😦 Yes, I made these accusations—cherry picking, intellectual dishonesty, etc.—but I have at least attempted to justify my opinion in this and other articles to which I linked. I do not feel that I have “ridiculed” those ministries, however, so perhaps you can elaborate.

    You might disagree with my assessment, but to respond simply with “Wonderful.” is disconcerting. Am I not allowed to critique? If you observed a non-Christian ‘cherry picking’ biblical texts to undermine its reliability, would you not call it out?

    I understand that you might be put off by my critical tone, but please understand that I am attempting to tackle pervasive intellectual dishonesty, which has splintered the church. I’ve been part of that movement; since then, I’ve watched it destroy one individual’s faith after another. It’s not simply that I find the arguments of AiG and others to be scientifically flawed, but they have misled millions of believers to a false hope with blatantly false claims. I deem this a serious offense by a self-proclaimed Christian ministry. So please, forgive my somewhat aggressive tone—it’s often difficult to maintain a gracious character.

    • Thanks for stopping by and commenting. Firstly, I believe we’re both brothers in Christ seeking to honor and glorify God with the work we’re doing. It’s easy to switch into an aggressive tone when we passionately disagree with fellow believers over theological issues rather than maintain a gracious character.

      Certainly you attempted to justify your opinions, but I don’t believe those accusations were justified. For example, you accuse AiG of arbitrarily compressing the time needed to grow and melt the ice sheets and claim they disregard the physical evidence and natural law. But I think you’ve misinterpreted their model because they do indeed consider the physical evidence in light of Scripture, and they contend that it’s those who adhere to some kind of long age model who are disregarding the physical evidence. The physical evidence points to one Ice Age, not many.

      That’s why I said you were ridiculing those ministries- claiming they’ve disregarded the physical evidence or fabricated a post-Flood Ice Age. I’d say that those who are disregarding the evidence are the ones that disregarded the physical evidence in favor of astronomical models in order to find multiple ice ages that never existed. I’ve also seen a lot of fabrication from those who believe in long age models as if their stories are fact.

      My response to the ridicule was “Wonderful” because I don’t believe it was deserved. Yes, you’re allowed to critique, and indeed I have called out non-Christians for cherry picking Biblical texts, but I think you’ve got it backwards. I certainly didn’t mean to be disconcerting, but it’s troubling when fellow believers in Christ support secular beliefs that contradict the Bible and lead people towards secularism and away from Christ. How does supporting a secular earth history lead anyone towards Christ when it contradicts a plain reading of Biblical history? If anything, an atheist who realizes that a Christian agrees with his naturalistic explanation will be justified in his mind that God is not necessary to explain the history of the world or universe and would think you’re one step closer to being an atheist yourself. In fact, I’ve heard atheists express that very sentiment.

      You accuse creationists of intellectual dishonesty, but I reject that. And even if I accept the premise that they have splintered the church (which I don’t), it’s only because so many believers have sided with the very secularists who reject God and the Bible in favor of naturalistic explanations, confusing fellow believers. Creationists are pointing others towards the Bible and defending Scripture, so I have difficulty understanding how we’re the ones splintering the church. But I can understand how someone could fall away after being told that science has disproven the Bible, and that Scripture isn’t reliable on historical or scientific matters. People can read what the Bible says, and if one Christian tells a new believer that, even though the Bible tells us that God created the heavens and earth in six days, that’s not what it means because science has proven otherwise. Then that new believer may reject God because they can’t trust what Scripture says. In order for a believer to mesh Scripture with secular science, one must do spiritual gymnastics, and those who realize that could have their faith destroyed. If, on the other hand, all believers unified behind God’s word (rather than man’s word), fewer people would have their faith destroyed.

      • Thanks for sharing your thoughts, and yes—we do respectively want to honor God’s truth in our work. By the way, I don’t want to flood your page with line-by-line responses to every comment, so I’ll try to be brief and—if you wish—refrain from dragging out a discussion here. But I do want to touch on a couple points.

        When I accuse the folks at AiG/ICR of fabricating the ‘biblical ice age’ and disregarding physical evidence, my reasoning is such:

        1) There is no unambiguous evidence from Scripture that documents a climate substantially different from modern. In my opinion, the evidence cited (e.g. in Job) is incredibly weak, because it is entirely consistent with modern weather patterns and Job certainly was written loooong after the supposed post-flood ice age (I devoted an article specifically to this topic, if you’re interested). We can safely posit that *without* geologic evidence for ice ages, no biblical reader would conclude that such an event ever took place.

        2) Therefore, YEC ministries rely solely on geologic evidence to infer the past existence of major ice sheets, such as: uniquely carved terrain and deposits of glacial till, moraines, eskers, proglacial lakes, and more. Up to this point, we should all be in agreement.

        3) However, if YEC’s accept these glacial deposits as evidence for a past ice age, then they ought to accept the buried sedimentary cycles (e.g in the Baltic and southern Siberia), which exhibit transitions from floodplain to glacial till to proglacial lake sediment and back to floodplain, as evidence for multiple episodes of glacial advance and retreat.

        4) Therefore, YEC geologists must discard or ignore the vast physical evidence for multiple ice ages. Note that up to this point I am not even considering the evidence from cave, lake, and pollen records, isotopic records in ice and marine cores, and even the rhythmic pattern in Mid-Ocean Ridge basalts that fluctuate with sea level (all of which support the hypothesis of astronomical forcing as the primary trigger). That’s what I mean when I contend that they compress the timeline artificially and fabricate a single recent, albeit dynamic, ice age.

        Again, I feel confident in my critique because I’ve read the works of Oard, Snelling, Reed, Austin, and many others. I’ve also spoken to a couple of them in person. I know that they know better, yet confidently claim the opposite, which concerns me greatly. If that’s not intellectual dishonesty, then what is?

        Secondly, I must take issue with this: “…when fellow believers in Christ support secular beliefs that contradict the Bible.”

        It was biblical study primarily that convinced me of the errors of YEC. I don’t think it’s difficult to establish that this “plain reading” to which you refer betrays the text and is anything but plain. Regardless, I strongly disagree with your labelling these as “secular beliefs”. This is God’s universe! Whatever truth our scientific study reveals is also God’s truth. If we affirm that His word is infallible, then we must also affirm that His creation is infallible, meaning that it cannot communicate errors to us, except by our own negligence and misjudgment. The preponderance of evidence, confirmed by the vast majority of Earth scientists—Christian or otherwise—points to an ancient Earth. There is no question about that among those who study it. Therefore, those long ages are not ‘secular Earth history’ but God’s history, God’s timeline—an intricate, beautiful record of divine work.

        “..an atheist who realizes that a Christian agrees with his naturalistic explanation will be justified in his mind that God is not necessary to explain the history of the world or universe and would think you’re one step closer to being an atheist yourself.”

        I do not believe in God because I feel there is no other way to explain my own or this world’s existence—this reasoning is to miss the point and caricatures the biblical Creator. Any atheist that would reason “well I can explain how we got here via cosmic/biological evolution, so I don’t need to believe in God” is searching for a God that doesn’t exist anyways. Similarly, if a Christian loses faith because they feel God is unnecessary to explain how we all got here, I would be skeptical of their faith in the first place.

        “In order for a believer to mesh Scripture with secular science, one must do spiritual gymnastics..”

        Despite your contention, the vast majority of Christians have no difficulty resolving the apparent conflict between the Bible and geological history, for the same reason most Christians had no difficulty resolving the apparent conflict between the biblical cosmos and the observed solar system/galaxy/universe. Prior to the age of the telescope, nearly all believed that our flat Earth was no larger than the edge of our sky, and the Bible strongly supports this ancient view. Yet we understood that Scripture spoke the language of its immediate culture, and that exploring our world beyond the text could only magnify God. We understood that if the universe were greater in space than we could possibly have dreamed, then God would only be glorified all the more. Similarly, a world far greater in *time* than we possibly could have dreamed should only glorify him all the more. Hence, we Christians who accept this knowledge of God’s world (not ‘secular science’, for there is no such thing) are not only comfortable in our faith, but we feel it has been strengthened by such knowledge.

        “If all believers unified behind God’s word (rather than man’s word), fewer people would have their faith destroyed.”

        Perhaps, yes. But this is a false dichotomy, which falsely assumes that we can easily distinguish between the two. Reading *always* involves interpretation (i.e. man’s judgment), and one can recite and apply the Bible in such a way that it no longer is God’s word. Science is a method of knowing the tangible world that is neither secular nor biblical. Potentially, it informs our faith, because it uniquely connects us to our creator. If we conduct science in a way that accurately communicates the inner workings of this world, then what is it but another means of accessing God’s Word, by whom all things were made?

    • On a more personal note, I once stood on your side of the court, believing in long ages. I didn’t really think anyone knew for certain how old the earth or universe were, but I soundly rejected young earth creationist arguments as absurd and took offense when they attacked old earth creationists and evolutionists, like Hugh Ross. There was no way they could persuade me to become a creationist. Unless they could demonstrate that Scripture taught the earth was young, and I was convinced that that wasn’t the case. I interpreted the days of creation to be long ages, and I had no problem with fitting the Bible into such a paradigm. Nonetheless, I delved into their research, and after several years I was convinced that Scripture did teach a young earth. According to Mark 10:6, “But at the beginning of creation God ‘made them male and female’”. I studied this verse over and over, and I found that it was futile to reinterpret this in order to rescue my belief in long ages. At that point I became an unapologetic creationist, and I strongly oppose my previous way of thinking because I realize that it was inconsistent.

      So for now we may have our disagreements, but someday Jesus will reveal the secrets of all these mysteries, and we’ll all realize just how wrong we were about so many things. In the meantime, I do believe the Bible teaches a young earth, and I’ll happily defend that premise.

      I didn’t get to read the rest of your comments yet, but I’m looking forward to doing that tomorrow.

      • One of your statements jumped out at me:

        “I once stood on your side of the court, believing in long ages. I didn’t really think anyone knew for certain how old the earth or universe were….”

        I don’t mean to sound condescending, but these two statements are really quite incompatible. Those of us on this “side of the court” actually do know for certain (within the bounds of experimental variation) how old the Earth and Universe are. So if you didn’t think this was something that could be reliably determined, you really weren’t ever on our “side of the court”.

        You also suggested that your convictions about the age of the Earth may have originally stemmed largely from the repeated examination of a single passage in Mark. That’s problematic. Whenever we hang our hats on one interpretation of one particular passage, we can miss the big picture pretty easily.

    • I enjoy a good, honest dialogue, so I appreciate your response.

      I agree there’s no unambiguous evidence from Scripture that documents an ice age, particularly in Job, and I had read your article. I don’t think creationists are being dogmatic about Job referring to an ice age. And I personally don’t believe Job is referring to an ice age. However, I also don’t think it’s an absurd idea either. It has merit, but there’s no way to know one way or the other, so I disagree that this is an example of them disregarding physical evidence. It’s fair to speculate whether or not any of the early believers would have made some kind of reference to the extreme weather conditions had they witnessed it.

      I don’t think creationists have refused to accept the buried sedimentary cycles. It’s just that they interpret the evidence from a young earth perspective rather than an old earth. Here’s an article from Oard. Not sure if you’ve read this before. Let me know your thoughts. I think he makes some good points about a snowball earth, freeze-fry and such. And I’d like to know how you account for the fossil evidence of many ice ages. Animals tend to grow larger during ice ages, such as Megatherium, mammoths, megalonyx, Smilodon, and Castoroides. If there were many ice ages, shouldn’t we find a rise and fall of such large creatures as they adapt to these cycles of cold-weather conditions?

      https://creation.com/images/pdfs/tj/j16_1/j16_1_06-09.pdf

      I’m a little concerned about your claim that Oard, Reed, Austin and others “know better” than to deny secular models, and that they’re intellectually dishonest. How do you know their heart? Sounds judgmental. If they confidently claim that they’re convinced the data points to a young earth, why not believe them? Would they not be justified to claim that you’re being intellectually dishonest? I’ve spoken with them as well, and I find them to be quite honest and fair.

      I’d love go deeper into the science of the ice age, but I’d also like to challenge you on these Biblical matters that convinced you of the YEC errors. By a “plain reading” of Scripture I mean that we need to read it in context, and if we do so, the Bible infers a young earth. It doesn’t provide absolute dates, so we must interpret Scripture against Scripture with respect to how it was originally written, and interpret it against our best translations.

      I use the term “secular” model because they’re independent of Scripture and void of God. They’re purely naturalistic and reject the supernatural events described in the Bible. This is in contrast to creationist models that acknowledge supernatural events, such as a six-day creation, Noah’s Flood, the dispersal at Babel, existence of the behemoth, prophecies of the Messiah, the Exodus, and the life, death and resurrection of Jesus Christ. So I think it’s fair to point out this contrast between models that accept the Biblical evidence as opposed to those that reject Biblical evidence.

      I agree this is God’s universe; he gets to set the rules, and we should accept them. God said he made the heavens and earth in six days, and I believe him. After all, as you pointed out, it’s his universe.

      Now I strongly disagree with your claim that “Whatever truth our scientific study reveals is also God’s truth”. Keep in mind that this very truth you’re referring to once claimed there were only 3-8 ice ages. So was that belief God’s revealed truth? Does God’s truth always change with scientific “truth”? Or is God’s truth independent of scientific “truth?” I’d suggest that God’s truth is true regardless of what scientists proclaim. Otherwise God’s truth becomes dependent upon man, which I reject.

      I do affirm God’s word to be infallible, therefore I accept it when he declares that he created the heavens and earth in six days. I also agree that any perceived errors are human errors, and that’s why I don’t elevate Scientism over Scripture. Therefore, even if I accept your premise that the “majority” of Earth scientists believe the evidence points to an ancient earth, I still put my faith in God over man. Nonetheless, science isn’t up for a vote, so just because the majority of scientists believe something, doesn’t mean it’s true. There are many examples of the majority of scientists being wrong. Take the Big Bang for example. The majority of scientists initially rejected that. Majority rule doesn’t override God’s rule. Never has, never will. I would only accept an ancient Earth if the Bible inferred it. Instead it infers a young Earth.

      You claim the majority of Christians have no difficulty resolving the apparent conflict between the Bible and geological history. Even if I accept that as true (which I don’t, unless you mean Biblical geologic history), most Christians probably haven’t been confronted with the task of doing so. It’s interesting that you claim nearly everyone believed in a flat earth. But remember that you also claimed the majority equals scientific truth and God’s truth, so does that mean you believe the earth is flat? (just pointing out the contradiction).

      I agree with your description of a false dichotomy. I was attempting to address your concern that creationist beliefs are responsible for driving people away from their faith. Since you also agree we can’t easily distinguish between God’s word and man’s word, then perhaps you should be less judgmental of creationists.

      Question: What if you find that science contradicts some part of your faith? For instance, the majority of scientists deny that people can rise from the dead, walk on water, or calm a storm? How do you reconcile areas of Christian faith that are in conflict with science?

      • “I don’t think creationists have refused to accept the buried sedimentary cycles. It’s just that they interpret the evidence from a young earth perspective rather than an old earth.”

        You’ve gotta get this notion out of your head. Contrary to what you’ve been told over and over again, science isn’t a bunch of people who are merely bringing different “perspectives” through which they interpret data. Actual scientists construct hypotheses to explain data, THEN use those hypotheses to make testable predictions in order to see whether they have any predictive power. If they don’t, they are changed or discarded.

        Creationists aren’t merely interpreting the evidence from a different perspective; they’re handwaving away the evidence and hoping no one notices.

        “If [Oard and others] confidently claim that they’re convinced the data points to a young earth, why not believe them?”

        Because we’ve caught them lying.

        “By a ‘plain reading’ of Scripture I mean that we need to read it in context, and if we do so, the Bible infers a young earth.”

        This is what you’ve been told, yes. This is your claim. It is not accurate.

        “I use the term ‘secular’ model because [they] reject the supernatural events described in the Bible. This is in contrast to creationist models that acknowledge supernatural events, such as a six-day creation, Noah’s Flood, the dispersal at Babel, existence of the behemoth, prophecies of the Messiah, the Exodus, and the life, death and resurrection of Jesus Christ. So I think it’s fair to point out this contrast between models that accept the Biblical evidence as opposed to those that reject Biblical evidence.”

        Science accepts that the accounts in the Bible exist and demand an explanation. It just has explanations which are far, far better than the anachronistic fantasy that the Bible is a history book. If the evidence supported a recent global flood, that is what mainstream science would hold to.

        “What if you find that science contradicts some part of your faith? For instance, the majority of scientists deny that people can rise from the dead, walk on water, or calm a storm? How do you reconcile areas of Christian faith that are in conflict with science?”

        The miracles you’re describing claim the suspension of natural law. If creationists believed in a miraculous flood that left no evidence, that would be one thing, but they instead argue that the flood progressed according to natural laws and laid down existing strata layers by natural processes and was followed naturally by a natural ice age. These are not miracle claims; these are claims about how nature works. And they are wrong. Nature does not work this way.

    • You questioned my statement: “I once stood on your side of the court, believing in long ages. I didn’t really think anyone knew for certain how old the earth or universe were….” and called these two statements incompatible. I’ll elaborate. I recognized there were well-educated scientists on both sides of the spectrum espousing evidence for an ancient or young universe. I wasn’t prepared to dogmatically declare that either side knew for certain what the truth was, even though they both claimed certainty. The one thing I did know for certain was that all scientists are biased in their favored paradigm, and those biases will affect their interpretation. Therefore, it was reasonable to conclude that no scientist could know as much about the distant past as they claimed. So I took what seemed like a reasonable middle-ground, namely that nobody could know for certain how old the earth or universe was, including you. The only possible way one could know these things with certainty is if you were God, or if that information were revealed to you by God.

      Nonetheless, I believed the overall evidence overwhelmingly pointed to an ancient earth and universe. It’s just that I refused to pigeonhole myself into any kind of definitive age. So perhaps my thinking wasn’t perfectly aligned to where you are now, but I definitely sided with long ages over young.

      I’ll take issue with your claim to know with certainty the age of the earth and universe. Firstly, certainty isn’t what science is about. Even secular scientists have admitted this to me many times over. Science is about the best interpretation of the data available at the time, based upon observed evidence and repeated experimentation. Science is about acquiring knowledge, but it’s not about certainty because new evidence could overturn the chosen paradigm. I’m glad you did provide a disclaimer, but to claim that you know the age with certainty demonstrates a weaknesses of science- namely the bias of infallibility and the dependency of elevating man’s intellect over God (1 Corinthians 1:25). I’ll take my chances with God over man anytime.

      Lastly, if you believe you know the age of the earth or universe with certainty, then apply this logic to forensic science in our justice system. By your logic, we shouldn’t have any false convictions, and only true convictions as substantiated by the evidence. But we’re constantly faced with false convictions because the science is based on human reasoning, not objective conclusions. Therefore, if we can’t be certain that person X is guilty of a crime that happened within our lifetime, then how can you be so certain of events that happened many billions of years ago? Such certainty defies credulity.

      Now I agree with you about hanging our hats on one particular passage. My point was that it was this passage in Mark that convicted me. The examination of this passage led me to go back and examine other passages in Scripture, such as Exodus 20:11, the genealogies in Matthew and Luke, and other passages in both the old and new testaments. I didn’t want to believe Mark 10:6 was implying that Jesus believed humans were present at the beginning of creation; I liked my particular position and was hoping I could explain it away without having to do spiritual gymnastics, but I could no longer do that and be honest with myself.

    • Ok, so you claim scientist’s interpreting data according to a particular worldview is a false notion. If you’re right, then you should be able to make real-world predictions with accuracy, right? What testable prediction can you make with accuracy for the next ice age? I’ve read reports that the next ice age has already begun and will last 200 years. Others report that the next glacial period could begin 50,000 years from now, and still others report that the next glacial maximum is 80,000 years away. Wikipedia says it was conventional wisdom that the typical interglacial period lasts about 12,000 years, but that has been called into question. So what would you have us believe? Are you willing to make a bold prediction that can be falsified by the evidence?

      I’d guess most of your predictions will extend beyond our lifetime, so you may never have to worry about being falsified. I’ll predict there won’t be another Ice Age because we don’t have the flood-like conditions that triggered the first one.

      Because there are so many different predictions, this is evidence that the conclusions are driven by interpretation and worldview. If this were not the case, then there’d be a consensus driven by one possible conclusion, and it would always be substantiated by time. By your reasoning, secular models should never change or be discarded. But the real reason why they need to be is because the evidence was misinterpreted for various reasons. When examining history, there’s no such thing as an objective-driven conclusion.

      What’s your evidence that Oard and others are lying? You’ve made accusations, but haven’t substantiated it.

      If you disagree with my interpretation of Scripture, then please elaborate. I’d love to discuss further.

      I’m quite certain that if the Bible didn’t mention a global flood, then secular scientists would propose one because the evidence is so overwhelming. Consider Mars for instance; even though there’s no liquid water there, scientists have proposed a global flood. Yet they deny a global flood on earth even though about 71% of its surface is covered by water. So I reject your notion that science would support a global flood if the evidence supported this.

      You deny that the Bible is a history book, yet it records many historical events substantiated by the evidence. Many secular archaeologists have touted its historical accuracy. Archaeologist Nelson Glueck said, “It may be stated categorically that no archaeological discovery has ever controverted a Biblical reference. Scores of archaeological findings have been made which confirm in clear outline or exact detail historical statements in the Bible. And, by the same token, proper evaluation of Biblical description has often led to amazing discoveries.”

      Noah’s flood was a natural event put into effect by God. There’s always an element of natural processes in every supernatural miracle. They’re not independent of the other. There may be the suspension of a natural law, and we can see these elements in the way God called the animals into the ark. Nothing happened until God ordained it, including the timing and duration.

    • No, I’m not saying that there’s something suspect about using evidence to expand existing theories. Of course we should. I’m saying there’s something suspect about how we go about drawing conclusions and interpreting the evidence. I’m saying that all evidence is interpreted against a worldview.

      Take forensic science for example. Is the suspect guilty because the murder weapon has the suspect’s fingerprints? The murder weapon (say a gun) is the evidence. If you’re the prosecutor, you demand prosecution because we have sufficient evidence to substantiate guilt. But if you’re the defendant, and you believe your client is innocent, you may draw a different interpretation. Perhaps someone else used the weapon and committed the murder. So based on the evidence in this example, can you tell me with certainty if the suspect is guilty or not? I haven’t given you enough information to draw any conclusion, but this is little different than you concluding that X many ice ages have occurred because the evidence “told you so”. In this case, concluding that the suspect is guilty may be a mistake simply because we haven’t seen the whole picture. But suppose we find out that the suspect’s credit card was used 750 miles from where the murder took place? Is that enough evidence to prove innocence? One worldview is trying to get a conviction, while the other is trying to substantiate innocence. Who’s right? Well, whether or not the suspect is guilty is independent of your conclusion. If you misinterpret the evidence, then it’s possible we could have a false conviction. This is not uncommon in our justice system, so your insistence that secular models are correct and independent of interpretation or worldview goes against what we already know from forensic science. To suggest otherwise means that somehow you’re omniscient, and that science is the ultimate arbiter of innocence or guilt.

      It’s true that creation science has the upper hand because we do have revelation from God. Secular science, on the other hand, may be chasing phantoms because they’ve overlooking like a supernatural creation that happened recently. Secular science will never appeal to a supernatural creation, even if it’s the only possible solution.

      You say the previous model for few ice ages was ultimately incomplete but accurate based upon the initial evidence. Are you now suggesting that the evidence is now sufficient enough that it is complete? Will you predict that no new evidence will come to light contradicting the current model?

  2. I do have some comments regarding your response, if that’s okay?

    “…after that they abandoned their own model and began to recognize anywhere from 30 to 58 different ice ages…”

    This comment is rather misleading. Prior to the use of stable-isotope analysis in ice/marine cores, we only had direct evidence for 3-5 major glacial advances. That’s because glacial advance tends to wipe the surficial sediments clean (like a bulldozer), removing the recent geological history. Even today, we have direct evidence only for the last 5-8 “ice ages”.

    Therefore, the model never was “only 3-4 ice ages, nothing more”, so nothing was ‘abandoned’ with the advent of isotopic evidence. Rather, all isotopic records from Antarctica and hundreds of marine cores *also* document those 3-4 ice ages inferred from glacial sediments on land. The current “model” (I don’t really like that term in this context) is complementary to glacial geology of the early-mid 20th century, not a reversal in thought.

    “The creationist model, on the other hand, hasn’t changed much and basically recognizes only one Ice Age…”

    This comes as no surprise, given the young-Earth timeline. It’s already physically impossible for continental glaciers to advance 3-8 times over the NA/Eurasian continents during a single 700-year ice age. It’s already physically impossible for Earth’s climate and biosphere to rebound from full glacial conditions less than 5,000 years ago. Hence, proposing multiple ice ages on a YEC timeline would only multiply impossibilities.

    The other reason the creationist model hasn’t changed is that it does not incorporate accumulated data from glacial geology. For example, every publication I’ve read on the biblical ice age has used only the Last Glacial Maximum (21,000 years ago) to describe the extent of continental glaciation. Why is that? Glacial extent was much greater in Eurasia during previous glacial episodes (e.g. ~135,000 years ago). In effect, they’ve reduced the size of ice sheets in their model, which already can’t explain the accumulation of that much ice in such a short time span. This is a classic example of cherry picking data.

    “In fact, the evidence for only one Ice Age is very strong, while evidence for multiple Ice Ages is weak. We know, for example, the earth was fairly warm prior to the Ice Age; there’s sedimentary evidence suggesting there were no cold-weather environments or glaciation prior to the Ice Age, with the exception of Antarctica and some high mountain ranges.”

    This statement would never pass scrutiny in an introductory class on glacial and Quaternary geology. Geological evidence for multiple ice ages is overwhelming (see the volume Quaternary Glaciations – Extent and Chronology: A Closer Look, for example). Eurasian sedimentary sequences, for example, commonly contain glacial tills and proglacial lake sediments sandwiched between warm-climate floodplain, paludal, and lacustrine sediments, replete with warm-adapted species of pollen and animal fossils. In short, the claim is false. There is abundant evidence for cold episodes prior to the last glacial maximum.

    “Supposedly, what causes repeated ice ages is a decrease in solar radiation as a result of changes in the earth’s orbit every 100,000 to 40,000 years.”

    Essentially, yes, and the theory is well corroborated by multiple independent lines of evidence (from ice/marine cores to lake sediments and cave samples—I’ve written about several). But it’s important to note that radiative forcing (small changes in incoming solar energy) only begin the process, which is amplified by changes in ice-sheet cover, vegetative cover, sea level, etc. Nobody has ever posited that Milankovitch forcing *alone* causes ice ages to begin/end.

    I really don’t know why you call astronomical forcing “assumption ridden and complicated”. Every hypothesis has assumptions, but that’s why we test them. 🙂 Since the assumptions of Milankovitch hypothesis turned out to be verified by those tests, for example with respect to the timing, we now call it a theory. Astronomical forcing does indeed pace glacial cycles.

    • I don’t think it’s misleading to suggest that secular scientists abandoned their own model of 3-4 ice ages for 30 to 58. At least not any more so than you suggesting that creationists are guilty of abandoning historical science when I don’t believe that’s the case. However many ice ages secular scientists once believed in, that belief was abandoned in favor of another belief in many ice ages based on different criteria.

      I understand your point that glacial advance tends to wipe the surface sediments clean, but when you claim that we only have direct evidence for the last 5-8 ice ages, I have to disagree. Creationists contend that the evidence points to a single ice age advancing and retreating over a period of time.

      It’s not impossible for the glaciers to have advanced and retreat over the 700 years proposed by creationists. We’re not talking about 5-8 separate and complete advancements and retreats. We’re talking about rapid advancements and retreats over 700 years, and we do see something similar today as indicated by observations in Greenland, where satellite images point to a record glacial flow at 46 meters per day. There’s no reason why that rate couldn’t have been faster in the past at a time when extreme weather conditions would have been common.

      Yes, creationists do recognize the last Glacial Maximum, but not the long ages (21,000 years ago). Nonetheless, I don’t see how previous glacial episodes poses a problem for creationists when we’re talking about extreme conditions.

      I disagree with your criticism of creationist interpretation vs. secular interpretation. Of course creationist explanations would never pass scrutiny in a secular geology class. And I’m quite certain a secular interpretation wouldn’t pass scrutiny an introductory class at a creationist university either. Creationists aren’t saying that there weren’t cold episodes prior to the last glacial maximum, just that the earth was a fairly warm place prior to the start of the ice age.

      • You seem to hold a view of science and theory in which there is somehow something suspect about using evidence to expand existing theories. There is not. I can understand how, from a religious framework, it is embarrassing to admit you didn’t see the whole picture, but the very nature of science requires us to never assume we’ve seen the whole picture.

        Creationism, it seems, is an attempt to prove what you’re already sure of. Science is the challenge to improve upon the theories you’re gathering evidence for.

        In your example, recognizing the evidence for additional ice ages doesn’t mean abandoning past models; it means accepting that those models were accurate with respect to the initial evidence but ultimately incomplete. That’s how science works.

  3. “The belief in multiple ice ages is merely based on assumptions and circular reasoning, such as the ability to make the evidence fit the paradigm through manual calibration, not any kind of objective truth that is self-evident or plain to all. Without such circular reasoning, the Milankovitch mechanism wouldn’t work.”

    Every marine core we analyze exhibits evidence of major fluctuations in Earth’s hydro/cryosphere according to a regular rhythm. We have dozens of stalagmites from around the world documenting multiple climatic cycles—the timing of which corresponds perfectly to radiative forcing proposed by Milankovitch (I can provide these papers, on request). The accusation of circular reasoning here is totally unwarranted, and alone is a good reason why YEC’s will never persuade researchers/academics of the legitimacy of their movement. We already know better.

    “…including the fact that there would need to be a cooling of more than 50 degrees in summer temperatures in the northern United States along with a massive rise of snow for thousands of years.”

    Since I’ve been reading multiple papers on glacial modeling in an attempt to publish my own research, I already know this claim to be in error. Perhaps you can provide a source?

    “In other words, the evidence in Alberta points to one ice age.”

    No, the evidence in Alberta is consistent with the fact that glacial advance has repeatedly affected Alberta, because continental ice sheets remove surficial sediments.

    “So the author of this article demonstrates a lot of arrogance, tossing around accusations when the model he adheres to contain significant flaws.”

    My accusations were hardly “tossed around”. I linked to other articles where I attempted to defend my opinions. Does it make me arrogant simply to critique others’ errors? This is a moot point.

    If by “contain significant flaws” you recognize that science advances through falsifying competing hypotheses, then I can agree. But you have not elucidated any particular error in the ‘secular models’. Rather, you’ve only made a handful of false statements that hardly account for the most recent research.

    “Does he wish to dogmatically tell us exactly how many ice ages he believes in, and how and why he’s accepted this arbitrary number along with the duration of each one?”

    Since when are scientific hypotheses framed as a dogmatic code of beliefs? I’m a little baffled by this question, to be honest, but to answer I would defer you to the work by Zachos et al.:

    http://www.essc.psu.edu/essc_web/seminars/spring2006/jan18/Zachosetal.pdf

    “Or can he tell us with certainty that the dynamic advancing and retreating of a single ice sheet over time produces complex sedimentation that can be differentiated from a completely separate ice age thousands of years apart without circular reasoning or bias?”

    Yes, I can, and I’m not alone. We have no trouble discriminating between short-term dynamics and long-term (multimillennial) interglacials.

    “Does he understand the astronomical model well enough to explain how the coils in sea shells provide irrefutable evidence of many ice ages in spite of the criticism offered by other secular scientists?”

    Yes, I do. The main criticism is that the tuning models were derived through circular reasoning. Originally, this critique was valid (except that the 100:40:21 ratio demonstrated between significant periodicities in raw data do corroborate independently, but we’ll leave that aside). Once you account for ash markers in marine cores as independent tie points and especially age models derived from speleothems, the critique is no longer valid. That’s why nobody makes it anymore, outside of the YEC community. We understand that the science has progressed and dealt with these legitimate concerns. You’ll find the same story with respect to the “100,000-year problem”. Yes, it was a legitimate critique, but no longer. See papers by Kohler et al. (“Temperature variations over the last 800,000 years”), for example, to understand why. The short story is: there is no real 100,000-year periodicity in glacial cycles; rather, it’s an 80 or 120 thousand-year cycle related to obliquity-forced shifts in circulation patterns and temperature gradients. The 100-kyr cycle was an artifact of the spectral analysis, which at the time was too rudimentary and not appropriate for these geologic data.

    “And when the evidence shifts, will he admit that his previously held belief was wrong? And if he was wrong about many of his beliefs, is he willing to accept that, just maybe, the creationist model could be correct?”

    Yes! That’s why I abandoned the YEC models offered by AiG and ICR. The evidence I encountered completely undermined their claims and their models. I could not maintain honesty and support their beliefs. If that ever happens with respect to the geologic evidence I’ve summarized very briefly here, then please feel free to hold me accountable.

    Thanks again for interacting with my post. I do appreciate the feedback!

    • I don’t doubt there is evidence of regular rhythms and climactic cycles, but I don’t think the evidence demands we interpret these rhythms as separate ice ages.

      The source referencing the cooling of 50 degrees in summer temperatures was linked in my article, but here it is: https://answersingenesis.org/environmental-science/ice-age/where-does-the-ice-age-fit/

      The evidence in Alberta points to one ice age, even with glacial scrubbing. Demanding multiple ice ages is an assumption according to secular scientists, like Robert Young and et al. Other secular scientists have said there’s no evidence of more than one glaciation, so it sounds convenient to conclude that all evidence for the other glaciations was completely wiped away.

      http://geology.gsapubs.org/content/22/8/683.short

      http://creation.com/images/pdfs/tj/j29_2/j29_2_12-13.pdf

      Of course you’re welcome to critique others, and I welcome your critique of me. My point is that others can be just as critical of your work. In your article you came across as if your conclusions are unquestionable facts. But had you done your work in the 1970’s, I suspect you’d come to a different conclusion than you do today, and I’m willing to bet your conclusions will be much different 30-40 years from now. Of course that’s how science works, but if your conclusions are constantly proven wrong with time, then, is it possible that secular science has it all wrong? I think it is.

      As for me describing your beliefs as dogmatic, it was the judgmental tone in your article that led me to that conclusion. It came across as if you’re the ultimate authority that cannot be questioned, as if you don’t make errors, but creationists do. So I brought this tone of certainty to light by calling it dogmatic. Good science, obviously, has nothing to do with dogmatism.

      According to your link, the astronomical model is calibrated. To me, this suggests that it’s assumption ridden; it’s calibrated to fit the evidence. So how can it be falsified if it’s incorrect? I think that’s why Zachos et al describe it as nearly impossible to extend the geological time scale back into the early Cenozoic. They also agree the ice sheets in Antarctica are extremely dynamic, as creationists contend.

      I do appreciate your explanations and will certainly have to do further research, but I do hope when the evidence shifts you’ll see that accepting those old-earth paradigms is a mistake. For the record, how many ice ages do you believe in?

      Please continue to respond as you see fit. Thanks again,

      • Just wanted to pull out one quote, since it’s in regard to something I’ve studied extensively:

        “According to your link, the astronomical model is calibrated. To me, this suggests that it’s assumption ridden; it’s calibrated to fit the evidence.”

        Again, I don’t want to sound condescending, but your statement demonstrates that you misunderstand the basic elements of what we are dealing with. There are various types of calibration. The calibration of ice sheet and benthic data to radiocarbon dating and astronomical climate forcing is used to line up datasets which are already proven to be in sync; this calibration merely eliminates small percentage errors that accumulate due to low-level noise and local variation.

        Creationists seem obsessed with “assumptions”, but science does not EVER function on the basis of assumptions. It functions on the basis of hypotheses. An explanation of data is only a hypothesis if it can be used to make testable predictions; once those predictions are tested and verified, it becomes a working theory. Assumptions never come into play, no matter what quote-mining creationist talking heads might claim.

        Calibration is like sighting a rifle. You line up your barrel using an established benchmark and use that to correct for wind, barrel defects, and other factors. But an uncalibrated rifle will still fire a bullet forward, not backward. That’s the sort of difference we’re talking about here.

  4. It’s worth pointing out that all the posturing and explanation surrounding changing models and ice age mechanisms is really quite unnecessary because it ignores the point of the original post. I wouldn’t accuse anyone of deliberately following red herrings; it just seems to be very typical in creationist rhetoric.

    The argument that needs to be addressed is quite simple.

    700 years is not sufficient time to compress rock enough to produce measurable isostatic rebound today. Therefore, there was no 700-year ice age.

    If creationists wish to argue that a single 700-year ice age COULD be responsible for the measurable isostatic rebound observed today, then the localization of isostatic rebound in Canada shows that those continental glaciations occurred in separate episodes from other continental glaciation, proving that there was not just one ice age.

    This argument defeats the creationist model regardless of whether we know how many ice ages there were or how long they lasted or what caused them.

    • David, the reason why creationists are “obsessed” with “assumptions” is because it’s unquestionable that this happens. You even admitted this when you said, “Every hypothesis has assumptions, but that’s why we test them.” Your statements are contradictory. Either science does not EVER function on the basis of assumptions, or every hypothesis has assumptions. It can’t be both.

      I think it’s fairly obvious when science rests on assumptions. This commonly happens when dealing with the unobservable past. I suspect scientists don’t like to admit this because they want to be thought of as objective and evidence-driven, but the problem is they’re still human.

      We both agree science functions on hypotheses, but no matter how testable the hypotheses is in the present, it’s impossible to demonstrate that one’s conclusions about the distant past are correct.

      Okay, let’s consider if there were 111 ice ages over the last 2.6 million years. The assumption is that there’s no missing data, unknown variables, or misinterpretations. But none of us are God or omniscient. The number 111 could be incorrect, and, if so, it’s impossible to know how many we’re off by because we can’t observe the actual events themselves; we must infer them from all the available evidence (ice cores and marine cores, cave samples, lake sediment, pollen records), and that’s where the assumptions lie. You can’t compare the hypothesis against reality. You must assume your hypothesis equals reality.

      If you still disagree, then this number shouldn’t change. It would stand the test of time and could not be questioned. But this assumes you’ve seen the whole picture, even though you’ve stated that the very nature of science requires us to never assume we’ve seen the whole picture.

      As to the point of the article, it’s my intent to find out if a single 700-year ice age could be responsible for the measurable isostatic rebound observed today, or if there are alternative explanations.

  5. Hi Jonathan,

    Sorry, I haven’t had time to keep up daily with comments, or send you a full batch of those references. Work, family—I’m sure you understand. 🙂 Also, I think the comment thread is becoming a bit chaotic, with too many minor points building up unresolved. That’ll make it harder to continue.

    So it’s at this point that I’d propose “Hey, let’s chat about this over coffee, so we can focus on points 1 by 1 and not talk past each other.” But since logistically that could be a challenge, would you be interested rather in a coffee chat via Skype or something similar? I think it would be much more productive that taking hours of each other’s time writing back and forth. If you’re interested, send me a message and we’ll arrange.

  6. In the meantime, I want to make a couple brief comments, so you know I’m not ignoring you. 😉

    “However many ice ages secular scientists once believed in, that belief was abandoned in favor of another belief in many ice ages based on different criteria.”

    I need to reiterate why this statement is misleading, in a way that is damaging to the discussion. When geologists described the 3-4 major ice ages, they did so from physical geologic evidence in N. America and Eurasia. They interpreted that evidence to the best of their ability/knowledge at the time. The conclusion reached was never “There were *only* 3-4 ice ages, and no more”, but “We have documented evidence for at least 3-4 major glacial advances over the northern hemisphere.” The underlying assumption always remains: We could potentially discover new evidence that modifies our current understanding. That’s how science progresses, is it not?

    Similarly, it would be ridiculous to say “Biologists abandoned their belief in only 100 species of this taxa for a belief in thousands of species!” Obviously, as we discover new species, that number will change. Nobody pretends that we’ve exhausted the geological archives for all evidences of Earth history.

    Again, those 3-4 ice ages described early on by sedimentary/geomorphic evidence are included in the current total (11 major glacial advances in the last 1 million years, nearly 100 glacial advances in the past 2.6 million years, known as the Quaternary Period). The difference is that now, we have a variety of independent methods to estimate that total, whereas 40+ years ago, most evidence was very spotty and always contingent.

    “It’s not impossible for the glaciers to have advanced and retreat over the 700 years proposed by creationists…we do see something similar …in Greenland, where satellite images point to a record glacial flow at 46 meters per day.”

    It is impossible; these numbers don’t even come close to adding up (especially because that high flow rate cannot be applied over a wide surface area). We’d have to discuss this in more detail on a separate thread. But consider at least that each glacial advance requires a volume of ice equivalent to ~120 meters of water spread over the whole oceans being moved onto land and then melted away. You can speculate about extreme weather and hypercanes all you want; this is pure fantasy fiction. You’re better off contending that it was miraculously added/removed.

    “I don’t think creationists have refused to accept the buried sedimentary cycles. It’s just that they interpret the evidence from a young earth perspective rather than an old earth.”

    I have read that article by Oard, but it doesn’t address *any* of the sedimentary cycles to which I referred (and linked the main volume, summarizing sedimentary sequences from every high-latitude country around the world). So my point stands: the evidence has not been dealt with, period. Whether or not they have ignored it intentionally, I cannot know.

    “If they confidently claim that they’re convinced the data points to a young earth, why not believe them?”

    Either they’re being dishonest or they sincerely are unaware of thousands of studies, available in milliseconds via modern search to any competent geologist. I know they are not incompetent, so my best judgment is that they’re being dishonest. Of course I might be wrong; I wish I were.

    “The source referencing the cooling of 50 degrees in summer temperatures was linked in my article…”

    This doesn’t answer my request. I want to know how this number was calculated, because in the dozens of articles I have that utilize climate models to estimate changes in summer temperature, none of them have suggested anything like this. I am certain that Oard didn’t use his own supercomputers and coupled climate models, so I can only assume that he got the number from a single study at some point. But since that number is not consistent with modern research (even in 2007, when he wrote it), his critique holds no weight whatsoever.

    “The evidence in Alberta points to one ice age, even with glacial scrubbing.”

    How? Every glacial geologist would disagree with you on this point. Not only did you ignore my references, you linked to an article from Geology that does not support your contention by any stretch of the imagination. This particular study looked at a single area near Edmonton, and it made a simple conclusion:

    1) The Laurentide Ice Sheet advanced to that area during the Late Wisconsin (~20-40,000 years ago), and not prior. That’s important, because the Wisconsin “ice age” lasted several orbital cycles and was comprised of several smaller advances. These authors contend that while the smaller advances reached other parts of Canada, it did not reach their study site.

    What does that have to do with the question of how many ice ages there were? Absolutely nothing! Because these authors refer only to the *Laurentide Ice Sheet*, which formed during the most recent glacial episode. Their research focus was the Winsconsin glaciation (~21-100,000 years ago), not the Illinoisan, etc. In other words, they do not comment on previous ice sheets, for which there *is* evidence in Canada and the U.S.

  7. A few more points:

    “I’m willing to bet your conclusions will be much different 30-40 years from now. Of course that’s how science works, but if your conclusions are constantly proven wrong with time, then, is it possible that secular science has it all wrong?”

    Yes, the goal of science is to disprove hypotheses to discover which ones remain supported by the evidence. Had I been working in the 70’s, I would not be able to contend confidently that there were dozens of ice ages over the past 2 million years, because that evidence was not readily available. On the other hand, I would not be able to disprove the current prevailing hypothesis, which is that glacial advances occur every ~41,000 years in response to orbital forcing. The fact that we still have not disproven this hypothesis lends credence to it’s plausibility. I am sure that my conclusions will be different 30-40 years from now (if not, I haven’t made any progress!), but not substantially so. The chances that in 30-40 years, geologists will conclude that “Nope, there was only one ice age, we got that wrong!” is effectively zero. It is as likely as physicists reverting back to a geocentric model of the solar system. Even in the case of major paradigm shifts, the supporting evidence doesn’t disappear. And like I said (and cited), the evidence for dozens of glacial cycles is beyond overwhelming.

    “To me, this suggests that it’s assumption ridden; it’s calibrated to fit the evidence. So how can it be falsified if it’s incorrect?”

    Why? Calibration doesn’t mean “calibrated to fit the evidence”. In this case, the peaks/troughs in the isotopic record were calibrated to the physical model of Milankovitch-style changes in solar radiation, because that model is already known to be accurate (it’s basic physics, the kind that allows us to land a rover on Mars, predict eclipses, or chase down a comet) and it’s already been established that the isotopic record reflects insolation forcing of climate through independent means (like cave/coral records, etc.). Therefore, the age model with higher error bars (ages of ocean sediments) is calibrated to the age model with better precision.

    This model could easily be falsified. For example, ocean sediments and ice cores contain some volcanic ash layers. We can use the isotopic record to predict the age of those volcanic ashes, based on the assumption that isotopic values track Milankovitch cycles. Then we date the ash layer independently. If ash layers consistently yield ages far outside the lab uncertainty of the predicted ages, then we’d know there is a problem. But we find the opposite: radiometric dates agree excellently with the predicted age based on the astronomical model (e.g. see Lisiecki and Raymo’s paper on the ocean stack: http://lorraine-lisiecki.com/stack.html).

    Additionally, if it were shown that isotopic changes in ice/marine cores didn’t correspond to other climatic variables, such as greenhouse gas concentrations or sea level, then potentially we would have falsified the astronomical model. But instead, they do correlate almost perfectly:

    https://ageofrocks.org/2015/07/13/correlation-of-temperature-and-co2-in-a-young-earth/

    This list goes on. There are dozens of tests that potentially could falsify our prevailing theory for glaciation and the timing of ice ages. But our models have passed each test and the essentials remain unchanged: glacial advances are paced by changes in solar radiation, amplified by feedbacks in the climate system.

    “I think that’s why Zachos et al describe it as nearly impossible to extend the geological time scale back into the early Cenozoic.”

    No, that’s not why. It has rather to do with the reduced number of overlapping marine cores (a number that will change as we collect more data from around the world). Those ships can cost upwards of $150,000/day to operate!

    “For the record, how many ice ages do you believe in?”

    Again, see the papers by Zachos et al. (2001) and Lisiecki and Raymo (2005) for a composite record. There were 11 major glacial advances in the past 1 million years, and nearly 100 over the past 2.6 million years (the Quaternary Period). Prior to that, glacial episodes were less extreme because the planet was overall warmer (feedbacks were dampened), but climate still oscillated according to Milankovitch cycles.

    • “The peaks/troughs in the isotopic record were calibrated to the physical model of Milankovitch-style changes in solar radiation, because that model is already known to be accurate (it’s basic physics, the kind that allows us to land a rover on Mars, predict eclipses, or chase down a comet) and it’s already been established that the isotopic record reflects insolation forcing of climate through independent means (like cave/coral records, etc.). Therefore, the age model with higher error bars (ages of ocean sediments) is calibrated to the age model with better precision.”

      For clarification, I’ll point out that if the isotopic record did not represent the same time period as the physical Milankovitch model, it would not be possible to “calibrate” it to match, just like it wouldn’t be possible to “calibrate” an elephant’s footprints to fit ordinary human stride.

      Ice core data without layer counting matches the Milankovitch model. Ice core data with layer counting matches the Milankovitch model. Benthic sedimentary data matches the Milankovitch model. Dendrochronology matches the Milankovitch model. Speleotherms match the Milankovitch model. Coral growth rings match the Milankovitch model. All of these patterns match EACH OTHER, independently of the Milankovitch model. This is open and shut.

      And, as has been pointed out, there are NUMEROUS places where ash layers and other signatures in the data could potentially falsify it.

    • I fully understand your explanation for the change in the number of accepted ice ages over the years, and yes, it certainly sounds like progress based on your explanation. But it’s also biased. And I think it’s not only possible, but likely, that the 111 major glacial advances in the last 2.6 million years that you recognize may not be reality. I do understand your certainty that this is so, but the one thing we know with absolute certainty is that our ability to ascertain the past, when compared with reality, is flawed. This is why our justice system will never be able to accurately convict suspected criminals 100% of the time- despite the advances we’ve made in forensic science. It’s just unreasonable to expect this, and even more so when we stretch the time frame millions of years into the past. The science becomes even less certain, especially when we can’t verify the accuracy. Any perceived accuracy must be believed by faith.

      Please understand, I don’t intend for my views to be damaging to the discussion because I really do enjoy the opportunity to learn and understand your views. It’s just that I can’t accept your conclusions based on what we’ve learned from history (and the Bible). People have been put to death as the result of unfortunate mistakes made in the name of science. Forensic science is piecing together the past. But the problem is there are a lot of missing pieces, some very similar pieces, and there’s no picture to compare the results to. That’s a problem, no matter how much advancement we make.

      Let’s look at your analogy- abandoning a belief in only 100 species for a belief in thousands of species. Who gets to define a species? Perhaps another scientist only accepts 300, while another 50. Not all will agree with the conclusion that specimen A is a different species than specimen B. There are many examples where one species becomes recognized as two separate species, or where two separate species become recognized as the same species. In the same way, what you recognize as a separate ice age may be interpreted by others as one ice age.

      Now I don’t have access to all the research available to you, but as I searched the net, there’s little certainty as to how many ice ages there have been or what causes them. According to this link, http://www.bbc.co.uk/science/earth/water_and_ice/ice_age , “There have been many ice ages during the last 2.6 million years”, and “What causes ice ages is not completely understood.” There’s no consensus. Some claim there have been at least 5 major ice ages in Earth’s past; and in the last 2.6 million years, cycles of glaciation every 40,000 – 100,000 years. But few seem willing or confident enough to provide an actual number; they just present this vague range. I found many other answers, including: “There are many different schools of thought on whether there have been many ice ages.” Another says, “It depends on your definition of ice age. Was the “little” ice age of the middle ages, an Ice age.” Some claim the ice age began some 40 million years ago. Some experts claim there were only four ice ages. A Live Science article indicates the present ice age began 1.8 million years ago. A Science Daily article indicates at least 4 major ice ages.

      So, with all due respect, forgive me if I find it hard to accept your conclusions.

      • Hi Jonathan,

        I’m a little confused by some of your comments, but I’ll try to be brief.

        You say the process/progress is biased. Why and how? I don’t quite understand, let alone how it’s relevant. Let’s assume it is biased—so what? The conclusions of glacial geologists and paleoclimatologists are published in a public forum, where their work is subject to constant critique.

        “And I think it’s not only possible, but likely, that the 111 major glacial advances in the last 2.6 million years that you recognize may not be reality.”

        Sure, it’s possible, but you have yet to offer any reason why it’s *likely*. There are multiple lines of evidence by which we ascertain the glacial history of the Quaternary, and none of them have been reasonably challenged.

        Regarding certainty—who cares? I don’t mean to sound crass, but I sincerely must ask why it matters that we’ll never attain certainty about the past. No scientist has certainty as their goal! Besides, it’s a two-way street. 🙂

        “Any perceived accuracy must be believed by faith.”

        I don’t agree with this statement, because it’s not true that we can’t verify the accuracy of claims regarding the past. Of course we can, just as we can test such claims in the courtroom: “I never handled that gun with my bare hands!” “But your fingerprints are all over it..?” “Assumptions! Faith!” The better term here (against uncertainty) is confidence, which sometimes can be quantified. For example, we are highly (99%) confident that the last glacial maximum occurred within 1,000 years of 21,000 years ago. We are similarly 99% confident that a glacial dam in central Canada burst between 8,400 and 8,000 years ago and that the resulting discharge cooled European climates by up to 1-4°C.

        “Let’s look at your analogy.. Who gets to define a species?”

        I think you’ve missed the point of my analogy, which obviously assumed that we all use the same definition of species.

        Nonetheless, your question as to how we define an ice age is valid. The answer: an ice age is characterized by significant advance of continental ice sheets, cooling of global climates, and lowering of sea level, relative to the mean long-term state. That definition is intentionally a little vague, because nobody really cares how to define an ice age with greater precision. It really is inconsequential. That’s why in scientific research, we define our terms up front, which allows those definitions to expand or be molded as necessary. So if one scientist wants to redefine the term ‘ice age’ so that the ~100 Quaternary ice ages were actually 1 long glacial episode… Well, ok. They can do that, I suppose. It doesn’t change the underlying science, only the rhetoric.

        “..as I searched the net, there’s little certainty as to how many ice ages there have been or what causes them.”

        That’s why I sent the papers that I did: it demonstrates the consensus on all the basics, such as how many glacial episodes occurred, and the major forces behind their inception and end. A BBC article stating that it’s not *completely* understood (is anything really?) doesn’t change those facts.

        “Some claim there have been at least 5 major ice ages in Earth’s past..”

        Yes, there have been at least 5. But every researcher knows the number is far higher.

        “But few seem willing or confident enough to provide an actual number; they just present this vague range.”

        Why do you keep bringing this up? I linked to and sent the Lisiecki & Raymo paper, which labels every single glacial advance over the past 5 million years. Nobody disagrees with their numbering, so you’ve had the number all along.

        “There are many different schools of thought on whether there have been many ice ages.”

        You won’t find a single peer-reviewed article in the past 40 years claiming that there has been only 1 ice age in Earth history.

        “It depends on your definition of ice age. Was the “little” ice age of the middle ages, an Ice age?”

        Not sure where you found this, but it’s a very silly statement to make. Again, not because it would change the underlying science (it doesn’t), but because the rhetoric is impractical. If we deem the so-called Little Ice Age an “Ice Age” (it wasn’t, by any stretch), then we undermine the whole distinction between glacial and interglacial. Why do that? It’s a terrible way to communicate and therefore to make scientific progress. It’s like saying, “It depends on your definition of species. What if we just call everything with hair that’s warm blooded the same species?” What’s the point?

        “A Live Science article indicates the present ice age began 1.8 million years ago.”

        That is false. What they mean to refer to is the start of the Quaternary period, which now is considered to be 2.6 million years ago to present (that’s *about* when the 41,000-year glacial rhythm began to stand out against the mean climate state). In the context of this article, the term “Ice Age” is not being used in the same way that we have used it in our discussion.

        “So, with all due respect, forgive me if I find it hard to accept your conclusions.”

        Well, I can see why! It will be helpful to keep all terms straight and not focus on arbitrary rhetoric and scientific terms. Rather, we should focus on the details, like the specific evidences for glacial episodes or dating techniques. Wouldn’t that be preferable?

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