Tree Rings

Copyright © 1996 by Sean Mewhinney (

Another important record of past climatic fluctuations is found in the annual growth rings of trees. And in Earth in Upheaval there is a brief section on the tree-ring record, as it relates to the catastrophes of Worlds in Collision. Part One of Worlds in Collision describes a series of close encounters with the planet Venus that allegedly left the earth wrapped in dense clouds of dust and hydrocarbons ("manna") ---clouds dense enough to blot out the sun.

For a long time there was no green thing seen; seeds would not germinate in a sunless world. It took many years before the earth again brought forth vegetation (Worlds in Collision, p. 133.)

This condition prevailed for decades, and only very gradually did the dust subside (WiC, p. 127.)

These were the forty years of wandering in the desert, when the Israelites fed on manna, attended by the "shadow of death."

At the time Velikovsky wrote this, the longest tree-ring record known came from the giant sequoias of California. And the oldest sequoia known started growing in the late fourteenth century B.C. --more than a century after the date Velikovsky assigned to his Venus encounter, when the forests must have died. To Velikovsky, this was no coincidence:

Thus it appears that no tree has survived to modern times from the days of the great catastrophe of the middle of the second millennium. The sequoias are protected against fire by a bark often two feet thick, which resists combustion almost as well as asbestos. In order to survive through the days of global catastrophe a tree had also to withstand hurricane and tidal wave, and live in a sunless world under a canopy of dust clouds that enshrouded the world for many years. (Earth in Upheaval, p. 175)

Just one year before these words appeared in Earth in Upheaval, dendrochronologist Edmund Schulman had expressed a similar thought. Noting that "some believe [sequoias] may enjoy perpetual life in the absence of gross destruction, since they appear immune to pest attack," he speculated:

Does this mean that shortly preceding 3275 years ago all the then living giant sequoias were wiped out by some catastrophe? 1

This reasoning rests on a dubious premise: that there is any species with an unlimited natural lifespan, whether animal or vegetable, not subject to aging and decay. Only two years later, it was Schulman himself who discovered bristlecone pines more than 4,000 years old. 2 This was one of the difficulties for Velikovsky's theories brought up by Leroy Ellenberger in his series, "Still Facing Many Problems" (Part I, Kronos X:1 (Fall, 1984), "Tree Rings," pp. 94-97.) But it was a problem lightly dismissed by Shulamit Kogan, Velikovsky's daughter, in a rejoinder she called "Still Facing Unfair Criticism" (Kronos XII:3 (Spring, 1988), "Tree Rings," pp. 67-69.) In exceptionally hard years, bristlecone pines sometimes do not produce a growth ring at all. Kogan sees a simple solution in this:

Apparently, the few bristlecone pine trees (all in one small area 10,000 feet high) which did survive the Exodus events of a long overcast Sun did so because they were, as were not the Sequoias, able to "shut up shop" and survive without producing any rings. (p. 68.)

They cannot do so indefinitely, however, and these trees would have to survive not one year, but decades of darkness, if Velikovsky's words are to be taken seriously. Asked whether a bristlecone pine could survive as long as two years without growing a ring, C. W. Ferguson, who spent many years studying these trees, answered, "Probably not." 3

Nor is it true that all bristlecone pines presently known to surpass 3500 years in age come from one small area. Trees exceeding this age have been found in several different stands concentrated in two areas about 240 miles apart. One is in eastern California; the other in eastern Nevada. 4 There is no way to know how many other stands scattered throughout the American southwest contain equally ancient trees without undertaking a systematic survey on a truly vast scale. It is not obvious to the eye which trees are the oldest. They are not giants, but stunted. The only way to tell how old they are is to remove a sample.

Of course, the point is not whether living trees of great age can be found, but whether trees were living throughout the period when these catastrophes are said to have occurred. Different trees, responding to the same climatic conditions, lay down broad or narrow rings in the same years. A continuous overlapping chronology can be built up by cross-matching the pattern of alternating broad and narrow (or occasionally, in some specimens of bristlecone pine, missing) rings in different trees, whether still living or not.

Kogan mentions the high elevation of the bristlecones, as though this would provide protection of some sort. But a mountainside 10,000 feet up is not sheltered from winds or from darkness. On the contrary, it is precisely the most long-lived trees which would be most vulnerable to climatic stress, and least likely to survive a catastrophe. The oldest trees are those whose rate of growth is limited by adverse environmental conditions. 5 Any additional stress in a period of unusually severe climate could push them over the edge of survival.

At the upper treeline, cold, in particular, is the limiting climatic factor. Heat, as well as light, is necessary for photosynthesis to take place. And a dust veil reduces both heat and light. In fact, stratospheric dust veils produced by some of the major volcanic eruptions of history have caused severe frost damage in bristlecone pines near the upper treeline.6 The dust veil caused by a major explosive eruption subsides in a few months, and it leaves no perceptible residue. This hardly compares with the dense clouds which, according to Velikovsky, rained manna for years.

Bristlecone pines are hardy trees, but there is not the slightest reason to believe that they could survive such conditions as Velikovsky describes. In any case, it is not just a question of bristlecone pines. By cross-matching records from nearby sites, dendrochronologists in western Europe have built up a continuous overlapping master chronology of oak trees covering more than 7,000 years.7 Unlike bristlecone pines, oak trees cannot "shut up shop" without producing a growth ring for even a single year. Within the past 7,000 years, there never was a time when no oaks were growing in Europe. The existence of these trees forces us to conclude that there could not have been any clouds of dust or other material as thick and long-lasting as Velikovsky claimed.

Velikovsky was not aware of the existence of bristlecone pines or oaks dating to the mid-second millennium B.C. when he wrote Earth in Upheaval. Sequoia growth rings from the 8th and 7th centuries B.C. were known to exist, however the measurements were published in 1919 8 -- and Velikovsky had to say something about them, for this is the period when the earth supposedly underwent a series of natural catastrophes caused by the planet Mars. What he said sounds very much like hedging to me.

...those trees that survived the Klimastürze of the eighth and seventh centuries (hurricanes, floods, lava, and fire) were stimulated to growth by the increased presence of carbon dioxide in the air, yet impeded by a screen of clouds and dust; they might have been invigorated by electrical discharges in the atmosphere and possibly magnetic storms, and benefited from the addition of ashes to the soil. The singeing of leaves and changed conditions of ground water, as well as the change of climate generally, must have entered the picture. All in all, strong oscillations in the size of tree rings must be expected in years of great natural catastrophes. These are clearly recognizable on the annual rings of sequoias formed about the years 747, 702, 687 B.C., and generally in that century. (Earth in Upheaval, p. 177.)

One would expect to find, not "strong oscillations," but constricted growth rings or damaged wood in "years of great natural catastrophes." But that is plainly not what we find in the record, so Velikovsky lists, not only agents of destruction, but probably everything he could think of that might have a positive effect on growth. The stimulative effects of lightning bolts and magnetic storms, however, sound unconvincing.

Velikovsky does claim to find something different in the pattern of the rings for this period, though-- "strong oscillations." Are the oscillations in the 8th/7th centuries more pronounced than in other periods? One picture says it all-- There is nothing exceptional about growth rings for the period in question, or about year-to-year oscillations (See Fig. 1.), as Robert Jastrow pointed out in an article in 1980. 9

Tree ring oscillations, 900-500 BC

Pattern of oscillations in tree rings from 900 to 500 BC.

(Higher resolution figure here.)

Both Jastrow and Velikovsky missed something, however. It is clear from Velikovsky's remarks that he did not realize Douglass used a year zero for mathematical convenience, so that the year he calls 687 B.C. was actually the historical year 688 B.C.

The graph [not a graph, but a table] actually reveals a spurt of oscillations around the year 747 B.C. . There is an unusually high crest in the last years of the eighth century and the beginning of the seventh century. After a record high crest of six-year duration there is in 687 B.C. a precipitate drop. (Earth in Upheaval, p. 176.)

Actually, both years mark troughs, not peaks, in the curve, neither of which is especially pronounced. Velikovsky says that "the identification of the rings as to their years is approximate." It is not. It is exact.


1. Edmund Schulman, "Longevity under Adversity in Conifers," Science, March 26, 1954, p. 399.

2. Edmund Schulman, "Bristlecone Pine, Oldest Known Living Thing," National Geographic, Vol. 113, no. 3 (March, 1958), pp. 355-372.

3. See Ingrid U. Olsson, ed., Radiocarbon Variations and Absolute Chronology (Wiley, 1970), discussion, p. 246.

4. See Valmore C. LaMarche, Jr., "Environment in Relation to Age of Bristlecone Pines," Ecology, Vol. 50, no. 1 (1969), map, p. 57.

5. Ibid., op. cit., passim; see also Schulman, op. cit.

6. Valmore C. LaMarche, Jr. and Katherine K. Hirschboeck, "Frost Rings in Trees as Records of Major Volcanic Eruptions," Nature, Jan. 12, 1984, pp. 121-126.

7. J. R. Pilcher, M. G. L. Baillie, B. Schmidt, and B. Becker, "A 7,272-year Tree-ring Chronology for Western Europe," Nature, Nov 8, 1984, pp. 150-152.

8. A. E. Douglass, Climatic Cycles and Tree Growth, Part I, (Wash., D.C., Carnegie Institution publication 289, 1919), tables, p. 118.

9. Robert Jastrow, "Hero or Heretic?," Science Digest special, Sept./Oct.1980, pp. 93-96.

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Last modified by pib on October 28, 2003.