What does the Book of Mormon tell us about the climate during Nephite and Jaredite times?

The limited information provided by the authors in the Book of Mormon about the climate in their lands during their times often makes it difficult to provide strict definitions for what their climate must have been like.  On the other hand, there are textual references at places and times that do establish some climatic boundaries that models of Book of Mormon lands can be compared against.

Some of these boundary conditions are:

  • At the place where Lehi’s party first landed, seeds that were planted would “grow exceedingly” at 589 BC (1 Nephi 18:24).
  • By tilling at Lehi-Nephi, “all manner of grain, and of fruit” could be grown from 420 BC (Enos 1:21) until at least 399 BC (Jarom 1:8) and probably until the group left those lands sometime between 279 BC and 200 BC.
  • By tilling in the land of Lehi-Nephi, corn, wheat, barley, neas, sheum, and all manner of fruits could be grown in 188 BC (Mosiah 9:9, Mosiah 10:4).  Starting sometime between 145 BC and 121 BC they “began to raise grain more abundantly”.  This group that practiced agriculture left those lands about 121 BC and travelled to Zarahemla.  In that same year we see our first mention of tilling in the land of Zarahemla when Mosiah “did cause his people that they should till the earth” (Mosiah 6:7)
  • The limited extent of agriculture practiced 35 years later (86 BC) can be inferred in the account of a war that included two battles fought at two specifically-named places near and on the banks of the river Sidon.  These battles were over in two days, but fields of grain had been “trodden down by the hosts of men” and the loss of the fields where this war happened caused the people to be “greatly afflicted” (Alma 4:2).
  • At “times or seasons” about 148 BC, wild beasts would infest a place was called “Mormon” (Mosiah 18:4)
  • About 72 BC, probably in Zarahemla, mention is made that fevers were frequent “at some seasons of the year” and that men were subject to diseases “by the nature of the climate”(Alma 46:40)
  • Describing events in the year 67 BC, Mormon makes mention of a day when Amalikiah’s armies were fatigued because of their labors and because of the “heat of the day” (Alma 51:33)
  • Mormon describes a season of grain and a season of fruit when he describes the effects of a 1-year drought that affected both the Nephite and Lamanite lands from 17 BC – 16 BC(Helaman 11:6, 13)
  • Nephite “flocks” and “herds” could be supported by the climate in many areas of Nephite and Lamanite lands with mentions of them being made from 588 BC until 23 BC.
  • Jaredite “flocks” could also be supported by the climate in their lands during at least two periods:  Once related to the story of the dearth and serpents during Heth’s reign and once during Morianton’s reign when “flocks” and “herds” are mentioned together.  Morianton’s reign (Ether 10:12) was “many years” (Ether 10:9) after Heth.

Some assumptions that seem consistent with the text:

  • Some or all of the time from 589 BC to 121 BC the climate around the city of Nephi, the land of Shilom, and the place of Lehi’s landing in the land of Lehi-Nephi was suitable for agriculture.
  • The climate seems to be suitable for raising flocks and herds in many places that the Nephites and Lamanites posess during at least the period from 588 BC until 23 BC.
  • Agriculture was introduced by (and perhaps in) the year 121 BC in Zarahemla and continued for at least a century.  During at least the first 35 years of that century, enough of the agriculture was centered around the river Sidon that losing those fields was a significant event in the history of the people.  Citing this specific loss of agricultural production does not mean that other Nephite lands around Zarahemla did not have agriculture, but this story shows that at that time, agriculture practiced around the only named river in the Nephite lands seems to have special significance.
  • There are no textual references giving us an ending boundary on the practice of tilling the ground or raising flocks or herds in the Nephite record, but no mention of it is made after 23 BC.
  • At least one day was hot around 77 BC.  There is no other mention of temperature in the Nephite or Jaredite records.
  • The climate during Jaredite times could support flocks and herds during at least two periods, but there is no boundary on when this practice started or ended.  There is only one reference to tilling the earth in the Jaredite is recorded shortly after the second time that flocks and herds are mentioned.  There are also no statements giving us boundaries on when the Jaredites started or ended the practice of agriculture.
  • The mention of “famine” in the wilderness between Zarahemla and Lehi-Nephi (Mosiah 9:3) implies that the climate in this wilderness is probably dry.  Since there is no distinction between the climate of this wilderness and the many other wildernesses mentioned in the text, the term “wilderness” in the Book of Mormon it is reasonable that the word “wilderness” implies highly arid deserts.  We also know that many Lamanites had an affinity for loincloths, particularly in the area around Lehi-Nephi, so the climate in those areas was loincloth-friendly.
  • Snow is never mentioned in Jaredite or Nephite lands.

How does the current climate of the areas presented in this model compare to these expectations?

The climate references in the text do not contradict the current climate of Baja or Southern California.  The number of references to raising grains, fruits, flocks, and herds may imply, but do not demand wetter conditions in the Baja peninsula during Nephite times compared to the climate today.

Has the climate in the modelled areas changed since Book of Mormon times?

Current conditions are drier than they were during Nephite times.  We can look to one particularly well-resolved record of the climate at a specific place and time during the Nephite years.  It’s from a packrat midden discovered near the city of Catavina, Baja California.  Like any study of past conditions, the strengths and limitations of the study are important in order to understand the context and applicability of the results.  The contents of this packrat midden can be directly dated to 1720bp (230 AD) +/- 60yrs which falls directly during late Nephite times.  The contents of the midden represent conditions about 30-50 meters around this one particular location at this one particular time.  The study concludes that:

“only about 51% of the midden plants still occur within 100m of the site.  Another 8 species have moved into the area….The modern climate is drier than 1,770 years ago…The abundance in the midden of mesquite and other taxa which today live over 100m from the midden suggests that these plants were growing on the boulders during the late Holocene (1,770 years B.P.) indicating greater soil development on boulder surfaces.” 

-Late Holocene Plants, Catavina, Baja California, Julia T. Stankey, Thomas R. Vand Devender, and William H. Clark; The Southwestern Naturalist 46(1):1-7, Vol. 46, No. 1 (Mar., 2001) (pp. 1-7)

If conditions were actually less dry during Nephite times, what can explain the change in climate?

The answer to this question can be found by comparing the effects of the El Niño Southern Oscillation (ENSO) in Baja to evidence that these ENSO events happened at high strength and unprecedented frequency during Nephite times.

The fact that ENSO events bring significantly increased precipitation to Baja is well established.  One example of this is a recent study that concluded:

“During strong El Niños, annual precipitation departed more than one standard deviation from normal at all stations in southern California and northern Baja California, with the upper bound reaching 270% of normal from San Quintín to Punta Prieta…average precipitation departures increased equatorward along the Pacific coast, with the maximum values near San Quintin (ca. 200%).  Departures decreased to 150% of normal both southward to Rancho Alegre and northward to southern California”

-The El Niño/Southern Oscillation and Precipitation Variability in Baja California, Mexico; Richard A. Minnich, Ernesto Franco Viscaino, Raymond J. Dezzani; 2000

The fact that ENSO events can bring increased precipitation to Baja helps establish a mechanism that can bring significantly more moisture to the land, but what evidence is there that these events actually occurred during Nephite times?

The answer to this can also be found in many sources.  One example is a recent high-resolution study of ENSO variability conducted in the Galapagos Islands from which a highly detailed set of data was produced documenting ENSO events going back many thousands of years.  This study also compared its results with many other well-accepted publications and concluded that there is broad agreement that for the period of ~2500bp until 1000bp (roughly 550 BC until 950 AD) there was an “Unprecedented” increase in ENSO cycles. (Conroy, Jessica L., et al. “Holocene changes in eastern tropical Pacific climate inferred from a Galápagos lake sediment record.” Quaternary Science Reviews27.11 (2008): 1166-1180.)

The combination of the increased number of ENSO cycles and the strength of the ENSO events, combined with the effect that ENSO events are known to have on Baja California, gives us a good indication of the mechanism that caused the wetter conditions and better soil conditions documented in the packrat midden during Nephite times.  In addition, current science from many sources indicates that the pattern of these increased ENSO cycles was established from the beginning to the end of the time period that the Book of Mormon describes for the Nephite civilization.

During Jaredite times, ENSO events were apparently much less frequent, but not too dissimilar from modern times.  The lands that we suggest as the Jaredite lands in Southern California do not present the same climate questions that the areas of the Nephites in Baja presented and the minor details that we know about the Jaredite climate fit well with knowledge of current or past conditions in coastal Southern California.