The Little Ice Age in Central Mexico
Cuna, E., Zawisza, E., Caballero, M., Ruiz-Fernandez, A.C., Lozano-Garcia, S. and Alcocer, J. 2014. Environmental impacts of Little Ice Age cooling in central Mexico recorded in the sediments of a tropical alpine lake. Journal of Paleolimnology 51: 1-14.
As their contribution to the subject, Cuna et al. developed "new information about the nature of the LIA in central Mexico based on a decadal-resolution sediment sequence from high-altitude tropical Lake La Luna, in the Nevado de Toluca volcano," which they did via analyses of "magnetic susceptibility, charcoal particles, palynomorphs [organic-walled microfossils], diatoms, cladoceran [small crustacean] remains and multivariate statistics."
In discussing their findings the six scientists say the coldest period of the LIA occurred "between 1660 and 1760, an interval that broadly corresponds with the Maunder Minimum in solar activity," which they say "is also consistent with the timing of the coldest northern hemisphere temperatures during the last millennium," citing Jones and Mann (2004) and Matthews and Briffa (2005). As for the more recent past, they say "biological assemblages that showed rapid changes during the LIA have remained relatively stable during the last few decades." They also report that these modern assemblages "resemble those in the lake ~500 years ago, during the MCA." And they say that "no clear evidence of modern, human-induced environmental change was recorded."
In light of Cuna et al.'s several findings regarding the climate of central Mexico, there is ever more reason to accept the fact that there is nothing unusual, unnatural or unprecedented about Earth's current level of warmth.
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