Peru Had A MWP & LIA

By Paul Homewood

 

I noted the other day that ice cores in Peru indicate that temperatures were warmer there from 8400 to 5200 years ago. Adding to this evidence is the discovery of plant remains are being uncovered as the Quelccaya Glacier, also in Peru, recedes. Radiocarbon dating shows these to be about 5000 years old. Furthermore, more seem to be being discovered (the report was made in 2007), so it is highly likely many more remain to be found deeper under the glacier.

 

Glaciologist, Lonnie Thompson, also produced this temperature graph, using ice cores on the Quelccaya, which clearly show higher temperatures back in the MWP.

 

http://www.co2science.org/data/mwp/studies/l2_quelccaya.php

 

 

Note that the temperatures are presented decadally, and the “current” ones are 1991-2000. (The study was made in 2003). Also note the steep rise in the 11thC, much steeper than in recent years.

And, for good measure, note that the recent warming began in the 19thC, long before any impact from humans. It’s also interesting that, apart from the sharp fall and subsequent recovery in the 1980’s, temperatures have been pretty flat since the mid 20thC. ( The El Chichon volcano in Mexico exploded in 1982; this may well have had a major effect on temperatures that decade in Peru).

 

Taking a longer perspective look at the 19thC, it is worth remembering what Lonnie Thompson wrote in 1995, about another glacier in Peru, the Huascarán:

 

“that the climate was warmest from 8400 to 5200 years before present, and that it cooled gradually, culminating with the Little Ice Age (200 to 500 years before present). “

https://notalotofpeopleknowthat.wordpress.com/2014/04/05/peru-was-warmer-5000-years-ago/

Clearly, from a historical point of view, there is nothing remotely unusual about temperatures in this part of Peru.