The medieval warm period began in the mid-tenth century, around and about  950 AD. A warmer climate led to higher agricultural yields, and in an agricultural society that meant surplus profits. These were invested in building monasteries and cathedrals; they attracted the attention of larcenous Scandinavians, who became known as the Vikings. Benefiting from warmer temperatures, they traveled widely, built colonies from Greenland to Ireland to central Russia. Nor were they alone. Medieval people settled in sparsely populated internal regions, like Yorkshire, and Abruzzi. And one of the many consequences of this wealth and growing cosmopolitan sphere was a wealthier and vigorous reforming Roman papacy.

Europe was not alone in experiencing social, economic, and cultural changes caused by the Medieval warm period. While the climatic changes were different everywhere, my  guest Timothy Pauketat argues that in Meso America the medieval warm period also brought about a period of cultural interchange, stretching from the Mayan kingdoms north across Mexico, into what is now the American southwest, and as far east and north as  the central valley of the Mississippi River. 

Timothy Pauketat is a Professor of Anthropology at the University of Illinois Urbana-Champaign, and as Illinois State Archaeologist is the Director of the Illinois State Archaeological Survey. He is the pre- eminent archaeologist of the Mississippian civilization that centered on the area around modern St. Louis, and his latest book Gods of Thunder: How Climate Change, Travel, and Spirituality connects the Mississippians to their neighbors near and far. It gives the reader a unique portrait of a world now almost completely lost to us–but still visible, in places, if you know where to look.

 

For Further Investigation 

One of the unique things about Tim Pauketat's book is that each chapter concludes with a list of places to visit that have been mentioned in the chapter, or are related to something in the chapter. Here are a few of them; the descriptions are his own, from Gods of Thunder

Teotihuacan, Mexico: "No archaeological site in the Americas, possibly the entire world, is greater in ruins than the Classic-period city of Teotihuacan, north of Mexico City." The website CultureTrip provides the "Ultimate Guide to Discovery Mexico's Teotihaucán."
Tamtoc (Tantoc), Mexico: "Fly to the site virtually using Google Earth (Ruinas deTamtoc) before you arrive in the city of Tamuín by car or air.Tamtoc park sits on the inner bend of the Tampaon River, and only the central core of the site is publicly owned. Other portions lie in fields and pastures outside the park boundaries, including the eastern half of the site’s largest mound."
Horseshoe Lake State Park, Illinois: "To begin your tour of the archaeological site of Cahokia, start with some environmental context... Entering the park, you will immediately see a great oxbow lake in front of you.The other side of this lake is actually an island, with the oxbow and the park continuing to the industrial landscape on the horizon. Even today, Horseshoe Lake and its teeming animal and plant life give you a good idea of the richness and variety of the landscape a thousand years ago."
Cahokia Mounds State Historic Site, Illinois: "After touring the Interpretive Center, exit the building on the west side and walk into the site’s Grand Plaza. Ignore the mowed green grass, which would not have covered the grounds centuries ago. It takes ten to fifteen minutes to traverse the plaza to the front steps of Monks Mound, which you climb to reach the 100-foot-high summit. From the top, you can see Horseshoe Lake to the north, St. Louis to the west, and the bluff horizon to the east and south."