The diggers and sifters of the past have been at work in Illinois researching an ancient society, Cahokia, about which there have been varied opinions on its rise and fall.
The article is linked from Archaeologica dot org Archaeological News from EurekAlert and The Prairie Research Institute, University of Illinois.
I suspect that this kind of debate is unlikely to take place in any UK University.
Social collapse that occurred it is thought might not be due to warming or cooling, or even running out of resources.
You will be shocked to read that it is argued that people might be the problem.