Socio-environmental systems
The dynamic and two-way relationship between changing environments and cultural changes is the subject of our research topic "Socio-environmental systems". For our research, we integrate archaeological, social, ecological, climate, economic and demographic data, and we use optimality-oriented behavioral model approaches such as agent-based and trait-based models.
Long-term human demography
We're intrigued by the question of how much influence climate has had on human populations. We identified that population growth and climate variability are quite synchronized globally and continentally (Wirtz et al., Nature Communications 2024). We found that climate instabilities modulated the European wave of advance of first agriculture (Lemmen et al. 2014), and that the periodicities found in the climate system showed a marked shift around 6000 years ago (Wirtz et al. 2010). We could link the deurbanization of the Indus Valley Civilization around 3000 years ago rather to social dynamics than climate triggers (Lemmen & Khan 2012). We developed the first model that describes regionally resolved and global prehistoric demography, land use and technology and explained the differential onsets of agriculture/herding during the Holocene around the globe, which later led to very delivery trajectories of cultural and technological evolution (Wirtz & Lemmen 2003).