Anthropologists and archaeologists have claimed that climate change can promote the occurrence of warfare because of competition over scarce resources. This chapter aims to illustrate a counterexample to this claim using a case-study of prehistoric hunter-gatherers in the Jōmon period of Japan (13,000 cal BC–800 cal BC). We demonstrate the effects of climate change on ecological and sociocultural aspects of Jōmon society. The most notable consequence is population decline and the collapse of large settlements at the end of the Middle Jōmon sub-period. Based on the bioarchaeological data, we show that mortality attributable to violence remained at a low level throughout the Jōmon period and did not change in association with climate change, implying that climate change did not lead to an increase in violent behavior. Finally, we explore various non-violent strategies of Jōmon society for responding to harsh environments. Our results suggest that human societies can have a variety of buffers, including violent and non-violent ways, to react to environmental changes and thus the consequence of human-environment interactions can be diverse depending on their socio-cultural backgrounds.