Abstract: This final chapter looks back at the impact of agriculture on human populations, and looks forward to a highly uncertain future for both farming and humanity. The relatively stable Holocene climate enabled the development of farming and a forty-fold increase in human numbers by 2,000 BP. The recent dramatic increases in crop yields due to science-based agriculture have led to a further ten-fold population rise over the past two centuries. The world is now overwhelmingly dominated by complex techno-urban civilizations sustained by high-input farming regimes that rely on cheap and plentiful energy sources and a relatively stable climate. As energy becomes more expensive and the current period of climatic stability draws to a close, it will be increasingly difficult to maintain present levels of population and complex urban societies. As in previous eras, human populations may fall and undergo cultural simplification in response to such climatic uncertainties.

Keywords: population increase, hunger, food production, climate change, complex societies, collapse, techno-urban civilization,