The Polycrisis Apocalypse: A pessimistic scenario for the exposure integral and the long tail of an unsafe climate

This report develops a pessimistic long-term polycrisis scenario centered on what it terms the P-integral: the cumulative person-years lived under elevated climate, environmental, and institutional stress rather than a snapshot of conditions in 2100. Drawing on demographic projections, climate persistence literature, pollution research, and state-fragility case studies, it argues that Africa and Southern Asia will account for the majority of global person-years during the twenty-first century and an even larger share of exposure to long-duration environmental risks. The report distinguishes between measured demographic and climate projections through 2100 and speculative post-2100 scenarios, emphasizing that warming, sea-level rise, and related impacts persist on millennial timescales even after emissions cease. The analysis frames the polycrisis as an interaction among climate change, pollution, water stress, food insecurity, conflict, demographic shifts, infrastructure decline, pandemics, and institutional weakness. It argues that cumulative exposure is shaped not only by environmental change but also by the capacity of states and societies to maintain repair, adaptation, and social order. Using Haiti as an illustrative case of institutional collapse and the Dominican Republic as a comparative control, the report highlights governance and institutional resilience as key determinants of outcomes rather than population ancestry or geography alone. The report concludes that the most important question is not the temperature reached by 2100, but the scale and distribution of person-years lived under unsafe conditions over centuries and millennia. While explicitly presented as a pessimistic scenario rather than a median forecast, it contends that demographic concentration in vulnerable regions, combined with the long persistence of climate forcing, could produce an extended period of human exposure unless adaptation, institutional capacity, and development accelerate sufficiently to outpace accumulating stresses.