Cascading global catastrophic risks toward 2075: How optimism and expertise shape perceptions of systemic threats

This study provides the first systematic empirical analysis of cognitive biases in catastrophic risk perception, examining how 164 respondents assess five systemic threats to humanity scenarios targeting 2075. We investigate how optimism levels and expertise influence public perceptions of five systematically developed extinction scenarios, using survey data across expert and non-expert populations. Results reveal that respondents found Climate Cataclysm and World War III scenarios significantly more plausible than AI, Synthetic Biology, or Growth and Collapse scenarios. Crucially, we identify a robust negative correlation between self-reported optimism and perceived scenario plausibility (p < 0.05 for Climate Cataclysm and World War III), suggesting that cognitive biases systematically influence catastrophic risk assessment. Contrary to expectations, expertise did not significantly differentiate risk perceptions, indicating that specialist knowledge may not overcome fundamental cognitive biases in long-term risk evaluation. This finding aligns with research demonstrating that lay knowledge incorporates experiential understanding that differs from but complements technical expertise (Wynne, 1992). These findings provide the first empirical foundation for improving public engagement with existential risk scenarios and inform evidence-based approaches to catastrophic risk communication essential for building societal resilience.