Definition
An existential risk is a threat that could cause human extinction or permanently and drastically curtail humanity's long-term potential. It is distinguished from ordinary disasters by the irreversibility and global scale of its consequences.
The category includes both natural threats, such as asteroid impacts or supervolcanic eruptions, and human-made ones, such as nuclear war, engineered pandemics, runaway climate change, and risks from emerging technologies.
Why it matters
How it works
Existential risk thinking weighs not just the probability of an event but the permanence of its outcome. A disaster that kills millions but allows recovery is categorically different from one that ends human civilization for good. Because the modern world is interconnected and equipped with powerful technologies, certain failures — a major nuclear exchange, an uncontrolled pandemic — could cascade globally. Managing these risks requires sustained cooperation, foresight, and institutions willing to invest in preventing rare but catastrophic outcomes.