Global Risk from Extreme Geophysical Events: Threat Identification and Assessment

This document identifies and analyses the global risks which arise from extreme geophysical events. 'On a vast scale, global geophysical events (GGEs) are natural phenomena capable of having wholesale deleterious consequences for the world's environment, economy and society. These may arise (i) due to a global physical effect, such as an episode of severe planetary cooling in response to a volcanic ˜super-eruption' or large comet or asteroid impact, or (ii) as a result of subsidiary ramifications for the global economy and social fabric of a cataclysmic regional event, such as an Atlantic- or Pacific-wide ˜mega-tsunami', or a more spatially confined event at a strategically sensitive location, for example the awaited major Tokyo earthquake. While very infrequent, the wide-ranging”and potentially ruinous”consequences of a GGE for the well-being of the international community make it essential that they are seriously considered within any comprehensive assessment of natural threats.