The global risks
The literature review from An indicative costed plan for the mitigation of global risks (Leggett, 2006) classed 15 risks as global risks.
These, listed in order of resulting likely loss at the next occurrence of the risk (if unmitigated), were seen (in 2006) to be as follows:
- High energy-intensity scientific experiments which would change the fundamental fabric of the universe in a way not previously seen in nature;
- Impact of asteroid/comet >10 km diameter (near-Earth object risk);
- DNA-based exponentially self-replicating nanomachines;
- Computers, robots surpassing human accomplishment;
- Biovorous nanoreplicators;
- Collapse of super-massive star causing intense Earth-irradiating pulse of gamma rays, cosmic rays and muon particles;
- Eruption of continental flood basalts;
- Anthropogenic global warming-induced release of methane from methane clathrates on the continental shelves and permafrost, causing double-size global warming or oxygen depletion;
- New ice age caused by natural cycle;
- New ice age caused by abrupt climate change from reduced Atlantic thermohaline circulation;
- Global warming (not causing methane release or ice age);
- Nuclear exchange (full superpower arsenal), including resultant nuclear winter;
- Asteroid/comet about 600m diameter (near-Earth object risk);
- Super-eruption, most particularly Yellowstone; and
- Avian influenza pandemic.
A further risk which has gained salience since 2006 is peak fossil fuel.
Of the foregoing risks, after the concepts of imminence and capacity for mitigation are taken into account, the following are the present subjects of Global Risk Progress:
- Climate change
- Peak fossil fuel
- Asteroid / comet strike
- High energy-intensity scientific experiments which would change the fundamental fabric of the universe in a way not previously seen in nature