Global catastrophes sometimes strike. In 1918 the Spanish Flu killed as many as one in twenty people. There have been even more devastating pandemics – the Black Death and the 6th century Plague of Justinian may have each killed nearer to one in every six people on this earth. More recently, the Cuban Missile Crisis brought us to the brink of nuclear war – President John F. Kennedy thought the chances were “between 1 in 3 and even”.

These represent global catastrophic risks – events that might kill a tenth of the world’s population. With theGlobal Challenges Foundation, we have just released a report arguing that these risks remain and may even be growing, and exploring options for the international community to reduce the risks.