A global catastrophic risk is one with the potential to wreak death and destruction on a global scale. In human history, wars and plagues have done so on more than one occasion, and misguided ideologies and totalitarian regimes have darkened an entire era or a region. Advances in technology are adding dangers of a new kind. It could happen again. In Global Catastrophic Risks 25 leading experts look at the gravest risks facing humanity in the...