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 21st century, including asteroid impacts, gamma-ray bursts, Earth-based natural catastrophes, nuclear war, terrorism, global warming, biological weapons, totalitarianism, advanced nanotechnology, general artificial intelligence, and social collapse. The book also addresses over-arching issues - policy responses and methods for predicting and managing catastrophes. This is invaluable reading for anyone interested in the big issues of our time; for students focusing on science, society, technology, and public policy; and for academics, policy-makers, and professionals working in these acutely important fields.