Mini advent calendar of Xrisks: nuclear war

The FHI’s mini ad­vent cal­en­dar: count­ing down through the big five ex­is­ten­tial risks. The first one is an old favourite, for­got­ten but not gone: nu­clear war.

Nu­clear War
Cur­rent un­der­stand­ing: medium-high­
Most wor­ry­ing as­pect: the mis­siles and bombs are already out there
It was a great fear dur­ing the fifties and six­ties; but the weapons that could de­stroy our species lie dor­mant, not de­stroyed.

There has been some re­cent progress: the sizes of the ar­se­nals have been diminish­ing, fis­sile ma­te­rial is more un­der con­trol than it used to be, and there is more geo-poli­ti­cal peace and co­op­er­a­tion.

But nu­clear weapons still re­main the eas­iest method for our species to de­stroy it­self. Re­cent mod­el­ling have con­firmed the old idea of nu­clear win­ter: soot ris­ing from burn­ing hu­man cities de­stroyed by nu­clear weapons could en­velop the world in a dark cloud, dis­rupt­ing agri­cul­ture and the food sup­plies, and caus­ing mass star­va­tion and death far be­yond the ar­eas di­rectly hit. And a creep­ing pro­lifer­a­tion has spread these weapons to smaller states in un­sta­ble ar­eas of the world, in­creas­ing the prob­a­bil­ity that nu­clear weapons could get used, lead­ing to po­ten­tial es­ca­la­tion. The risks are not new, and sev­eral times (the Cuban mis­sile crisis, the Petrov in­ci­dent) our species has been saved from an­nihila­tion by the slimmest of mar­gins. And yet the risk seems to have slipped off the radar for many gov­ern­ments: emer­gency food and fuel re­serves are diminish­ing, and we have few “re­fuges” de­signed to en­sure that the hu­man species could en­dure a ma­jor nu­clear con­flict.