A new proposal suggests using the world's largest-ever nuclear explosion - buried deep under the ocean - to combat climate change by pulverizing massive amounts of carbon-absorbing rock.

Truman informs the nation that an atomic weapon has been detonated in Japan. Sixteen hours ago an American airplane dropped one bomb on Hiroshima and destroyed its usefulness to the enemy.

The Halifax explosion on December 6, 1917 wiped out six square kilometres of the city. It was the largest manmade explosion the world had known. (National Archives of Canada) Ships carrying ...