The following list summarises a personal selection of one hundred decisive days in the twentieth century, from launching the Kodak Brownie camera in 1900 to signing the Kyoto Treaty on climate change in 1997. All one hundred items have a few thoughts plus a photo or image which can be reached by clicking on the link below. Every decade contributed something to this list but not in equal proportions. During the 1920s, for example, there are only six key moments in this list. Even though this included the creation of the BBC in 1922 and the discovery of penicillin in 1928, both in Britain and both causing society-wide global impacts, decisive events were more limited in this decade. Relatively more eventful decades were the 1940s, when World War Two preoccupied nearly every continent in fifteen crunch moments, and the 1960s, also with fifteen decisive forks in the road. The 1960s were particularly dominated by scientific advances in space exploration
