Johnson likened the Earth's position to that of fictional secret agent James Bond _ strapped to a bomb that will destroy the planet and trying to work out how to defuse it.

He told leaders Monday that 'we are in roughly the same position' _ only now the 'ticking doomsday device' is real and not fiction.

He was kicking off the world leaders' summit portion of a U.N. climate conference, which is aimed at getting agreement to curb carbon emissions fast enough to keep global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) below pre-industrial levels.

Britain's leader struck a gloomy note on the eve of the conference, after Group of 20 leaders made only modest climate commitments at their summit in Rome.