According to the Herald, New Zealanders last year set off 1,700 tonnes of fireworks. That means we beat the North Koreans puny 500 tonne nuke!! Suck that Kim Jong Il!
(Ok, so gunpowder only has 1/10 the energy of TNT but I still think we're getting pretty close. Everyone needs to buy more firecrackers this year so we can try and get well up into the small nuke range).