[quote=@FacePunch] I guess. I'm no expert on this kinda stuff, so I can't really argue. I'd bet that we could still kill almost every human being on the planet if a full on nuclear war was started with the intention of killing everyone. [/quote]Well, if suddenly without warning all nukes were launched and they successfully hit their target then the very least the major population centers would face something like 80-99% fatalities. Depending on how it's accomplished (how the nukes are concentrated). Been a while since I last checked how large portion of the world is living in the largest cities but it'd be likely a considerable percentage of all humans on Earth. The radiation and some environmental changes would also weigh on the survivors, along with the destruction of their government structure and key installations. The ensuring chaos and deaths would potentially match the numbers killed by the nukes. There's a considerable chance such all out nuking would result in the destruction of modern civilization and that we must start over. Though not guaranteed. The world is less centralized than you'd think. Overall it'd be the worst event in human history. Extinction, though? Unlikely. Not even Einstein's famous "sticks and stones" quote. I'm not encouraging all out nuclear war. It'd be terrible without a doubt. I just say we seriously overestimate ourselves if we think detonating our nuclear stockpile could actually destroy Earth. The planet is huge and it weathered worse.