[quote][b]Posted by:[/b] Elder Bias And you have no idea how physics work.[/quote]*Is working on a degree in Physics* Ironic irony is ironic [quote]Few good examples would be like this: Toba eruption, Yellowstone eruption, Karakota eruption (estimated to be 200 megatons),[/quote]Because you were alive 70,000 years ago, 640,000 years ago, and in 1883. Wow, you must be immortal. [quote]etc that caused nuclear-like winters for short of time. So yes, it will affect the life on earth via altering ecosystem and biosphere.[/quote]Even the recent Mt. Pinatubo only lowered the average temperature of Earth by a degree Fahrenheit. A few degrees is a far cry from a nuclear winter, where the Sun must be blocked out nearly completely so that the majority of photosynthetic organisms are obliterated. Even the method is different. 200 Megatons may be enough to cool the planet significantly if it is dumping [i][u]sulfur dioxide[/i][/u] into the stratosphere! This reflects some of the suns rays. Soon it settles and the Earth returns to normal. An extinction-level event, where the Earth is covered by dust and ash for generations, requires a much larger force. [quote]Gigatons = half to entire state killers. That's how it works. [/quote]Sounds close. Depends on the state, geography, water, etc. But it wouldn't eliminate life on a planet.