just another problem with life on this planet, we could be invaded by aliens or they might create a black hole that could destroy the world. but it's far more likely we will experience a weather related problem
I completely agree, and global warming is a natural cycle of the Earth's climate.
Look at how el Nino and la Nina affect the North American continent - and that's something that changes on a very regular cycle.
This planet has had ice ages, "greenhouse" ages, impacts from extraterrestrial objects, volcanic eruptions large enough to completely block out the sun and enough plate tectonic and earthquake activity to astound anyone that wants to really research it, but life on this planet has always managed to survive, albeit changed, in some form.
Yes, there may be a day when something happens to this planet that the Human race can't weather, considering we really do have a narrow temperate range (at least as we're evolved currently), and are susceptible to illness caused by too much radiation, but there are organisms on this planet that thrive in sub-freezing temperatures, and at temperatures high enough to peel the flesh right off our bones, and that can even withstand 5,000 times the radiation it would take to kill a human (
http://en.wikipedia.org/wiki/Deinococcus_radiodurans), and life is life.