[bduerst]

Really it depends on the context and what humans can control. Could we stop a volcanic eruption? Probably not. A meteor strike? Maybe.

Could we stop the poaching of near extinct species for some unproven alternative medicine? Hopefully.

[dm2]

It's amazing that we can throw nuclear weapons at both of those huge objects (volcano and meteor) and there is actually a chance that we can prevent them from destroying the world.

In other news, terrorists and other enemies of the US are trying to make the Yellowstone volcano explode, that's scary. Can we not "cool" the magma under Yellowstone? Maybe even use that heat? Are geothermal plants too expensive?