Why I am not so concerned about Climate Change

The other day (Sunday), an asteroid the size of a Canadian League football field (100 meters) zoomed by the planet. While reading about it Sunday morning, I was puzzled by these words:

Indeed, many space rocks are hurtling undetected through Earth's neck of the cosmic woods. Astronomers estimate that the number of near-Earth asteroids tops 1 million, but just 9,700 have been discovered to date.

Undetected objects can strike Earth without warning, as the surprise meteor explosion over Russia last month illustrated. The 55-foot (17 m) asteroid that caused the Feb. 15 Russian fireball detonated in the atmosphere before astronomers even knew it existed.

I read that and I thought... Gee, we've actually discovered about 1% of of near-Earth asteroids but scientists seem to think we're safe... "for now". Even after that one blew up over Russia without being detected in advance. That one was actually larger than the one we did know about.

And what if that 55 foot long (wide?) asteroid had penetrated deeper into the atmosphere and blown up just a little closer than it did?

I think, like I did during the Cold War years, that I hope I am very close to "ground zero" if and when the Big One hits.