[Not exactly true IMO, I read today that someone modeled what would have happened with the ozone layer if the world community hadn't stopped fluorocarbons. Projected irradiation levels would have gone up 3 orders of magnitude in some UV bands in a century or so. Ouch! Then we also have lowered nuclear threat compared to before, as well as effectively exterminated smallpox pandemics.]

But also that it is relatively easy and also constructive (learn a lot) to lower the risk appreciably, so we should do it anyway, sooner rather than later.

You are dead right in what you say but to conflate the issues is fallacious. None of the threats/risks you talk about or that we ‘currently face’ may cause the entire Earth to freeze over, or cause widespread, direct societal destruction as few-mile-wide meteor would!

Sure, the risk is minute but VERY real (unlike, say, a Blavk Hole gobbling us up).
To ignore this and to ignore potential greater efforts into protecting us from it is downright foolish!
It’s just the kind of ‘idiot-human’ legacy that fits too well with our past human experimentations – there are two crucial differences with this little experiment, however:

1) is that it could very really lead to our ultimate destruction.

2) In the past, such passiveness was forgivable since we did not have the knowledge, but now we have much greater knowledge, are very aware of the threat and are the most technologically advanced we have ever been.

as soon as you buy a white Persian cat, we’re going to fear you mightily

Well, I’m a cat person, but not a Persian person. I like my significant others catty, not big-headed with runny eyes.

That is from Dr. Evil, I presume?! Must see Mr “Mad” Mike Myers movies someday.

Btw, did Mini-Me have a mini-Persian? Or at least a white rat?!

[T]here are far greater threats on earth like drunks driving cars, the excessively greedy class of conmen known as CEOs, the biggest pyramid scheme of all (the stock market), and of course the acolytes of ignorance.

Such as Jennifer Ann “Jenny” McCarthy.

That could be a long wait; I’m a dog person. I can often be seen crawling on all 4 and sniffing other dogs’ butts. It’s unlikely I’d be possessed to get a cat. I can get a hairless chihuahua I guess – that looks like a cross between a cat and a rat – it certainly doesn’t look like a dog. I once had a cat; except for killing the occasional mouse and eating the roaches he wasn’t of much use – he wouldn’t play tag and he brought out all his claws whenever he was wrestled.

@Quasar: dead right; there are far greater threats on earth like drunks driving cars, the excessively greedy class of conmen known as CEOs, the biggest pyramid scheme of all (the stock market), and of course the acolytes of ignorance.