No, I understand them. I understand enough to know there's plenty I don't know about what actually allows life on a planet. I do know that humans would most likely wipe themselves out before even getting close to turning Earth into Venus.
And multi-nuking a planet isn't a one-off event? A meteor hitting Earth s more than just a big fat crater - and I'm positive you know this. Like I said before, mankind will have been reduced (in several ways) before we get a chance to do this kind of damage.
I simply don't buy into it. Nature always has a way of fixing itself. So I wouldn't worry about that. As for us humans, we simply don't learn from our own mistakes, we're too driven by profit. Mankind needs to take a massive blow to get it inside its thick skull. Consider Mother Earth the, well, mother. And we're her kids. And we're beyond a spanking. We need mom to open up a can of whoop-ass for us.
I don't know the unrealistic scopes of this, but mankind should try to learn to utilize sun energy and convert particles and such into energy. E= mc^2 ftw.
Excuse me, I may sound a bit unserious in this discussion but it's simply my way of expressing myself, I am very serious about the matter, and I could rant for pages on how downright shit it is that we're actually just messing up for ourselves with all the air polluting, the oil waste, toxic gas, the greenhouse effect, the holes in the ozon layer, the thinned-out atmosphere, the poisons we put in our soil, in our crops, in animals, in ourselves, the nature we destroy to build houses of concrete, stone and steel, remove forests in favor of complexes that do nothing to contribute to the life of nature and most likely - on larger scales - disturb the ecosystem - fill our lungs with shit (my bogers were 50% black after a few days in London), wipe out fields to put asphalt and stone bricks, completely mine out mountains to built all kinds of crap. I've thought about it, trust me: just go outside your house. Look at all the fences, the signs, every sign post, the railway, the cars you see, the bars on freeways, the coins in your hand - just look at all the amount of metal used when you take a stroll around town. Now imagine that there are millions of cities around the world that are the same. Then take a stroll to the industrial area of your town and check out all the metal used there. Multiply a few thousand times and add that to the amount. Then take that final amount and double it. Do not include the airplanes and satellites, mind you.
But it's just too much. I can't fathom how there are enough resources for this. And if there are, I can't imagine there being THAT much more. It's bound to run out. We're bound to hit a stop, somehow. We're going to screw ourselves up before we screw up nature, that's for sure - unless we deliberately screw nature up.