Vladd
If the moon turned into a black hole, the only difference we would notice, here on the ground, is that we could no longer see it, and there would be no moonlight. A loss, sure, but not a catastrophe. It would still raise tides, and have all its normal gravitational effects.
The moon is slowly moving away from the Earth (over many millions of years) and a moon sized black hole would do the same. The only disasters it would cause would be if an astronaut fell into the black hole.
Chris
I agree that the probability of the LHC causing a massive disaster is small. Where we might be in trouble is if something happens based on unknown science. Known science can predict certain things, but scientific research always turns up the unexpected. If the unexpected from the LHC happened to be lethal ....
The biggest comfort to me is the fact of high energy cosmic ray charged particles. However, there is no guarantee that the conditions within the LHC are exactly the same as those of cosmic ray impact, and something different might happen. If we knew what it was, there would be no risk. I am not paranoid about this - just skeptical of the odds as calculated by the very biased LHC scientists.
Sparrow
I did not say Stephen Hawking was infallible. Just used a quote from him to illustrate a point. Hawking, whatever his religious beliefs, is still a mega genius. His mathematical brain is a once per 100 years event, and he compares closest to Einstein. That does not make him infallible, but we still need to take heed when he say something.
On taking plants and animals with us out into the wider universe.
It will happen. Initially we will take genetically modified green algae to replenish oxygen atmospheres and remove CO2. We will use bacteria to destroy waste. Eventually, we will plant food bearing green plants in ground up rock mixed with bacteria treated waste to produce food and replenish atmospheres. We will introduce pollinating insects to increase yields. etc. etc.
It is inevitable that, when humanity terraforms other planets we will introduce Earth bacteria, archaea, fungi, protists, plants and animals. Terraforming requires a new ecosystem to be established.