What bothered me the most when seeing this video from 2010 was the upbeat techno music someone chose to go with it: "Automated Self Targeting Gun Turret - By Samsung" https://www.youtube.com/watch?v=Oa08Gbn6iqs

You can say the same thing about global warning.

A lot of worry about the fact that global average temperature will increase by 2 degrees in the following 50 years which will cause widespread disasters (50 years from now)

Not really. The point of the Ng quote is essentially:

We don't have the technology to populate Mars -> We can't overpopulate Mars.

and

We don't have the technology to create sentient computations -> robots won't decide to kill us.

Your analog would have been:

We don't have the ability to affect the climate -> no anthropogenic disasters.

But, we know the antecedent in this case is false. Now I'm not asserting that anthropogenic disasters will occur (based on these arguments), but just pointing out the flaw in your logic.

So we shouldn't worry about robots killing us until after we have the proof of the first sentient computer.