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.