I find it hard to believe that anyone takes this argument seriously. Let me try to make the fallacy here a bit more explicit with an example. Suppose someone tells you that by pushing a button, you can cure cancer with certainty, but there is a chance of 1 in 10^80 (roughly the number of atoms in the visible universe) that pushing the button will destroy all life on Earth. Should you push the button? I think almost anyone would agree that you should, even though the expected benefit is finite (curing everyone of cancer), and the expected cost is infinite (an infinite cost divided by 10^80 is still infinite). You could apply the same logic to asteroid impacts. Should we drop everything we're doing and devote all our economic resources to avoiding a future asteroid collision, no matter how improbable it may be? After all, the outcome is at least as bad as catastrophic global warming (*infinitely bad*, from a human perspective at least). I could come up with any number of such hypothetical scenarios, *each* of which demands that we focus all our attention on preventing it to the exclusion of all else. The fact that it's impossible to address all such hypothetical scenarios *even if* we accepted that we had a moral duty to do so should alert us that something's wrong here. And what's wrong is the neglect of opportunity costs. Trying to field a fleet of space-based nuclear weapons to destroy incoming asteroids means we have fewer resources to deal with global climate change. More seriously, trying to mitigate global climate change means we have fewer resources to address problems whose reality is not in doubt, like poverty and disease. The moral is 1) not every threat with an infinitely bad outcome needs to be taken seriously, provided it is sufficiently unlikely, 2) given that resources are finite, allocating more resources to one problem generally means allocating fewer resources to others, 3) for any serious public policy issue like global climate change, there can be no substitute for rigorous cost-benefit analysis, certainly not cheap, fallacious arguments like this one. Note that I am not taking either side on the global warming debate; I am simply saying that this video detracts from rather than contributes to that debate.