Well, I think the question of realism is that you put it in a calculation and an estimate, as opposed to what we know could happen.
Again, I would refer to the just-released 280-page report by the International Energy Agency, which is the pre-eminent source of information for governments on this particular issue. What you'll find is that they cast doubt on the calculation showing it's possible, given what's going on. In fact, they clearly doubt it; given the world as it is—that is, how we actually access minerals, how we process them, and where they're processed—you can't get there. They're not saying it's physically impossible in the pantheon of science and engineering; it's just not possible given what we now know and what we're now doing.
They give many specific examples. In fact, I would recommend the staff or the committee look at one particular graph they have summarizing data about electric vehicles. Under ideal circumstances, electric vehicles on average cut CO2 emissions, counting the mining and processing. That's on average. But it ranges from something like a 50% to 70% reduction, not zero. This is a big reduction, 70%, but it can go up to a slight increase. The range can involve an increase in CO2 emissions from using electric vehicles.
The fastest way to reduce CO2 emissions, which no one is proposing anywhere in the world, to my knowledge, is subsidizing more efficient internal combustion engines. That's just economic and engineering reality.