1) They don't believe in anthropocentric climate change (probably deflecting by taking this stance)
2) They don't believe the economic destructive power of climate change. Be that by disbelief, thinking it is over stated, or just not being good at thinking about the future (which a lot of humans aren't. We're terrible at it)
There are two issues here. One is, are we currently pricing carbon appropriately? And obviously not. But if we did then it would be an economic issue -- make emitting carbon more expensive than alternatives and people would naturally gravitate to alternatives.
But then we have the second issue, which is that we don't want the alternatives to be significantly more expensive than the status quo, and we may want to take some steps to ensure that.
If you tax carbon and so people switch to renewables and batteries and figure out how to make it scale efficiently, everything is fine. If not, people would then turn to nuclear because it would still be less than paying the carbon tax.
But if we wait to start building nuclear plants until after we've already established whether or not renewables can handle the entire grid, and then it turns out they can't, that could be problematic, because then you've waited too long.
It's a hedge. If we fix the nuclear regulations to remove the most egregious of the cost-wasting portions and start building nuclear plants now, and then we don't need them because renewables fully succeed, energy will cost modestly more than it would have. Or the investors in nuclear would lose money in that case. Whereas if we don't, and then we do need them, energy would cost dramatically more than it would have because of the shortfall. And as a result people would be inclined to pay the carbon tax, or repeal it, and then we get catastrophic climate change.
When "need it and not have it" is literally the end of the world, better to have it and not need it. That seems like a worthwhile hedge.
We already know that renewables can handle the entire grid. There are plenty of papers out there exploring this matter.
What we don't know yet is exactly what particular technologies we're going to end up with, especially for the last few percentage points. Probably a mix depending on location.
The reason for we don't know it is that wind and solar costs have been falling exponentially for many years now, while short-term storage is only now heating up and long-term storage not yet really started (well, except hydro).
We know tech that can be used, we know an upper bound on the cost (not prohibitively expensive), but anyone trying to look 10-20 years out in such a rapidly developing cut-throat market are basically just guessing.
10 years ago I was thinking we'd probably have to pay somewhat more for energy, perhaps up to 50%-100%. But in 2014 the Danish energy oversight body (Energistyrelsen) did a complicated analysis that said around 5% more in Denmark. And it didn't take more than a couple of years for their projected 2030 cost of offshore wind turbines to be reached by the market, more than a decade before anticipated.
So I'm beginning to think energy is probably going to be cheaper, perhaps a lot cheaper.
> We already know that renewables can handle the entire grid. There are plenty of papers out there exploring this matter.
This is all inherently speculation. If you assume the current cost trends continue, maybe everything is fine. But what happens if you scale production by a factor of fifty or more? Do raw materials prices for things like lithium or rare earth metals go up due to demand? Do average operating costs rise once the most cost effective installation sites are already occupied and the low hanging fruit has been picked in general? Are we analyzing numbers from existing installations that have selection bias in favor of factors that the remaining sites don't have, e.g. lower vs. higher population density?
Doing a long-term analysis on something with this level of complexity inherently has large error bars. Even if "everything will be alright" is a likely result, we still need to address the non-negligible probability that it isn't.
1) They don't believe in anthropocentric climate change (probably deflecting by taking this stance)
2) They don't believe the economic destructive power of climate change. Be that by disbelief, thinking it is over stated, or just not being good at thinking about the future (which a lot of humans aren't. We're terrible at it)