That's very true! In particular, I agree that technological improvements (possibly including nice safe modern nuclear reactors) are important solutions that should be pursued.
Yet we also need legislation (such as carbon tax and dividend methods, where the tax money returns directly to the people, so the net cost is zero for typical consumers). We need both.
Carbon tax and dividend would be a real game changer.
A carbon tax by itself can get attacked with all of the usual approaches used to shoot down new taxes, especially the ones about pushing families living on the edge into bankruptcy.
The dividend part neutralizes a lot of regular ways a method to raise taxes gets attacked as it lets us increase the cost of carbon emissions to create economic incentives for 1) increases in efficiency at both the individual consumer and corporate levels 2) adoption of current lower/zero emission alternatives by produces and 3) R&D into new tech for, all without squeezing poor families.
The other thing a carbon tax-and-dividend would do is create a built in constituency of people benefiting from the dividend that would advocate both against any future attempts to roll back the tax and probably for increases in the tax to increase the size of the dividend. Just look at how invested Alaskans are in their oil dividend.*
This provides a lot more regulatory certainty, so corps have bigger incentives to invest in new more-efficient/lower-emission infrastructure** as well as R&D with long term payoffs than with a regular tax or cap implemented by one president (or governor) where the optimal strategy for them may be to simply pay the tax for 4 or 8 years and then back a candidate who promises to repeal it.
So like you said, BicycleB, the combination of technology and regulation is greater than the sum of the individual parts.
*Although I will be the first to admit that the Alaskan example isn't perfect. It's better to have a strong firewall between dividend money and the regular government budget, so you don't produce situations like the one up there this year where the government tried to cut the budget of the university of alaska 40% to increate the size of the dividend they'd be able to pay.
**Which of course includes expensive nuclear reactors which take multiple elections to build.