Having an advanced civilization means we're going to exploit the environment and generate waste products. It doesn't mean we can't exploit the environment sustainably or let our waste products harm the environment, but it does mean that a choice has to be made. We have almost 8 billion humans to house, clothe, and feed. Windmills aren't going to cut it. Unless you want us to return to a hunter-gatherer lifestyle.
Fortunately, storage cost is falling even faster than wind or solar ever did, so by the time we need much, it will be very, very cheap.
At present the main value in storage is load smoothing, where you don't need much.
Renewable energy is actually more on track to solve the carbon emissions problem than nuclear energy.
"On track to solve" sounds like a forward looking statement, which goes back to my issue of people insisting on solving today's problem with tomorrow's technology. You simply can't put shovel in the ground today and build out a green solution to power manhattan, but you can start constructing a nuclear reactor with a proven design.
But it takes time to build out a wholesale replacement for existing global infrastructure. Fortunately, it takes much, much less time and expense than replacing with nukes, and much, much less expense than continuing to operate existing infrastructure.
We could have started this decades ago, and not be facing imminent catastrophe. Jimmy Carter (a former nuclear engineer) tried to get us on that road. The overwhelmingly biggest impediment to wholesale replacement for radically cheaper energy is social and structural inertia, chiefly apathy in the ruling class. Ignorance is the largest contributor.