I am still quite confused on the scientific consensus:

Should we double down on renewable energy and solve its issues with lots of batteries or should we invest in next generation nuclear energy?

Both at the same time?

Does anyone know?

Both at the same time. I don't see how putting all our eggs in a single basket benefits us.

China does: all of the above, where it makes sense.

Renewables and batteries to keep your AC, workplace EV charger, stove, pool heater and (since recently) green ammonia producer going, nuclear to prevent e.g. aluminium smelters from seizing up.

Also the cheapest way to make renewables work 24/7 is to build HVDC lines - they cost as much as a highway per unit length and even undersea cables would deploy for less and faster than equivalent nuclear.

The total length of HVDC lines just in China is currently more than 40k km, so they've literally deployed enough of them to wrap around the globe.

If your location already has a well-run nuclear energy sector (Finland, Sweden, South Korea): invest in nuclear energy.

If you don't: stick to renewables.

And it also depends on what you mean by "we". As a Dane, I don't think us Danish taxpayers should invest in nuclear energy, but I'm perfectly happy that private Danish investors invest in Seaborg/Saltfoss and Copenhagen Atomics.

When it comes to avoiding the worst impacts of the current catastrophic path we’re on, “nothing will work, but everything might”.

Do it all.

That's a political and economic question, not a scientific one. Science can provide input information, but the decision involves weighing all sorts of facts and considerations outside the scope of science.

NUclear partisans like to call renewables ideological, but I think this is another example of "the accusation is a confession".

The empirical evidence has nuclear being uncompetitively expensive. The current focus on variant reactor designs appears to be something of a Hail Mary attempt to get around this sad state of affairs.

You sometimes see them making an argument about energy density, which goes back to Vaclav Smil. But Smil used this argument to massively mispredict how solar would be go in the market. We don't hear him much anymore.

Nuclear advocates increasingly resort to conspiracy theoretic reasoning to explain away the failure of their technology to compete. This should be a red flag.

Government should tax / provide incentives based on negative externalities such as environmental impact and let the free market decide

https://unece.org/sites/default/files/2022-04/LCA_3_FINAL%20...

I think a low carbon mix will result in the cheapest, most reliable and cleanest energy grid.

next generation nuclear energy = fusion

Both.

We should be investing in all non carbon emitting sources and we should have been doing it since the 1970s when we figured out pretty conclusively that this would be a problem.

Instead we had right wing fossil fuel shills on one shoulder and unscientific woo woo greens on the other, the net effect being that we kept burning more carbon. We still have them, Trump with “beautiful coal” and greens now opposing even solar power and batteries, but climate change is no longer possible to ignore. Some still manage it but those people are nuts.

If we hadn’t stopped improving nuclear we’d probably have emitted half the CO2 we have. It would have become cheaper and safer and more scalable and then when China industrialized they would have copied that instead of burning so much coal.

France with its nearly zero carbon grid is the existence proof.

It wasn’t until the 2010s that solar and wind became grid scale in a big enough way to matter. That was too slow.

Whether someone is at least open to nuclear power is my litmus test for whether they take climate change seriously.

I do. If we hit 600, 800, 1000 ppm CO2, which is possible if the world keeps developing on the back of fossil fuels, we are entering existential risk territory. Earth has had those CO2 levels before, and higher, but our species was not alive then.

We already passed the FAFO threshold for ppm CO2 and now we will FO. But that’s not X-risk yet. I’m talking about the next threshold, which may start around 600 but really kicks in near 1000. This is where you actually start asphyxiating. You get lowered IQ and impaired judgement to a small degree, but across the globe at a time when we really don’t need it.