[Xixi]

The current trajectory of temperature increase is at least 4~5°C (rather optimistic) in 2100, which would mean that a pretty wide area surrounding the equator will, year-round or for significant parts of the year, have a wet-bulb temperature at or above 35°C. It is the limit at which human life (and mammal life in general) is entirely impossible, due to over-heating.

That unlivable area will include most of India, Indonesia, Nigeria, Brazil, etc. Hong-Kong and Taiwan, whether you consider them as part of China or not, will anyway not be livable anymore by then. What do you think will happen when India, a country of 1.3B armed with nuclear weapons, realize it literally has to move somewhere else for survival? Do you think all these people will agree to die in silence, peacefully so as to not inconvenience you?

On top of that grim outlook, agriculture has only been possible relatively recently in human history. Until about 10,000 years ago the climate was not stable enough to reliably grow crops, year after year. That stability is probably already gone. Note that the issue for agriculture (and forests, etc.) is less the actual temperature and more the rain/weather patterns (and evaporation, that links back to temperature).

There is absolutely no guarantee that we will be able to adapt our crops fast enough for agriculture to keep up, especially if there is too much instability around the globe. Without stable crops the number of people that can survive on Earth is not very large. China has recently launched a 'Clean Plate' campaign against food waste. As you can imagine it's not because food is plentiful... but because of excess rain, causing crop failures.

Radioactivity is scary and dangerous in high enough dose. Chernobyl and Fukushima are horrible disasters that should have been avoided, but sadly weren't. But compared to the threat of global warming, risks from nuclear power plants are small, known and manageable. To say it differently, rice from Fukushima may be dangerous, but it's still safer than certain death from lack of rice.

I'm not saying we should be building nuclear power plants everywhere, at all. In any case there's not enough U235 at hand to fill the energy needs of mankind. But I would much prefer we spend fewer resources on closing existing nuclear power plants, and more resources on tackling global warming (looking at my home country, France, and our lignite addicted neighbor, Germany).

Source (in French): https://www.youtube.com/watch?v=xgy0rW0oaFI

[aniro]

I have come to the unfortunate conclusion that "lack of rice" (and lack of clean water) is going to be a major issue whether we build out nuclear or not. I think humanity is in for a dark couple hundred years. The window hasn't closed, but we are hard pressed dealing with all the wrong fights and time is losing.

The less "1000 year tail of disaster" opportunities we can have available when things start to unravel the better. I am less afraid of us killing each other over rice and water than I am of us forcing those that come in the aftermath to deal with our effluence for 50+ generations.

[Xixi]

How do you make cement (and by extension concrete)? Limestone calcination: CaCO3 → CaO + CO2

The world concrete production is a larger source of GHG than the entire world fleet of trucks used for goods transportation, with some margin. And that's only accounting CO2 emitted by the chemical reaction itself, not even accounting for the production of the energy necessary for the reaction, that often comes from natural gas.

That CO2 is not being displaced by nuclear power plants, solar panels, wind turbines or batteries in fancy cars. It's being replaced by not using concrete anymore. My point is that GHG emissions go way way further than just electricity production or gasoline to power cars or planes: it's chemistry (fertilizers, concrete, etc) and metallurgy.

I don't hear much about it, not least because I think it's a very hard problem: right now, using less concrete means less constructions. There aren't enough trees, and they don't grow quickly enough, to do everything using wood, although that could be a partial solution. But the construction sector employs A LOT of people. So the path to less concrete is a path to fewer jobs, and a shrinking economy...

We are in for a very rough ride indeed.

[aniro]

There are a whole host of issues that stem from industrialization that are complex and require organized and disciplined action in order to contain. Cohesive action by the entire community of industrial nations is just not on the table at this point without some absolutely massive dislocation of economics or political power. Force is going to be required for change or desperation is going to force compliance. I can only assume based on history that this will all come to force of arms before any other rational solution (systemic enough that it will a difference) is pursued.

I just don't see any road forward without a horrifying body count. It is not impossible to avert that future, it just seems vanishingly improbable.

[medium_burrito]

Yeah, I think grandparent and parent are spot on.

Look at the current wave of government collapses and civil wars that are exacerbated by the current crisis (ethiopia, peru, bolivia, argentina, zambia, etc.). It will be way worse.

Then think about places that are relatively safe, ie Europe, and relatively easy to migrate from the ME and Africa to. That's 500+M people trying to make their way over. That spells serious unrest in Europe too. And that's not even talking about Vietnam's sand mining catastrophe.