Fusion reactor 8 light minutes away does not burn out for a good long while, long enough that we can consider it indefinite for the current climate debate.
So we have an energy source that we can use to rearrange the stuff that IS finite, ie the big rock with water on it.
What we don't want is for the rock to end up in a state where we can't live on it comfortably.
Now, as for growth, we could reach a state where people have roughly the replacement number of kids. In fact, it looks like that will happen. Then we just have to make sure the average amount of consumption doesn't take us over some limit.
Note that GDP is also a pretty imperfect measure. It was conceived in an era where having more stuff generally meant a better life, because some of that stuff was useful things like medicine, insulation, and so on. Nowadays a lot of things go into GDP that is perhaps not measuring what you really want.
> The earth is a finite world, sustainable or not you won't be able to grow indefinitely.
It's not "indefinitely". It's just "long enough that we can bootstrap a space economy and expand into the Solar System", or alternatively "long enough so that we can fix the environmental damage, get rid of poverty and most diseases, and slowly S-curve the economy into some acceptable state". Or some combination of that.
Moreover, not all growth is tied to physical space and resource use. We're also not using the space and resources we have efficiently. There's plenty of room on Earth for us to grow, but it might start looking more like improving things than expanding them.
> if we go back that would impact the GDP.
Switching to a sustainable level of growth will require that - slowing down the growth itself, and even a temporary shrinking of the economy.
In theory Growth could be detached from energy consumption, if I cook my neighbours a meal tonight and charge them £20 and tomorrow they do the same for me then GDP has grown by £40 but energy consumption has staid the same.
In reality it seems most of the things we find valuable do involve energy consumption. We are so far from completely decoupling it that you might as well consider money and energy to be the same thing. The more you spend and the richer you are the more damage you are causing the environment.
It seems politicians (of the environmental kind) who tell you we can grow and save the planet are almost certainly lying.
Energy consumption is indeed tied to anything interesting and useful we can do. But the problem isn't and never was energy use itself (global warming isn't caused by waste heat). The problem was a) unsustainable energy sources, which threaten energy security long-term, and b) polluting energy sources, which cause climate change (it so happens that a) and b) generally overlap, so people confuse this point).
Put another way: if we could suddenly switch transportation to electric and replace all our power generation with renewables with some surplus power on top, why would anyone want to limit energy consumption? That would be equivalent to saying, let's reverse civilization, bring back more poverty and suffering, because it was all cool and games 300 years ago.
> We are so far from completely decoupling it that you might as well consider money and energy to be the same thing.
With market setting prices according to supply and demand and business model shenanigans, and with lots of externalities everywhere unaccounted for, I'd say prices on everything are pretty well decoupled from energy use. It would be a better world if they weren't.
If we had a perpetual motion machine with zero emissions, we could build machines that carefully filtered the oceans and removed the plastic straws, and the environment would be fine.
That's the thing with energy, and why I'm arguing that aiming for reduction in energy production would be self-destructive for our civilization: with enough surplus energy, you can do near anything. We could remove from the air and the seas all the pollution we emitted so far. We could keep turning air into combustible hydrocarbons all day long and enjoy high-density hydrocarbon fuels that are carbon neutral. There's lots of things that could help which we aren't currently doing, because they don't make economical sense. With more cheap energy, they would.
Sure, I see what you're saying, and to an extent I agree - I don't think that us having clean energy, or producing more energy, is a bad thing in and of itself.
I'm more wary about the idea that we can solve all problems if we just have more energy.
What we're doing, and show no signs of slowing down on, is fundamentally restructuring how the planet works. We're building housing, industry, solar farms, roads, railroads, you name it - everywhere we can afford to, and having more energy makes that even easier.
You can suck CO2 out of the atmosphere; you can attempt to clean plastic from the oceans (I suspect that this would be difficult without side effects even with limitless energy; how do you avoid disturbing life on the seabed?).
But can you create natural wilderness? Can you provide habitats for wildlife? We don't even know what that means. Can we produce cities for humans rather than endless car-based hellscapes?
I vividly remember discussing this with my fellow students almost a decade ago now. The idea that we are going to turn the planet into a farm because we can.
I don't want to live on a farm. I want to live on a natural Earth that we live in symbiosis with, not an extremely efficient well-tuned machine.
> I don't think that us having clean energy, or producing more energy, is a bad thing in and of itself.
That's good; but unfortunately, people do fixate on "growth" and "energy use" as sources of problems, when they're not. To better evaluate what we can and should do, we need to keep in mind where exactly the problems come from.
> I'm more wary about the idea that we can solve all problems if we just have more energy.
I'm not saying we will or would, but we definitely could solve most of them. Energy is a necessary but not sufficient component of almost everything we do, and "more energy" is a necessary component of some ways of fixing climate that we currently aren't deploying - like e.g. synthesizing hydrocarbons instead of digging them up from the ground.
> But can you create natural wilderness? Can you provide habitats for wildlife?
Yes, we can. The best way to do it is to transplant some existing wilderness. The habitat will build itself, that's exactly what life is good at.
> Can we produce cities for humans rather than endless car-based hellscapes?
In theory, we can. In practice, this is where technology ends, and economy and politics start.
> I don't want to live on a farm. I want to live on a natural Earth that we live in symbiosis with, not an extremely efficient well-tuned machine.
Same, but that's because Earth already is a pretty decent machine, full of self-regulating feedback loops. It works well without supervision, and it's kind of dumb of us to break the feedback loops only to then have to maintain them "by hand", because they're crucial to our survival. We should be able to let it mostly be, enjoy it, and focus on doing other cool stuff. I still believe nature is there for us to exploit, but we're doing it the dumb way instead of the smart way.
Fusion reactor 8 light minutes away does not burn out for a good long while, long enough that we can consider it indefinite for the current climate debate.
So we have an energy source that we can use to rearrange the stuff that IS finite, ie the big rock with water on it.
What we don't want is for the rock to end up in a state where we can't live on it comfortably.
Now, as for growth, we could reach a state where people have roughly the replacement number of kids. In fact, it looks like that will happen. Then we just have to make sure the average amount of consumption doesn't take us over some limit.
Note that GDP is also a pretty imperfect measure. It was conceived in an era where having more stuff generally meant a better life, because some of that stuff was useful things like medicine, insulation, and so on. Nowadays a lot of things go into GDP that is perhaps not measuring what you really want.