Housing for everyone, food for everyone, clean energy (nuclear power, though we would do well to advance the tech a little is immanently practical).
Those are all easy mode stuff that would dramatically improve the world for a lot of people, but we could do more.
Hard mode: Orbital rings.
We would have to develop some tech, but not nearly as much as you might think.
Don’t even need nuclear, renewable energy at its current pace will get us to 100% renewable by 2050, which is about as far away as any nuclear plants you started constructing today for way, way less money and zero waste storage issues.
There’s basically no point building any other kind of energy at this stage. Giant, expensive power plants that require huge amounts of expensive fuel and large expensive workforces simply can’t compete with panels pumped out by factories you can install anywhere that generate free energy for decades with little to no maintenance.
The problem with only panels and wind is the fluctuation. We need at least a small “baseline” power supply that works when there is no wind at night. Storing large amounts of energy is the missing piece here to get rid of conventional power plants altogether. We’ll get there eventually.
