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.
A massive high speed railway network across North America, coast to coast. Russia did it, China did it, most of Europe did it. Canada and the USA have no excuse.
Property acquisition costs and legal fees are immensely more expensive in the US. Have to obtain those thousands of miles of land for rail development from somebody.
Property acquisition in the US more expensive than in Europe? I think not, at least for the immense swaths of land that make up most of the US’ land mass.
The legal fees I see, but that’s why most developed nations have legislature for disowning property owners of land necessary for infrastructure at a set compensation. Whether that’s fair or just is up for ideological debate, I’m sure.
Canada’s excuse is “we’re roughly as big as the US but have a way smaller population and GDP. I really don’t think it’d be financially justifiable for them to build a rail equivalent to the trans-Canadian highway. It’d be a non-starter in a political sense.
The US, on the other hand… yeah. We genuinely have no excuse.
