sink england

De-nazification of the USA.

bioengineer a fungus that can digest plastic and seed the Pacific with it

Pumping enormous state resources into breaking every record in the Guiness book of world records by such a large margin that they are forever out of reach for any non-state actors. Just draft 100 000 people to break the record for baking the world's biggest cinnamon bun. Pour all of our medical resources into surgically making some CEO 5 meters tall just so it is obvious that the record will never ever be broken again and they eventually have to stop publishing new editions.

Universal conlang

IRL Moria. Just make a big fucking dwarven keep IRL in the cascades or the himilayas or norway or literally anywhere idc. Carve a massive stone complex into the side of a mountain, dammit

When I was a kid I had the bright idea during a daydream that if I were to officially acquire Antarctica as territory, either as part of my current country or as a brand new country, I could make the claim that air pollution from other wealthy nations is causing me to lose territory (glaciers melting from climate change). Then, I can fight back against other countries for their inaction towards climate change.

Other idea, build massive communities under the ice and snow in Antarctica, utilizing primarily wind energy above the surface for electricity.

A rail that runs from South Africa to Chile across the Bering Strait and the Darien Gap

A 10,000 year breeding program to create the Kwizatch Haderatch.

Providing arsenals of nuclear ICBMs to every country so the world can go completely MAD.

Honestly it would probably end in unmitigated disaster but goddamn would we see an end to war and put imperialism on the permanent back foot if it happened.

Trains. Everywhere.

I'm talking a dedicated line from your front door to every one of your friends.

And not just high speed trains either. Themed old timey steam engines for local transportation.

There's a depression in the middle of Australia that's lower than sea level. If we just built the right canal, we could change the climate and ecology of what is currently Central Australia by a wild degree.

something like Libya's Great Man-Made river.

Project Orion

https://en.m.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)

Vending machine economy.

Turn stores into giant vending machines. Turn restaurants into automats. Public vending machines with basic human things in them like toilet paper, instant coffee, OTC medicines, first aid, etc. We would create virtually indestructible vending machines and mechanisms. Vending machines and the products inside would use local branding. You would also have exclusive treats that reflect a local culture. Also, no currency to use them, just biometrics.

High speed rail everywhere

Russia-Sakhalin-Hokkaido Tunnel,

ban cars, destroy and recycle them all, give everyone an electric tricycle

Cougar Domestication Project.

There are many problems with house cats, they're too small to cuddle, they can't take down fully grown deer, they're dangerous to local birds.

Mountain Lions solve all these problems, we just have to get them to tolerate human habitats and not eat children until we can have a population of semi-feral mountain lions that live with us the way house cats do.

I'd build the world's first international spaceport. If it was USA, I'd build it up the side of the Hawaii volcano. The goal is to get it as high as possible, as close to equator as possible, to take advantage of earth's angular velocity. If possible, building in the Andes would be even better.

Startram gen 2 or bust. https://en.wikipedia.org/wiki/StarTram

Humanity has to cut the cost of space launches by 99% or more if we are ever going to advance to the next phase of history: Mining the asteroid belt for necessary minerals. All progress comes from raw materials in some capacity and the asteroid belt is a near unlimited source.

Destroy the moon

Transcontinental package delivery via pneumatic tube

In a slightly more reasonable answer: Antarctica colony. Put a big fucking climate control dome over it. Build some wind farms for cheap electricity. Build a giant statue of Lenin like the Colossus of Rhodes there too while you're at it. Establish socialism at the south pole where the imperialists aren't looking

underground cities

make a bunch of those compact walkable linked micro-district cities i have designed in Workers & Resources

where everyone basically lives in a luxury resort designed to cater to their needs while they aren't at work

shit didn't read the bad idea part

Berring strait land bridge. Damming the Mediterranean.

Make Siberia more livable by building a shit ton of dams in the mountains, creating a vast amount of lakes. I don't know if this will actually do anything. But maybe a lake effect will change the Siberian Highs that causes massive cold weather patterns to hold in the area and it's surroundings? Was an idea to maybe make Vladivostok and the Russian Far East more like Seattle weather wise. More rain, more movement of air generally, lots of fresh water stocked up, maybe routed to central Asia. Idk what would actually happen but it'd be fun to see

Hyper intelligent octopuses. They're already very smart, civilizing them is worth a shot.

make roko's basilisk and a time machine for the express purpose of bullying techbros for eternity.

After that? figure out how centralized of a metropolitan city can be made to make the smallest footprint yet densest population possible to see how that society would change when placed in such an environment.

Maybe figure out how to create seed space ships filled with bacteria'n'shit or whatever to possibly jump-start life on foreign planets, make them as resilient or whatever as possible to survive for immeasurable periods of time and attempt to seed life on all possible life-bearing planets. Definitely never will see any results from it and nobody will definitely will know if it's successful or not, but it seems like a neat thing to do.

maybe make a human machine immortality project that makes a gestalt entity out of all the people that hook up to it and let their noggins get uploaded to it before croaking and see if we can make a single super-entity that transcends the mortal form and possibly creating a new step in the evolution of humanity.