Doing Something About the Climate
The Isaac Arthur video I watched today was about mitigating climate change. So it's less political let's put it in terms of the Kardashev scale. One of the aspects of becoming a Type I civilization is learning to control the climate of the home planet. How much control do humans have now or in the near future over the climate?
One of the basic ways to change the climate is altering Earth's albedo (the amount of sunlight reflected back into space). Just lowering or raising Earth's albedo one percent would make a significant difference.
On the surface of the Earth more plants could grow, sulfides could be sent into the atmosphere or simply covering more of the Earth's surface with solar panels. In space aluminum or steel could be mined from the moon to create large reflectors to reflect sunlight before it reaches the surface of the Earth. More speculatively asteroids could be mined for precious metals, broken into small rocks and be sent to burn up in Earth's atmosphere to create a thin layer of grainy material. That last speculation probably wouldn't be the preferred way to reduce sunlight reaching the surface of the planet.
The video goes into some detail about the economics of climate change mitigation. The cost of sending materials into space, computer modeling climate and other systems. Going back to the idea of light sails and power satellites those could be used as reflectors while serving other purposes.