1. Building the Tres Amigas SuperStation would have the biggest physical impact. Only eliminating industrial subsides would be easier, which is why the latest draft infrastructure bill is a sad joke. https://theintercept.com/2021/08/03/bipartisan-infrastructur...
This might sound dumb, but it's crazy to me that we're actually (going to) use superconductors in real projects. Still sounds like science fiction to my ear... but I'm getting old :)