I was thinking fusion power would make a new era of unfathomable giant machines. Machines the length of the entire ocean, 10 stories tall submerged to clean the ocean. They would would be built to clean the water 24/7 and could sway with the water by opening and closing with AI to allow currents to pass

Or every city on earth with giant blimps the size of football fields that fly all day capturing carbon 24/7.

Giant machines never made sense because there would be no safe or effective way to power them. But fusion could solve that problem.