[nitrogen]

My armchair/spectator interest in fusion comes from the idea of significantly increasing the energy available per capita, without increasing carbon footprint. Traditional renewables might meet our current energy needs eventually. Fusion could let everyone on the planet enjoy the same, or even a significantly increased, lifestyle. As the saying used to be long before I was born, "energy too cheap to meter" (though obviously it still would be metered).

With enough surplus energy, you could run entire reactors just for carbon sequestration, or nation-scale desalination, or climate engineering, or what have you.