Take a look at this NASA map of the Earth at night. It gives you an idea of the scale of the problem. Look in particular at Africa, how dark it is. It's a sign of the dramatic energy poverty there. Note: Don't take the bright areas as a unambiguously positive thing. Light pollution is a genuine environmental issue that we need to address. But the stark contrast between the electricity haves and have-nots here is the thing the emphasize.
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