Greenpeace USA is making the following claim, "The United States now has more people working in the solar industry than in coal mining."
This claim is used to bolster the further idea that the U.S. is moving away from carbon-based and earth-extractive sources of energy, i.e. that Greenpeace is on the winning side of history and everyone might as well clamber on board the bandwagon.
As for the big claim ... whatever.
As for the comparative employment figures from two industries, I'll make two observations here:
1) I haven't looked into it sufficiently to say whether I believe it -- there are different ways of defining who belongs to what "industry" after all, so the question might be complicated. Greenpeace takes its numbers on the coal industry from one source and its numbers for the solar industry from another source, so I have a suspicion that this is an apples-and-oranges thing.
2) Even if true, I'm not sure what it means in terms of the Big Picture we're invited to contemplate.
The coal industry is automating, so that fewer miners are needed to get a given quantity of coal out of the ground now than were needed a decade ago. If that is a sufficient explanation of the relatively low employment in that industry, then it doesn't suggest that the U.S. is headed toward a greener, non-carbon-dependent economy at all. It only suggests that the ways the carbon is extracted are changing.
And that may be a good thing, since robots don't get black lung disease and no one cries when they are the victims of a cave in.