The last two sentences of the article seem to at least obliquely address this: > In this century, we urgently need to undo some of the consequences of the last

The last two sentences of the article seem to at least obliquely address this: > In this century, we urgently need to undo some of the consequences of the last great boom by developing affordable zero- and negative-emissions technologies. That's another hard problem—and to solve it, we'll need to recapture some of what made the “special century” so special.