That's not what the study concluded.
It saw that based on the scenarios in the study the two that matched best was that we have already changed course with exceptionally high technological development and adoption will stabilize or that we would collapse in 2040.
It's just that such a statement wouldn't attract as much attention.
(That the study cannot tell such radically different outcomes apart hints at a problem, and selecting proxies after the fact is also methodologically problematic - in the 1970/1980s one might have thought of using CFC as a proxy for pollution; but that is no longer an issue.)
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Installed wind power has gone from 50TWh to 1,400 TWh per year in this century.
Solar power generation has gone from even less to >800TWh per year during the same time (might already be 1,000 TWh this year - it's growing exponentially).
Seems fairly profitable. Obviously more is needed - including other industries but that is worked on, and nimbyism is an issue.