I the book "Collapse", it gives a survey of dozens of civilizations tackling problems like this and how they did, or didn't, solve them. There are many cases each of market or grassroots based solutions and top down government based solutions.

My conclusion from this empirical evidence is that there are many ways to arrive at solutions, what is important is that someone makes it happen. Anyone claiming that only government, or only free markets can do it, is probably wrong.