Richard Heinberg is best known for his work on peak oil. 'Peak Everything' is a little broader in scope, a series of essays based around the idea of a century of decline and the need for a global downsize. Some essays you'll find useful, others not, which why I give it three stars.
"Our starting point," writes Heinberg, "is the realization that we are today living at the end of the period of greatest material abundance in human history - an abundance based on temporary sources of cheap energy that made all else possible." Having dealt with the depletion and its solutions elsewhere, Heinberg writes more about life after the peak here, the nature of the transition - what kind of culture will emerge, how will we cope?
Some of the essays here are very speculative, interesting asides that clearly didn't fit into other books. There's a chapter on the possible aesthetics of post-industrial design for example, or the psychology of language, some musings on popular culture.
Less esoterically, there's a useful chapter on farming, as "re-ruralization will be a dominant social trend of the 21st century." He also addresses population, expounds five `axioms of sustainability', reflects on the legacy of the `boomer' generation, and helpfully maps some of the intersections of climate change and peak oil campaigning.
Those wanting more on peak oil are better off with previous books, and there's no detail on the `peak everything' hinted at in the title. It is nevertheless a thoughtful and diverse set of ideas from one of the sharpest minds working on resource depletion.