So at this same blog, the blogger writes about stocks and flows in his top-level post. This is a straightforward directed graph with flow between the states as those who frequent the Azimuth Project forum will find familiar

https://andthentheresphysics.wordpress.com/2019/12/04/stocks-and-flows-2

This is a comment I added which is under moderation

> One stock and flow pattern is that for fossil fuel usage. The stock is discoveries of crude oil and the flow is production from these known reserves. This idea was what enabled King Hubbert in the late 1950's to accurately predict peak oil for the USA after a lag of 14 years. The already declining stock was all that Hubbert needed that turned out to be "the single best long-term forecast that everyone ever gotten right. For those of us that work on Wall Street, we realize how difficult it is to get anything right, but here is a guy that looked 14 years in the future and managed to get it right" according to this oil investor video (6 minute mark) from a couple of days ago

> https://youtu.be/dhc6vyxVsDs

This is the stock and flow lagged shift that Hubbert described, with the blue arrow indicating the prediction (screen shot from the YouTube presentation)

![](https://imagizer.imageshack.com/img923/8418/otg6y3.gif)

Hubbert nailed this but didn't anticipate the recent fracked shale oil nor the Gulf of Mexico or Alaskan discoveries, which didn't invalidate the model but instead pointed out how it could be used in a wider geographic context.

The YouTube video is long but interesting to sit through as it is predicting a scarcity of crude oil as the fracked shale oil production starts declining in the coming years.