Resource limits are invisible, so most people don’t realize that we could possibility be approaching them. In fact, my analysis indicates resource limits are really financial limits, and in fact, we seem to be approaching those limits right now.
Many analysts discussing resource limits are talking about a very different concern than I am talking about. Many from the “peak oil” community say that what we should worry about is a decline in world oil supply. In my view, the danger is quite different: The real danger is financial collapse, coming much earlier than a decline in oil supply. This collapse is related to high oil price, and also to higher costs for other resources as we approach limits (for example, desalination of water where water supply is a problem, and higher natural gas prices in much of the world).
The financial collapse is related to Energy Return on Energy Invested (EROEI) that is already too low. I don’t see any particular EROEI target as being a threshold–the calculations for individual energy sources are not on a system-wide basis, so are not always helpful. The issue is not precisely low EROEI. Instead, the issue is the loss of cheap fossil fuel energy to subsidize the rest of society.