http://casaubonsbook.blogspot.com/2008/01/why-is-this-apocalypse-different-than.html
Why Is this Apocalypse Different than All Other Apocalypses: Making the Case for Peak Oil and Climate Change Now
..............Going back, for a moment, to _The Limits to Growth_, one of the things that appears a lot in later modeling, in, for example, the 30 Year Update of TLTG, is that feedback loops and intersections are a bigger problem than any individual problem. And for those people wondering whether these problems are really as bad as they think they are, this is probably the most important thing to know – in the 1970s, we were worried about individual problems – a shortage of oil, for example, or about pollution, or a coming ice age. Right now, the biggest concern we have is of the intersection of inter-related problems. That is, the problem is not our ability to respond to one problem, but our ability to respond to multiple, overwhelming simultaneous crises.
The Limits to Growth: The Thirty Year Update_ found that almost all its “business as usual” scenarios led to collapse , *EVEN IF* the sheer quantities of resources available were *DOUBLED* over what we have any evidence at all for – that is, even if we had enough energy to go along, pollution built and cancer rates skyrocketed, while soil erosion rose to make food production fail to keep pace with population growth. That is, these scenarios don’t depend on a shortage or crisis in any single place – they operate as a system of feedback loops influencing one another. As the authors put it,
A second lesson is that the more successfully society puts off its limits through economic and technical adaptations, the more likely it is to run into several of them at the same time. In most World3 runs, including many we have not shown here, the world system does not totally run out of land or food or resources or pollution absorption capability. What it runs out of is the ability to cope."
In the 1970s, environmental activists were responding to the very first warning signs of depletion and climate change. Many of them interpreted scientific warnings on these points to mean that we were facing an immediate, definite crisis down to the particulars. But that’s not what they were being told. Instead, people were being warned about the longer term consequences of their actions in no uncertain terms. And in fact, our ability to cope managed to push these issues off, in many cases for decades, but again, as we put our limits further off, we drew our resources down further. Soon, the bill comes due................
Business as usual scenarios lead to collapse. Thats the path we are currently on.