Despite an enormous attack against this book by economists and conservatives, it's point was and still is valid. Do not believe others that make claims about what this book contains, such as that they predict that there will be a catastrophe by 1990 or that once the cold war is over all will be OK. This is not true at all; they did not make any such predictions and you have to read it carefully to note that they are very cautious about calling the computer outcomes predictions at all. The book does not take into account technology changes explicitly, but changes in technology will only be of use if they have an effect on resources, pollution, nutrition, population control and all of these factors ARE part of the computer model. For example they would test the effect of increasing the abundance of known resources and seeing what happened. All of the outcomes show that overshoot occurs before 2100, even the models based on very unrealisticly optimistic values for resources, nutrition etc have this result.
Despite the limitations of the information available to the authors, some forecasts have proved surprisingly accurate - such as that the population would reach over 6 billion by the year 2000 - which it did. There are a number of other forecasts that researches have since found to be surprisingly accurate.
It is time that this work is taken seriously. It is foolishness to believe that technology alone can resolve the problems of overshoot before it produces serious effects on our standard of living. Signs of overshoot have already begun, as you can easily see from reading the book. For example pay attention to hypothetical impacts on services and think of the NHS in the UK and or medicare/aid in the US.
The book does have a positive message and the authors believe that action can be taken to avoid the outcomes modelled. Unfortunately they have not been taken seriously enough and now there is much less time to act. This book must be read so you can make up your own mind...