Lazs, what really is based on exponential math is growth. Each year, GNP is expected to grow by a certain percentage, if it doesn't grow as expected the economy start to falter. What is proven with arithmetics is, that the economy can not continue to grow forever, while people expect it to. It's a false expectation, as what is driving the economy is raw materials, natural resources. These resources (primarily oil) are finite, a supply bound to run out.
It's all very very simple. See the above post, we have to change something. If we don't, something will change anyway whether we like it or not. Like Dr Bartlett points out to us, we do have the option to change things before it starts to slip out of our hands. Once it's slipped away, we will not be in control any longer and nature will have it's course whether we like it or not. It's not a matter of change or no change, change will happen. It's how that change will happen that we may have some say about, if it's not already too late.