We constantly here from the government and the economic wizards how great it is for our economy to have growth. Not just ours, the the whole world as well. However we live on a finite planet. How then can we sustain growth forever ? Well we can't and to attempt to is not only impossible but also abusive to the planet and it's inhabitants as well.  As Derrick Jensen says in this essay.

Once a people have committed (or enslaved) themselves to a growth economy, they’ve pretty much committed themselves to a perpetual war economy, because in order to maintain this growth, they will have to continue to colonize an ever-wider swath of the planet and exploit its inhabitants. I’m sure you can see the problem this presents on a finite planet. But in the short run, there is good news for those committed to a growth economy (and bad news for everyone else), which is that by converting your landbase into weapons (for example, cutting down trees to build warships), you gain a short-term competitive advantage over those peoples who live sustainably, and you can steal their land and overuse it to fuel your perpetual-growth economy. As for those whose land you’ve stolen, well, you can either massacre these newly conquered peoples, enslave them, or (most often forcibly) assimilate them into your growth economy. Usually it’s some combination of all three. The massacre of the bison, to present just one example, was necessary to destroy the Plains Indians’ traditional way of life and force them to at least somewhat assimilate (and become dependent upon the growth economy instead of the land for their very lives). The bad news for those committed to a growth economy is that it’s essentially a dead-end street: once you’ve overshot your home’s carrying capacity, you have only two choices: keep living beyond the means of the planet until your culture collapses; or proactively elect to give up the benefits you gained from the conquest in order to save your culture.

A perpetual-growth economy is not only insane (and impossible), it is also by its very essence abusive, by which I mean that it’s based on the same conceit as more personal forms of abuse. It is, in fact, the macroeconomic enshrinement of abusive behavior. The guiding principle of abusive behavior is that the abuser refuses to respect or abide by limits or boundaries put up by the victim. As Lundy Bancroft, former codirector of Emerge, the nation’s first therapeutic program for abusive men, writes, “Entitlement is the abuser’s belief that he has a special status and that it provides him with exclusive rights and privileges that do not apply to his partner. The attitudes that drive abuse can largely be summarized by this one word.”

Yes. A perpetual growth economy is as impossible as perpetual motion and to believe in it is just as insane.