This title sounds like a contradiction but it is deadly serious. In the discussions around sustainability all turn around the eternal lifetime of everything. In fact a lot of our current problems and crisis turn around unjust sustainability of human systems that cause severe unbalans in the world. The sustaining of a financial system for instance, that tries to keep up powerpositions that collaps one after another. Or a health organization that keeps people alive no matter what. Or an educational system that contradicts with everything children have to cope with on the internet or society. Sustainability is not about keeping systems in place. It is about keeping the human existance in place.
To do that we need to accept that old ways of thinking are abolished, die a natural death and are not kept alive for sustainability sake only. As a human being it is tough to die with present medical attention, let alone a system invented by humans. Death is needed to allow renewal to florish.
Nature functions already for billions of years like that. Everything that grows too big disappears. It is allowed to die to sustain life as a whole. So when we talk sustainability in our society we need to accept death of our systems, our habbits and our politics as a process that allows continuous renewal.
To be sustainable as a human race we need to challenge ourselves continuously adjusting us intelligently to new circumstances as we go along, letting go of old solutions and finding new ones all the time, balancing them socially, ecologically and economically all the time. We need to allow death in order to be sustainable.