The global economy will in the near future have to adapt to its dependence on the limited ecological system. Only renewable energy sources can provide a truly sustainable supply of energy. In an environmental ranking of the various energy options, it is pointed out, however, that also the use of renewable energy sources can be unsustainable and otherwise damaging to the environment, if vigorously exploited. Since the energy saving options are more gentle to the environment than any supply options, we will be best off by keeping energy consumption very low.
Technological efficiency can lower energy consumption by a factor three to five.
But it is stressed, that these efficiency gains can easily be eaten up by decline in efficiencies in the ways we conduct our lifestyles and run our economies. To apply such an overall effciency view, however, turns out to pose a threat to the presently prevailing economic growth practice. We have to face this challenge, if we want to secure a decent material well-being for all people on earth, also the generations to come. Countries with econmies in a transition do in fact have some advantages, if aiming directly at a sustainable economy. Conference Proceedings of the 5.