@Xenoche,
This is silly... but let me try again. First of all a science lesson.
Human beings mistakenly think that we are significant. In the history of the world, we are not. In fact if you represented the entire existence of the Earth by a mile, modern humans came around in the past couple of inches. Even in terms of resource, sure we are hurting ourselves... but from the point of the Earth, we are insignificant.
There are two types of resources. The first is matter (i.e. the atoms that are available for us to use). The second is energy.
1. There is very little matter that is leaving the Earth. The things we have put into orbit will come back (and be accessible to future humans). We have put a little matter on the moon, and a couple of robots on Mars or in space-- but besides that, we haven't lost any resources.
2. We are using energy that was from the sun, but was stored over the past million years or so. Most of the energy we use comes from the sun. It is not renewable in our lifetime (seeing as it takes tens of thousands of years to make fossil fuel), but on the timeframe of 1 million years, it is completely renewable and will be accessible to future humans.
I think you are missing the time frame involved.
The Earth will be destroyed in 5 billion years. Compared with the span of human life, even all life, this is a very very long time.
In the time before we need to leave the Earth, plastics will decompose, the continental shelves will move exposing brand new minerals to the surface, the surface of the Earth will be renewed. There will be new supplies of oil. The effects of todays humans will be completely insignificant well before 50 million years (just 1 percent of the time the Earth has left).
In fact, even if we destroy all human life, we will have more than enough time (and resources) to evolve all over again.