This is a very interesting topic. Yes we have made great strides, regarding Longevity and the quality of life in the older years. The question remains, can our planets resources sustain the increases in population, and longer living inhabitants.
If the earth suffers the damages that can be caused by over population, then what will that mean to the overall quality of life anyway.
I guess we really need to kick this into gear, and get ourselves to the point where we can travel to other planets, to populate.
Hope there's nobody there already, that we need to kick out to do so.
How about if there is Life after Death. That we do exist somewhere after we die. Another Dimension, or another world.
I guess we wouldn't have to worry about all this.