To what extent should societies attempt to meet present needs, and to what extent should they try to provide for the future
to the extent that they provide enough needs for now, and what is left is left. Theres old/extremist political views called libertarianism and socialism. Basically it boils town to the fact that the Earth belongs to men in common, so you can only take something from the earth if you left enough for the well-being of the common of man. Get it? Its kind of a take just what you need so there'll be plenty to go around.
What needs are you concerned about? Once you indicate this, we can give you a better answer. Societies need to be aware of the available resources currently and in the future to make decisions. Also there might be costs in implementing plans, which can offset the advantages of future plans.
I hope this helps a little more. If not, please repost your questions in more specific terms. Thanks for asking.