Clearly, there are conflicts between these goals. More equity may mean less
efficiency. In the short term, it may not be possible to meet the needs of the
present without consuming resources, for example by burning oil or clearing
areas of natural forest. Decision-makers have to consider the trade-off
between different goals but, if the system as a whole is to survive, the use of
natural assets must be compensated by the development of human or
physical assets of equal or greater worth.