If all value is relative then there is no such thing as value at all. Of course the converse statement, that "inherent value" is a construct is true, since people rarely agree on the value of any given object, and generally the only way we can speak meaningfully about value is to take something that people agree has value. That said, there are certain types of objects that have been considered by most people to have value at most points in history. Gold, a fungible, maleable, shiny metal has been considered to be this for most of human history. There are other things of course, water being a very good example. The problem for currencies has historically been that alternative valuable objects either are not especially limited or not fungible, making them a bad base for a currency.

There may also be things that have "inherent value" insofar as they are necessary to the continued existence of humanity, whether or not we perceive them as so. Damaging our environment beyond a certain degree would certainly be this. Unfortunately international governance has not risen to this particular challenge and fully utilized available technology (e.g. carbon credits).