In the big picture, I think of my work in two ways. First, the world’s resources are scarce and often mismanaged. There exist a seemingly constant conflict between want of development and necessity of conservation. My research into environmental and resource economics are small but potentially important contributions towards these issues. My work will almost certainly have no effect in the short run but may have a some effect in the longer run. Devoting my admittedly limited intellectual powers to this end form a motivation to put up with the many irrational incongruencies of present day academia and, according to some, low pay. (My view towards the latter vary, largely in phase with the size of my bank account.)
Second, we are just small, insignificant critters basking in a soup of organic chemistry on a speck of dust in an enormous universe that we hardly understand. My work has no significance, but I sometimes like doing it.
It is in the latter way I often understand art. Life is utterly meaningless, so why not make something beautiful.