Hi Dave
It’s a good question, in fact one of our assistants is going preach on the topic of Christian’s and the environment in the next month.
It seems to me that from Genesis 1 and 2 the reason we are to rule the world is so that we may fill it with humans. It makes good sense that if we are to fill the earth with humans then it would be good to have the food to feed them so we will need to employ some very careful management programs.
There is the issue that the Creation Mandate was given pre fall of Man-kind, so, does it still stand since this world is destined for destruction?
It is interesting that in the account of Noah’s flood, that God ensured that all animal kinds were given a chance to continue existing. It seems that they do matter to God. Therefore I’d suggest that even though this world is under a curse and groaning while it waits for Christ to return, as God’s appointed rulers it would be wise for us to conserve what we have.
Psalm 8 reminds us that creation is still our responsibility, yet Christ is the fulfilment of that passage because we have fallen short of our responsibility. It does not mean that we are relieved of our responsibility, just that this side of judgment we won’t rule the way we were intended to.