What are some criteria for ethical decision making?
There are many different systems of ethics that can be applied to business. One especially influential set is the Kantian one which lays out three major criteria that enable you to judge whether narrower principles and specific judgements are ethical.
First, any ethical precept should be universalizable, i.e. you should always ask what would happen if everyone acted like you do.
Second, you should always treat intelligent beings as ends in themselves rather than means to ends.
Finally, for an act to be moral, it must be intended as moral. In other words, if you improve efficiency to make money, and that reduces carbon footprint, even though the consequences are good, the act itself is not a moral one.