I realize that I risk appearing to be a “traditionalist” — gasp! — i.e., someone who believes that Lenten fasting has a specific purpose, defined by the history of its observance. But it does.
Kallistos Ware puts it succinctly and accurately: “The primary aim of fasting is to make us conscious of our dependence upon God. If practiced seriously…The purpose of this [fasting from food] is to lead us in turn to a sense of inward brokenness and contrition; to bring us, that is, to the point where we appreciate the full force of Christ’s statement, ‘Without Me you can do nothing’ (John 15: 5).”
So, when we begin to offer alternative fasts from things like “carbon,” in the name of demonstrating the relevance of the Church and in the name of launching yet another initiative to change the world, we actually do exactly the opposite of what a Lenten fast demands of us.
This isn’t to say that it might not be valuable to drive less and walk more (although heaven knows, until things change in China and the Indian subcontinent, such choices won’t make much difference). But it is to say that some forms of abstention have little or nothing to do with Lenten discipline.
This isn’t the first time that we’ve run from vulnerability before God in the name of demonstrating, yet again, that we aren’t really dependent upon God. Work hard to reduce your carbon footprint, if you feel morally obliged to do so, but don’t substitute that effort for a true fast which disciplines mind, body, and spirit in the name of learning that you are dependent upon God.