Challenging words, but beloved and I have been thinking a lot about them recently, and - with a bit of humming and hawing we're probably going to sign up to the 90% reduction plan (see here).
Seems like every day there are things bringing it home.
The world is changing around us. Because we (ie western society) are so rich we can put off the day of reckoning for a little longer than most, but that just means that the reckoning will be all the harsher when it comes. Shifting to a different pattern of life is just battening down the hatches in preparation for a storm.
UPDATE: this is useful (there have been others, but this seems particularly readable).