What Ryan Sager calls the “Giant Fraggin’ Mansion Effect,” from True/Slant:

Don’t pat yourself on the back too hard this Earth Day — it could be bad for the environment.
That is: If you’re too-well-satisfied that you’re a good greenie, you’re more willing to cut yourself slack when you hurt the environment.
Call it the Al Gore’s Giant Fraggin’ Mansion Effect.
According to a new study in Psychological Science, humans engage in a process called “moral self-regulation.” Basically, we’re constantly calculating the trade-off between being able to see ourselves as good people and the cost of engaging in all that non-advantageous goodness.
You might expect that being prompted (primed) to think of yourself as a good person would make you more altruistic or moral — but, in fact, the exact opposite appears to be the case. Primed to think about what a good person you are, your most likely reaction is to think you’ve paid your morality dues and go on about your business.
The researchers tested it this way, as recounted by Neuronarrative:
In the first experiment, participants were asked to write a self-relevant story using words that referred to either their positive or negative traits. After finishing, they were told that the research lab was interested in supporting social awareness and usually asks participants if they would like to make a small donation to the charity of their choice. Participants were told they could write down the charity and the amount they wanted to donate (note, they were not aware of any link between the story they wrote and the charity donation). The result: participants who used positive words about themselves in their stories donated one fifth as much money as those who used negative words.
In a follow-up experiment, subject were asked to pay to control pollution from a manufacturing plant. As in the first experiment, those primed with positive words about themselves chose the less-altruistic option: to pollute and maximize profit. . . .Now, I’m of the opinion that most “green” personal choices are already completely about moral vanity — their scale makes them meaningless while endowing the environmentalist with a great sense of self-worth. So, the real effect of Earth Day, I think, is for this smugness to get a significant one-day boost. Which, the research would suggest, gives the green-conscious an internal license to be total bastards in some other area of their lives.
Happy Earth Day!