I get uncomfortable when greener-than-thou environmentalists criticise others, because of their supposed hypocrisy. I think it leave us all vulnerable to a similar criticism, and seems lacking in empathy.
That doesn't mean that I think we shouldn't pay attention to our own environmental footprint. What it does mean is that when we are reflecting on our practice as change-makers of one kind or another, we can be a little more sophisticated, and avoid judging ourselves (and others) as either eco-sinners or saints.
In my own work, I've been able to help fellow climate-change champions to reflect in a structured way on their personal and collective environmental footprints, and how to manage the (inevitable) incongruence between what they espouse and their personal negative impact, using a workshop format.
That workshop format, and the results, are described in Being the Change for Climate Leadership, first published in Organisations & People, the journal of AMED (the Association of Management Education and Development).