"Many people who take pride in their green lifestyles—perhaps they bike to work and always carry a travel mug—also happen to be frequent flyers."

"This incongruity grows in part out of cultural factors. A certain type (and I count myself in this category) aspires to be both worldly and socially conscious. We would never think of driving an SUV, say, but we’ve been known to drop the names of far-flung capitals we’ve visited. To be sure, our portable bamboo utensil sets and canvas grocery bags accord with our principles, but they also accord with our self-image, our aesthetics, our personal brands. In other words, those choices are not sacrifices. Opting out of flying, by contrast, requires actual renunciation.... Changing our lifeways means reassessing not only conference design but also our personal customs. It might mean some amount of sacrifice.... Renunciation conveys to those around us that the situation is serious. Especially in the case of climate change—where the effects are dispersed, gradual, and tenuously linked to the causes—this kind of social cue is crucial.... Universities that boast about their LEED-certified buildings but encourage excessive flying among their faculties; governments that neither tax jet fuel nor invest in low-carbon ground travel infrastructure—the people behind these decisions are the ones who really ought to get acquainted with flygskam."

From "Flight Shame: The Climate Hazards of Air Travel" by Rebecca Tuhus-Dubrow (NY Review of  Books).