With current world population and technologies, the sustainable level of CO₂ emissions per person is 3 tons per year. In Germany, with an above-average environmentally conscious way of life, I'm doing around 5 tons a year. In December, I'm flying to Vancouver for a conference, which will produce around 2 tons roundtrip (global warming equivalent). So while I don't feel ashamed, of course I don't feel great about it, shouldn't that be obvious?