I've picked a few out of campus publishing houses in Hall 3. Julian Buckhaus is headed to Frankfurt with a staff member. They're travelling by private jet（喷气式飞机）. Taking public transport is pretty gross（总的） at the moment. Sharing a cabin（小屋） with snotty-nosed people coughing everywhere, I avoid it as much as I can. It's a short trip from Wilhelmshafen to Frankfurt, just about 500 kilometers.

  Travelling by private jet may be convenient, but it certainly does the climate no favours（偏袒）. You don't care about climate change? I don't think about it much. If everyone behaved like you and flew as often as you do, then it wouldn't work. But luckily the population is split（劈开） into different groups, and I'm part of the small fraction（小部分） that can get away with it. Private jets, fast cars, yachts（游艇）.

  Generally the richer people are, the more they contribute（捐献） to global warming. In the last few years we've seen that one key element of being wealthy（ 富有的） is how much it harms（损害） the planet. How much longer can we afford the indulgent（放纵的） lifestyle of the rich? I'm just reading the article about you in Manager magazine. Very cool, congratulations. Julian Bachaus is a publisher of finance（财政） and business magazines.

  Today he's going to the Frankfurt Book Fair. The flight takes about an hour. What's the flight cost? About 4,000 euros per hour. So there and back, two hours will set you back 8,000 euros. More and more rich people travel this way.

  The number of private jet flights in Germany increased by 9% within one year. Don't you feel guilty living at the expense（花费） of others? That's not really the case. I'm not stopping anyone from doing the same. Others could do it, but they don't. Is that okay?

  It's okay for me. And I don't think I'm actively（活跃地） harming（损害） anyone. If that were the case, I'd probably think about it more often. But so far I haven't seen how I'm deliberately（ 故意地） or actively（活跃地） harming（损害） anyone. But carbon（碳） emissions（(光、热等的)散发） are harmful（有害的） to others. In fact, to all of us.

  A flight by private jet emits（发出） tons（吨） of greenhouse（温室） gases. We're already experiencing the consequences of climate change today. After all, the climate crisis（危机） has long since arrived. Fires. Droughts（干旱）. Floods.

  With increasing frequency（频率） in more and more places. If global warming is not slowed down soon, large parts of the Earth will become uninhabitable（不适宜居住的）. I believe that civilization（文明） as we know it would end. And certainly our idea of a humane（仁慈的） society would be over. Professor Hans Joachim Schellenhuber is one of the most renowned（有名的） climate researchers in the world. His findings（发现） are simple and unequivocal（明确的）.

  Humans must severely（严重地） restrict（限制） CO2 emissions（(光、热等的)散发）. Our own survival（ 幸存） depends on it. To reach that target, we calculate（计算） that each person on the planet is allotted（分配） three tons（吨） of CO2 emissions（(光、热等的)散发） per year by mid-century. So on average, each person's carbon footprint（脚印） should be three tons（吨） of carbon（碳） dioxide per year. This short trip is responsible for three tons of emissions. In theory, Julian Backhaus has used up his entire（全部的） year's CO2 allowance（津贴） with this flight alone.

  I'm afraid I have some bad news. Due to heavy rain and eagles back, and because the runway is relatively（ 相对地） short, we've decided to fly to Frankfurt Main. Would Julian Backhaus cut down on flights and accept a CO2 cap? That's the same for everyone. I think restrictions（ 限制） like that are pointless（无意义的）. We live in a world that affords us a certain abundance（丰富）, and I think everyone should have the right to enjoy that.

  And he does have that right. No one is stopping Julian Backhaus from flying by private jet as often as he likes. Can you contact Eggelsbach? My chauffeur is waiting there. Already done. Can you send him to Frankfurt Main?

  Already done. He's on his way over. Terrific（极好的）. See you later. Thank you. Very few people can afford private jets or other luxuries which are harmful to the climate.

  Do these few people make（使） a big difference? Data（资料） shows that the richest 1% of the world's population emit（发出） extremely high amounts of greenhouse（温室） gases. 8.5 billion tons per year. To put that into perspective（透视画法）, that's more than the 6.1 billion tons（吨） produced by the entire（全部的） poorer half of the world's population. Meanwhile in the German town of Sande in Lower Saxony, Elvira Klein is cycling home from work. Flights by private jet are inconceivable for the Klein family.

  Bicycle is the family's main means（平均值） of transportation（运输）. We don't want to use our car too much. Fuel prices are really high and we're thinking about the environment. She has to leave soon to take her daughter to choir（唱诗班） practice. Emma, time to go. Her husband works as a cook in a hospital.

  Combined, the Klein's net（纯粹的） monthly（每月的） income（收入） totals about 2,600 euros. That puts them in the bracket（括号） of lower middle class. Come on. Coming. Have fun. See you later.

  Money has always been tight for the Klein's. Now that prices keep rising, it's becoming a real problem. Taking their daughter to choir practice is one of the rare occasions when they use their car. We drive there because Emma can't manage it by bike in that time. It's 10 kilometers each way. Her diesel（柴油机） car emits（发出） 0.005 tons（吨）, or 5 kilograms of CO2.

  Elvira Klein would be able to drive her daughter to choir practice 600 times before she equalled the carbon footprint of a short trip in a private jet. But given（做） the high fuel prices, it's unlikely to come to that. When diesel is expensive, we spend more on that and there's less left over for food and clothing. We have to cut back（在后） on other things. Mostly it eats into our vacation budget（预算）. That's not so bad.

  Visiting Aunty is like going on vacation. She's got a huge pool with LED lights. But we still have to drive there, Emma. That costs money too. Is driving a luxury for you? It's become one.