co2 is a legitimate reason, and may justify the investment. Costs.. agreed in theory. But in practice, modern low cost airlines supported by efficient airports

co2 is a legitimate reason, and may justify the investment. Costs.. agreed in theory. But in practice, modern low cost airlines supported by efficient airports are very hard to beat on price. There are economies of scale here too. Very best case scenario, HSTs are similar in price and convenience and it's a matter of taste.