I always remember working in a big bureaucratic mess, that at the end of the year we had to spend our budgets on anything, or risk 'use it or lose it'.
Now the airlines risk losing their coveted monopoly airport slots if they don't run empty jumbo jets across the Atlantic. Then they charge the remaining passengers fuel surcharges to cover this! So much for trying to minimize CO2 emissions! Who needs expensive carbon schemes, if you can just stop this crap! The airlines are totally to blame, since they live by the existing airport slot system, which allows them to charge extra high. The government goes along with it, because it's more money for them.