Hungarian ultra-low-cost carrier Wizz Air announced its December and overall 2022 passenger figures on Tuesday. And it makes for pleasant reading for Jószef Váradi and his colleagues. The budget airline doubled its figures from 2021 and carried 15% more people over last year compared to the pre-pandemic 2019. December was particularly significant, with holiday travelers bumping figures to 4.18 million, or 27% higher compared to the same period in 2019 and 58.4% compared to 2021. Meanwhile, the airline also managed to reduce its CO2 emissions by 13.3% in December last year compared to the same month the year before. Wizz prides itself on being "one of the most sustainable airlines in Europe." Fleet renewal and latest technology aircraft are at the heart of Wizz's sustainability strategy. The mainline carrier currently operates a fleet of 153 aircraft - 66 of which are neo jets - with an average of only 5.4 years, according to data from ch-aviation. It also has substantial orders for more Airbus A320neo family aircraft, waiting to take nearly 300 more. Over the 12 rolling months ending on December 31, 2022, Wizz managed to lower its CO2 emissions per passenger kilometer to 55.2 grams from 65.3 grams the year before, representing a decrease of 15.4%.