Athletes continue to give stunning performances in figure skating and speed skating at the 2022 Winter Olympics. It's made possible by the eco-friendly ice, the first in Winter Olympics history to use CO2 as a refrigerant. Peking University Professor Zhang Xinrong, the person behind the eco-friendly ice, told CGTN anchor Tian Wei that the trans-critical CO2 direct cooling system can simultaneously make the cold energy and thermal energy for humidification, and produce hot water for athletes.