This Thursday marks the 100-day countdown to the 80th anniversary of the founding of the United Nations. 80 years later, unilateralism, hegemony and bullying pose serious threats, and humanity once again stands at the crossroads of unity or division, dialogue or confrontation, win-win or zero-sum. At this important juncture, CGTN's World Insight launches a series of high-level interviews, "United for the Future: The UN at 80." We bring you a special interview with Selwyn Hart, special adviser to the UN Secretary-General and assistant secretary-general for Climate Action, on current dilemmas of multilateral cooperation facing the global climate governance system.