The absence of the U.S. at the 30th United Nations climate change conference, commonly known as COP30, in Brazil casts a pall over global climate action as the summit kicked off. U.S. environmental strategist and writer Evaggelos Vallianatos told CGTN's Tian Wei that climate change could spell out life and death to humanity. He is quite impressed with China's contribution to ecological governance. Jay Jones, a professor emeritus of biology at the University of La Verne, said that, with its absence weighing down on sustainable development, the U.S. needs a massive change in administration policy right now.