Wen Bo started the China Green Student Forum, China's first network of student environmental organizations. He is now codirector of Pacific Environment's China program, based in Beijing. Mr. President: As the two largest contributors of global greenhouse gases, the time is ripe for the United States and China to champion the fight against climate change. The next U.S. administration can take leadership by setting high domestic environmental standards, supporting multilateral agreements, and aiding in the transfer of clean technology and sound environmental-management skills to developing countries. It is time for U.S. consumers to recognize their contribution to China's environmental woes, especially when U.S. corporations outsource manufacturing to China and shirk their corporate and social responsibilities to the communities in which they operate. The next administration has the opportunity to hold U.S. corporations to higher standards, whether their factories are located in Pittsburgh, Pennsylvania, or Guangzhou, Guangdong. China's environmental groups are organizing conservation efforts, leading education programs, and engaging community members to fight climate change at the grassroots level. But they need international solidarity. The next U.S. administration should support the growth of an environmentally active citizenry in China--the best hope for a sustainable future in China, and the world.