"The U.S. withdrawal could hinder global efforts to curb greenhouse gases because it “gives other nations the excuse to delay their own actions and commitments,” said Stanford University climate scientist Rob Jackson, who chairs the Global Carbon Project, a group of scientists that tracks countries’ carbon dioxide emissions. It will also be difficult to achieve meaningful progress on climate change without cooperation from the U.S., one of the world’s largest emitters and economies, experts said. The U.N. Population Fund, the agency providing sexual and reproductive health worldwide, has long been a lightning rod for Republican opposition, and Trump cut funding for it during his first term. He and other GOP officials have accused the agency of participating in “coercive abortion practices” in countries like China. When President Joe Biden took office in January 2021, he restored funding for the agency. A State Department review conducted the following year found no evidence to support GOP claims. Other organizations and agencies that the U.S. will quit include the Carbon Free Energy Compact, the United Nations University, the International Cotton Advisory Committee, the International Tropical Timber Organization, the Partnership for Atlantic Cooperation, the Pan-American Institute for Geography and History, the International Federation of Arts Councils and Culture Agencies, and the International Lead and Zinc Study Group."