In February 2007, a report by the Intergovernmental Panel on Climate Change (IPCC), representing the work of 2,500 scientists, economists, and policymakers from more than 120 countries, said that humans have been the primary cause of global warming since 1950.
政府间气候变化专门委员会代表了来自超过120国家的2,500名科学家、经济学家和政策制定者，2007年2月，委员会称自1950年人类活动成为全球变暖的主要原因。