The Union of Concerned Scientists (UCS) is a nonprofit alliance of some fifty thousand scientists and citizens across the United States. The group's stated goal is to combine rigorous scientific analysis with committed citizen advocacy in order to build a cleaner environment and a safer world. The group focuses on issues such as global warming and the environmental impact of vehicles and various energy sources.

The UCS was formed in 1969 at the Massachusetts Institute of Technology, where a number of faculty members and students banded together to protest what they saw as the abuse of science and technology for military purposes. The new group called for greater emphasis on the application of scientific research to solve social and environmental problems. In its early years, the organization issued statements urging an end to the nuclear arms race and a ban on space weapons...