Union of Concerned Scientists

• 1. Introduction

  ›

  The Union of Concerned Scientists put up two billboards in August 2008. One stood near the airport in Denver, Colorado, and the other near the airport in Minneapolis-Saint Paul, Minnesota. Both cities were about to host a presidential nominating convention, one Democratic and one Republican. Each billboard placed the host city inside a set of cross hairs. The warning read that when only one nuclear bomb could destroy a city, "we don't need 6,000." The name of Senator John McCain or Senator Barack Obama followed the image. Beneath it ran a line: "It's time to get serious about reducing the nuclear threat."

  That blunt message would soon provoke a swift response from a major airline. It also sits at one end of an organization founded decades earlier by university scientists who wanted research pointed away from weapons work. Its members have signed open letters alongside thousands of Nobel laureates. They have clashed with a sitting White House over how science gets used in policy. They have also argued internally about whose voices get heard inside the group itself. What set that founding generation of scientists in motion, and what has the organization done with the influence it built up since?

• 2. Founding and Mission

  ›

  In 1969, faculty and students at the Massachusetts Institute of Technology founded the Union of Concerned Scientists. Their founding document called for a critical and continuing examination of government policy wherever science and technology carried real or potential significance. It also set a goal: turning research away from military technology and toward pressing environmental and social problems. The organization went on to employ scientists, economists, and engineers working on environmental and security issues, alongside executive and support staff.

  One of its co-founders, the physicist and Nobel laureate Henry Kendall, served for many years as chairman of the UCS board. Kendall would soon carry that role onto a much bigger stage, when he presided over one of the organization's largest public declarations.

• 3. Petitions and Declarations

  ›

  In 1992, Kendall presided over the World Scientists' Warning to Humanity. The declaration called for "fundamental change" to address a range of security and environmental issues. It was signed by 1,700 scientists, including a majority of the Nobel prize winners in the sciences.

  Five years later, in 1997, the UCS presented its "World Scientists Call For Action" petition to world leaders negotiating the Kyoto Protocol. The petition stated, "A broad consensus among the world's climatologists is that there is now 'a discernible human influence on global climate.'" It urged governments to make "legally binding commitments to reduce industrial nations' emissions of heat-trapping gases." It also called global warming "one of the most serious threats to the planet and to future generations." More than 1,500 of the world's most distinguished senior scientists signed it, including a majority of the Nobel laureates in science.

  A rival petition, questioning that consensus, was circulated by the Oregon Institute of Science and Medicine, a small, privately funded institute. It gathered more than 17,000 signatures from science graduates. UCS called it "a deliberate attempt to deceive the scientific community with misinformation." On the 11th of December 2006, UCS issued a statement calling for the restoration of scientific integrity to federal policy-making. The statement was signed by 10,600 leading scientists. Signers included 52 Nobel laureates, 63 National Medal of Science recipients, and almost 200 members of the National Academies of Science. That reputation for mobilizing large numbers of scientists would soon collide with a smaller, more local dispute over one of its own advertising campaigns.

• 4. Billboards and Backlash

  ›

  Northwest Airlines, headquartered in Minnesota and serving as the official airline of the Republican convention, complained about the ads, and both billboards came down.

  UCS pushed back hard, accusing Northwest of "taking on a new role as censor." The organization argued that Northwest pulled the ads because it saw the Minneapolis billboard as "scary" and "anti-McCain." Campaigns like that draw on a funding base that outside evaluators have scrutinized in detail.

• 5. Funding and Governance

  ›

  According to the George C. Marshall Institute, UCS was the fourth-largest recipient of foundation grants for climate-related activities in the 2000-2002 period. A quarter of its $24 million in grant income during that period went toward climate work.

  Charity Navigator is an independent nonprofit that evaluates American charities. It gave UCS a four out of four star rating for the fiscal year ending in September 2018. The rating carried an overall score of 91.85 out of 100.

  UCS's IRS Form 990 covered the tax year that ran from the 1st of October 2017 to the 30th of September 2018. It reported $39.9 million in total revenue, $3.1 million in expenses, and $48.8 million in net assets. Those numbers describe an organization built to sustain long fights, including one it picked with a sitting presidential administration over how government scientists were treated.

• 6. A Fight Over Integrity

  ›

  In February 2004, UCS published a report called "Scientific Integrity in Policymaking." The report accused the administration of President George W. Bush of "politicizing" science. Its allegations included altering information in global warming reports from the Environmental Protection Agency. UCS also said scientific advisory panel members were chosen for their business interests rather than their scientific experience.

  In July 2004, UCS released an addendum accusing the Bush administration of improperly altering reports on West Virginia strip mining. The addendum also said "well-qualified" nominees for government posts, such as Nobel laureate Torsten Wiesel, were rejected because of political differences.

  On the 2nd of April 2004, John Marburger, director of the White House Office of Science and Technology Policy, issued a statement. He called the report's incident descriptions "false," "wrong," or "a distortion," and dismissed the whole report as "biased." UCS responded that Marburger's claims were unjustified, and later wrote that the Bush administration went "virtually silent" on the issue afterward. A very different kind of reckoning would arrive from inside the organization itself, more than a decade later.

• 7. Internal Reckoning and New Leadership

  ›

  In June 2020, a UCS staffer named Ruth Tyson resigned and sent a 17-page open letter about racial inequality inside the organization. She wrote that ideas from black workers were routinely dismissed or given low priority. UCS president Ken Kimmell responded that her criticism was fair. He said he believed it reflected a wider culture of white supremacy in society, and he vowed to address issues and diversify the UCS workforce.

  His successor, Johanna Chao Kreilick, was chosen partly for "her track record of integrating racial justice into the work and culture of complex organizations." In February 2025, environmental scientist and policy advocate Dr. Gretchen Goldman became the organization's president. Those leadership changes sit alongside a wide range of policy fights the organization wages on the ground, from reactor design to outer space.

• 8. Issue Stances

  ›

  Edwin Lyman, a senior staff scientist at UCS, has criticized so-called Generation III reactor designs. He has specifically challenged cost-saving choices made for the AP1000 and the Economic Simplified Boiling Water Reactor.

  UCS endorsed the 2007 Forests Now Declaration, which calls for new market-based mechanisms to protect forests. The group has recognized that curbing deforestation matters to tackling climate change.

  UCS also supports government incentives for landowners who choose to preserve undeveloped land rather than sell it to developers. The organization opposes the use of space weapons, and it supports work to reduce the number of nuclear weapons worldwide.