He was known for rejecting the scientific consensus on several issues, including climate change,[4][5][6] the connection between UV-B exposure and melanoma rates,[7] stratospheric ozone loss being caused by chlorofluoro compounds, often used as refrigerants,[8] and the health risks of passive smoking.

He designed mines for the U.S. Navy during World War II, before obtaining his Ph.D. in physics from Princeton University in 1948 and working as a scientific liaison officer in the U.S. Embassy in London.

[9][12] In 1990 Singer founded the Science & Environmental Policy Project,[9][13] and in 2006 was named by the Canadian Broadcasting Corporation as one of a minority of scientists said to be creating a stand-off on a consensus on climate change.

[14][15] Singer argued, contrary to the scientific consensus on climate change, that there is no evidence that global warming is attributable to human-caused increases in atmospheric carbon dioxide, and that humanity would benefit if temperatures do rise.

He was discharged in 1946 and joined the Upper Atmosphere Rocket Program at the Johns Hopkins University Applied Physics Laboratory in Silver Spring, Maryland, working there until 1950.

Fired from a converted Navy LSM, they could reach an altitude of 50,000 feet (15,000 m) and had a complete telemetry system to send back information on cosmic, ultraviolet and X-rays.

Singer said that the firings placed "the exploration of outer space with high altitude rockets on the same basis, cost-wise and effort-wise, as low atmosphere measurements with weather balloons.

"[30] In February 1958, when he was head of the cosmic ray group of the University of Maryland's physics department, he received a special commendation from President Eisenhower for "outstanding achievements in the development of satellites for scientific purposes.

[33] He became a full professor at Maryland in 1959, and was chosen that year by the United States Junior Chamber of Commerce as one of the country's ten outstanding young men.

[34] In a January 1960 presentation to the American Physical Society, Singer sketched out his vision of what the environment around the Earth might consist of, extending up to 40,000 miles (64,000 km) into space.

[37] In a 1960 Astronautics newsletter, Singer commented on Iosif Shklovsky's hypothesis[38][39] that the orbit of the Martian moon Phobos suggests that it is hollow, which implies it is of artificial origin.

Singer wrote: "My conclusion there is, and here I back Shklovsky, that if the satellite is indeed spiraling inward as deduced from astronomical observation, then there is little alternative to the hypothesis that it is hollow and therefore martian made.

[48] In December 1965, The New York Times reported on a conference Singer hosted in Miami Beach during which five groups of scientists, working independently, presented research identifying what they believed was the remains of a primordial flash that occurred when the universe was born.

[citation needed] In 1987 he took up a two-year post as chief scientist at the U.S. Department of Transportation, and in 1989 joined the Institute of Space Science and Technology in Gainesville, Florida where he contributed to a paper on the results from the Interplanetary Dust Experiment using data from the Long Duration Exposure Facility satellite.

He believed in what Rachel White Scheuering calls "free-market environmentalism": that market principles and incentives should be sufficient to lead to the protection of the environment and conservation of resources.

Sagan argued that if enough fire-fighting teams were not assembled in short order, and if many fires were left to burn over a period of months to possibly a year, the smoke might loft into the upper atmosphere and lead to massive agricultural failures over South Asia.

He questioned the link between second-hand smoke and lung cancer, and was an outspoken opponent of the mainstream scientific view on climate change; he argued there is no evidence that increases in carbon dioxide produced by human beings is causing global warming and that the temperature of the Earth has always varied.

[16] A CBC Fifth Estate documentary in 2006 linked these two debates, naming Singer as a scientist who has acted as a consultant to industry in both areas, either directly or through a public relations firm.

[14] Naomi Oreskes and Erik Conway named Singer in their book, Merchants of Doubt, as one of three contrarian physicists—along with Fred Seitz and Bill Nierenberg—who regularly injected themselves into the public debate about contentious scientific issues, positioning themselves as skeptics, their views gaining traction because the media gives them equal time out of a sense of fairness.

Singer told CBC's The Fifth Estate in 2006 that he stood by the position that the EPA had "cooked the data" to show that second-hand smoke causes lung cancer.

"[62] In 2006, the CBC's Fifth Estate named Singer as one of a small group of scientists who have created what the documentary called a stand-off that is undermining the political response to global warming.

[63] Singer argues there is no evidence that the increases in carbon dioxide produced by humans cause global warming, and that if temperatures do rise it will be good for humankind.

He predicted disastrous economic damage from any restrictions on fossil fuel use, and argued that the natural world and its weather patterns are complex and ill-understood, and that little is known about the dynamics of heat exchange from the oceans to the atmosphere, or the role of clouds.

[70] Rachel White Scheuering writes that, when SEPP began, it was affiliated with the Washington Institute for Values in Public Policy, a think tank founded by Unification Church leader Sun Myung Moon.

[9] In August 2007 Newsweek reported that in April 1998 a dozen people from what it called "the denial machine" met at the American Petroleum Institute's Washington headquarters.

Congresswoman Lynn Rivers questioned Singer's credibility during a congressional hearing in 1995, saying he had not been able to publish anything in a peer-reviewed scientific journal for the previous 15 years, except for one technical comment.

He wrote: "the Summary does not even mention the existence of 18 years of weather satellite data that show a slight global cooling trend, contradicting all theoretical models of climate warming.

[79] Singer prepared an NIPCC report called "Nature, Not Human Activity, Rules the Climate," published in March 2008 by the Heartland Institute, a conservative think tank.

[80] As with previous NIPCC reports, environmentalists criticized it upon its publication; for example, David Suzuki wrote that it was "full of long-discredited claims, including that carbon dioxide emissions are good because they stimulate life".

[83] In December 2009, after the Climatic Research Unit email controversy, Singer wrote an opinion piece for Reuters in which he claimed the scientists had misused peer review, pressured editors to prevent publication of alternative views, and smeared opponents.