Ever since Pythagoras suggested more than 2,000 years ago that the earth was spherical rather than flat, and Aristotle provided the first known evidence for that, science has been continually expanding and advancing. In Pythagoras’s day, the majority of people were illiterate, and to them, if the earth looked flat, it was flat. A tiny minority of people, usually with little education, still think Pythagoras and Aristotle were con-artists.
Although science has also had its reversals along the way, the advance of science, more than anything else, has led to improved health, fuller employment, better education, higher living standards, and longer life expectancy for more people. Science has created a better world, and knocking science and scientists should not be undertaken lightly. But science is still an evolving world, a world that occasionally, and understandably, takes a wrong turn.
Perhaps one of the more spectacular reversals of science was the theory of Bondi, Gold and Hoyle who claimed that the Universe was in a ‘steady-state with no beginning,’ when it was superseded by the ‘big bang.’ In geography, the Island of California was later found to be part of the continent of North America. Until the 20th-century scientists believed that the earth was expanding, until the discovery of plate tectonics. Also in the world of science, astrology has been replaced by astronomy. Other obsolete branches of science include alchemy and numerology, both now regarded as pseudoscience, along with astrology. Witch doctors have mostly been replaced by registered GP’s.
Although observations of weather and its patterns can be traced back 5,000 years to India, it did not really evolve as a science until the 1800’s when modern meteorology brought together many earlier laws of physics and the use of early primitive measuring devices. and continued to evolve rapidly during the 20th century. The earliest reliable world weather statistics are little more than a hundred years old.
In 1938, Guy Stewart Callendar (1898-1964), a British seam engineer was the first to propose that global warming could occur due to carbon dioxide emissions. It was known as the Callendar effect and he considered that the warming would be a good thing because it would stop the glaciers returning to England. Callendar may have been a visionary, but not a scientist. Forty years later, environmentalists would take up his cause, but not in the name of goodness. After having previously scared the world with predictions of nuclear winter, the environmentalists predicted a meteorologically doomsday of catastrophic proportions.
It was scary stuff. Greenpeace came on board along with governments. Political parties were founded to fight global warming and scientists queued up for research funds. Within a short time, most of the world’s population were convinced that the threat was real, and it was considered inappropriate to criticize the ‘experts.’ Many distinguished climate scientists and meteorologists who took a different view lost their jobs. Some argued that global warming was not settled science. Others said the theory was plain wrong. Still, others said that global warming would actually have a beneficial effect on the world, which was what Callendar had proposed years earlier.
This writer has been asked by New Zealand Skeptics to provide a list of dissenting scientists, and that list (from Wikipedia) follows. The good work of NZ Skeptics is acknowledged. They generally support science over fallacies and conspiracy theories, but on the question of climate change, a closed-mind stance is detected with regard to a ‘science’ that is anything but settled.
List of scientists opposing the mainstream scientific assessment of global warming
From Wikipedia, the free encyclopedia
This is a list of scientists who have made statements that conflict with the scientific consensus on global warming as summarized by the Intergovernmental Panel on Climate Change and endorsed by other scientific bodies.
The scientific consensus is that the global average surface temperature has risen over the last century. The scientific consensus and scientific opinion on climate change were summarized in the 2001 Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). The main conclusions on global warming at that time were as follows:
- The global average surface temperature has risen 0.6 ± 0.2 °C since the late 19th century, and 0.17 °C per decade in the last 30 years.
- “There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities“, in particular emissions of the greenhouse gases carbon dioxide and methane.
- If greenhouse gas emissions continue the warming will also continue, with temperatures projected to increase by 1.4 °C to 5.8 °C between 1990 and 2100.[A] Accompanying this temperature increase will be increased in some types of extreme weather and a projected sea-level rise. The balance of impacts of global warming become significantly negative at larger values of warming.
These findings are recognized by the national science academies of all the major industrialized nations.
There have been several efforts to compile lists of dissenting scientists, including a 2008 US senate minority report, the Oregon Petition, and a 2007 list by the Heartland Institute, all three of which have been criticized on a number of grounds.
For the purpose of this list, a “scientist” is defined as an individual who has published at least one peer-reviewed article in the broad field of natural sciences, although not necessarily in a field relevant to climatology. Since the publication of the IPCC Third Assessment Report, each has made a clear statement in his or her own words (as opposed to the name being found on a petition, etc.) disagreeing with one or more of the report’s three main conclusions. Their views on climate change are usually described in more detail in their biographical articles. Few of the statements in the references for this list are part of the peer-reviewed scientific literature; most are from other sources such as interviews, opinion pieces, online essays and presentations.
NB: Only scientists who have their own Wikipedia article may be included in the list.
Scientists questioning the accuracy of IPCC climate projections
These scientists have said that it is not possible to project global climate accurately enough to justify the ranges projected for temperature and sea-level rise over the next century. They may not conclude specifically that the current IPCC projections are either too high or too low, but that the projections are likely to be inaccurate due to inadequacies of current global climate modelling.
- David Bellamy, botanist.
- Lennart Bengtsson, meteorologist, Reading University.[unreliable source?]
- Piers Corbyn, owner of the business WeatherAction which makes weather forecasts.
- Judith Curry, Professor and former chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology.
- Freeman Dyson, professor emeritus of the School of Natural Sciences, Institute for Advanced Study; Fellow of the Royal Society 
- Steven E. Koonin, theoretical physicist and director of the Center for Urban Science and Progress at New York University
- Richard Lindzen, Alfred P. Sloan emeritus professor of atmospheric science at the Massachusetts Institute of Technology and member of the National Academy of Sciences
- Craig Loehle, ecologist and chief scientist at the National Council for Air and Stream Improvement.
- Patrick Moore, former president of Greenpeace Canada
- Nils-Axel Mörner, retired head of the Paleogeophysics and Geodynamics Department at Stockholm University, former chairman of the INQUA Commission on Sea Level Changes and Coastal Evolution (1999–2003)
- Garth Paltridge, retired chief research scientist, CSIRO Division of Atmospheric Research and retired director of the Institute of the Antarctic Cooperative Research Centre, visiting fellow Australian National University
- Denis Rancourt, former professor of physics at The University of Ottawa, a research scientist in condensed matter physics, and in environmental and soil science
- Harrison Schmitt, geologist, Apollo 17 Astronaut, former U.S. Senator.
- Peter Stilbs, professor of physical chemistry at Royal Institute of Technology, Stockholm
- Philip Stott, professor emeritus of biogeography at the University of London
- Hendrik Tennekes, retired director of research, Royal Netherlands Meteorological Institute 
- Anastasios Tsonis, distinguished professor at the University of Wisconsin-Milwaukee
- Fritz Vahrenholt, German politician and energy executive with a doctorate in chemistry
Scientists arguing that global warming is primarily caused by natural processes
Graph showing the ability with which a global climate model is able to reconstruct the historical temperature record, and the degree to which those temperature changes can be decomposed into various forcing factors. It shows the effects of five forcing factors: greenhouse gases, man-made sulfate emissions, solar variability, ozone changes, and volcanic emissions.
These scientists have said that the observed warming is more likely to be attributable to natural causes than to human activities. Their views on climate change are usually described in more detail in their biographical articles.
- Khabibullo Abdusamatov, an astrophysicist at Pulkovo Observatory of the Russian Academy of Sciences
- Sallie Baliunas, retired astrophysicist, Harvard-Smithsonian Center for Astrophysics
- Timothy Ball, historical climatologist, and retired professor of geography at the University of Winnipeg
- Robert M. Carter, former head of the school of earth sciences at James Cook University
- Ian Clark, hydrogeologist, professor, Department of Earth Sciences, University of Ottawa
- Chris de Freitas, associate professor, School of Geography, Geology and Environmental Science, University of Auckland
- David Douglass, solid-state physicist, professor, Department of Physics and Astronomy, University of Rochester
- Don Easterbrook, emeritus professor of geology, Western Washington University
- William M. Gray, professor emeritus and head of the Tropical Meteorology Project, Department of Atmospheric Science, Colorado State University
- William Happer, a physicist specializing in optics and spectroscopy; emeritus professor, Princeton University
- Ole Humlum, professor of geology at the University of Oslo
- Wibjörn Karlén, professor emeritus of geography and geology at the University of Stockholm.
- William Kininmonth, meteorologist, former Australian delegate to World Meteorological Organization Commission for Climatology
- David Legates, associate professor of geography and director of the Center for Climatic Research, University of Delaware
- Anthony Lupo, professor of atmospheric science at the University of Missouri
- Tad Murty, oceanographer; adjunct professor, Departments of Civil Engineering and Earth Sciences, University of Ottawa
- Tim Patterson, paleoclimatologist and professor of geology at Carleton University in Canada.
- Ian Plimer, professor emeritus of mining geology, the University of Adelaide.
- Arthur B. Robinson, American politician, biochemist and former faculty member at the University of California, San Diego
- Murry Salby, atmospheric scientist, a former professor at Macquarie University and University of Colorado
- Nicola Scafetta, a research scientist in the physics department at Duke University
- Tom Segalstad, geologist; associate professor at University of Oslo
- Nir Shaviv, professor of physics focusing on astrophysics and climate science at the Hebrew University of Jerusalem
- Fred Singer, professor emeritus of environmental sciences at the University of Virginia
- Willie Soon, astrophysicist, Harvard-Smithsonian Center for Astrophysics
- Roy Spencer, meteorologist; principal research scientist, the University of Alabama in Huntsville
- Henrik Svensmark, physicist, Danish National Space Center
- George H. Taylor, retired director of the Oregon Climate Service at Oregon State University
- Jan Veizer, environmental geochemist, professor emeritus from the University of Ottawa
Scientists arguing that the cause of global warming is unknown
These scientists have said that no principal cause can be ascribed to the observed rising temperatures, whether man-made or natural.
- Syun-Ichi Akasofu, a retired professor of geophysics and founding director of the International Arctic Research Center of the University of Alaska Fairbanks.
- Claude Allègre, French politician; geochemist, emeritus professor at Institute of Geophysics (Paris).
- Robert Balling, a professor of geography at Arizona State University.
- Pål Brekke, solar astrophysicist, senior advisor Norwegian Space Centre.
- John Christy, professor of atmospheric science and director of the Earth System Science Center at the University of Alabama in Huntsville, a contributor to several IPCC reports.
- Petr Chylek, space and remote sensing sciences researcher, Los Alamos National Laboratory.
- David Deming, a geology professor at the University of Oklahoma.
- Ivar Giaever, professor emeritus of physics at the Rensselaer Polytechnic Institute and a Nobel laureate.
- Vincent R. Gray, New Zealand physical chemist with expertise in coal ashes
- Keith E. Idso, botanist, former adjunct professor of biology at Maricopa County Community College District and the vice president of the Center for the Study of Carbon Dioxide and Global Change
- Antonino Zichichi, emeritus professor of nuclear physics at the University of Bologna and president of the World Federation of Scientists.
Scientists arguing that global warming will have few negative consequences
These scientists have said that projected rising temperatures will be of little impact or a net positive for society or the environment.
- Indur M. Goklany, science and technology policy analyst for the United States Department of the Interior
- Craig D. Idso, faculty researcher, Office of Climatology, Arizona State University and founder of the Center for the Study of Carbon Dioxide and Global Change 
- Sherwood B. Idso, former research physicist, USDA Water Conservation Laboratory, and adjunct professor, Arizona State University
- Patrick Michaels, a senior fellow at the Cato Institute and retired research professor of environmental science at the University of Virginia
This section includes deceased scientists who would otherwise be listed in the prior sections.
- August H. “Augie” Auer Jr. (1940–2007), retired New Zealand MetService meteorologist and past professor of atmospheric science at the University of Wyoming
- Reid Bryson (1920–2008), Emeritus Professor of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, said in a 2007 magazine interview that he believed global warming was primarily caused by natural processes:
- Robert Jastrow (1925–2008), American astronomer, physicist and cosmologist. He was a leading NASA scientist. Together with Fred Seitz and William Nierenberg, he established the George C. Marshall Institute to counter the scientists who were arguing against Reagan’s Starwars Initiative, arguing for equal time in the media. This institute later took the view that tobacco was having no effect, that acid rain was not caused by human emissions, that ozone was not depleted by CFCs, that pesticides were not environmentally harmful and it was also critical of the consensus view of anthropogenic global warming. Jastrow acknowledged the Earth was experiencing a warming trend but claimed that the cause was likely to be natural variation.
- Harold (“Hal”) Warren Lewis (1923-2011), Emeritus Professor of Physics and former department chairman at the University of California, Santa Barbara. In 2010, after 67 years of membership, Lewis resigned from the American Physical Society, writing in a letter about the “corruption” from “the money flood” of government grants.
- Frederick Seitz (1911–2008), a solid-state physicist and former president of the National Academy of Sciences and co-founder of the George C. Marshall Institute in 1984.