Principia Scientific International (PSI) – Bias and Credibility

Principia Scientific International - Conspiracy - Right Bias - Fake News - Not CrediblePrincipia Scientific International - Pseudoscience - Right Bias - Fake News - Not Credible

Factual Reporting: Low - Not Credible - Not Reliable - Fake News - Bias


Sources in the Conspiracy-Pseudoscience category may publish unverifiable information that is not always supported by evidence. These sources may be untrustworthy for credible/verifiable information; therefore, fact-checking and further investigation is recommended on a per article basis when obtaining information from these sources. See all Conspiracy-Pseudoscience sources.

  • Overall, we rate Principia Scientific International (PSI) a strong conspiracy and Pseudoscience website promoting anti-vaccine propaganda and frequent misinformation regarding climate change.

Detailed Report

Bias Rating: RIGHT
Factual Reporting: LOW
Country: United Kingdom
MBFC’s Country Freedom Rating: MOSTLY FREE
Media Type: Website
Traffic/Popularity: Minimal Traffic
MBFC Credibility Rating: LOW CREDIBILITY


Founded in 2010, Principia Scientific International (PSI) is an organization based in the United Kingdom which promotes fringe views and material to claim that carbon dioxide is not a greenhouse gas. PSI has also published a book titled “Slaying the Sky Dragon: Death of the Greenhouse Gas Theory.” According to their about page, “Principia Scientific International (PSI) is the only independent science body in the world that is legally incorporated to champion the traditional scientific method, as set out in the work of Karl Popper.” The founder and current CEO of Principia Scientific International are John O’Sullivan. For more background information on John O’Sullivan, see here and here.

In November 2019, the PSI Facebook page was banned: Facebook Bans Principia Scientific International Without Explanation. As of 3/13/2020, it does not appear to have been restored.

Read our profile on UK’s government and media.

Funded by / Ownership

Principia Scientific does not list names regarding ownership; however, they state, “Since June 2017 Principia Scientific International is legally registered in the UK as a company incorporated for charitable purposes. We are a ‘Community Interest Company’ overseen and regulated by Companies House.” Revenue is generated through donations.

Analysis / Bias

In review, PSI claims as their number one mission to “be the leading independent voice for principled science as per the Traditional Scientific Method (TSM),” which scientific philosopher Karl Popper championed. Popper’s general philosophy is that scientists should actively attempt to falsify a hypothesis rather than prove it. The right-leaning American Council on Science and Health has written why this method may not be the best.

Principia Scientific covers many science areas; however, most stories center around climate change (global warming) and vaccinations. When it comes to climate change, PSI disagrees CO2 is the primary driver of global warming (Pseudoscience). However, according to its Fifth Assessment Report, the Intergovernmental Panel on Climate Change, a group of 1,300 independent scientific experts from countries all over the world, concluded: “there’s a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane, and nitrous oxide have caused much of the observed increase in Earth’s temperatures over the past 50 years.”

Further, the National Center for Education states that human-influenced climate change deniers promote a form of pseudoscience: “these deniers attempt to sabotage science education with fringe ideas, pseudoscience, and outright lies.” Finally, according to the Stanford Encyclopedia of Philosophy on Science and Pseudoscience, “Philosophers and other theoreticians of science differ widely in their views on what science is. Nevertheless, there is virtual unanimity in the community of knowledge disciplines on most particular issues of demarcation. There is a widespread agreement, for instance, that creationism, astrology, homeopathy, Kirlian photography, dowsing, ufology, ancient astronaut theory, Holocaust denialism, Velikovskian catastrophism, and climate change denialism are pseudosciences.”

PSI takes vaccinations to another level through promoting conspiracies with stories like this: Doctors Who Discovered Cancer Enzymes In Vaccines All Murdered! (Conspiracy). This story is sourced to Neon Nettle, which we rate as a quackery-level pseudoscience and tin foil hat conspiracy website. This story is listed as a Pants on Fire claim by Politifact.

In general, the information found on this website falls along the right biased spectrum of science. Although this source claims to champion the traditional scientific method, they promote human-influenced climate change denial on the website, which further promotes climate change as a grand conspiracy with scientists “fudging” data.

Failed Fact Checks

Overall, we rate Principia Scientific International (PSI) a strong conspiracy and Pseudoscience website promoting anti-vaccine propaganda and frequent misinformation regarding climate change. (D. Van Zandt 7/18/2017) Updated (02/16/2022)

Source: or

This poll is for entertainment purposes and does not change our overall rating.

Last Updated on August 25, 2023 by Media Bias Fact Check

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