Principia Scientific International

Principia Scientific International


Principia Scientific International (PSI) is an organisation based in the United Kingdom which promotes fringe views and material to claim that carbon dioxide is not a greenhouse gas.

PSI claims it provides its members with a “reliable port of call to ascertain the facts behind the news stories to better judge whether information being presented by third parties is accurate information and reflects a balanced view of all facets of the subject.” 

The PSI website says the organisation is “for everyone who supports the traditions [sic] scientific method against the rise of sinister and secretive government funded 'post normal science'.”

The group claims on its website to be a “not-for-profit community interest subsidiary of PSI Acumen Ltd.” 

PSI Acumen was registered with Companies House in the UK in March 2013 as a private company, with an address in Battersea Park Road, London. In July 2013, the business address of PSI Acumen was changed to an address in Great Yarmouth, Norfolk, which is the same as the home address of John O'Sullivan, the organisation's founder and chief executive officer.

The two named directors were John O'Sullivan, of the UK, and a Walter James O'Brien, with a US address listed in Fargo, North Dakota. Emails published by climate sceptic blogger Pete Ridley suggest that Walter James O'Brien no longer has any connection to the PSI Acument company.

Stance on Climate Change

PSI regularly publishes commentary which claims that carbon dioxide is not a greenhouse gas and that it could actually cool the planet. For example, in an article published in November 2013, “PSI Staff” wrote:

Scientists at Principia Scientific International (PSI), who peer-reviewed Nahle's paper, are currently advising colleagues that the most reliable data available now confirms that CO2 is shown to act as a coolant in earth's climate. As such, the notion of a so-called 'greenhouse gas' warming effect may be regarded as refuted, while environmental measures by governments and individuals to reduce “carbon emissions”  to combat climate change are, in turn, rendered pointless. 

In 2013, PSI also began to promote unfounded claims that wind turbines make people sick and that childhood vaccines were “one of the largest most evil lies in history.”


PSI is described on its website as being part of PSI Acumen Ltd — a private company registered in the UK with two named directors. No accounts have been filed for the company.

PSI asks for donations on its website and also seeks members. Membership is free, but PSI asks people applying to make a voluntary donation.

Key People

John O'Sullivan - chief executive officer

Terry (Terri) Jackson - recruitment officer

Tim Ball - founder member and former chairman

John Sanderson - chairman

Dr Pierre R. Latour - vice chairman (north)

John N Elliston - vice chairman (south)

Hans Schreuder - chief financial officer


PSI maintains a “selected” list of members and “friends/supporters” on its website. Among them are:

Climate sceptic blogger Pete Ridley has claimed that several people previously listed as members of PSI have withdrawn.

An entry on the PSI website from May 2013 said that Russian physicist Habibullo Ismailovich Abdussamatov had “resigned,” but a list accessed by DeSmogBlog in December 2013 still had Dr Abdussamatov as a member.


July, 2013

PSI offers to host a sacked Australian climate sceptic professor, Dr Murry Salby, for speaking engagements in London. 

PSI says it has secured funding from publisher Stairway Press for the trip. A later website entry made during Salby's trip says that Ken Coffman, of Stairway Press, had donated a four figure sum to cover expenses for the Salby trip, which conisted of two speeches in London, one in Cambridgeshire, and two more in Edinburgh.

A speech given in the UK parliament was sponsored by British Labour Party MP Graham Stringer and attended by PSI membership officer Terri Jackson. A speech given in the Scottish Parliament was hosted by Scottish Conservative Party MSP Murdo Fraser.

May, 2013

In April and May 2013, PSI chief executive John O'Sullivan became emboriled in a public row with prominent climate science denier Lord Christopher Monckton.

O'Sullivan wrote a letter to Monckton, saying he should not accept the basic physics showing carbon dioxide was a “greenhouse gas.”

O'Sullivan wrote: “Greenhouse gas predictions (and thus the science) are shown to be wrong.”

Monckton wrote back, describing O'Sullivan as “confused and scientifically illiterate.” O'Sullivan responded, saying Monckton's “belief in the greenhouse gas 'theory' is premised on misunderstandings, misrepresentations and half truths.”

May, 2013

The Australian newspaper's environment editor Graham Lloyd cites Principia Scientific International in a news article suggesting there was a debate among scientists about the possibility of a coming ice age. The story cited an interview with Dr Habibullo Ismailovich Abdussamatov published on the PSI website. The interview had actually been published more than five years earlier on the Canadian National Post website.

Dr Abdussamatov “resigned” his membership of PSI soon after.

January, 2011

John O'Sullivan launches a crowd-funding campaign to raise cash for PSI.  As of December 2013, the campaign had raised just $450 of its stated $15,000 goal. The plea for funds said:

Give generously for this good cause knowing you can help to counter the creeping folly of misguided societies that appear to have been commandeered by political lobbyists and shills serving self-interested corporations or misguided national governments.

November 2010

Accoding to the PSI website, the organisation was originally conceived after several authors came together to write the book “Slaying the Sky Dragon: Death of the Greenhouse Gas Theory.” The book, published in November 2010 online and then in print by Stairway Press in January 2011, claims to be the “only full volume refutation of the greenhouse gas theory of man-made global warming.”

Authors listed were John O'Sullivan, Hans Schreuder, Claes Johnson, Tim Ball, Charles Anderson, Alan Siddons, Joseph A. Olson and Martin Hertzberg.

Related Organizations

PSI appears to have no official affiliations with any other organisations.