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Barry Brill: The Taxonomy Of Climate Opinion

Barry Brill, Watts Up With That

For 20 years or more, there has been a clear gap between the ‘most likely’ positions held by mainstream (3°C) and skeptic (1°C) groups. But the WG1 report of AR5 largely bridges that gap. This merging could be an uncomfortable time for both parties.


I’ve had it with tax-funded over-educated fools like Lewanadowsky presuming to categorize me on the basis of his own delusions. And I don’t appreciate Cook & co locating people in a 3% minority on the basis of infantile spin-driven surveys.

The debate over climate change is not, and never has been, divided into two monochromatic tribes who have been brainwashed into unanimity . There are as many different opinions are there are participants in the discussion. (“quot homines tot sententiae” as Christopher Monckton might say).

For those who insist upon a tidy taxonomy, I offer the following first draft:


Whilst there are quite large numbers of people who are unconvinced that human activities can have any material effect on global average temperatures, the “Principia Scientific International” consortium, aka “Slayers of the Sky Dragon” strongly reject the enhanced greenhouse effect theory (AGW) which underpins mainstream climate science.

I’ve appropriated the term “Skeptics” to cover the broad tent of opinion which accepts that there has been some global warming since the LIA, to which human activities would have made some (probably trivial) contribution, through increased GHG emissions.

There is a collective view that average temperatures would increase by about 1°C if atmospheric CO2 concentration were to double from 280ppm (pre-1950), but a wide disparity of views regarding the sign and amplitude of net feedbacks. Most believe warming will be beneficial in the foreseeable future and none believes it poses a significant threat.

Lukewarmers are a subset of skeptics, who believe net feedbacks from warming to be slightly positive.

The ‘Breakthrough’ label is borrowed from the “Breakthrough Institute” but covers all who favour (limited) Government action other than emission-mitigation. This grouping broadly accepts IPCC temperature projections but believes the impacts have been exaggerated. They consider that an element of future threat arises and would combat this by promoting Government-sponsored breakthroughs in energy technology.

The IPCC, which presents “official” or “governmental” views, covers the broad tent which believes AGW is dangerous and should be combated by expensive emission-reduction programs. Its main controversial drivers are a belief in large net feedbacks (high ECS) and the use of unlikely scenarios to supply worst-case impacts.

Alarmists believe that irreversible and abrupt climate change is much more likely than indicated by Table 12.4 of AR5WG1, re-interpret the SREX report, and blame AGW for numerous other current or potential ills. They see climate change as a great moral challenge and believe decarbonization of the global economy is inevitable. This group (along with activists) controls a host of spin levers and secures a hugely disproportionate share of mainstream media attention.

Activists are usually members of groups which make a living from public donations and whose success depends upon maximising public fears. A sizeable proportion are malthusians or doomsayers who are philosophically opposed to economic growth/capitalism. Other members are lobbyists for commercial interests such as suppliers of renewables, carbon traders, consultants, gas producers, re-insurers, foresters and (until recently) bankers. They ignore all scenarios except the most extreme and are now adherents of the new RCP8.5.

The futility of consensus-seekers such as Cook and Oreskes is clear from the fact that the majority of almost all groups accept some 20th century warming (although now aware of “the pause”) as well as AGW theory. The dividing lines lie elsewhere.

The most visible division between climate opinion groups is the value they ascribe to equilibrium climate sensitivity (ECS). This, along with the associated transient climate response (TCR), is the key determinant of future temperatures and the extent of future threats, if any.

Full analysis