BY CHRIS MORRISON
Activist climate scientists, journalists and Net Zero-obsessed politicians are in shock following an official admission from the Intergovernmental Panel on Climate Change (IPCC) that a set of key assumptions promoting a climate ‘crisis’ since 2011 are “implausible”. The notorious set of always-improbable RCP8.5 ‘pathway’ assumptions which fed into computer models trying to measure an unmeasurable climate are no more. Since around 2011, these ‘business as usual’ assumptions have produced outlandish claims of future climate catastrophe which have been lapped up by lap dog journalists and politicians. The influential writer Roger Pielke Jr. called RCP8.5’s demise, “the most significant development in climate research in decades”.
Others might observe that we have not heard the last of RCP8.5. Its gross misuse is likely to be given a starring, central role when the history of the Great Climate and Net Zero Scam comes to be written.
Pielke lays it out clearly what has happened:
What matters today is that the group with official responsibility for developing climate scenarios for the IPCC and broader research community has now admitted that the scenarios that have dominated climate research, assessment and policy during the past two cycles of the IPCC assessment process are implausible. They describe impossible futures.
He goes on to note that tens of thousands of research papers have been and continue to be published using these scenarios. In addition, a similar number of media headlines have “amplified their findings”, while governments and international organisations have built these implausible scenarios into policy and regulation.
It cannot be over-emphasised how important this finding of implausibility is. It means that almost every fearmongering mainstream media climate headline and story that has been written over the last 15 years is junk. Of course it also explains why a growing band of sceptical commentators have refused to accept the political concept of ‘settled’ science and have engaged in widespread debunking. Shooting fish in a barrel is one way of describing this work. At times, with just a modicum of investigative scepticism, the stories can be seen as little more than an insult to average human intelligence.
When the RCP8.5 assumptions are loaded into computer models, they run politically-convenient red hot suggestions that the temperature in 2100 will rise by about 4°C from a 1850-1900 baseline – in other words, a rise of nearly 3°C in the next 80 years. Only the most deranged eco loons will claim such large short-term rises out loud, so the activist scientists quietly loaded garbage assumptions into their computers to arrive at their garbage-out Armageddon scares. The writing was on the wall for RCP8.5 last year when President Trump’s executive order titled ‘Restoring Gold Standard Science’ effectively banned the use of RCP8.5 for scientists on the United States federal payroll. It also noted one of the unrealistic RCP8.5 assumptions driving deliberate climate psychosis to be that end-of-century coal use will exceed estimates of recoverable reserves.
At the time, the climate researcher Zeke Hausfather dismissed the Trump Administration’s claims about RCP8.5 by stating that the research community had moved on. But Pielke has taken issue with this ‘nothing to see here’ claim. He states that from 2018 to 2021, Google Scholar reported 17,000 articles published using RCP8.5 compared with 16,900 in the next three year period. “Some shift,” he observed.
Again, those using less charitable words might note that the ultimate climate crackpipe has proved difficult to put down. A long and painful process of rehabilitation now seems likely.
RCP8.5 assumed high emissions of carbon dioxide leading to a radiative forcing (extra energy trapped in the Earth’s atmosphere) of 8.5 watts per square metre. The new pathways act as agreed guidelines for computer models that will then provide information for the IPCC’s forthcoming seventh assessment reports. Pielke has run the figures and estimates that the new high scenario will produce 3°C of warming by 2100, a reduction from 3.9°C but still an improbable 1.8°C rise in less than 80 years. Of course these new scenarios are just assumptions anyway, and on past observational evidence of atmospheric gas ‘saturation’ stretching back 600 million years they still grossly overestimate the warming effect of a few trace gases. Much higher levels of CO2 were the norm in the past in a complex, chaotic, non-linear and ultimately unmeasurable atmosphere. Climate scare bingo based on sightings in mainstream media of ‘scientists say’ will likely continue as long as an audience, albeit a diminishing one, still believes in the politicised agitprop of a ‘climate emergency’.
It's official: the world's climate policy was built upon "implausible" climate model scenarios, now dumped.
🗑️A decade of "doomer" research of "worst-case scenarios" … never happened.
🚨RCP8.5 is Officially Dead – by @RogerPielkeJr https://t.co/ZOMdXL5NMW pic.twitter.com/yuQMssu85W
— Ryan Maue (@RyanWeather) April 29, 2026
