Acclaimed Australian journalist and climate change researcher Peter Clack has challenged the scientific and political weight placed on the concept of “global average temperature,” arguing that the metric is fundamentally flawed yet central to some of the most expensive policy decisions in modern history.
In a detailed critique shared on social media, Clack said the global average temperature—frequently cited as the key indicator of climate change—is not a direct measurement but a constructed estimate derived from models, adjustments and assumptions.
He argued that for decades the figure has been used as a blunt instrument to justify net zero policies, which he described as potentially the most costly economic experiment ever undertaken, already involving trillions of dollars in public and private spending.
Clack questioned how a single planetary temperature can be calculated with confidence, noting that it relies on a patchwork of land-based weather stations with uneven geographic coverage, particularly before 1950. Many stations, he said, have been relocated over time from rural settings to urban or airport environments, introducing possible distortions such as urban heat island effects. Large gaps in historical data—especially over oceans and in the Southern Hemisphere—are filled using computer algorithms, while raw readings are routinely adjusted through processes that are complex and often opaque.
He noted that multiple global temperature datasets produced by organisations such as NASA, NOAA, the UK Met Office, Berkeley Earth and the EU’s Copernicus programme use differing methodologies and can diverge on details, even if they broadly agree on a warming trend since the late 19th century. In Clack’s view, this makes the global average temperature less a thermometer reading and more a modelled reconstruction.
Clack also challenged claims of an unfolding climate emergency, pointing out that the observed warming since the pre-industrial period is commonly estimated at around 1.2 to 1.5 degrees Celsius. He suggested this may partly reflect natural climatic recovery from the Little Ice Age rather than unprecedented human-driven change. Over geological timescales, he said, Earth has often been significantly warmer than today while supporting abundant life.
Citing assessments from bodies such as NOAA and the IPCC, Clack argued that there is no clear long-term increase in global hurricane frequency, that severe heatwaves occurred well before modern industrial emissions, and that global polar bear numbers are stable or higher than in the mid-20th century, despite regional challenges.
He warned that future climate impacts are often projected decades ahead—far enough away to avoid immediate verification—while critics of prevailing narratives are increasingly labelled as spreading disinformation. According to Clack, this environment discourages legitimate scientific debate while benefiting corporate and international interests involved in climate policy and renewable energy transitions.
“True science depends on questioning assumptions,” Clack said, arguing that basing trillion-dollar policies on what he described as an uncertain and potentially illusory metric risks significant economic and social harm with unclear benefits.
His comments add to ongoing international debate over how climate data is measured, communicated and translated into policy, and whether the tools used to guide decision-making are as robust as their consequences demand.
For forty years, we’ve been sold a single magical number: the ‘global average temperature’. This figure has become the barometer for countless policy failures, justified by appeals to climate alarm and dismissive attitudes rooted in historical inequities. Yet this number is… pic.twitter.com/CTIik390Wl
— Peter Clack (@PeterDClack) December 13, 2025
Even a 5 year old could figure out the maths doesnt add up. Normally a closed box of modelled data that we wont share or tell you how it was produced. We delete the original information so you can’t use that and only our modelled values.
Once it makes it to politics you know there will be zero logic applied.
Same narrative is an old narrative, learn from history and you will see that older civilisations eg Egyptians etc were promoting similar messages “from the gods” to reduce their population (usually death cults & offerings) or else Earth will die etc etc.
And yet these are the same demonic expressions described in Revelation because it promotes harm to life – and the sole thing Earth (and only Earth) supports is Life. Anything to the contrary is hostile to life and not in humanities interest.
That includes tampering with food, farming, chemical, water & waste management, ecosystems & environment, just about anything that involves our entire way of living on Earth
There must be hundreds, at least, of analyses preceding this one by Peter Clack, saying the same thing. From right back at the start of the whole manufactured panic. I remember Dr Vincent Gray, who I knew, including this in his numerous criticisms.
Even IF there is an “average” temperature that is “rising”, there is no valid automatic assumption that this is a bad thing; because an increase in the low-end temperatures will put this average up without meaning in the least that HEAT per se is going to cause problems. Who cares about a midwinter being slightly less cold, or 3am being slightly less cold than it used to be? This whole thing is riddled with flawed assumptions