People spend astonishing amounts of time arguing about simulated temperature data when a healthy dose of common sense would get them much farther.
The reality is rather simple. We possess more or less reliable temperature measurements for significant portions of the globe going back to roughly the end of the Second World War. Before that, the picture becomes increasingly patchy. The farther back one travels, the fewer measurements exist, the fewer locations are covered, and the larger the uncertainty attached to every number.
Beyond a couple of centuries, the situation changes entirely.
At that point we are no longer talking about measurements at all.
We are talking about conjecture.
Assumptions.
Interpretations.
Educated guesses—and quite often spectacularly uneducated ones.
When scientists drill an ice core, they do not extract temperature. They extract ice and then apply a theory to infer what the temperature may have been.
When they study tree rings, they do not discover temperature. They discover rings and then apply another theory to infer temperature.
When they examine sediments, pollen deposits, cave formations, shells, or any of the countless other proxies, they are not measuring temperature directly. They are measuring something else entirely and then constructing a model intended to translate that observation into temperature.
The entire process rests upon layers of assumptions stacked atop one another like a tower of increasingly ambitious guesses.
And those guesses have an unfortunate habit of being wrong.
Frequently wrong.
Spectacularly wrong.
Wrong often enough that I would hesitate to use them to predict next week’s lottery numbers even if somebody handed me the ticket for free.
Yet somehow we are expected to believe that these same methods can reconstruct temperatures centuries or even millennia ago with precision down to tenths of a degree.
Really?
That is the claim?
Humanity struggles to forecast next month’s weather accurately, yet we are supposedly capable of determining whether a hillside in central Europe was 0.4 degrees warmer or cooler in the year 732 AD.
One should perhaps admire the confidence.
What strikes me as far more convincing are not the models but the fingerprints left behind by reality itself.
Mountain passes long sealed beneath ice suddenly reveal evidence of ancient human activity. Settlements emerge from glaciers that supposedly covered them for countless generations. Archaeological remains appear where no human community could have existed under permanent ice.
The Romans left written records discussing viticulture in regions of northern England where modern commentators often speak as if grapes should barely survive.
In Greenland, retreating ice has exposed ancient birch root systems buried beneath what many confidently described as eternal ice.
Eternal, it turns out, is often a shorter period than advertised.
These are not simulations.
They are not computer models.
They are not proxy chains linked together through statistical gymnastics.
They are physical remnants of people who actually lived in those places.
People who farmed there.
Traded there.
Built there.
Raised families there.
One does not establish vineyards in climates fundamentally unsuitable for vineyards.
One does not grow forests beneath permanent ice sheets.
One does not construct settlements in locations that are eternally frozen and uninhabitable.
The evidence is sitting in plain sight.
A warmer past is not a radical proposition. It is written directly into the landscape.
Repeatedly.
Consistently.
Across continents.
Across cultures.
Across time.
The truly remarkable thing is not that warmer periods existed. Human beings have known that for a very long time.
The remarkable thing is the modern obsession with replacing obvious historical evidence with increasingly elaborate statistical storytelling.
We have become a civilization so enamored with models that we sometimes forget to look out the window.
The past leaves clues everywhere.
It leaves them in the soil.
In abandoned settlements.
In historical records.
In forests.
In glaciers.
In forgotten trade routes and long-lost harvests.
One does not need a supercomputer to notice them.
One merely needs the courage to trust observation before simulation.
The funny thing is that we never truly needed the guesses in the first place.
Reality had already left us plenty of evidence.
We simply stopped paying attention.
https://wattsupwiththat.com/2026/06/06/glaciers-have-advanced-and-retreated-before/