Can We Really Trust the Global Temperature Record
How erased heatwaves, adjusted data, and fragile assumptions underpin the climate crisis narrative
Almost every claim about a looming climate crisis rests on a single foundational assumption. We are told that scientists have a precise and reliable understanding of global temperature. We are told that we know what the planet’s temperature was in the past, that we know what it is today, and that the difference between those two numbers proves something unprecedented and dangerous is underway.
If that assumption is wrong, or even deeply uncertain, the entire structure built on top of it becomes unstable. Climate models lose their anchor. Policy prescriptions lose their urgency. Trillion-dollar decisions begin to look far less justified.
That is why the global temperature record matters so much, and why it deserves far more scrutiny than it receives. This is not an argument against measuring temperature, but an argument for understanding how much judgment and interpretation is embedded in the number we are told to trust.
In recent years, that scrutiny has begun to expose uncomfortable cracks. Historic heatwaves quietly disappearing from national records. Extreme modern temperatures recorded next to jet engines and asphalt. Adjustments that consistently cool the past while warming the present. Individually, each issue is brushed off as technical or trivial. Taken together, they point to something far more serious.
Before getting into the details, it is worth asking a basic question.
What exactly is this metric that everything depends on?
The Metric Everything Depends On
When I speak publicly about climate science, I often begin with the longest continuous instrumental temperature record on Earth, the Central England Temperature series. It stretches back to the late seventeenth century and shows dramatic swings long before industrial emissions or modern energy use. There are periods where temperatures rose or fell more quickly than anything we observe today.
The response is always the same. England is only one region. Climate change is global, not local.
That response sounds reasonable, but it quietly shifts the discussion to a much weaker metric. Once we move away from individual observations and toward a single global average temperature, we leave the realm of direct measurement and enter the world of statistical construction.
That distinction is rarely made clear to the public.
What Global Temperature Actually Represents
The Earth does not have a single temperature. It has deserts and rainforests, oceans and mountains, cities and ice sheets. Temperature varies enormously across space and time. There is no physical instrument that measures a global average.
To produce a global temperature number, scientists combine surface weather stations with ocean measurements from ships and buoys, then use statistical techniques to fill in the vast areas where no measurements exist. This process relies heavily on assumptions about how temperature behaves across distance and time.
Much of the planet, especially the oceans and large portions of the Southern Hemisphere, had extremely sparse coverage well into the twentieth century.
Even today, the oceans dominate the global average, yet direct measurements there are limited and constantly changing in method.
Global average temperature is therefore not a simple observation. It is a constructed metric. A blend of measurements, estimates, and adjustments.
That does not automatically make it wrong. But it does make it fragile.
I laid this out in detail in my earlier work on why a single global number props up the climate crisis story and why global mean temperature is physically meaningless as a diagnostic metric.
What makes the situation far more troubling is what has happened to the data over time.
A Persistent Pattern in the Adjustments
When people hear that temperature records are adjusted, they are usually told not to worry. Adjustments are described as small, technical corrections meant to improve accuracy. In isolation, that sounds reasonable. No measurement system is perfect, especially one that spans more than a century.
The problem is not that adjustments exist. The problem is the direction they overwhelmingly move.
When we examine official temperature datasets over time, a clear and consistent pattern emerges. Earlier temperatures tend to be revised downward, while more recent temperatures tend to be revised upward. Each change may appear minor, sometimes just a few tenths of a degree, but over decades, the cumulative effect is significant. The past becomes cooler and less variable, while the present becomes warmer and more extreme.
This is not speculation. It is visible directly in the data.
I explored this pattern in detail in my work examining how the Intergovernmental Panel on Climate Change has treated past climate variability, particularly the Medieval Warm Period. The Medieval Warm Period was a well-documented interval of elevated temperatures roughly a thousand years ago, evident in historical records, proxy data, and regional reconstructions across much of the Northern Hemisphere.
Earlier assessments acknowledged this warmth. Later assessments progressively minimized it.
Through selective reconstruction choices, aggressive smoothing, and the privileging of certain proxy networks over others, the Medieval Warm Period was gradually flattened and reframed as minor or purely regional. The effect was to make modern warming appear more unique, more uniform, and more alarming than the broader historical context supports.
What makes this relevant today is that the same philosophical approach appears to be at work in modern temperature records. Variability in the past is treated as noise to be suppressed. Variability in the present is treated as a signal to be emphasized.
Natural warmth becomes something to explain away. Modern warmth becomes something to highlight.
This creates a powerful narrative bias. The climate record increasingly tells a story of a stable past suddenly disrupted by human influence, even when historical evidence shows periods of comparable or greater warmth long before industrial emissions.
And this is where the Netherlands enters the story.
A Warning Sign from the Netherlands
In the Netherlands, early twentieth-century heatwaves quietly vanished from the official temperature record following historical adjustments. Events that were once documented simply no longer counted.
After years of criticism and scrutiny, several of those heatwaves were quietly reinstated.
I will walk through exactly how and why that happened in the subscriber section below. For now, it is enough to recognize what this episode represents. It is not an isolated clerical error. It is a glimpse into how fragile and malleable our climate history has become.
Before we even get there, however, there is another question worth asking.
If we are willing to debate tenths of a degree in century-old data, why are we so confident in modern “record” temperatures measured next to jet exhaust, tarmac, and concrete? How many headline-making extremes are influenced not by climate, but by ideology?
That question alone should give us pause.
Just Before the Paywall
Taken individually, each of these issues can be dismissed. Together, they raise a far more unsettling possibility.
What if the global temperature record is not a neutral scientific archive, but a continuously curated narrative?
What if past warmth is being erased and present warmth amplified, not through fraud in the criminal sense, but through incentives, methodology, and institutional momentum?
In the subscriber section, I will show how this played out in detail in the Netherlands, why the reversal matters far beyond one country, and why the global average temperature may be one of the most misleading metrics ever elevated to policy-making authority.
