by Daniel Brouse
March 26, 2025
It is crucial to understand that the rate of climate change is accelerating rapidly. Weather and climate normals are essentially moving averages used to establish a baseline for comparing current weather and climate conditions. These averages help define what is considered “typical” for a location over a given period. However, it’s important to note that “normal” is only defined in relation to the very recent past. When you hear about “normal” temperatures or rainfall, it refers only to the average of the last decade or so. These calculations are continuously updated and reflect only recent climate patterns, without including pre-industrial conditions (before 1850). As a result, this creates a skewed perception, where “normal” climate baselines shift along with the ongoing warming trend, rather than revealing how much temperatures have diverged from pre-industrial levels.
Moving Averages in Weather and Climate Normals
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Weather Normals: These refer to averages over shorter periods (often 10 years or less) and are used primarily for operational meteorology—forecasting, monitoring seasonal trends, and comparing day-to-day conditions.
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Climate Normals: The most commonly used climate normals are 30-year averages, as recommended by the World Meteorological Organization (WMO) and the National Oceanic and Atmospheric Administration (NOAA). These are updated every decade (e.g., 1981–2010, 1991–2020, etc.), effectively making them a moving average that shifts forward in time.
Since these calculations continuously update, they only reflect recent climate patterns and do not incorporate pre-industrial conditions (before 1850). This creates a skewed perception where “normal” climate baselines shift along with the warming trend, rather than showing how much temperatures have diverged from pre-industrial times.
Why This Matters
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Masking Long-Term Change: Since climate normals shift every decade, they fail to capture the full extent of human-induced warming. If we were to compare today’s temperatures to pre-industrial levels (rather than just the past 30 years), the warming trend would appear much more severe.
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Underestimating Climate Change: Because recent normals already include warming trends, they make present-day extreme weather seem less unusual than it actually is when compared to historical records.
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Shifting Baselines: With each update, the perception of what is “normal” changes, meaning that extreme heat events today may appear less anomalous when compared to a newer, warmer climate normal rather than a true historical baseline.
The Acceleration of Climate Change
It is crucial to understand that the rate of climate change is accelerating rapidly. Climate change is a complex, dynamic, and non-linear system, and we have observed a dramatic reduction in the “doubling time” of its impacts—the rate at which these effects intensify. Initially, the doubling time was about 100 years, but it has since decreased to 10 years, and more recently, to just 2 years. This means the damage caused by climate change today is already double what it was two years ago. In just two more years, the damage could be four times worse; in four years, eight times worse; and within a decade, potentially 64 times worse. These projections are conservative, assuming the doubling time does not continue to shorten further.
Alarmingly, this rapid acceleration does not appear to be an anomaly. If this trend continues, the consequences will likely be far more catastrophic than previously anticipated.
The evidence is clear: climate change is rapidly accelerating, and the costs — both economic and human — are growing exponentially. The future demands decisive and immediate action to curb greenhouse gas emissions and prevent further environmental and societal collapse. Our updated climate model, now integrating complex social-ecological factors, shows that global temperatures could rise by up to 9°C within this century — far beyond previous predictions of a 4°C rise over the next thousand years. This kind of warming could bring us dangerously close to the “wet-bulb” threshold, where heat and humidity exceed the human body’s ability to cool itself, leading to fatal consequences.