The Temperature Illusion

Introduction

Have you ever been on one of those moving walkways at the airport? You are walking forward at your own pace, but the floor beneath you is moving too. If you walk faster, you move quickly. If you stop, you still glide forward. And if you slow down or hesitate, it might feel like you are not going anywhere, even though the walkway is still carrying you ahead.

That is a lot like how we experience climate change. We notice a cold winter or a year that does not break a record, and it can feel like warming has stopped. But what we are really seeing are the short-term ups and downs, the natural variability, layered on top of a long-term trend that keeps moving in one direction. The system has not stopped; it is just not moving in a straight line.

Today, we are talking about what I call the Temperature Illusion: why record-breaking years tend to come in clusters, why cleaning up air pollution can briefly reveal more warming, and why a so-called "pause" in warming is usually a misunderstanding of how the system works. Welcome back to the podcast. I'm Dr. Mac, and this is The Climate Translation.

Weather vs. Climate

Tell me if this sounds familiar. You are sitting around a dinner table during the holidays or in the middle of a blizzard, and the topic of climate change comes up. Someone says something like: "Okay, but if the planet is warming, why was it so cold this winter?" I hear this all the time. The question at first sounds reasonable because it is based on what we experience. You step outside, it is freezing or maybe even record cold in your area, and it does not match the idea of a warming world. But then, fast forward a few months to July. You are having an outdoor barbecue, the air feels humid and heavy, and it is the middle of a record-breaking heatwave. Now, the same people are asking: "Why is it so hot this year? This is miserable."

You have two completely different experiences based on two opposing seasonal variations. The root of the issue is a misunderstanding of a key concept we use all the time in climate science but do not always explain well: the difference between weather and climate. Weather is what you feel when you walk outside. It is today, it is this week, and it is the cold snap, the thunderstorm, or the heatwave. Weather is short-term and local, swinging wildly from one day to the next or from season to season. Climate is the long-term pattern. It is the average of all those ups and downs over time, and it is typically measured over decades rather than days.

Here is a simple way I explain this to students in my introductory meteorology classes: if weather is your mood, climate is your personality. Your mood can change quickly from a bad day to a great day, but your personality does not change overnight. The same is true for the climate system. In a warming climate, we will still have cold days, snowstorms, and cooler years. None of that is going to disappear. What is changing is the baseline those events are happening on.

Think back to that airport walkway from the opening. The short-term ups and downs, such as a colder winter or a milder summer, are your footsteps. Just as you can walk faster or slower, the climate can temporarily run cooler or warmer. But the walkway underneath represents the long-term warming trend, and it is steadily moving in an upward trajectory. Averages and trends are harder to visualize because humans naturally focus on the here and now. People expect climate change to look like a smooth, steady increase, like a line on a graph that goes up a little bit every single year. But that is not how Earth behaves.

The climate system is influenced by many moving parts, including ocean cycles like El Niño and La Niña, volcanic eruptions, changes in air pollution, and natural atmospheric variability. All of these can push temperatures up or down in the short term. When you zoom in on a single year or a handful of years, the data can look messy, flat, or even appear to go in the wrong direction for a little while. But when you zoom out over decades, the picture becomes clear. Over the last century, the global average temperature has increased by a little over 1 degree Celsius, or about 2 degrees Fahrenheit. That increase has not been a straight line; it looks more like a wobbling staircase.

Imagine you are on a busy interstate in a large metropolitan city surrounded by drivers moving at different speeds depending on their vehicle, age, the grade of the road, or the traffic around them. Stuck behind someone slow before weaving past someone faster, it is hard to gauge your exact travel time. However, if you view the highway from a drone high above, you see that overall traffic speed is steadily increasing over time. There are many variables in the atmosphere that create short-term weather, but taken together, the average trendline is unmistakable. What makes things even more noticeable is that extreme years no longer appear as randomly as they did in the past; they are starting to occur in clusters, which is one of the clearest signals that the underlying system is changing.

The Cluster Effect

The past decade has given climate scientists serious cause for concern. The overall trendline is upward, and the extreme years where we break global records are happening more frequently. You will hear that a particular year was the hottest on record, only for that record to be broken again the following year and the year after that. It starts to feel like records are not just being broken, but constantly surpassed and replaced.

Why do hot years cluster together instead of being spread out? When we look back at historical climate data over past millennia, we see a balanced mix of cooler, average, and warmer years fluctuating around a stable baseline. Recently, human influence, primarily carbon dioxide emissions from industrialization, has shifted that mean baseline. Think of a pair of dice. In the past, the climate system was like rolling a fair set where you had an equal chance of rolling a cool, average, or warm year. But now, weight has been added to the dice toward the higher numbers. You can still roll a low number, but the odds have shifted so that high numbers appear far more often, frequently several times in a row. Raising the baseline temperature means that even a "cool" year by modern standards is often warmer than what was considered average just a few decades ago.

The second piece of the cluster effect involves where heat is stored. Over 90 percent of the excess heat from global warming goes into the oceans rather than staying in the air. The oceans do not release that heat all at once; they store it and release it gradually over time. Once the system warms up, it tends to stay warm, producing several hot years in succession as the ocean feeds heat back into the atmosphere.

A third piece shapes how these clusters feel at the regional level. As the Arctic warms faster than the rest of the planet, the weakened temperature contrast between the pole and the equator can cause the jet stream to become wavier and slower-moving. When that happens, weather patterns can get stuck, allowing heat domes or cold air masses to linger over a region for extended periods. While the exact atmospheric mechanics remain an active area of research, the rising baseline temperature is a well-established reality that underpins these extreme clusters.

The Mask

In our earlier episode, "The Invisible Mirrors," we talked about aerosols, which are tiny airborne particles produced by burning coal, diesel combustion, and wildfires. Some of those particles act like mirrors, reflecting a portion of incoming sunlight back into space before it reaches the surface and cooling the planet slightly in certain regions. It is not enough to stop global warming, but it is enough to mask part of it like a thin veil over the system. The heat from greenhouse gases continues to build underneath, even if it does not immediately show up at the surface.

For much of the twentieth century, high levels of aerosol pollution in heavily industrialized regions reflected enough sunlight to offset some greenhouse warming. But unlike long-lived greenhouse gases, these reflective particles fall out of the atmosphere within days to weeks. Over the past several decades, clean air regulations in the United States, Europe, and parts of Asia successfully reduced sulfur pollution and aerosol emissions. While this is a major public health victory that has saved millions of lives, it comes with a notable climate side effect.

As we remove those reflective particles, we also remove the mask. More of the underlying warming that was already present suddenly becomes visible. This explains why warming does not always appear gradual, why certain decades seem to heat up faster than others, and why record-breaking years can arrive in sudden waves. Cleaner air does not worsen warming; it simply removes the filter that was hiding the true trajectory. Once that filter is gone, the underlying trend becomes impossible to ignore.

The "Pause" Illusion

Earth's climate is complex, and regional variations or mild seasons often lead people to ask if global warming has stopped or if temperatures have flattened out. This idea of a "pause" in warming comes from looking at the right data but asking the wrong question. Climate change does not disappear just because one year is less extreme than the previous one, as our cumulative greenhouse gas emissions have locked in a long-term trajectory. When people talk about a pause, they are usually focusing on a narrow slice of time and expecting it to mimic the multidecadal trend.

Year-to-year temperatures fluctuate due to natural variability like El Niño, La Niña, volcanic eruptions, and ocean cycles. If you choose an unusually hot starting point, such as a strong El Niño year, and compare it to the immediate years that follow, the short-term trend can appear flat or slightly downward. That is not the system stopping; it is natural variation occurring on top of a rising baseline. When you look at global temperatures over decades, the upward trend is unmistakable.

It is like looking at the stock market: daily fluctuations or weekly dips do not define the long-term economic trajectory. In the same way, short-term climatic variability does not cancel out the broader trend. When scientists examine these so-called pause periods, they find that total planetary energy accumulation never stopped because the oceans continued absorbing heat. The energy was simply distributed away from the surface for a brief period. The moving walkway continues forward, the baseline continues to rise, and short-term slowdowns are just normal behaviors of a complex system.

Conclusion

The changes in our planet's climate do not appear as a perfectly straight line on a graph. There will always be cooler, average, and warmer years, but what matters is the average trendline over time. That is the fundamental difference between weather and climate. Cold winters do not disprove warming, hot summers do not define it, and a few quieter years do not mean it has stopped.

When we examine long-term data, the direction of the system is clear: the baseline is rising, the odds are shifting, and the patterns we observe match our expectations for a warming planet. It is time to look past the confusion and see the climate for what it really is: a complex system reacting to human inputs, where those physical reactions will become increasingly evident over time.

I'm Dr. Mac. This has been The Climate Translation. If you have a question about the climate that you have been too afraid to ask, or if you have a differing opinion, I want to hear from you. I can use your viewpoints in a future episode. You can reach me at TheClimateTranslation@gmail.com. I'll see you next time.