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The Temperature Illusion · The Climate Translation

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Have you ever been on one of those moving walkways at an airport?
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You're walking forward at your own pace, but the floor beneath you is moving too.
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If you walk faster, you move quickly.
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If you stop, you still glide forward.
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And if you slow down or hesitate, it might feel like you're not going anywhere, even though
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the walkway is still carrying you ahead.
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That's a lot how we experience climate change.
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We notice the cold winter, or a year that doesn't break a record, and it can feel like
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warming has slowed or stopped.
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But what we're seeing are short-term ups and downs, the natural variability that's layered
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on top of a long-term trend that is continuing in one direction.
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The system hasn't stopped, it's just not moving in a straight line.
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Today, we're going to talk about the temperature illusion, why record-breaking years tend to
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come in clusters, why cleaning up pollution can briefly reveal more warming, and why a
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so-called pause in warming is usually a misunderstanding of how the climate system works.
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Welcome back to the podcast, I'm Dr. Mac, and this is The Climate Translations.
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Tell me if this sounds familiar.
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You're sitting around a dinner table, maybe it's the holidays, maybe you're in a middle
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of a blizzard, and the topic of climate change comes up.
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Someone says something like, okay, but if the planet is warming, why is it so cold this
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winter?
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I hear this all the time, and the question at first may sound reasonable, and it's based
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on what we experience.
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You step outside, it's freezing, maybe even record cold in your area, and it doesn't
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match the idea of a warming world.
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But then, fast forward a few months, it's now July, you have an outdoor barbecue.
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The air feels humid and heavy, it's the middle of a heat wave that is breaking records
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all over your area.
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Now the same people might be saying, why is it so hot this year?
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This is miserable.
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You have two completely different experiences based on two opposing seasonal variations.
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But the root of the issue is a misunderstanding of a key concept we use all the time in
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climate science, but often it's not explained well.
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It's the difference between weather and climate.
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Weather is what you feel when you walk outside.
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It's today, it's this week, it's that cold snap, a thunderstorm, that heat wave.
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Weather is a short term situation, it's local, it can swing widely from one day to the
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next, or one season to the next.
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Climate is something different.
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Climate is the long term pattern, it's the average of all those ups and downs over time,
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and it is typically measured over decades, not days.
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Here's a simple way I explain this to students in my Introduction to Meteorology classes.
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If the weather is your mood, the climate is your personality.
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Your mood can change quickly, you can have a bad day, you can have a great day, maybe
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something in between.
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But your personality, your long term overall pattern, it doesn't change overnight, and
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the same is true for the climate system.
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In a warming climate, we are still going to have cold days, we will still have snowstorms,
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we still have colder years, none of that it's going to disappear.
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What's changing is the baseline those events are happening on.
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Take back to that airport walkway that I discussed in the opening.
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The short term ups and downs, the colder or warmer winter, or the milder or more extreme
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summer, those are your footsteps.
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Just like you can sometimes move faster and sometimes slower, the climate can sometimes
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be cooler or warmer than usual.
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But the walkway underneath, that's the long term warming trend, it's still moving,
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and in the case of the climate of our planet, it's moving in an upward trajectory.
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Averages and trends are harder to visualize and understand.
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We as humans have short term memories, the here and now is often more important and impactful
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to us.
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People expect climate change to look like a smooth, steady increase, like a line on a graph
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that just goes up a little bit every single year.
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But that's not how our Earth behaves.
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The climate system is influenced by many moving parts, many of which we've discussed
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in this podcast in the past.
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Ocean cycles like El Niño, La Niña, volcanic eruptions, changes in air pollution, the natural
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variability in the atmosphere.
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All of these can push temperatures up and down in the short term, so when you zoom in
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and look at a single year, or even a handful of years, it can look messy.
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You can look flat, it can look like it's going in the wrong direction, but when you zoom
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out and plot things over decades, the picture becomes more clear.
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Over the last century, the global average temperature has increased by a bit over a degree
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Celsius or two degrees Fahrenheit.
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But that increase hasn't been a straight line.
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If you've seen these charts online or in the news, they look more like a wobbling
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staircase.
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Another way to think of it is this, imagine you're on a busy interstate in a large metropolitan
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city.
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There are drivers all around you.
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Some of the drivers are driving fast, some are driving slow, some are influenced by
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the car they're driving.
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The age they are, the grade of the road, even the driver in front or behind them.
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Perhaps, at times, you're stuck behind someone who's moving slower, so you weave your
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way to where someone's moving faster.
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It's hard for you to get a handle on how long it will take you to get your destination,
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or what the overall traffic pattern is like.
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However, if you were to get into a drone and zoom up above the roadway, you might notice
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that the overall trend is the speed is increasing over time, when taken as an average.
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There are a lot of variables in the atmosphere that lead to our short-term weather, but when
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taken together, we can get an overall pattern of the trend lines in the average.
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What makes things more complicated is that the extreme years, the cold winters or the
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hot summers, don't show up randomly like they used to in the past, we're starting to
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see them occur in groups.
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And that pattern, those clusters, is one of the clearest signals that the underlying
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system is changing.
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The past decade or so is given a lot of climate scientists cause for concern.
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I mentioned that the overall trend line is upward, but the extreme years, the years
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where we seem to be breaking records across the globe, they're happening more frequently.
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You'll hear something like, this was the hottest year on record, and then the next year,
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it's broken again, and then again.
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It can start to feel like instead of records being broken, they're constantly being surpassed
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and replaced.
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So what's going on?
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Why do hot years cluster together instead of being spread out?
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When we look back at the historical climate record from the past million years or so,
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we can see a mix of cooler years, average years, and warmer years.
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Sometimes the trend line went up, sometimes it went down.
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But on average, things were relatively stable.
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However, recently, because of human influence, primarily the production of carbon dioxide
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from industrialization, the baseline average has shifted, the mean has been altered.
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Think of a pair of dice.
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In the past, the climate system was like rolling a fairly balanced set.
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At any given roll, you have an equal chance of getting a cool year, an average year,
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or a warm year.
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And now let's say someone slowly added weight to the dice, specifically towards the higher
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numbers.
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You can still roll a low number, that hasn't disappeared, but the odds have shifted.
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Now high numbers come up more often, and sometimes they come up several times in a row.
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In the historical climate record, we've seen this due to natural variability, perhaps
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a volcano explosion, led to cooling globally.
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We've seen ice ages.
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But now we're seeing anthropogenic warming, warming due to human influence that's raising
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the baseline temperature of the planet.
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Because of greenhouse gases, carbon dioxide, methane, and others, we're trapping more
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heat in the system.
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That in turn raises the floor that all weather sits on.
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So today, even a cool year by modern standards, is often warmer than what used to be considered
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average just a few decades ago.
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That's the first piece of the cluster effect, but there's more going on.
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The second piece has to do where more heat is stored.
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I've mentioned before that over 90% of the excess heat in global warming doesn't stay
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in the air, it goes into the oceans.
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And the oceans don't release that heat all at once.
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They store it, and then they release it gradually over time.
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That means once the system warms up, it tends to stay warm.
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You don't just get one hot year, you get several, because the ocean is feeding that heat
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back into the atmosphere year after year.
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Now there's the third piece that can shape how these clusters feel at a regional level.
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Some research suggests that as the Arctic warms faster than the rest of the planet, it
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can affect the jet stream, the fast-moving river of air that steers weather systems.
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When the temperature difference between the Arctic and the equator weakens, the jet stream
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can become more wavy and slower moving.
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Weather can get stuck in those processes.
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Heat can sit over regions for longer periods, or cold air can linger in one place longer
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than usual.
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It's an active area of research, and scientists are still working to understand exactly what
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the connection is, but what we're confident about is this.
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There is a rising baseline, and that's a foundation of everything else.
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In my earlier episode, The Invisible Mirrors, we talked about aerosols, which are tiny
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particles in the air produced by things like burning coal, diesel engines, and wildfires.
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Some of these particulates act like mirrors.
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They can reflect a portion of the sunlight back into space before it reaches the surface.
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And when that happens, the planet can cool slightly, especially in certain regions.
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It's not enough to stop the average global warming across the planet.
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But it's enough to mask it.
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You can think of it like a thin veil over the system.
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The heat from the greenhouse gases is still building underneath, but not all of it is showing
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up at the surface right away.
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From much of the 20th century, especially in heavily industrialized regions, the effect
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was significant.
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Air pollution was high, aerosols were abundant, and in some places they were reflecting enough
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sunlight to offset some warming caused by greenhouse gases.
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But particulates like these don't stay in the atmosphere very long.
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They fall out in weeks to months.
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Which means they only stick around if we keep emitting them.
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And over the past decade, we've started cleaning the air.
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Regulations in the United States, Europe and parts of Asia have reduced sulfur pollution
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and other aerosol-producing emissions.
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From a public health standpoint, it's a huge success story.
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Cleaner air has saved millions of lives.
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But from a climate perspective, it comes with an interesting side effect.
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As we remove those reflective particles, we remove the mask.
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And when that happens, more of the underlying warming that was already there becomes visible.
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This helps explain something that can otherwise feel confusing.
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Why warming doesn't always appear gradual.
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Why certain decades seem to heat up faster than others.
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And why in combination with that cluster effect we just talked about, record breaking
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years can seem to arrive all at once.
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Without the noise, without that veil, you can see the climate trends more clearly.
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And this is one of the reasons climate science can feel counterintuitive to some.
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Sometimes progress in one area, like cleaning air, can temporarily make the problem look worse.
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But the reality is, it's not making it worse, it's removing the filter.
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And once that filter's gone, the underlying trend is becoming harder to ignore.
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The climate of the earth is complex.
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It's not as simple as looking at a graph or chart to determine what's going to happen
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next.
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When we have regional variations, or a mild year or season, it can be confusing.
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I think this is one of the reasons we hear things like, the global warming stop for a
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while, or, I read temperatures haven't increased the last few years.
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This idea of a pause and warming has shown up periodically.
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And like a lot of misconceptions, it comes from looking at the right data, but asking the
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wrong question.
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Climate change doesn't disappear just because one year is less extreme than the other before
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it.
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We have baked in a trajectory based on our rapid production of greenhouse gases over
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the past few centuries.
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When you see news stories, or hear people talk about a pause and warming, or a change in
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the weather, they're focusing on a very short slice of time, months or even years, and
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expecting it to behave like a long-term trend.
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But as we've stated, the climate system doesn't work that way.
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Year-to-year temperatures are influenced by natural variability, things like El Nino
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and La Niña and those volcanic eruptions, even ocean cycles.
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Those factors temporarily can push temperatures up or down.
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If you start picking a point that happens to be a warm year, maybe like a strong El Nino
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year, and then compare it to years that follow, the trend can look flat or even reduced.
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But that doesn't mean global warming has stopped or reversed.
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It's the system fluctuating on top of a rising baseline.
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This is something we can clearly see in long-term data.
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If you look at global temperatures over decades and centuries, the upward trend is unmistakable.
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But if you zoom in too closely, just a few years of the time, you can find short periods
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that look like pauses.
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I guess when it comes down to it, it's a matter of scale.
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It's kind of like looking at the stock market.
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On any given day, prices can go up or down.
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For a week, you might see a dip, but that doesn't tell you the long-term direction of
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the market.
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To understand that, you have to step back and look at the bigger picture.
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The same is true of climate.
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Short-term variability is not canceling out long-term trends.
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And in fact, when scientists study these so-called pause periods, they find the energy in
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the system never stopped increasing.
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The oceans continue to absorb heat.
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The planet continued to gain energy overall.
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It just wasn't all showing up in the surface air temperatures in a short time.
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So the idea of a pause or a reduction in warming isn't really about the climate stopping
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or reversing direction.
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It's about where we're looking and how much time we're looking at.
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When we focus on narrow windows, it can be easy to miss the larger pattern.
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By zooming out, the signal becomes clear.
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That moving walkway is still moving forward.
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The earth's baseline is still rising.
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Average temperatures are still increasing.
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Short-term slowdowns are just part of how a complex system behaves.
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The changes in our planet's climate aren't going to show up like a straight line on
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the graph.
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They're going to be times when we have lower, average, or warmer years.
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But what's more important is the average, that trend line.
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That is the difference between weather and climate.
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Cold winters don't disparage warming.
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Hot summers don't define it.
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And a few quiet years don't mean it stopped.
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What matters is the overall direction of the system over time.
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When we step back far enough and truly look at what the data is telling us, the direction
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is clear.
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The baseline is rising.
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Our odds are shifting.
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And the patterns we're seeing are exactly what we expect from a global system that's
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warming.
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It's time to move past the rhetoric and the confusion and see the climate system for
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what it truly is.
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Very complex, but reacting to human inputs.
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And we can expect those reactions to become more evident as time passes.
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I'm Dr. Mac and this has been the Climate Translation.
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If you have a question about the climate you've been too afraid to ask, or if you have
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a differing opinion, I want to hear from you.
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I can use your viewpoints in future episodes.
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You can reach me at theclimatetranslation at gmail.com.
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I'll see you next time.