Hot House

By Tom Yulsman | May 6, 2013 9:30 am

The 50 hottest years on record. (Source: World Meteorological Organization)

I plucked this graphic from a report just released by the World Meteorological Organization, summarizing the status of the global climate in 2012. It shows the 50 hottest years on record, and I find it to be a new and interesting way to depict the progress of global warming over the decades.

The vertical axis of the graph shows how temperature for a given year departed from the long-term average. And the color-coding of the bars is a way of depicting the distribution of the temperature records on a decadal timescale. (The size of each bar, by the way, is an indication of the uncertainty inherent in each record. The longer the bar, the greater the uncertainty.)

The take-home message of the graph can be seen in the red and orange bars: Of the 20 hottest years on record, 19 have occurred since 1990. And of the 10 hottest, nine have occurred since 2000.

I suspect the graph will be something of a climate-politics Rorschach test. Those who accept the scientific consensus that humans are having a significant impact on the climate system, as I do, will see confirmation of global warming here. But those who are skeptical may view it as a way of obscuring the fact that warming has slowed since the turn of the century, as this graph makes evident:

Global temperature change from 1880 to the present. (Image: NASA Goddard Institute for Space Studies)

The slowdown in warming has occurred despite the fact that the concentration of carbon dioxide in the atmosphere has kept rising. What’s up with that? Physics would seem to dictate that with more greenhouse gases in the atmosphere, heat has to be building up somewhere. But where?

My friend and colleague over at Climate Central, Michael Lemonick, had a good explanation of it back in March:

The answer, according to a new paper in Geophysical Research Letters, is that a lot of it is being stored in the deep ocean, more than a half-mile down. “We normally think about global warming as what we experience on the Earth’s surface,” said co-author Kevin Trenberth, of the National Center for Atmospheric Research, in an interview. If extra heat is temporarily stored elsewhere thanks to natural climate variations, we won’t necessarily notice it.

Until that heat starts coming back out.

CATEGORIZED UNDER: Climate, Global Warming, select, Top Posts
  • JonFrum

    I suggest the writer needs to become acquainted with Andy Revkin’s ‘whiplash journalism’ concept:

    Anyone who thinks that a single published paper settles a dispute like anthropogenic climate change has no business taking money to write on science. And in this case, anyone who doesn’t know the story of Trenberth’s ‘missing heat’ has no business quoting Trenberth.

    Post hoc rationalizations do not good science make. When the real world data didn’t fit Trenberth’s mathematical models, he stewed, and then explained away the data after the fact. Science is supposed to predict, not back-date. .

    • Tom Yulsman

      Mr. Frum, I am well acquainted with Andy’s concept. In fact, Andy has been a friend and colleague since 1981, and we both began writing about global warming not long thereafter. Journalistically, we don’t see perfectly eye to eye on everything about this issue. But much closer than not.

      In any case, perhaps if you look in the mirror more closely you will see that you are being weighed down by a huge chip on your shoulder. Get rid of it, and then we can have a reasonable discussion about this topic. Until you do, however, I will just say this: Nowhere in this blog post did I say anything even remotely close to “this single published paper settles the dispute of anthropogenic climate change.” Go ahead. Read it again.

      But please, do me a favor and first store the chip in a drawer.

      • Tom Fuller

        I actually like and appreciate the measured tone you use in writing this–and other posts and comments I’ve seen of yours, here and elsewhere.

        But I can’t help wondering what the state of the political discourse on climate change would be like today if others had been writing with the same tone ten and fifteen years ago.

  • erbarker

    My, my. The 50 hottest years out of 125 years. That is really impressive. Go for it all. It is hotter now then it was 100 thousand years ago. 50 years out of the earth’s 4.5 billion years is less then a flea sexing a elephant asking the elephant “Hey baby did I hurt you?”. We are not in a “Hothouse” state. We are in a “Icehouse” state. Glaciation only occurs in a “Icehouse” state. We are still coming out of the last glaciation period. We transitioning into a inter-glaciation period. What do you think happens when the earth comes out of a glaciation period. 1. Does it get colder? 2. Does the temperature stay the same? 3. Does it get warmer? Get real!

    • ChrisArc

      I am sure you think that you know more than all of the scientist and the scientific data but you are wrong. The ice cores show the temp and CO2 levels for hundreds of thousands of years and we are getting hot and the ice is melting faster than ever during that time and I apparently think it is a coincidence that it has gotten much hotter since the start of the industrial age!

    • DashingLeech

      I don’t think you have a grasp of the situation. It is somewhat likely that it was hotter 400,000. But the oceans were also about 75 meters higher because of that. Take a look around the world and imagine what that would do to most of civilization. Of course predictions aren’t only that it will rise on the orders of centimeters to tens of centimeters in the next 100 years or so, but that alone will wipe out many coastal cities around the world to the economic costs of trillions of dollars. Remember, beaches are at a shallow slope. A few cm to 10 cm average (not just waves) will move the cost inland hundreds of meters to kilometers in some areas. Waves and storm surges alone will wipe out major portions of cities.

      As for post-glaciation, the issue isn’t whether it is warming or not, it is the rate of warming. If the coastline moved a few meters over 1000 years it wouldn’t be a big deal as our buildings and cities shift with it. But over 10 years the same change would devastated cities and countries. And, for the record, warming and sea level rise reached equilibrium about 8000 years ago post ice age, and have been pretty level since then. A quick search at Wikipedia for “sea level” can show this.

  • @leathermangx

    The only scientists still on the, broken down, global warming bandwagon are the ones still getting government money to study it.

    • Seraph of the I.

      What, you mean 95%+ of all climatologists ?

  • MattWriter

    Serious question: If the recent flattening of surface temperatures is deceiving because the heat is being absorbed into the deep oceans, why wasn’t the heat from the decades before that absorbed in the deep oceans? In other words, assuming the total heat/energy has been rising, why did it shift from showing up in surface temps to showing up in the depths? – Matt Bille, member, NASW

  • James Cook

    Deep ocean heat only accounts for about 30% of the missing quantity, according to Trenberth. We don’t know that the other 70% didn’t go to outer space, or if simply reflects a miscalculation of some other variable.

  • Bruno Girin

    What about the theory that the recent slowdown in warming is due to BRIC countries using more and more CFC that is banned elsewhere? Does that theory has any legs in it? Note that I am not a climatologist so please correct me if that theory is complete nonsense.

  • John Holman

    MattWriter, this is my understanding. Ocean Heat Content Anomaly – It’s the amount of energy being added to the oceans each year. The imbalance at the top of the atmosphere results in more energy coming into the earth system than leaving; hence, warming. In general, once heat is stored in the deep ocean it will not come back out until the imbalance at the TOA reverses: like in an ice age. What Trenberth means by “coming back out” is a period where of the amount of energy coming in, less goes into the ocean and more warms the atmosphere, and then goes back to outer space: a lower OHC anomaly and a higher SAT anomaly. Also known as periods of ocean dynamics that tend to warm the SAT. The atmosphere does not store much energy. That is why running trend lines off of 1998, or any other hottest year, is as stupid as it gets.



ImaGeo is a visual blog focusing on the intersection of imagery, imagination and Earth. It focuses on spectacular visuals related to the science of our planet, with an emphasis (although not an exclusive one) on the unfolding Anthropocene Epoch.

About Tom Yulsman

Tom Yulsman is Director of the Center for Environmental Journalism and a Professor of Journalism at the University of Colorado, Boulder. He also continues to work as a science and environmental journalist with more than 30 years of experience producing content for major publications. His work has appeared in the New York Times, Washington Post, Audubon, Climate Central, Columbia Journalism Review, Discover, Nieman Reports, and many other publications. He has held a variety of editorial positions over the years, including a stint as editor-in-chief of Earth magazine. Yulsman has written one book: Origins: the Quest for Our Cosmic Roots, published by the Institute of Physics in 2003.


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