"Let me introduce you to my little friend": 2014, warmest year

Andrew Revkin has this commentary at the New York Times: How ‘Warmest Ever’ Headlines and Debates Can Obscure What Matters About Climate Change.

I will argue below that Revkin has, inadvertently or not, linked a science denialist trope to the important scientific finding that 2014 is the warmest year on record, as part of his presumably well intentioned effort to focus on trends rather than individual points. (See his comment on this blog below.) Yes, the trend is more important than a given data point, but the headline does not really obscure, but rather, underscores.

I'm afraid the devaluing of 2014, or any year, as a new data point in measuring global surface temperature change will become yet another climate science denialist claim. The strength of this claim would lie entirely in absurd idea that one data point in set a of data demonstrating a trend, with N=130, is not important if it is not "statistically significant" in difference from nearby points. That is actually what we expect when adding new data to the end of a trend, when the trend itself is real and there are already sufficient data points to lend a high degree of confidence. Indeed, the temperature anomaly estimate for 2014 is exactly what we would expect under conditions of continuous global warming.

Like this:

2014 is exactly where we expect it to be assuming that the long term trend is well represented by current data and models.  That is Significant with at big 'S'. 2014 is exactly where we expect it to be assuming that the long term trend is well represented by current data and models. That is Significant with at big 'S'.

In his State of the Union Address, President Obama said, "2014 was the planet’s warmest year on record. Now, one year doesn’t make a trend, but this does — 14 of the 15 warmest years on record have all fallen in the first 15 years of this century." The President refers here to last Friday's announcement by the key US government agencies that study climate and weather, NOAA and NASA, that 2014 was the warmest year in a record of temperatures that goes back to 1880. President Obama correctly notes the milestone of 2014 being the warmest year, and that the larger, more important, fact, is that all of the warmest years we've experienced since industrialization have been very recent.

Revkin notes the NOAA/NASA report and links this to criticisms from the Daily Mail (one of the most notorious rags at the fringes of journalism), the right wing "The Federalist," and an extreme climate science denialist site. This has the effect of creating a balance between established government scientists and agencies who say one thing, and critics providing an alternative view. What this really is, of course, is a false balance between mainstream science on one hand and rather extreme science denialism on the other. By uncritically providing their point of view along side the findings of NOAA and NASA he effectively elevates cranks to the status of expert. This slight of hand seems to have had the function of allowing Revkin to note that "it's a distraction to focus on records ... given how year-to-year differences in global temperature are measured in a few hundredths of a degree Fahrenheit, and given the implicit uncertainty in such measurement."

So. 2014. Shiny! Since we are capable of thinking about only one thing, lets' avoid thinking about 2014? No. That would be wrong.

Revkin previously claimed that when writing about science he tries to only refer to scientists, in a 2006 interview conducted by Paul Thacker:

Thacker: Scientists consistently complain that the journalistic practice of "balance" allows skeptics to gain an unfair toehold in media coverage, which ignores consensus in favor of controversy. Do you agree, and do journalists need to rethink their approach to covering complex scientific issues?

Revkin: Balance is a necessary evil, a crutch, particularly in daily journalism, but only works with coverage of the science –policy interface if the journalist works hard to label the voices in a story to reflect what they represent (a consensus or knowledgeable minority) and certainly to reflect their motivation or potential conflict (paid by industry? on staff at an environmental group?). When I'm writing strictly on a scientific finding, I avoid voices from anyone other than scientists. When I'm writing on policy, I'll quote those with an agenda, but only if I label their agenda.

He did not do this in his latest New York Times commentary.

Much of the rest of Revkin's post is a foray into probability and statistics that ends up not being very helpful, mainly because the meaning of 2014's surface temperature estimate was not appreciated.

Here is what is going on. The value of a given year when it is one of 130+ data points is limited. That was true before 2014 turned out to be the warmest in that data set, it would have been true if 2014 had turned out to have been a bit cooler or warmer. It applies to each and every one of the years for which surface temperatures have been estimated by a half dozen or so agencies or research groups. What we are really measuring here is change over time, over decades of time. We do not decide if there is a trend of change over time in such a data set by looking at a given year. We look at the trend itself, incorporating all of the data.

At the same time, every single point counts. The trend is an accumulation of annual averages of individual years arranged across time. We are ultimately asking two questions of these data. First, we are asking about patterns in the past, since humans started releasing copious amounts of the greenhouse gas CO2 into the atmosphere. We are seeking other relationships over that time frame as well, looking at the strength of the sun over time, the effects of atmospheric dust spewed by volcanoes or human activities, and complex interaction between "surface temperature" (the thing these data sets measure) and the actual global temperature which includes the ocean (containing well over 90% of this heat). In order to examine this record in light of all of those variables, we have to pay attention to each and every year. And, the most important year is always the one we just got, because it serves as a tiny but helpful test of our running hypothesis. And, it is more data! It is like finding a new friend.

The second question we are asking is what will happen in the future. Right up until the start of January, the year 2014 was in the future. The temperature value estimated for 2014, or more exactly, the degree (literally) and direction of this year as an anomaly reflected against a long term average, is the very point of this research, and of course, this applies to 2015, 2016, and so on. The relative position of 2014 in relation to the long term data is of great interest. Had that value been substantially less than the trend predicts, there would be some 'splainin to do. Had the value been way higher than the trend predicts, there would be some 'splainin to do. As it turns out, 2014 couldn't have been much closer to the exact value the long term trend line predicted. It was dead on under the assumption of continued warming. That, ladies and gentleman, is a data point of worthy note.

2014's temperature value is significant for the very fact that it is not statistically different from expectations under the widely accepted model of anthropogenic global warming. That is the meaning of 2014's surface temperature estimate.

Please remember that the "surface temperature" is only the measurement of the air near the ground and the surface of the sea, combined. This is less than 10% of the total heat containing portion of the planet affected by global warming. The surface temperature is an important indicator of change over time, and for historical reasons this is a measurement we use. But it is like the tail of the dog, where the dog is the ocean, where the other 90% or so of heat resides. John Abraham just posted a commentary on the most recent data, just updated, on ocean heat content, and it has been rising apace. (See also this paper on that topic, and this post by Joe Romm.)

90% of the Earth's energy balance involves the ocean's heat, shown here. Note that there is no current pause, and that surface temperature estimates (see graph above) tend to underestimate the total amount of anthropogenic global warming because much of this heat, routinely, goes into the ocean. We can expect some of this heat to return to the atmosphere in coming years. 90% of the Earth's energy balance involves the ocean's heat, shown here. Note that there is no current pause, and that surface temperature estimates (see graph above) tend to underestimate the total amount of anthropogenic global warming because much of this heat, routinely, goes into the ocean. We can expect some of this heat to return to the atmosphere in coming years.

2014's surface temperature estimate obscures nothing, it reveals. It is not a distraction. It is the point.

I think it is important to note that the reality of global warming, and tracking it, is complex. This was, in fact, the warmest year on record. The fact that a new warmest year will almost always be only a little warmer than a previous recent warmest year does not diminish the importance of the new top rank year, but rather, underscores it, since all the "warmest years" are recent. If this year beat out the next warmest year by only a small amount, and that next warmest year was from 1881, we would not be impressed. But since this new warmest year's friends, the other previous winners of this particular numerical beauty contest, are all very recent, we are impressed. And we should be worried.

It would be odd to not acknowledge a new warmest year when the data come out, and it would be odd to not recognize its significance.


More like this

Your comments in the thread on Dot Earth are far more useful than this weird attempt to portray my piece as false balance on the science. The whole point of the piece was to explain why trend matters far more than parsing levels of confidence in any particular year's estimated temperature - and I agreed with Gavin Schmidt's input that the doubt sowers out there will change. What's up?

By Andy Revkin (not verified) on 22 Jan 2015 #permalink

Andy, thanks for the comment.

I agree with and appreciate the idea that the trend is the point. But there is in fact an effort in the denialosphere (sp?) to devalue the importance of the trend by devaluing the importance of the warmest year (2014). Unfortunately you did in fact produce a false balance by linking three such efforts to the NOAA/NASA announcement, despite your own claim that you would address critique of science from within the world of science.

However, I will be happy to add a note to the post encouraging people to see your .earth post in the light you suggest.

Andy... Part of the issue here, and much of the frustration I see among many scientists, is that you have a very large megaphone with the NYT DotEarth blog. All too often the words coming through that device are all too often conveying a less than urgent message.

This issue with the 2014 record is a case in point. Your post blunts the fact that 2014 was a significant record in stating that the trend is more important. The trend absolutely IS more important, but there are many aspects of the 2014 record that are highly significant. It was a large jump in surface temperature without the assist of an El Nino. This record clearly indicates that the trend is remaining on track with the long term trend. And on and on.

Far from obscuring what really matters, the 2014 record actually accentuates what really matters. This record is an exclamation point at the end of a strong statement!

By Rob Honeycutt (not verified) on 22 Jan 2015 #permalink

Andy... Perhaps a better way to have approached this subject would have been the title:

How "Warmest Ever" Headlines Punctuate What Really Matters About Climate Change

By Rob Honeycutt (not verified) on 22 Jan 2015 #permalink

Andy, What really matters about rates of change is what the rate is .

Greg's trope that < 1microKelvin an hour is an "existential threat" is a threat to its own credibility-- the hyperbole in which mechants of fear indulge merely legitimates the motivational rhetoric of mechants of doubt .

By Russell Seitz (not verified) on 22 Jan 2015 #permalink

Rob, good suggestion. It is a point. But a point can punctuate. They do it all the time!

Complete miscue Greg- Your FAQ's are scarcely relevant to what I have just written. , because the issue is not absolute temperture , but rather the magnitude of rates of change whatever the choice of degrees : as a simple matter of the anthropology of science I reflexively chose degrees K because i'm a physicist and Kelvin's are what degrees are called in the vernacular of physics.

It would nor much signify if they were F. C. Reamur or Rankine- any way you cut it , the world is and has been warming at a tate of some tens of microdegrees per day,

While this is bad news for temperate and boreal forest ecotremes, I think it way over the top to call it an existential threat,

By Russell Seitz (not verified) on 22 Jan 2015 #permalink

@ ^ Existential threat for some for sure.

Maybe not an existential threat for you just yet but the implications and the damage and carnage already being wrecked and almost certain to be wrecked. Is bloody well grim. Not to be downplayed and underestimated.

By Astrostevo (not verified) on 22 Jan 2015 #permalink

PS. Oh & Russell Seitz who here brought up the quibble over which temperature unit you use to measure things exactly?

Whatever unit you use, reality is what it is.

Our globe is overheating because of the GHG emissions we're pumping into our atmosphere and its having grave consequences and has worse implications that we're finding coming faster than predicted.

Do you really disagree with the words in the above paragraph and, if so, why and what evidence have you to say otherwise?

By Astrostevo (not verified) on 22 Jan 2015 #permalink

Thanks for your effort to clarify the issues here. While I would like to focus Andy Revkin's argument with which I largely agree, the fact that his comments are dominated by the worst kind of cleversides distractionalism makes it hard. Every effort to introduce reasonableness into the conversation simply enables the reverse. He seems unable to perceive that he is encouraging the thieves of reason. He tends to blame the victims, not the perpetrators.

The problem with that kind of "skepticism" is that it is not skeptical at all. It has a monofocus on "proving" that nothing in the conversation is relevant except removing any obstacles to big fossil's deregulation and expansion efforts.

By Susan Anderson (not verified) on 23 Jan 2015 #permalink


"That kind of 'skepticism'" does not refer to Andy Revkin. While I deplore his embrace of "bridge fuels" I do know this is a matter of proportion and he does make an effort to point out the dangers of extreme fuels. In addition to promoting big fossil, the self-labeled "skeptics" are eager to discredit any development of clean energy sources and any effort to control/regulate the more dangerous effects of fossil exploitation. This attempt to slam the door on progress does not serve them, as humans inhabiting the planet in common with the rest of us, but rather condemns them to the same difficult future we all face.

By Susan Anderson (not verified) on 23 Jan 2015 #permalink