by Greg Laden
In an ongoing effort to discredit mainstream climate science, climate contrarians have incorrectly asserted that there is a “pause” in the rate of global warming. This was never true, but now, it is even less true.
Greg Laden teaches anthropology at Century College and blogs for National Geographic Scienceblogs.com. He is a long time resident of the Twin Cities and has written extensively on matters of climate change and other areas of science.
To any objective observer, the Earth is now a world warmed. The decade 2001-2010 was the hottest decade on record, and every single month since March 1985 has been warmer than the 20th century average. The present year promises to be the sixth warmest year on record. Already this year, our fellow Americans out West have been confronted by record breaking wildfire, extreme drought, and devastating floods. All this in addition to the ongoing pine beetle epidemic ravaging our forests. All of these “natural” disasters are exactly what climate scientists expect from a world warmed by human emissions.
Despite all these facts, the contrarians have been heavily (and somewhat successfully) asserting that the world isn’t warming, that global warming has paused.
While this has always been a blatantly misleading argument that deliberately confuses short-term variation with long-term trends, a new study makes it perfectly clear that the world has warmed.
Contrarians focused on the rate of warming since 1998, which was an exceptionally hot year due to climate change and El Nino. This makes later years appear to be relatively cool, and is a form of lying with statistics. They draw a line on a graph showing the rate of warming from that unnatural peak in 1998 to now, and make it look like warming has continued at a steady pace, and not accelerated as expected (an argument that would fail any Statistics 101 class, as it ignores “regression to the mean”).
With this cherry-picked and statistically laughable graph in hand they cry “Global warming has paused! The climate models have failed!” as though the rate of acceleration of temperatures is somehow going to make or break the fact that carbon dioxide (CO2) is a greenhouse gas. This would be quite the achievement, considering CO2’s greenhouse characteristics have been known since the 1820’s!
Our current system for measuring temperatures has a relatively large area around the poles that is not well covered. This new research uses advanced techniques to fill in the gaps in our measurements. When these holes are filled, what looked like a slight stagnation in the rate at which temperatures were increasing rose to agree with model projections.
What Cowtan and Way found, to the dismay of contrarians, was that when the poles are included the rate of global temperatures has been on pretty much the same upward trajectory since at least the 1950s. Climate change has continued to get worse and worse, despite what contrarians claim.
This means that not only is the “pause” a statistically unsound argument, but now we know it never existed in the first place!
So for those keeping score, the contrarians have only a debunked and imaginary pause in the rate of acceleration of warming, while there is a 97% consensus among climate scientists that humans cause warming, the UN’s climate change panel states 95-100% certainty that humans are causing warming, every major scientific institution endorses the consensus that humans cause warming, there have been almost 345 consecutively warm months in a row, and broken extreme weather records all over the world.
For those that may be wondering what motivates contrarians, since it clearly isn’t the science, other new research finds the answer is exactly what you would suspect. Fame and fortune seemingly outweigh the condemnation that comes with resolutely denying the realities of our warmed world.
Given that sad fact, we begrudgingly await for the contrarians next excuse, now that they have been caught trumpeting this “faux pause.”
Categories: Environment/Nature, Politics/Law/Government, Science/Technology
Progressive Culture | Scholars & Rogues 
“They draw a line on a graph showing the rate of warming from that unnatural peak in 1998 to now, and make it look like warming has continued at a steady pace, and not accelerated as expected (an argument that would fail any Statistics 101 class, as it ignores ‘regression to the mean’).
“With this cherry-picked and statistically laughable graph in hand they cry ‘Global warming has paused! The climate models have failed!’ as though the rate of acceleration of temperatures is somehow going to make or break the fact that carbon dioxide (CO2) is a greenhouse gas.”
Greg, if as you would have the the “skeptics” state, “warming has continued at a steady pace” then this means that temperature is increasing. “Warming” means that the temperature is rising. But then this contradicts their view that warming has “paused”, that is, that the temperature is not rising, or as some would even have it, that the temperature is decreasing because now we are experiencing a “cooling trend”.
Warming at a constant rate would imply rising temperatures over time. As such, global “warming” needn’t necessarily imply that the rate at which temperatures are rising is itself “accelerating”. And as a matter of fact, there is no statistically significant acceleration, at least if what you are looking at is surface temperature (as the study has done) rather than at the climate system’s total heat content, which would include the ocean.
Please see:
“These results indicate that the slowed warming of average global surface temperature is not as significant as previously believed. Surface warming has slowed somewhat, in large part due to more overall global warming being transferred to the oceans over the past decade. However, these sorts of temporary surface warming slowdowns (and speed-ups) occur on a regular basis due to short-term natural influences.”
Global warming since 1997 more than twice as fast as previously estimated, new study shows
Dana Nuccitelli (Guardian UK), 13 November 2013
http://www.theguardian.com/environment/climate-consensus-97-per-cent/2013/nov/13/global-warming-underestimated-by-half
Please feel free not to post my comment once you have corrected the text as at that point it would be superfluous.
An error in the article:
“…considering CO2’s greenhouse characteristics have been known since the 1820’s!”
The facts are as follows:
James Tyndall proved the existence of GHGs in the 1860s.
Svante Arrhenius proved CO2 was a GHG around 1890.
This does not void the message in this article, far from it – but I feel it is important to get things right.
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By the way, fame and fortune is not the only motivation for contrarians:
There seems to be more “skeptics” among conservative-leaning people, than among liberals and democrats. This may be because the “cure” for climate change involves gov’t…
Joseph Fourier argued for a greenhouse effect in 1824.
Timothy, I’m not entirely clear on what you are arguing here. There are two things going on, one the impetus for this discussion, the other having been a matter of discussion for some time. Second one first: The measurement we use to estimate the effects of greenhouse gasses is a combined measurement of the atmosphere and the surface of the ocean. The main reason for using this measurement is that we have the measurement at hand and with a great deal of data. However, this overlooks other effects including, and mainly, the overall warming of the ocean, at various depths. We are now pretty sure that at both moderate (but below sea surface measurements) and great depths there is a lot of heat going into the oceans. The total overall heat that builds up with the greenhouse effect is in fact mainly in the ocean as a whole, though we only have good and long term data for the surface. This is like measuring the amount of business the stores in a shopping mall gets by doing exit interviews of the people only leaving by one, minor exit. It would be an estimate but it could be very wrong if, for example, a big box store on the other side of the mall has a major change in business levels. The big box store is the deep ocean, the minor entrance is our important but smallish sample of overall effects.
The other thing that is happening is that the measure of “surface” warming, the air and sea surface temperature combined, as left out because of sampling problems certain areas of the globe (parts of Africa, the Arctic, etc.). This recent study addresses that. It is quite possible that techniques that get at those blank spots in the data could turn the surface warming estimate downwards, leave the prior estimates more or less unchanged, or increase them. It turns out that they are increased. What was a more or less flattish looking squiggle near the present has bent upwards. It is still, the case, however, that over 90% of the heat is going into the parts of the ocean that are not measured by this entire exercise including the newer data.
Thomas Remme, regarding the history of science…
In 1824, Jean Baptiste Joseph Fourier posited that the earth is warmer due to the atmosphere reducing the rate at which the earth loses heat, “… because heat in the state of light finds less resistance in penetrating the air, than in repassing into the air when converted into non-luminous heat.”
As such Fourier was aware of the greenhouse effect but did not identify specific greenhouse gases. In an article published in 1861, John Tyndall identified carbon dioxide as a greenhouse gas.
Specifically, his experiments were performed in 1859 and described in:
Tyndall, John, 1861. On the Absorption and Radiation of Heat by Gases and Vapours, and on the Physical Connection of Radiation, Absorption, and Conduction. ‘Philosophical Magazine ser. 4, vol. 22, 169-94, 273-85.
… which is available in pdf form at:
National Science Digital Library: ClassicArticles/GlobalWarming/Article3
http://nsdl.org/sites/classic_articles/Article3.htm
… demonstrated that several gases were greenhouse gases due to their absorption of longwave radiation. Among them were carbon dioxide (“carbonic acid”), carbon monoxide (“carbonic oxide”), water vapor (“aqueous vapour”) and nitrous oxide.
Further, he was clearly aware of the role that greenhouse gases might play in climate change. He states on page 277,
“De Saussure, Fourier, M. Pouillet, and Mr. Hopkins regard this interception of the terrestrial rays as exercising the most important influence on climate. Now if, as the above experiments indicate, the chief influence be exercised by the aqueous vapour, every variation of this constituent must produce a change of climate. Similar remarks would apply to the carbonic acid diffused through the air, while almost inappreciable admixture of any of the hydrocarbon vapours would produce green effects on the terrestrial rays and produce corresponding changes of climate. It is not, therefore, necessary to assume alterations in the density and height of the atmosphere to account for different amounts of heat being preserved to the earth at different times; a slight change in its variable constituents would suffice for this. Such changes in fact may have produced all the permutations of climate which the researches of geologist reveal.”
Svante Arrhenius estimated the greenhouse effect due to carbon dioxide in 1896. His paper:
Arrhenius, Svante, 1896. On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground. Philosophical Magazine ser. 5, vol. 41, 237–276.
… is available in PDF form at:
http://nsdl.org/sites/classic_articles/Article4.htm
For more, please see:
NSDL: ClassicArticles/GlobalWarming
http://nsdl.org/sites/classic_articles/GlobalWarming.htm
Greg, the problem I am having is primarily with your essay’s use of the term “accelerating”. Looking just at the surface temperature as the essay does, we are still warming, and in fact, warming at a rate that is approximately 2.5 X what we thought, but the rate of warming has *not accelerated* (from previous years). The rate of warming has actually slowed. Therefore one could validly say that warming has “decelerated” even though the deceleration is by no means statistically significant.
Similarly, the essay unintentionally and over generously misrepresents the “skeptics'” view. The essay states, “They draw a line on a graph showing the rate of warming from that unnatural peak in 1998 to now, and make it look like warming has continued at a steady pace”. Saying that “the world is warming at a steady pace” would be the same as stating that “the world’s temperature is rising at a steady pace”.
“Skeptics” wouldn’t agree to this, at least if they say that the “warming has paused”. What they would say is that the world is no longer warming. And they would draw a line on a graph, making it look like the warming has stopped, and in some cases might even try to make like the warming has been replaced by cooling.
Finally, I agree that the surface temperature will not simply rise at a steady rate but will actually accelerate over time. However, this hasn’t happened yet. Simply looking at the surface data as Cowtan and Way do, comparing the last decade to previous decades, would show that the warming has slowed, that is, that the rate warming has decelerated, even though this is entirely within the bounds of natural variability.
Quoting from the Guardian piece covering Cowtan and Way’s paper:
“Surface warming has slowed somewhat, in large part due to more overall global warming being transferred to the oceans over the past decade. However, these sorts of temporary surface warming slowdowns (and speed-ups) occur on a regular basis due to short-term natural influences.”
Global warming since 1997 more than twice as fast as previously estimated, new study shows
Dana Nuccitelli (Guardian UK), 13 November 2013
http://www.theguardian.com/environment/climate-consensus-97-per-cent/2013/nov/13/global-warming-underestimated-by-half
Incidentally, Cowtan and Way (2013) is now open access, available as a PDF that may be downloaded for free at:
Cowtan, Kevin, and Robert G. Way. “Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends.” Quarterly Journal of the Royal Meteorological Society (2013).
http://onlinelibrary.wiley.com/doi/10.1002/qj.2297/abstract
Timothy, that is correct, Fourier is getting more credit than he deserves here. The greenhouse effect dates to the early 19th century, the specific role of CO2 dates to the middle 19th century with further understanding developed through the rest of the 19th cntury. So, the origins of the scientific understanding of global warming flanks the American phase of the “Industrial Revolution” transition from messy but not smoky water power to messy and smoky coal burning. Point is, we really should know better by now, as this is the 21st century!
“””
Similarly, the essay unintentionally and over generously misrepresents the “skeptics’” view. The essay states, “They draw a line on a graph showing the rate of warming from that unnatural peak in 1998 to now, and make it look like warming has continued at a steady pace”. Saying that “the world is warming at a steady pace” would be the same as stating that “the world’s temperature is rising at a steady pace”.
“Skeptics” wouldn’t agree to this, at least if they say that the “warming has paused”. What they would say is that the world is no longer warming.
“””
You are probably right, the level of sophistication of skeptics may be overstated here!
I don’t think we are different in our understanding of warming, but different people use the term “accelerating” differently. This comes in part from a bit of muddle in how we think CO2 operates. CO2 is not heat, it is not warming the earth. CO2 in the atmosphere changes the chemistry of the atmosphere in such a way that the amount of the sun’s energy that is trapped routinely, for longer, before exiting the system is increased. Every big batch of CO2 that goes into the atmosphere is roughly analogous to a little further depression on a gas pedal of a car. (Though not perfectly analogous)
If we stopped putting CO2 into the atmosphere right now, the warmth of the system would continue to rise, it would not level off, for a considerable period of time. Added CO2 accelerates the long term process.
“Finally, I agree that the surface temperature will not simply rise at a steady rate but will actually accelerate over time. However, this hasn’t happened yet. Simply looking at the surface data as Cowtan and Way do, comparing the last decade to previous decades, would show that the warming has slowed”
Looking at only the data of part of the system doesn’t allow us to make that statement at all. Over 90% of the excess heat goes into the ocean not measured by SST. The standard deviation of ocean heating may well be a very large percentage (in amount) of the “surface” heating.