Reconciling differences in interpretations of global warming hiatus

May 4, 2017 by Bob Yirka report
Magnitude of and interest in the hiatus. a, Running 10-yr global-mean temperature trends for different observational datasets (coloured lines), where the time indicates the last year of the trend. The natural variability (5th–95th percentile of 10-yr trends) from control simulations of 42 CMIP5 models around the long-term (1951–2012) trend in the observational estimate from Cowtan & Way (thick grey dashed line) and the ensemble mean of the CMIP5 models (thick black dashed line) is given a grey shaded bar (right). Thin dashed lines illustrate the lower bounds on the natural variability around the long-term trends. b, Peer-reviewed studies published annually (histogram) by the end of 2016 that contributed to the understanding of the hiatus (178 papers in total excluding ‘news and views’ and commentaries) and monthly output from ‘Google trends’ for the search criteria “global warming pause” and “global warming hiatus”, normalized to the maximum number of monthly searches for “global warming pause”. Credit: (c) Nature (2017). DOI: 10.1038/nature22315

(Phys.org)—A team of researchers with the Institute for Atmospheric and Climate Science has conducted an analysis of the events surrounding the global warming hiatus of 1998 and 2012 and has concluded that inconsistencies reported by scientists can be attributed to natural short-term weather variations, incomplete data and different methods of modeling. In their paper published in the journal Nature, the group contends that the evidence still shows that long-term global warming is and has been occurring for multiple decades and that it will continue to do so in the future. James Risbey and Stephan Lewandowsky with the Oceans and Atmosphere Commonwealth Scientific and Industrial Research Organization and University of Western Australia offer a News & Views take on the work done by the team in the same issue.

By now, it's common knowledge that most scientists believe the planet is slowly growing warmer, and that the is due to greenhouse gasses emitted into the atmosphere by human activities. Many have also heard that for the period between approximately 1998 to 2012, there was a "pause" or warming hiatus, which many believed meant that the planet ceased growing warmer for approximately fourteen years. This was not the case, the researchers note; the hiatus was, in fact, a period of time when the planet "appeared" to grow warmer at a slower pace than it had been, and in so doing, defied many models that had been built to predict how fast our planet would heat. In this new effort, the researchers went back and looked at the work done by scientists around the planet regarding and the apparent hiatus. They report that what they found were some minor inconsistencies between calculation methods, changes in monitoring methods, natural weather variations and, perhaps most importantly, that scientists are not nearly as good at predicting short-term global changes as they are at predicting long-term global changes.

The researchers point out short-term monitoring methods can create large differences in results—the conversion from boat-dragged temperature gauges to thermometers tied to buoys, for example, caused ocean readings to drop a little due to the absence of heat generated by the boats dragging the sensors. They also note that the first year of the hiatus followed a record-setting heat wave due to an El Niño event—also, there were wind events during the hiatus that could have carried the heat to places that were not being monitored. It was minor events like these, they suggest, that led to inconsistencies in reporting by scientists working on the problem, and because of that, they should not be interpreted by the media or public as disagreement among scientists regarding the magnitude of the problem. Global warming is happening, they emphasize, and while there might be subtle shifts along the way, there is no evidence that it is slowing.

Explore further: El Nino and the end of the global warming hiatus

More information: Iselin Medhaug et al. Reconciling controversies about the 'global warming hiatus', Nature (2017). DOI: 10.1038/nature22315

Abstract
Between about 1998 and 2012, a time that coincided with political negotiations for preventing climate change, the surface of Earth seemed hardly to warm. This phenomenon, often termed the 'global warming hiatus', caused doubt in the public mind about how well anthropogenic climate change and natural variability are understood. Here we show that apparently contradictory conclusions stem from different definitions of 'hiatus' and from different datasets. A combination of changes in forcing, uptake of heat by the oceans, natural variability and incomplete observational coverage reconciles models and data. Combined with stronger recent warming trends in newer datasets, we are now more confident than ever that human influence is dominant in long-term warming.

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34 comments

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SamB
2.3 / 5 (15) May 04, 2017
...defied many models that had been built to predict how fast our planet would heat.


So, just go back and keep tweaking your climate modelling program. That way it will always be right at any specific time and you will always show perfect results. Sounds like a plan.

I remember when the climate prediction programs showed the Maldives sinking by 2010. I guess they junked that program.
PTTG
4.6 / 5 (9) May 04, 2017
It helps if you see the whole data.

https://www.ncdc....ear=2017
Scroofinator
2 / 5 (8) May 04, 2017
has concluded that inconsistencies reported by scientists can be attributed to natural short-term weather variations

If we can attribute short term variations to natural causes, why is it so hard to believe that long term variations can also be (at least in part) natural? The impending grand solar minimum will certainly shed some light on this.
tblakely1357
2.1 / 5 (14) May 04, 2017
Unfalsifiable, snake oil, pseudo science.
BackBurner
2.1 / 5 (14) May 04, 2017
"...there were wind events during the hiatus that could have carried the heat to places that were not being monitored."

The dog ate my global warming. I wonder if these folks have any idea at all how ridiculous they've become?
HannesAlfven
1.9 / 5 (9) May 04, 2017
Be aware that Anthony Watts' site is running a very different headline ...

"A new paper has been published in the Analysis section of Nature called Reconciling controversies about the 'global warming hiatus.' It confirms that the 'hiatus' or 'pause' is real."
IronRain
1.9 / 5 (17) May 04, 2017
It is without any shadow of doubt the most embarrassing failure of modern science that physics lends its name to this evidence-free, self-evidently ludicrous pseudoscientific voodoo cult. Any of you people who are supporting this for purposes of grant funding are on he short list for the Phil Jones charlatan-of-the-year award.
philstacy9
1.7 / 5 (12) May 04, 2017
Political activist "scientists" are publishing fake science as propaganda.
Da Schneib
3.7 / 5 (9) May 05, 2017
There was no "global warming hiatus." This is about the fifteenth article I've read that presents data that show it; put them together and the picture is very clear.

Deniers gonna deny. But the truth will out.
Professor Plum
1.8 / 5 (5) May 06, 2017
I wouldn't hazard to pick a side. I see both arguments and read a lot, including the Farmer's Almanac which has been predicting weather some 200 years based on solar cycles. Like the local weather channel, they're never spot on so I don't imagine anthropogenic climate scientists are any more capable of exact predictions. Still, it doesn't take a scientist to see that pollution caused by humans or a volcano spilling lava into the ocean for decades can't be good.
Dingbone
May 06, 2017
This comment has been removed by a moderator.
Mayday
2 / 5 (4) May 06, 2017
If natural short term variations make local forecasting unreliable and inconsistent, how does any of this work? Is the veracity of any measurement simply based on how well it matches the measuring party's agenda? Broad-scale global measurements barely go back 200 years. Surely that's not enough time to tease out all the noise and variability of a system that operates on millennial time scales(like taking a measurement in a boat's wake!). We have very little idea of the natural short term variability before, what, 1600? And less and less the farther back we look. Can I ask the qualified brains in the room to take a breath and think about this like scientists rather than politicians or social engineers? Or does even asking such a question brand me as evil?
cantdrive85
2.6 / 5 (5) May 06, 2017
Here we show that apparently contradictory conclusions stem from different definitions of 'hiatus' and from different datasets.

They seem to have taken a page from jonesdumb's book, hiatus really means 'hiatus'... Amusing!
And remember, always use the right datasets, i.e. 'cherry pick' until the 'data' conforms to the chosen view.
Sounds so sciency.
A combination of changes in forcing, uptake of heat by the oceans, natural variability and incomplete observational coverage reconciles models and data.

Just take a page from the other pseudoscientists (astrophysicists) and call it 'dark hot'. We're experiencing 'dark warming', or 'dark AGW'. Oops, that might be construed as anthropogenic profiling.

Unfalsifiable, snake oil, pseudo science.

Without a doubt, plain and simple truth.
Da Schneib
3.4 / 5 (5) May 06, 2017
@"Professor" then you have accepted the climate crank arguments. And since they cannot stand rigorous examination, as we see regularly on this site, either you have not properly examined them, or you are not imposing the same rigorous standards on both sides. So the only question is whether you accept arguments unexamined, or have double standards.
zz5555
3.7 / 5 (6) May 06, 2017
If natural short term variations make local forecasting unreliable and inconsistent, how does any of this work?

Because climate is very different to weather. The short term variations are parts of cycles which cancel out over the long term. This makes climate projections possible.
Surely that's not enough time to tease out all the noise and variability of a system that operates on millennial time scales

Millennial time scales are fairly irrelevant to the current warming since it's happening on much shorter time scales than that. An increase of ~0.9C over the last 50 years. The time scale for some internal cycle would have to be much less than 1000 years to cause this.

Cont'd.
zz5555
3.4 / 5 (5) May 06, 2017
We have very little idea of the natural short term variability before, what, 1600? And less and less the farther back we look. Can I ask the qualified brains in the room to take a breath and think about this like scientists rather than politicians or social engineers?

We already do. Think of it this way: Direct measurements show that there is any energy imbalance in the climate system. More energy comes in than goes out. This means that internal variability cannot explain the warming. The external sources are the earth's core and the sun. Both are ruled out, the core because it's contribution is too small and it's not changing, and the sun because it's been providing us with less energy over the last 50 years. (The long shot of cosmic rays have also been ruled out.)

Cont'd.
zz5555
3.7 / 5 (6) May 06, 2017
Projections based on the well known physics of greenhouse gases agree quite well with the observations. All this points to climate scientists as being correct. There's always the chance of an error somewhere, but with all the data and physics we currently have, that's an extremely unlikely possibility.
Or does even asking such a question brand me as evil?

Those aren't bad questions, but consider that scientists, as a group, are actually quite intelligent - despite what the politicians say ;). These questions have been asked and answered long ago. And climate science is quite old and mature for an area of study. Climate science is over 100 years old - older than the theories of relativity and quantum mechanics.
zz5555
3.9 / 5 (7) May 06, 2017
Those aren't bad questions, but consider that scientists, as a group, are actually quite intelligent - despite what the politicians say ;).

I'll also add that, in my experience, scientists are very honest - at least in the hard sciences like physics which make up the bulk of climate science. (I don't have any experience in the softer sciences, like biology, so I won't make that claim here. I would hope it's the same.) Lying about the science and your data is one of the fundamental ways to ruin your career and reputation. This has happened with a number of the "contrarian" scientists.
Mayday
4.2 / 5 (5) May 06, 2017
zz5, thank you for the considered perspective. Much appreciated.
Da Schneib
3.4 / 5 (5) May 06, 2017
@zz5555, my experience is that scientists have no choice but to be honest because their results are checked. This is what peer review provides, and it has been demonstrated to reject false results. Falsification of analysis is rejected immediately; falsification of measurement is rejected after conflicting measurements are published. In either case, the reputation of the scientist is irrevocably damaged. And you are correct, the reputations of contrarians who misrepresent analysis or data have been so ruined.
Da Schneib
3.4 / 5 (5) May 06, 2017
I challenge @"Professor" Plum to present rigorously analyzed evidence to support its assertions that the evidence supporting AGW is somehow equivalent to the Farmer's Almanac.

I'll be frank: I think this is bullpucky. Good luck, @"professor" with no degree.
Da Schneib
3 / 5 (4) May 06, 2017
Obviously the #climatecranks are voting 1s for jebus. Amusing to watch; now watch as you get overruled. And suck on it.
Benni
2.6 / 5 (5) May 06, 2017
Fossil fuels have been the main driver of human prosperity and are responsible for adding decades to life expectancy and increasing gross domestic product and living standards.

If the green crowd that is pursuing the 80 percent greenhouse-gas emissions reduction envisioned by the negotiators of the Paris climate agreement succeed in their goals, he report concludes, "world gross domestic product would be approximately only 4 percent of what it would otherwise be in 2050, with each person living off just $1,200 per year, instead of the $30,600 projected by economists absent carbon-dioxide restrictions.

Who here will be the first to commit their income to $1200/yr so you can live with the Paris Agreement Climate Accords?

Schneibo, you?

Stumpy?

Maybe RNP?

Aw, cmon, somebody other than George be the first to raise your hand.
antigoracle
3 / 5 (4) May 06, 2017
LMAO
"Reconciling differences in interpretations...."
That's AGW Cult speak for covering up the over 60 lies they fabricated to explain the hiatus.
So, what's one more.
Da Schneib
5 / 5 (3) May 07, 2017
@Lenni, I'm doing it but I don't brag about it. And it doesn't cost me $1200/yr. What costs me $1200/mo is the crappy health insurance your buddies forced and then called "Obamacare." It's not Obamacare, it's Reprehensiblecare. Fix it instead of trying to blame it on the black dude.

Maybe the real question is what you're doing. But you won't answer that.
Da Schneib
5 / 5 (2) May 07, 2017
It's probably appropriate that I'm listening to Pink Floyd-- Pigs-- right now. It's all about people who make up stories in order to justify their nasty habits.
zz5555
4.2 / 5 (5) May 07, 2017
That report is from the Heartland Institute, which is well known for just making things up, especially as regards climate change. They also deny the cancer of smoking - so that's an indication of just how incompetent you must be in order to be listening to them. One of the authors of the report is Craig Idso, who is also well known for making things up. He used to have an anti-science website that claimed the MWP was much warmer than the data shows - and linked to actual studies that proved that it wasn't.

Their claim is that life expectancy has increased while CO2 levels have increased - therefore CO2 isn't a problem - which is idiotic on the face of it. Basically, any improvement in economy, medicine, or agriculture is due solely to fossil fuels and increased levels of CO2 have absolutely no negative effects. Both of which are idiotic claims.

And I regret having read another of Benni's silly posts.
Captain Stumpy
4 / 5 (4) May 07, 2017
@benjiTROLL the idiot illiterate math failure
Who here will be the first to commit their income to $1200/yr so you can live with the Paris Agreement Climate Accords?
are you sure you got the math right? after all, if you look at your basic math fail (here: https://phys.org/...als.html ) you can't do simple addition

so i will have to ask: where is the link/reference where you can substantiate your claim?

more to the point: is that in US dollars and based upon any specific area or is that in some other currency based on the cost of living in Bunbonayili, Ghana?

your argument sounds more like some idiotic conspiracy of IPCC world takeover and some bullsh*t redistribution crap
antigoracle
2.6 / 5 (5) May 07, 2017
How "ingenious" of the AGW Cult, to chop of the part of the graph that shows 1998 was the hottest. The cult understands their ignorant Chicken Littles, very well.

One more thing. During this period, manmade CO2 did not slow down, nor stop...go figure.
humy
4.3 / 5 (6) May 08, 2017
...defied many models that had been built to predict how fast our planet would heat.


So, just go back and keep tweaking your climate modelling .

SamB

Yes, that is the way valid science always works; change the theory to fit the data rather than change the data to fit the theory. Anything else is religion and pseudoscience.
Da Schneib
3.7 / 5 (3) May 08, 2017
Trust @Lenni to publish non-peer-reviewed claims from the Fartland "Institute" and claim they're science. @Lenni wouldn't know a science if it jumped up and bit him on the hindquarters.
Davy_Crockett
4.2 / 5 (5) May 08, 2017
The astronaut-scientist Piers Sellers said, and I will paraphrase his words:

The Denier faction is not operating from a scientific basis. They deny the theory, the facts, and the scientific method that has defined anthropogenic warming. They make attacks on the people who present the facts, and set up mock arguments, trying to create and sow confusion in a rear guard action to extend the use of fossil fuels farther into the future.

The worst part is that these clever and educated people KNOW they are pretending and being devil's advocates to promote a pseudo debate with the aim of maximizing the status quo revenue stream.
mtnphot
5 / 5 (4) May 08, 2017
For those who cherry pick; what do you see if you look at the NOAA climate at a glance chart from 1880 to 2017. Do you see a decreasing temperature trend? I guess some Chinese hacker put those numbers there just to perpetuate the hoax. Why waste time learning when ignorance is instantaneous.
Da Schneib
not rated yet May 08, 2017
@mtnphot, "up" pretty much covers it. One really does have to wonder about a mind that is incapable of looking at a graph with higher and higher peaks and valleys and doesn't see "up."

#climatecrank is the right hashtag for this, ummm, noumenon. Use it liberally.

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