New Study: No "hiatus" in AGW

[PB GFI]

Judith Curry 

 

http://judithcurry.com/2015/06/04/has-noaa-busted-the-pause-in-global-warming/ 

 

 

2 camps .

 

 

“NOAA is confirming what we have been saying for some time that the ‘hiatus’ in global warming is spurious,” Berkeley team chief and physicist Richard Muller said in an email. Muller said global warming continues but in “many fits and spurts.”

 

 

John Christy of the University of Alabama Huntsville, one of the minority of scientists who dispute the magnitude of global warming, said the Karl paper “doesn’t make sense” because satellite data show little recent warming. “You must conclude the data were adjusted to get this result” of no warming pause, Christy wrote in an email. “Were the adjustments proper? I don’t know at this point.”

[donsutherland1]

I agree with the caution expressed by Dr. Stott and, to some extent, Dr. Curry, while noting the possible confirmation of the Berkeley view. IMO, a careful analysis of the Karl paper and its underlying adjustments, which is now underway in the scientific community, will need to be completed before one can have much greater confidence in the paper's conclusions regarding a possibly weaker or non-existent hiatus.

 

Dr. Christy is making sort of an apples-oranges comparison. The Karl paper concerns land and ocean surface temperatures. The satellite data covers lower tropospheric readings and there is little dispute that atmospheric warming has lagged surface warming, a lag that has damped the warming trend in the satellite data.

[The_Global_Warmer]

Judith Curry

http://judithcurry.com/2015/06/04/has-noaa-busted-the-pause-in-global-warming/

2 camps .

“NOAA is confirming what we have been saying for some time that the ‘hiatus’ in global warming is spurious,” Berkeley team chief and physicist Richard Muller said in an email. Muller said global warming continues but in “many fits and spurts.”

John Christy of the University of Alabama Huntsville, one of the minority of scientists who dispute the magnitude of global warming, said the Karl paper “doesn’t make sense” because satellite data show little recent warming. “You must conclude the data were adjusted to get this result” of no warming pause, Christy wrote in an email. “Were the adjustments proper? I don’t know at this point.”

Is Christy saying he doesn't know of

If the adjustments he made were right?

[PB GFI]

Is Christy saying he doesn't know of

If the adjustments he made were right?

Sorry , just saw this .

Just a guess ..... 

 

In summary 

This is a highly speculative and slight paper that produces a statistically marginal result by cherry-picking time intervals, resulting in a global temperature graph that is at odds with those produced by the UK Met Office and NASA

 

 

1. They make 11 changes (not all are explained) producing the ERSSTv4 Sea Surface Temperature (SST) dataset that includes new estimates for the different way SSTs are measured from ships (intake or buckets). They also add 0.12°C to each buoy to bring their measurements in line with those taken from ships. These issues have been raised before by the UK Met Office when compiling their HadSST3 ocean surface temperature dataset, see, ‘A review of uncertainty in in situ measurements and data sets of sea surface temperature’

 

 

 

6. they do not include any data from the Argo array that is our best coherent data set on ocean temperatures. The authors state this is because Argo temperature data is not surface data. However, ship-derived temperatures can be from as much as 15 m below the surface. The Argo array samples 5 m below the top of the ocean. From 2004 to 2013 it shows considerable variation and little trend. The non-ARGO data aptly demonstrates the problem of starting trend analysis in 1998 or 2000

[The_Global_Warmer]

Ok thanks

I wasn't sure what he was talking about.

[WXheights]

"Our new analysis suggests that the apparent hiatus may have been largely the result of limitations in past datasets, and that the rate of warming over the first 15 years of this century has, in fact, been as fast or faster than that seen over the last half of the 20th century," said Thomas R. Karl, LHD, Director, NOAA's National Centers for Environmental Information.

 

Ok Spin that!

[ORH_wxman]

"Our new analysis suggests that the apparent hiatus may have been largely the result of limitations in past datasets, and that the rate of warming over the first 15 years of this century has, in fact, been as fast or faster than that seen over the last half of the 20th century," said Thomas R. Karl, LHD, Director, NOAA's National Centers for Environmental Information.

 

Ok Spin that!

 

 

Gerald Meehl, a climate researcher at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, told Mashable in an email that while he finds the new study laudable for improving temperature measurements, there are flaws in how the researchers interpreted the data. For example, Meehl says there is still a lower warming trend from 1998 to 2012 compared to the previous base period of 1950 to 1999, “… Thus there is still a hiatus defined in that way.”

Meehl says that adding two years to the time period by including 2013 and then 2014, which was a record warm year, makes the warming trend appear to be 38% larger than previous studies that did not include those two years.

“My conclusion is that even with the new data adjustments, there still was a nominal hiatus period that lasted until 2013 with a lower rate of global warming than the warming rate of the last 50 years of the 20th century,” Meehl says, “and a factor of two slower warming than the previous 20 years from the 1970s to 1990s.”

 

 

 

This is even assuming the data adjustments they did hold up under heavier scrutiny now that the paper is out. 

[The_Global_Warmer]

Well unless the OHC data turns out to be bunk which it won't the hiatus is over.

I can't do it. But there is something like a 90%+ correlation between 0-700m OHC data and surface temps.

This is even higher post Argo.

Of course this is adjusted for lag and smoothed to 3 or 6 months can't remember.

Its very unlikely that is magically going to break down now.

Id guess a modest nina would get giss down to 0.55-0.60C.

A 2008 one maybe 0.50C.

If we only go to neg neutral/ weak Nina then back to Nino by 2017/18 then I think a major jump by 2020 will be in order.

[AvantHiatus]

I remain confident that moderate/strong la nina is no longer possible. The 2008-2012 events filled the deep ocean with 400,000 Hiroshimas' a day.

 

In the unlikely event that this el nino peaks at 3.5C+, only then will we have a chance for the Ocean to recharge w/ moderate la nina.

[ORH_wxman]

I remain confident that moderate/strong la nina is no longer possible. The 2008-2012 events filled the deep ocean with 400,000 Hiroshimas' a day.

 

In the unlikely event that this el nino peaks at 3.5C+, only then will we have a chance for the Ocean to recharge w/ moderate la nina.

 

 

You claim of moderate or strong La Ninas no longer being possible are completely baseless. 

[AvantHiatus]

You claim of moderate or strong La Ninas no longer being possible are completely baseless. 

I know why intuitively. If you understand climate thermal budgets and radiative imbalance you would come to the same conclusion. The radiative forcing has increased by 15% in just the last 10 years and if this rate continues, the natural pattern of ocean dynamics will be overwhelmed by the GHG forcing. This will also cause widespread anoxic events in the long-run.

 

Hear me out for a bit, wait 10 years before throwing my prediction out the window.

[ORH_wxman]

I know why intuitively. If you understand climate thermal budgets and radiative imbalance you would come to the same conclusion. The radiative forcing has increased by 15% in just the last 10 years and if this rate continues the natural pattern of ocean dynamics will be overwhelmed by the GHG forcing. This will also cause anoxic events in the long-run.

 

Hear me out for a bit, wait 10 years before throwing my prediction out the window.

 

 

I do understand them and come to a completely different conclusion. So does the rest of the scientific community. 

[SVT450R]

I guess my idea of a "hiatus" is different then how others look at it.  I look at the hiatus as a continuation of a slower warming rate then what we seen from say 1980-2000.  Do those that say the hiatus is over feel we are moving back to that kind of warming rate?

[chubbs]

I guess my idea of a "hiatus" is different then how others look at it.  I look at the hiatus as a continuation of a slower warming rate then what we seen from say 1980-2000.  Do those that say the hiatus is over feel we are moving back to that kind of warming rate?

 Yes. We are currently above the 1979-2015 regression trendline so temperatures today are not far from what would have been predicted by extrapolation before the hiatus. Expect this trend of roughly 0.16C per decade to continue. However if the models are right we could accelerate to over 0.2C per decade.

[nflwxman]

I guess my idea of a "hiatus" is different then how others look at it.  I look at the hiatus as a continuation of a slower warming rate then what we seen from say 1980-2000.  Do those that say the hiatus is over feel we are moving back to that kind of warming rate?

The hiatus only solidifies faster warming in the future.  La Ninas and -PDOs increases the overall planetary energy imbalance.  I hope people realize that.

[stadiumwave]

The hiatus only solidifies faster warming in the future. La Ninas and -PDOs increases the overall planetary energy imbalance. I hope people realize that.

I DO NOT mean this as a negative, but just a general statement.

It's not known that it "solidifies" faster warming. The theory is that it will. However, with all the uncertainty of all the many variables, both known & unknown, I'd prefer the more humble approach.

It's not a simple matter. If it were there would be zero disagreement among experts in the field...and there are disagreements.

[chubbs]

I DO NOT mean this as a negative, but just a general statement.

It's not known that it "solidifies" faster warming. The theory is that it will. However, with all the uncertainty of all the many variables, both known & unknown, I'd prefer the more humble approach.

It's not a simple matter. If it were there would be zero disagreement among experts in the field...and there are disagreements.

There are no disagreements among those who understand the radiative physics. Its counterintuitive, but the oceans warm fastest during hiatus/La Nina periods because the radiative imbalance that causes the oceans to warm is largest then.

 

[stadiumwave]

There are no disagreements among those who understand the radiative physics. Its counterintuitive, but the oceans warm fastest during hiatus/La Nina periods because the radiative imbalance that causes the oceans to warm is largest then.

allan_etal_2014_imbalance_small.png

Chubbs....there are disagreements.

[vortmax]

Interesting quotes about models by George E. P. Box:

 

"Since all models are wrong the scientist cannot obtain a "correct" one by excessive elaboration...Just as the ability to devise simple but evocative models is the signature of the great scientist so over-elaboration and over-parameterization is often the mark of mediocrity."

 

"Now it would be very remarkable if any system existing in the real world could be exactly represented by any simple model. However, cunningly chosen parsimonious models often do provide remarkably useful approximations. For example, the law PV = RT relating pressure P, volume V and temperature T of an "ideal" gas via a constant R is not exactly true for any real gas, but it frequently provides a useful approximation and furthermore its structure is informative since it springs from a physical view of the behavior of gas molecules. For such a model there is no need to ask the question "Is the model true?". If "truth" is to be the "whole truth" the answer must be "No". The only question of interest is "Is the model illuminating and useful?"."

[SVT450R]

 Yes. We are currently above the 1979-2015 regression trendline so temperatures today are not far from what would have been predicted by extrapolation before the hiatus. Expect this trend of roughly 0.16C per decade to continue. However if the models are right we could accelerate to over 0.2C per decade.

But hasn't the hiatus period depending on where you start and which data set you use, we see something like a 0.09C rise at least from what i have read here.  I don't have the data or know the exact way of determining the trends so maybe someone else could chime in but after the El nino comes to an end how much would that change the warming trend when we will probably cool back off to something like 12-14 levels.  This is what I'm trying to understand when i hear the hiatus is over when most agree that the hiatus represents a slower warming rate.

[chubbs]

But hasn't the hiatus period depending on where you start and which data set you use, we see something like a 0.09C rise at least from what i have read here.  I don't have the data or know the exact way of determining the trends so maybe someone else could chime in but after the El nino comes to an end how much would that change the warming trend when we will probably cool back off to something like 12-14 levels.  This is what I'm trying to understand when i hear the hiatus is over when most agree that the hiatus represents a slower warming rate.

Unfortunetely we have two hiatus threads. I posted the chart below in the other hiatus thread (see the other thread for source). As you can see the hiatus hasn't had any noticeable effect on 30-year trends centered after 1980. The stable 30-year trend is the one I would extrapolate forward.

 

[StudentOfClimatology]

There are no disagreements among those who understand the radiative physics. Its counterintuitive, but the oceans warm fastest during hiatus/La Nina periods because the radiative imbalance that causes the oceans to warm is largest then.

Usually that's the case, but they didn't during the last La Niña dominated timespan from 2006-2012, in fact their warming slowed.

This begs the question: Is OHC reflective of shorter/decadal-scale changes in radiative forcing and subsequent disequilibrium? The answer to that is no. Due to the thermal inertia involved, the deep oceans would take hundreds of years to equilibrate, even to an unchanging radiative forcing that occurred 50+ years ago.

For all intents and purposes, the OHC is largely irrelevant to what we need to do here.

[AvantHiatus]

Usually that's the case, but they didn't during the last La Niña dominated timespan from 2006-2012, in fact their warming slowed.

This begs the question: Is OHC reflective of shorter/decadal-scale changes in radiative forcing and subsequent disequilibrium? The answer to that is no. Due to the thermal inertia involved, the deep oceans would take hundreds of years to equilibrate, even to an unchanging radiative forcing that occurred 50+ years ago.

For all intents and purposes, the OHC is largely irrelevant to what we need to do here.

I believe that was the case only for 0-700m. The pattern was exceptional in its ability to drive heat from the surface thru a combination of factors such as the -IPO and -PDO.

[Msalgado]

The hiatus is irrelevant and yet so many people focus on whether it exists or it doesn't and when it started and when its going to end.  Decadal periods like this with little or no warming are part of the normal distribution of events that would occur in a warming world.  They've happened before, and they will happen again, so in the end they say very little about the long term outcomes of AGW.  By the same token, decadal periods of a faster warming trend have happened and will happen agai nand don't say all that much.

 

I get why people on the internet discuss them, but it's a bit frustrating to see researchers focus on them so much.  Its one thing to examine the mechanisms of short term variability but its another to spend time trying to answer questions just because skeptics focus on the so called hiatus.

[stadiumwave]

The hiatus is irrelevant and yet so many people focus on whether it exists or it doesn't and when it started and when its going to end. Decadal periods like this with little or no warming are part of the normal distribution of events that would occur in a warming world. They've happened before, and they will happen again, so in the end they say very little about the long term outcomes of AGW. By the same token, decadal periods of a faster warming trend have happened and will happen agai nand don't say all that much.

I get why people on the internet discuss them, but it's a bit frustrating to see researchers focus on them so much. Its one thing to examine the mechanisms of short term variability but its another to spend time trying to answer questions just because skeptics focus on the so called hiatus.

One big reason....95%+ of Climate models did not predict a hiatus. Since climate models are based on our understanding of the climate system I'd say it's worth discussing. Also discussion of Climate sensitivity & future predictions come into play also.

Your correct in the sense that a hiatus does not bring into question basic AGW science.

[chubbs]

One big reason....95%+ of Climate models did not predict a hiatus. Since climate models are based on our understanding of the climate system I'd say it's worth discussing. Also discussion of Climate sensitivity & future predictions come into play also.

Your correct in the sense that a hiatus does not bring into question basic AGW science.

Climate models can't simulate the proper timing of ENSO/PDO/AMO so the hiatus doesn't say much about climate models at all. Need to focus on longer-term trends for model evaluation.

[stadiumwave]

Climate models can't simulate the proper timing of ENSO/PDO/AMO so the hiatus doesn't say much about climate models at all. Need to focus on longer-term trends for model evaluation.

But climate models have greatly exaggerated global temps to this point....not even close. Even if the slowdown has stopped, I do not see a great enough increase to catch up the to model predictions. Therefore, it's important.

[ORH_wxman]

But climate models have greatly exaggerated global temps to this point....not even close. Even if the slowdown has stopped, I do not see a great enough increase to catch up the to model predictions. Therefore, it's important.

 

 

I agree on the skepticism of catching the GCM-level warming....regardless of the importance of the hiatus itself. Some of lower TCR GCMs might be realistic, but I think the upper half of them are going to be quite difficult to match. But we shall certainly see how things shake out over the next decade.

[chubbs]

But climate models have greatly exaggerated global temps to this point....not even close. Even if the slowdown has stopped, I do not see a great enough increase to catch up the to model predictions. Therefore, it's important.

Not true. The chart below shows global temperatures are catching up with model predictions.

 

http://www.climate-lab-book.ac.uk/comparing-cmip5-observations/

 

[StudentOfClimatology]

I agree on the skepticism of catching the GCM-level warming....regardless of the importance of the hiatus itself. Some of lower TCR GCMs might be realistic, but I think the upper half of them are going to be quite difficult to match. But we shall certainly see how things shake out over the next decade.

I'm skeptical of this skepticism. The paleoclimate data strongly suggests that ECS/TCR vary significantly over time, in relation to any radiative forcing. The ECS/TCR are governed exclusively by wind/circulation/convective/photochemical processes, so extrapolating those into the future really has no purpose, in my opinion.