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How Long Will the Hiatus Period Last?

Snow_Miser

By Snow_Miser,
in Climate Change

How Long Will the Hiatus Period Last?  

44 members have voted

  1. 1. How Long Will the Hiatus Period Last?

    • Until the 2010s
      7
    • Until the 2020s
      9
    • Until the 2030s
      13
    • Until the 2040s
      1
    • Until the 2050s or Later
      14

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PhillipS

PhillipS

Posted
Posted

I would define it as any time a 15 year trend of +.15/decade or greater appears. Or a 10 year trend of +.25 or greater. Even if the trend were Nina to Nino, it would probably indicate substantial warming is occurring (faster than the current rate). Right now even starting in 1999 the trend is not .15C/decade.

 

I didn't phrase my question well, and part of that may be a vagueness in what is meant by the term 'hiatus'.  It seems that every journalist and blogger uses it to mean whatever they want.  If they are talking temps, they use whichever temperature metric supports their position, and the same is true if they are talking trends, they cherry pick the period which 'proves' their point.  A vague and ill-defined term has little value in this discussion.  The dictionary definition for 'hiatus' is [source]:

 

hi·a·tus   [hahy-ey-tuhthinsp.pngthinsp.pngs]  Show IPA
noun, plural hi·a·tus·es, hi·a·tus.
1. a break or interruption in the continuity of a work, series, action, etc.
2. a missing part; gap or lacuna: Scholars attempted to account for the hiatus in the medieval manuscript.
3. any gap or opening.
4. Grammar, Prosody . the coming together, with or without break or slight pause, and withoutcontraction, of two vowels in successive words
 or syllables, as in see easily.
5. Anatomy . a natural fissure, cleft, or foramen in a bone or other structure.

 

I think most of us will agree that the first definition is the relevant one.  Yes?  No?

 

Okay, so the next question is  - an interruption in what, exactly.  

  • Surface temps? (which temperature record?  Daily?  Monthly?  Annual?)
  • Energy imbalance at TOA?  
  • OHC?  
  • Sea levels?
  • Sea ice (Arctic?  Antarctic?  Global?  Area?  Extent?  Volume?)
  • Glacier and Ice Sheet mass balance? 
  • Extreme weather events (Floods? Droughts?  Snowfall? Wildfires?)

And next, of course, is agreeing on the time period needed to constitute a hiatus.  Because most climate and weather metrics have an annual cycle I sincerely hope that nobody on this forum is going to advocate for a period less than a year.  When talking about climate issues 30 years is the accepted minimum period for calculating a statistically valid trend - but I know that many on this forum won't accept that (their reasons for wanting a shorter period are left as an exercise for the reader).  Okay, what period longer than 1 year and shorter than 30 years will be acceptable for our definition of a climate hiatus?  10 years?  15 years?  Or, perhaps a variable period that allows posters to cherrypick the period which suits their wishes. (No warming in 15 years, 16 years, no wait 17 years oh hell since 1997!)

 

And, finally, what criteria will need to be met to say that the hiatus is over and AGW has resumed?  Global warming at a specified rate for a specified period?  Statistically significant global warming for the specified period (95% confidence level?  75% confidence level?)?  A record setting year?  A return to the long-term (1850 to present) rate of warming?  A return to 20th century average rate of warming?  Or something else?

 

My own opinion is that the 30 year minimum period for climate metrics was chosen for the sound reason of evening out natural quasi-periodic climate fluctuations (the weather noise such as ENSO and PDO) and clarifying the underlying climatic trends.  In terms of climate, longer is better - and anything less than a decade is pretty silly.

 

As for which metric to focus on - that's a tough one.  Global climate is complex so focusing on one metric, one facet, and largely ignoring the others seems pointless to me.  But if I had to pick just one metric it would be energy imbalance at TOA.  So long as there is more energy entering the global earth-air-ocean system than is leaving there will be warming.  Internal processes will move that energy around and the energy increase will manifest itself in various ways but there is no getting around the fact that warming is continuing.  So by the criteria of a 30 year trend and energy imbalance at TOA there is no hiatus.

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GaWx

GaWx

Posted
Posted

My guess is we won't see a 15 year trend exceed 0.15C per decade until 2023 at the earliest...the starting point of 2008 would probably be the most likely time period to see that type of trendline.

 

In 2023, we could very well be just coming out of the deepest 11 year cycle minimum since the Dalton cycles. By then, we should have already finally known if this current grand solar minimum will have had a significant cooling effect.

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ORH_wxman

ORH_wxman

Posted
Posted

In 2023, we could very well be just coming out of the deepest 11 year cycle minimum since the Dalton cycles. By then, we should have already finally known if this current grand solar minimum will have had a significant cooling effect.

 

We'll probably need several strong El Ninos in the next 10 years to produce that type of 15 year warming trend by 2023. In the current Pacific regime, I'm a bit skeptical of that but the only real way to find out is to wait and see what these next several years bring.

 

But again, I think the more interesting question is how long and by what magnitude the observations continue to diverge from climate models versus whether or not the trend line stays negative/flat since 2001. We may warm enough in the next decade to produce a positive trend since 2001 by that time, however, if the warming is muted, it won't fix the divergence of observations from climate models.

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PhillipS

PhillipS

Posted
Posted

My guess is we won't see a 15 year trend exceed 0.15C per decade until 2023 at the earliest...the starting point of 2008 would probably be the most likely time period to see that type of trendline.

 

Just so we're clear - 2008 through 2023 is a 16 year period.  Did you mean 2022?  And are you talking about global surface temps?  GISS?  HADCrut?  UAH?

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ORH_wxman

ORH_wxman

Posted
Posted

Just so we're clear - 2008 through 2023 is a 16 year period.  Did you mean 2022?  And are you talking about global surface temps?  GISS?  HADCrut?  UAH?

 

Yes, to the end of 2022 would be more accurate. For global surface temps, I use Hadcrut and GISS as their trendlines do not differ to any significant extent. You can actually include NCDC in there too. Taking the average of datasets is probably the best way to verify a measurement.

 

For TLT, average of RSS/UAH is what I would suggest. Though their long term trends don't differ much either. They have diverged a bit in very recent years.

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tacoman25

tacoman25

Posted
Posted

Lol @ citing Spencer and Braswell. The paper contained so many egregious errors the editor of the journal resigned and apologized for its publication. 

 

Predicting .5C of warming by 2100 is a denier. It is complete denial of the physics of GHGs and the evidence that feedbacks are at the very minimum slightly positive.

 

What evidence? The only rock solid evidence we have so far is what has occurred. We've seen huge increase in CO2 concentration over the last 90 years, and in that time we've seen roughly .5C of warming. Predicting an additional .5C of warming over the next 87 years is certainly expecting minimal warming compared to most and goes against popular thinking, but it does not equal denial of AGW. 

 

If negative feedbacks and/or ocean absorption is greater than current assumptions, it is not out of the realm of possibility that we see no increase in the rate of warming over the coming 87 years.

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tacoman25

tacoman25

Posted
Posted

I didn't phrase my question well, and part of that may be a vagueness in what is meant by the term 'hiatus'.  It seems that every journalist and blogger uses it to mean whatever they want.  If they are talking temps, they use whichever temperature metric supports their position, and the same is true if they are talking trends, they cherry pick the period which 'proves' their point.  A vague and ill-defined term has little value in this discussion.  The dictionary definition for 'hiatus' is [source]:

 

hi·a·tus   [hahy-ey-tuhthinsp.pngthinsp.pngs]  Show IPA
noun, plural hi·a·tus·es, hi·a·tus.
1. a break or interruption in the continuity of a work, series, action, etc.
2. a missing part; gap or lacuna: Scholars attempted to account for the hiatus in the medieval manuscript.
3. any gap or opening.
4. Grammar, Prosody . the coming together, with or without break or slight pause, and withoutcontraction, of two vowels in successive words
 or syllables, as in see easily.
5. Anatomy . a natural fissure, cleft, or foramen in a bone or other structure.

 

I think most of us will agree that the first definition is the relevant one.  Yes?  No?

 

Okay, so the next question is  - an interruption in what, exactly.  

  • Surface temps? (which temperature record?  Daily?  Monthly?  Annual?)
  • Energy imbalance at TOA?  
  • OHC?  
  • Sea levels?
  • Sea ice (Arctic?  Antarctic?  Global?  Area?  Extent?  Volume?)
  • Glacier and Ice Sheet mass balance? 
  • Extreme weather events (Floods? Droughts?  Snowfall? Wildfires?)

And next, of course, is agreeing on the time period needed to constitute a hiatus.  Because most climate and weather metrics have an annual cycle I sincerely hope that nobody on this forum is going to advocate for a period less than a year.  When talking about climate issues 30 years is the accepted minimum period for calculating a statistically valid trend - but I know that many on this forum won't accept that (their reasons for wanting a shorter period are left as an exercise for the reader).  Okay, what period longer than 1 year and shorter than 30 years will be acceptable for our definition of a climate hiatus?  10 years?  15 years?  Or, perhaps a variable period that allows posters to cherrypick the period which suits their wishes. (No warming in 15 years, 16 years, no wait 17 years oh hell since 1997!)

 

And, finally, what criteria will need to be met to say that the hiatus is over and AGW has resumed?  Global warming at a specified rate for a specified period?  Statistically significant global warming for the specified period (95% confidence level?  75% confidence level?)?  A record setting year?  A return to the long-term (1850 to present) rate of warming?  A return to 20th century average rate of warming?  Or something else?

 

My own opinion is that the 30 year minimum period for climate metrics was chosen for the sound reason of evening out natural quasi-periodic climate fluctuations (the weather noise such as ENSO and PDO) and clarifying the underlying climatic trends.  In terms of climate, longer is better - and anything less than a decade is pretty silly.

 

As for which metric to focus on - that's a tough one.  Global climate is complex so focusing on one metric, one facet, and largely ignoring the others seems pointless to me.  But if I had to pick just one metric it would be energy imbalance at TOA.  So long as there is more energy entering the global earth-air-ocean system than is leaving there will be warming.  Internal processes will move that energy around and the energy increase will manifest itself in various ways but there is no getting around the fact that warming is continuing.  So by the criteria of a 30 year trend and energy imbalance at TOA there is no hiatus.

 

Read the original post. It's clear the poster was referring to surface/LT temps. You know, the primary way global warming has always been measured.

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tacoman25

tacoman25

Posted
Posted

I would define it as any time a 15 year trend of +.15/decade or greater appears. Or a 10 year trend of +.25 or greater. Even if the trend were Nina to Nino, it would probably indicate substantial warming is occurring (faster than the current rate). Right now even starting in 1999 the trend is not .15C/decade.

 

I think this is fair. Though I might go more with a 3 year running average. Since, for example, in 2010 someone could have used a 10 year 2000-2010 trend and gotten close to .25C/decade.

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tacoman25

tacoman25

Posted
Posted

My guess is we won't see a 15 year trend exceed 0.15C per decade until 2023 at the earliest...the starting point of 2008 would probably be the most likely time period to see that type of trendline.

 

Given that we will probably remain in -PDO phase until at least 2030, and the -AMO phase should set in over the next 5-10 years and last until at least 2035 (which should result in a cooler Arctic), I don't think we'll see a return to .15C+/decade warming (on a 3 year running average) until at least 2030.

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ORH_wxman

ORH_wxman

Posted
Posted

I think this is fair. Though I might go more with a 3 year running average. Since, for example, in 2010 someone could have used a 10 year 2000-2010 trend and gotten close to .25C/decade.

 

 

I can't even get half this value in the sfc datasets.

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tacoman25

tacoman25

Posted
Posted

I can't even get half this value in the sfc datasets.

 

You're right, I looked at the graph wrong. Using the Wood for Tree Index (average of GISS/HadCRU/UAH/RSS), it looks like about .12C/decade. 

 

But I'd still prefer to go with a 3 year running mean, and if at any point 10+ years the trend reaches .15C/decade, I'd say the hiatus is definitely over.

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Isotherm

Isotherm

Posted
Posted

Good to see that there are plenty of independent thinkers in this forum based on the poll results. It's difficult to get that type of diversity of opinion in the mainstream, which indicates to me that we generally have an educated crowd in here. There are a wide range of possible outcomes over the next 100 years, and I think we need at least another 5-15 years to determine the influence of natural cooling factors w/ the continued increase in CO2 concentrations.

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The_Global_Warmer

The_Global_Warmer

Posted
Posted

As I said last night, it's actually at +.05 currently. The month to date is .052. If the second half of the month is also around .05, then we will see around .6 on GISS. 

 

However, I wouldn't be surprised if it bumps back up to the .1-.2 values we have been seeing for most of the last 2.5 months outside of the spike down in August and the spike down in early October.

 

 

Good call it made it up to .25C today on the real time graph.  For the month it's back up to .060C.  This spike will have to be short lived for the month to finish around where it is now.  I agree though on the rest of the month being mostly back up in the .1-.2C range.

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skierinvermont

skierinvermont

Posted
Posted

Good to see that there are plenty of independent thinkers in this forum based on the poll results. It's difficult to get that type of diversity of opinion in the mainstream, which indicates to me that we generally have an educated crowd in here. There are a wide range of possible outcomes over the next 100 years, and I think we need at least another 5-15 years to determine the influence of natural cooling factors w/ the continued increase in CO2 concentrations.

 

The wide range of opinions indicates an uneducated crowd ignorant of the facts. 

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ORH_wxman

ORH_wxman

Posted
Posted

We are currently tracking along the bottom of the earlier projections. 

 

attachicon.gifpost-564-0-10158300-1381754024.png

 

attachicon.gifpost-564-0-01870500-1381839628.jpg

 

 

 

The next 5-7 years will be a good test to see if the high increase in 0-2000m OHC translates to rapid surface warming. It has in the past going by the available data.

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ORH_wxman

ORH_wxman

Posted
Posted

The interesting thing is that the recent paper by Meehl shows the surface continuing to warm more slowly than

the deeper layers as long as we remain in this -PDO phase. My guess is that climate sensitivity will end up

being closer to 2C than 3C with the deeper oceans taking up the heat during -PDO phases.

 

http://www.cgd.ucar.edu/cas/Staff/Fasullo/my_pubs/Meehl2011etalNCC.pdf

 

http://link.springer.com/article/10.1007/s00382-013-1770-4

 

attachicon.gifpost-564-0-27985200-1381837872.png

 

 

Its too bad we don't have very good OHC data to 2000m prior to ARGO. The limited data we do have shows it tracking the 0-700m very closely previously which begs the question of what causes the recent discrepancy in the two...limited data previously or recent divergence as some response to -PDO? It didn't do that during the previous -PDO.

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Snow_Miser

Snow_Miser

Posted
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Posted

Its too bad we don't have very good OHC data to 2000m prior to ARGO. The limited data we do have shows it tracking the 0-700m very closely previously which begs the question of what causes the recent discrepancy in the two...limited data previously or recent divergence as some response to -PDO? It didn't do that during the previous -PDO.

 

Pretty sure the divergence is being caused by more data with ARGO. 

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AvantHiatus

AvantHiatus

Posted
Posted

Seems like we deal with a methane scare about every 6 months on this forum.

Regardless methane concentrations have been increasing at a steady rate for the past few years after a brief slowdown in the 2000's.

We require the ice to remain in a decent state so that solar radiation does not reach these methane deposits.

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PhillipS

PhillipS

Posted
Posted

Methane has not been increasing nearly as quickly as projected.

 

 

 

I wouldn't put too much weight on the outdated IPCC projections which the new AR5 admits were based on assumptions that didn't hold up.  I feel the actual observations are a better indicator.  Here's the ESRL plot for CH4 at Mauna Loa:

 

ccgg.MLO.ch4.1.none.discrete.all.png

Current CH4 level is around 1825 ppb and it is clear that the increase accelerated around 2007.  But WXHeights posted on arctic CH4 so lets look at the record for Barrow AK:

 

ccgg.BRW.ch4.1.none.discrete.all.png

Current CH4 is around 1925 ppb, a 100 ppb or so higher than the global concentration.  Note that at the start of the time series, in late 1983, global concentration was about 1640 ppb and the arctic was about 1700 ppb, a differential of 60 ppb.  The arctic CH4 concentration is increasing faster than the global concentration.  Also notice in the Barrow record the brief spikes of higher concentrations, some over 2100 ppb.  The ESRL caption says:

 

[Green] symbols are thought to be not indicative of background conditions, and represent poorly mixed air masses influenced by local or regional anthropogenic sources or strong local biospheric sources or sinks.

 

Methane plumes, possibly from undersea or permafrost sources.

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ORH_wxman

ORH_wxman

Posted
Posted

While I have no doubt methane has been increasing slower than projected, even under the AR4, I would prefer a chart that wasn't from WUWT.

 

The way that all the projections start from 1980 appears suspect to me. 

 

 

The figure was from the IPCC AR5 draft...just because its reposted on WUWT doesn't make it invalid. All those graphs that have the color coded like that are from the AR5 draft.

 

http://climatefailfiles.files.wordpress.com/2012/12/ch1-introduction_wg1ar5_sod_ch01_all_final.pdf

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