Sunday, April 17, 2016

Hilarious Statement Tries to Dismiss Consensus

Judith Curry just highlighted something from somebodies on some blog which (naturally) she agree with:
"In our view, the fact that so many scientists agree so closely about the [causes of the] earth’s warming is, itself, evidence of a lack of evidence for [human caused] global warming."

– D. Ryan Brumberg and Matthew Brumberg
This is a truly hilarious statement, that could only have been made by nonscientists. (I haven't been able to identify these Brumberg chaps, but I'd bet.) That any scientist, even Curry, would agree with it is quite puzzling.

By there logic, there is absolutely no evidence whatsoever for the existence of atoms or conservation of energy, because there's a universal consensus on both.

Look: scientists agree about a great deal in science -- yes, consensus is everywhere except at the edges where research is taking place -- and the sciences that are used to calculate global warming from the many possible physical sources is very well-established science. All scientists agree on the basic laws of quantum mechanics, including the Planck Law (its integral is the Stefan-Boltzmann law), and radiation physics, and the absorption/emission spectrums of the greenhouse gases. As well as the thermodynamics and other physics that go into atmospheric dynamics, which again, are not that complicated and about which there is near-universal agreement.

Given all this, it's just a matter of analyzing and calculating. The consensus of the underlying sciences doesn't mean the calculations are easy -- they certainly aren't, especially for the particulars of the carbon cycle. (Not many deniers seem to realize that the radiative transfer parts of global warming science are among the best known parts of the subject, because they are the most amenable to the standard techniques of analytical physics that physicists have been doing for a long time and are very good at.) Calculating climate sensitivity, which decades of successively more thorough calculations find to be ≈ 3°C ± 1.5°C (note: the uncertainty here just represents the range, not the standard deviation or uncertainly limit), is probably the most difficult calculation scientists have ever attempted. The error bars are still bigger than anyone would like -- but it may not be able to reduce them much more -- but not nearly so big as to justifying ignoring the problem or, given the huge amounts of greenhouse gases we're emitting, waiting for more information while the world keeps warming about about 0.15-0.2°C/decade, which has been the 30-year trend for over a quarter of a century now.

But scientists certainly haven't ignored all other potential causes of modern warming besides anthropogenic GHGs -- indeed, they've looked at them very thoroughly. Because that's what scientists do and how they operate. It's simply that the the data on other possible causes (like changers in solar irradiance) simply do not show they can create as much warming as we're seeing, by a long shot.

And no scientist accepts AGW because there is a "consensus" about it. Again, that's not how the scientists in the field operate (though, knowing what consensus is and isn't, scientists in other fields, knowing how science operates, tend to accept as the consensus as what scientists in the field say it is).

The funny thing is, the absolute best way for any scientist today to get noticed, get tenure, and certainly become famous, would be to prove AGW is wrong. There's a good reason that doesn't happen -- AGW isn't wrong.

Meanwhile, the theory and data on the enhancing the greenhouse effect do show the warming expected from aGHGs, within uncertainties.

Whoever these Brumberg fellows are, they have a poor understanding of science, including the science of anthropogenic global warming. And their excuse is not just laughable, but desperate.

The warmer it gets, the more nuts are falling out of the trees.

--
So why even mention the consensus?

There's only one reason it's talked about with regard to climate science, and that's because the issue is of such importance and too complicated for most of the public to fully understand.

Warming is proceeding so rapidly that societies need to make decisions about it now (and should have 20 years ago). These decisions are and will require changes in public policies, but how is the public supposed to know if the decisions are warranted? Since they're not going to learn quantum mechanics and radiative physics and the particulars of the carbon cycle, they need some other standard on which to base their reactions, and the only other thing that is available is the degree of agreement of scientists on the underlying cause(s) of global warming. And there is a consensus on that -- man's emissions of greenhouse gases from burning fossil fuels.

String theory need not involve the public, besides funding it. Or the search for the Higgs boson, or most of what the world's chemists, geologists, biologists, physicists and others are working on. But there are a few scientific topics that stand out as having important consequences at this point and time -- such as tobacco's health effects, ozone depletion, genetically modified organisms, CRISPR/Cas9, artificial intelligence -- and there "consensus" is about all nonspecialists have to go on if they are to form a judgement and what steps should be taken.

So attempts to gauge the degree of consensus are important (though personally I find them boring) and meaningful, and hence the recent Cook et al metastudy on it. But I don't see any more studies, such as metanstudies where n>1, are going to convince people who don't want to acknowledge the consensus in the first place for reasons that have nothing to do with science.

159 comments:

Peter Gleick said...

David, good column though you may have been too easy on JC. (But fyi, there are many typos... You might proofread a tad more... A bit distracting. Thx.)

Layzej said...

The Judith Curry Principal is a (hopefully soon to be) well known law of science. It is seemingly paradoxical but quite obviously true after close examination. Almost no scientists accepts it and therefor (by applying the principal) we can conclude that it almost certainly cannot be wrong.

magmacc said...

The Brumbergs are brothers from New York in their early 30s and working in finance. David Ryan Brumberg ran unsuccessfully for Congress (New York's 14th District) in 2010, as a Republican, naturally.

Ryan Brumberg lists a law degree from Stanford and Matthew Brumberg a bachelor's degree in mathematics and economics from Dartmouth.

Both brothers are being sued by San Francisco investment firm Thiel Macro LLC, which alleged they misappropriated source code and other confidential information in December 2013 and January 2014 while employed on a team developing a quantitative investment algorithm.

Dano said...

It's almost as if someone is using denialists as Internet Performance Art. Comedy writers keeping their chops between seasons? College drama classes?

Best,

D

David in Cal said...

I agree with David Appel's point. A high degree of consensus doesn't weaken a conclusion. However, there are two consensus tricks that continue to be used:

1. Omitting the quantifier: Consider the statement, "It is stated that around 97% agree that human activity, particularly carbon dioxide emissions, causes global warming." In fact the consensus is that human activity causes some amount of global warming. There is no consensus about how much warming is caused by human activity.

2. Saying there is a consensus on global warming, without saying what the consensus opinion is. This trick encourages a reader to imagine that there is a consensus about every aspect of climate change theory. Judith Curry explains that some parts of global warming theory have a scientific consensus and some parts don't.

Cheers

Layzej said...

There is a strong consensus on how much warming is caused by human activity.

From Cook et al 2013, 88% of the papers that quantify the cause find that humans are the primary cause of recent global warming. Still a strong consensus.

Verheggen et al 2014 find 90% of respondents with more than 10 climate-related peer-reviewed publications explicitly agreed with anthropogenic greenhouse gases (GHGs) being the dominant driver of recent global warming. Most believed that GHGs accounted for 75-100% of the warming, except for those with expertise in attribution or aerosols. Those with expertise largely acknowledged that GHGs accounted for >100% of recent warming.

David Appell said...

Thanks magmacc. I noticed this from their LinkedIn pages, but didn't feel like confirming it....

But this makes it clear they are nonscientists.... And clearly they do not understand science in the least.

David in Cal said...

Layzej - I have no confidence in that Cook paper. But, let's accept it for the sake of discussion. It still leaves no consensus on the actual rate of human-caused warming. Does human activity cause warming at a rate of 0.5° C per century? 3.0° C per century? 6.0° C per century? Some other figure? Even accepting Cook, there's no consensus on the specific rate of human-caused warming.

David Appell said...

DiC wrote:
"Does human activity cause warming at a rate of 0.5° C per century? 3.0° C per century? 6.0° C per century? Some other figure?"

How is it you are incapable of reading the literature (summarized in the 5AR) on this topic?

Layzej said...

DiC,

Please read the following papers:

1992 Implications For Global Warming Of Intercycle Solar Irradiance Variations Nature Schlesinger| Me; Ramankutty| N
1992 Past| Present And Future Levels Of Greenhouse Gases In The Atmosphere And Model Projections Of Related Climatic Changes Journal Of Experimental Botany Roeckner| E
1993 Evidence On The Climate Impact Of Solar Variations Energy Baliunas| S; Jastrow| R
1993 How Sensitive Is The Worlds Climate Research & Exploration Hansen| J; Lacis| A; Ruedy| R; Sato| M; Wilson| H
1994 Greenhouse Statistics - Time-series Analysis .2. Theoretical And Applied Climatology Tol| Rsj
1995 Climate Response To Increasing Levels Of Greenhouse Gases And Sulfate Aerosols Nature Mitchell| Jfb; Johns| Tc; Gregory| Jm; Tett| Sfb
1997 Assessments Of The Global Anthropogenic Greenhouse And Sulfate Signal Using Different Types Of Simplified Climate Models Theoretical And Applied Climatology Schonwiese| Cd; Denhard| M; Grieser| J; Walter| A
1998 A Bayesian Statistical Analysis Of The Enhanced Greenhouse Effect Climatic Change Tol| Rsj; De Vos| Af
1999 Cfc And Halon Replacements In The Environment Journal Of Fluorine Chemistry Mcculloch| A

Layzej said...

And also these:

2000 Causes Of Climate Change Over The Past 1000 Years Science Crowley| Tj
2000 Radiative Forcings And Global Warming Potentials Of 39 Greenhouse Gases Journal Of Geophysical Research-atmospheres Jain| Ak; Briegleb| Bp; Minschwaner| K; Wuebbles| Dj
2000 Recent Warming In A 500-year Palaeotemperature Record From Varved Sediments| Upper Soper Lake| Baffin Island| Canada Holocene Hughen| Ka; Overpeck| Jt; Anderson| Rf
2000 Response Of The Ncar Climate System Model To Increased Co2 And The Role Of Physical Processes Journal Of Climate Meehl| Ga; Collins| Wd; Boville| Ba; Kiehl| Jt; Wigley| Tml; Arblaster| Jm
2001 Strong Radiative Heating Due To The Mixing State Of Black Carbon In Atmospheric Aerosols Nature Jacobson| Mz
2002 Global Warming 2001 Journal De Physique Iv Berger| A
2002 Modeling Future Climate Changes: Certainties And Uncertainties Houille Blanche-revue Internationale De L Eau Le Treut| H
2003 Global Warming: Are We Confusing Cause And Effect? Energy Sources Khilyuk| Lf; Chilingar| Gv
2003 Do Models Underestimate The Solar Contribution To Recent Climate Change? Journal Of Climate Stott| Pa; Jones| Gs; Mitchell| Jfb
2003 Modern Global Climate Change Science Karl| Tr; Trenberth| Ke
2003 Utilization Of Carbon Dioxide As Soft Oxidant In The Dehydrogenation Of Ethylbenzene Over Supported Vanadium-antimony Oxide Catalystst Green Chemistry Chang| Js; Vislovskiy| Vp; Park| Ms; Hong| Dy; Yoo| Js; Park| Se
2004 Numerical Simulation Of Global Temperature Change During The 20th Century With The Iap/lasg Goals Model Advances In Atmospheric Sciences Ma| Xy; Guo| Yf; Shi| Gy; Yu| Yq
2004 Soot Climate Forcing Via Snow And Ice Albedos Proceedings Of The National Academy Of Sciences Of The United States Of America Hansen| J; Nazarenko| L
2005 Is The Sonoran Desert Losing Its Cool? Global Change Biology Weiss| Jl; Overpeck| Jt
2005 Mid-late Holocene Monsoon Climate Retrieved From Seasonal Sr/ca And Delta(18)o Records Of Porites Lutea Corals At Leizhou Peninsula| Northern Coast Of South China Sea Global And Planetary Change Yu| Kf; Zhao| Jx; Wei| Gj; Cheng| Xr; Wang| Px
2006 On Global Forces Of Nature Driving The Earth's Climate. Are Humans Involved? Environmental Geology Khilyuk| Lf; Chilingar| Gv
2006 Assessment Of Twentieth-century Regional Surface Temperature Trends Using The Gfdl Cm2 Coupled Models Journal Of Climate Knutson| Tr; Delworth| Tl; Dixon| Kw; Held| Im; Lu| J; Ramaswamy| V; Schwarzkopf| Md; Stenchikov| G; Stouffer| Rj
2006 Observational Constraints On Past Attributable Warming And Predictions Of Future Global Warming Journal Of Climate Stott| Pa; Mitchell| Jfb; Allen| Mr; Delworth| Tl; Gregory| Jm; Meehl| Ga; Santer| Bd
2006 Phenomenological Solar Contribution To The 1900-2000 Global Surface Warming Geophysical Research Letters Scafetta| N; West| Bj
2006 Positive Feedback Between Global Warming And Atmospheric Co2 Concentration Inferred From Past Climate Change Geophysical Research Letters Scheffer| M; Brovkin| V; Cox| Pm
2006 Study On Co2 Recovery System From Flue Gas By Honeycomb Type Adsorbent I - (results Of Tests And Simulation) Kagaku Kogaku Ronbunshu Matsukuma| Y; Matsushita| Y; Kakigami| H; Inoue| G; Minemoto| M; Yasutake| A; Oka| N
2006 Transient Climate Simulations With The Hadgem1 Climate Model: Causes Of Past Warming And Future Climate Change Journal Of Climate Stott| Pa; Jones| Gs; Lowe| Ja; Thorne| P; Durman| C; Johns| Tc; Thelen| Jc

Layzej said...

And these:

2007 A Model For The Co2 Capture Potential International Journal Of Greenhouse Gas Control Stanyeland| A
2007 Avoiding Self-organized Extinction: Toward A Co-evolutionary Economics Of Sustainability International Journal Of Sustainable Development And World Ecology Gowdy| J
2007 Co2 Emissions From Road Transport And Selected Parts In The Kosice City Acta Montanistica Slovaca Carach| V; Muller| G; Janoskova| K
2007 Global Climate Change And Children's Health Pediatrics Shannon| Mw; Best| D; Binns| Hj; Forman| Ja; Johnson| Cl; Karr| Cj; Kim| Jj; Mazur| Lj; Roberts| Jr; Shea| Km
2007 Global Warming Is Driven By Anthropogenic Emissions: A Time Series Analysis Approach Physical Review Letters Verdes| Pf
2008 Cooling Of Atmosphere Due To Co2 Emission Energy Sources Part A-recovery Utilization And Environmental Effects Chilingar| Gv; Khilyuk| Lf; Sorokhtin| Og
2008 Banagrass Vs Eucalyptus Wood As Feedstocks For Metallurgical Biocarbon Production Industrial & Engineering Chemistry Research Yoshida| T; Turn| Sq; Yost| Rs; Antal| Mj
2008 Carbonation Of Alkaline Paper Mill Waste To Reduce Co2 Greenhouse Gas Emissions Into The Atmosphere Applied Geochemistry Perez-lopez| R; Montes-hernandez| G; Nieto| Jm; Renard| F; Charlet| L
2008 Climate Policy Architectures For The Post-kyoto World Environment Aldy| Je; Stavins| Rn
2008 Cycle Analysis Of Low And High H(2) Utilization Sofcs/gas Turbine Combined Cycle For Co(2) Recovery Electronics And Communications In Japan Taniuchi| T; Sunakawa| D; Nagahama| M; Araki| T; Onda| K; Kato| T
2008 Energy Sources And Global Climate Change: The Byrazilian Case Energy Sources Part A-recovery Utilization And Environmental Effects Simoes| Af; La Rovere| El
2008 Implications Of "peak Oil'' For Atmospheric Co(2) And Climate Global Biogeochemical Cycles Kharecha| Pa; Hansen| Je
2008 Industrialization| Fossil Fuels| And The Transformation Of Land Use Journal Of Industrial Ecology Erb| Kh; Gingrich| S; Krausmann| F; Haberl| H
2008 Leaf Carbon Assimilation In A Water-limited World Plant Biosystems Loreto| F; Centritto| M
2008 On Avoiding Dangerous Anthropogenic Interference With The Climate System: Formidable Challenges Ahead Proceedings Of The National Academy Of Sciences Of The United States Of America Ramanathan| V; Feng| Y
2008 The Potential Of Water Power In The Fight Against Global Warming In The Us Energy Policy Kosnik| L
2009 Greenhouse Gases And Greenhouse Effect Environmental Geology Chilingar| Gv; Sorokhtin| Og; Khilyuk| L; Gorfunkel| Mv
2009 Potential Dependence Of Global Warming On The Residence Time (rt) In The Atmosphere Of Anthropogenically Sourced Carbon Dioxide Energy & Fuels Essenhigh| Rh
2009 Climate Change And Drying Of Agricultural Products Drying Technology Piacentini| Rd; Mujumdar| As
2009 Climate Changes And The Actions Of The European Union For Environmental Protection Metalurgia International Brezoi| Ag; Tharin| M
2009 Cost-benefit Analysis Of Climate Change Dynamics: Uncertainties And The Value Of Information Climatic Change Rabl| A; Van Der Zwaan| B

Layzej said...

And finally these:

2010 Empirical Evidence For A Celestial Origin Of The Climate Oscillations And Its Implications Journal Of Atmospheric And Solar-terrestrial Physics Scafetta| N
2010 On Some Achievements And Major Problems In Mathematical Modeling Of Climatic Characteristics Of The Ocean (critical Analysis) Izvestiya Atmospheric And Oceanic Physics Sarkisyan| As
2010 A Novel Formulation Of Carbon Emissions Costs For Optimal Design Configuration Of System Transmission Planning Renewable Energy Sadegheih| A
2010 Analysis Of The Global Warming Dynamics From Temperature Time Series Ecological Modelling Viola| Fm; Paiva| Sld; Savi| Ma
2010 Assessing The Climatic Benefits Of Black Carbon Mitigation Proceedings Of The National Academy Of Sciences Of The United States Of America Kopp| Re; Mauzerall| Dl
2010 Conceptual Design And Simulation Analysis Of Thermal Behaviors Of Tgr Blast Furnace And Oxygen Blast Furnace Science China-technological Sciences Zhang| H; Li| Hq; Tang| Q; Bao| Wj
2010 Consumption-based Accounting Of Co(2) Emissions Proceedings Of The National Academy Of Sciences Of The United States Of America Davis| Sj; Caldeira| K
2010 Dynamic Competition Under Cap And Trade Programs Infor Jeev| K; Campos-nanez| E
2010 Short-term Effects Of Controlling Fossil-fuel Soot| Biofuel Soot And Gases| And Methane On Climate| Arctic Ice| And Air Pollution Health Journal Of Geophysical Research-atmospheres Jacobson| Mz
2010 The Copenhagen Accord For Limiting Global Warming: Criteria| Constraints| And Available Avenues Proceedings Of The National Academy Of Sciences Of The United States Of America Ramanathan| V; Xu| Yy
2011 Is Global Warming Mainly Due To Anthropogenic Greenhouse Gas Emissions? Energy Sources Part A-recovery Utilization And Environmental Effects Zhao| Xb
2011 Coupled Climate-society Modeling Of A Realistic Scenario To Achieve A Sustainable Earth Journal Of Oceanography Ikeda| M
2011 Early Onset Of Significant Local Warming In Low Latitude Countries Environmental Research Letters Mahlstein| I; Knutti| R; Solomon| S; Portmann| Rw
2011 Earth's Energy Imbalance And Implications Atmospheric Chemistry And Physics Hansen| J; Sato| M; Kharecha| P; Von Schuckmann| K
2011 Emergent Dynamics Of The Climate-economy System In The Anthropocene Philosophical Transactions Of The Royal Society A-mathematical Physical And Engineering Sciences Kellie-smith| O; Cox| Pm
2011 Insights On Global Warming Aiche Journal Seinfeld| Jh
2011 Isolation And Application Of So(x) And No(x) Resistant Microalgae In Biofixation Of Co(2) From Thermoelectricity Plants Energy Conversion And Management Radmann| Em; Camerini| Fv; Santos| Td; Costa| Jav
2011 On The Time-varying Trend In Global-mean Surface Temperature Climate Dynamics Wu| Zh; Huang| Ne; Wallace| Jm; Smoliak| Bv; Chen| Xy
2011 Performance Of Amine-multilayered Solid Sorbents For Co(2) Removal: Effect Of Fabrication Variables International Journal Of Greenhouse Gas Control Jiang| Bb; Kish| V; Fauth| D; Gray| Ml; Pennline| Hw; Li| By
2011 Sensitivity Of The Attribution Of Near Surface Temperature Warming To The Choice Of Observational Dataset Geophysical Research Letters Jones| Gs; Stott| Pa
2011 The Relative Contribution Of Waste Heat From Power Plants To Global Warming Energy Zevenhoven| R; Beyene| A

Richard Mallett said...

I have two questions :-

Why do the scientists referred to in https://en.wikipedia.org/wiki/List_of_scientists_opposing_the_mainstream_scientific_assessment_of_global_warming take the opposing view ? Do they simply not understand the science as well as those who take the alarmist viewpoint ?

And can the science explain the periods of warming and cooling at http://berkeleyearth.lbl.gov/regions/global-land particularly those before CO2 had an effect ?

Layzej said...

Hi Richard,

You probably want to ask the dissenters why they oppose the mainstream science that you find alarming.

Regarding CO2 vs Temps, you can see how they compare here: http://phosphorus.github.io/app.html?id=104998758&full-screen=true

Red is CO2 and green is temp.

You can see that CO2 has overwhelmed other forcings over the last 100 years or so. If you are curious about what other forcings exist you can see chapter 8 of AR5: http://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter08_FINAL.pdf

Richard Mallett said...

Reply to Layzej :-

It would take a long time (and would be unlikely to provoke sufficient responses) to ask all those 60 scientists on the list why they hold the opinions that they do, especially when they have produced numerous scientific papers explaining just that.

Regarding http://phosphorus.github.io/app.html?id=104998758&full-screen=true I find the controls very difficult to operate accurately. Please tell me where I can find the data used to produce this chart. Many thanks in advance.

It is also a pity (and a surprise) that the red curve (which you say is CO2) doesn't go back anywhere near as far as the green curve (which you say is temperature) when both have been measured in ice cores.

Please tell me where I can find temperature and CO2 data for (say) the last 2000 years. Of course, I appreciate that the climate alarmists cast doubt on temperature proxies before 1750.

If we look at the last 100 years, from 1915-2015, compared to earlier periods, we can look at HadCRUT4 from 1850 and Berkeley Earth Land and Ocean from 1850. Taking the average of these temperature data sets. we find :-

Cooling from 1850 to 1861 at -1.25 C per century
Warming from 1861 to 1877 at +1.16 C per century
Cooling from 1877 to 1910 at -0.66 C per century
Warming from 1910 to 1943 at +1.44 C per century
Cooling from 1943 to 1955 at -0.97 C per century
Stasis from 1955 to 1975 at -0.06 C per century
Warming from 1975 to 2015 at +1.73 C per century

How does science explain these fluctuations ? Natural variability ?

Let us compare the rate of temperature increase before 1915 to the rate of temperature increase after 1915. To use comparable period lengths, we need to look at the BEST Global Land data, which go back to 1750.

Warming 1815 to 1915 (linear trend) = +0.55 C per century
Warming 1915 to 2015 (linear trend) = +1.12 C per century

Therefore the extra warming over the past century = +0.57 C per century. Why do the alarmists find this increase in the warming rate so alarming, when (so far) there seems to be no quantitative evidence of more extreme weather, and (for example) crop production has increased over that time ?

Warming periods throughout history seem to have been beneficial, while cooling periods seem to have been catastrophic.

David Appell said...

Richard wrote:
"Please tell me where I can find temperature and CO2 data for (say) the last 2000 years."

I do not like questions posed as challenges when the questioner clearly hasn't done their homework.

Richard, I see these data presented all the time, but I (or other commenters) aren't here to be your personal librarian. It's your obligation to find these data sources yourself. Then come back and continue your questioning if you want. But don't pretend these data aren't out there, because they obviously are.

David Appell said...

Richard Mallett said...
"Reply to Layzej :-
"It would take a long time (and would be unlikely to provoke sufficient responses) to ask all those 60 scientists on the list why they hold the opinions that they do, especially when they have produced numerous scientific papers explaining just that."

Again, do your own homework. If you aren't willing to ask or study those 60 scientists, why do you expect someone else to do it for you?

David Appell said...

Richard wrote:
"...when (so far) there seems to be no quantitative evidence of more extreme weather"

"Global warming already driving increases in rainfall extremes: Precipitation extremes are affecting even arid parts of the world, study shows," Nature 3/7/16
http://www.nature.com/news/global-warming-already-driving-increases-in-rainfall-extremes-1.19508

"Increased record-breaking precipitation events under global warming," J Lehmann et al, Clim. Change 132, 501–515 (2015).
http://link.springer.com/article/10.1007%2Fs10584-015-1434-y


"and (for example) crop production has increased over that time?"

Many factors determine crop production. You have to factor all the others out (or at least the major ones) to look for a climate effect. Like

“For wheat, maize and barley, there is a clearly negative response of global yields to increased temperatures. Based on these sensitivities and observed climate trends, we estimate that warming since 1981 has resulted in annual combined losses of these three crops representing roughly 40 Mt or $5 billion per year, as of 2002.”
-- “Global scale climate–crop yield relationships and the impacts of recent warming," David B Lobell and Christopher B Field 2007 Environ. Res. Lett. 2 014002 doi:10.1088/1748-9326/2/1/014002
http://iopscience.iop.org/1748-9326/2/1/014002

Layzej said...

"How does science explain these fluctuations ? "

Did you read chapter 8 of AR5? I even provided a link...

Layzej said...

"Warming 1815 to 1915 (linear trend) = +0.55 C per century
Warming 1915 to 2015 (linear trend) = +1.12 C per century"

Seems to be accelerating.

Richard Mallett said...

I tried to edit my comment in preview mode before posting, and it disappeared, so here is the shorter version. I now realise that I sdhould have clicked the edit link first.

Reply to Layzej :-

1. Yes I did look through AR5 chapter 8, but I didn't see any explicit quantitative discussion of warming and cooling periods. Could you please tell me where it is in AR5 chapter 8 ? Many thanks in advance.

2. Yes, I did show that the warming from 1815 to 1915 was less than the warming from 1915 to 2015. I even suggested that this increase of +0.57 C per century was due to anthropogenic effects. My question was why the alarmists find this anthropogenically influenced rise of +0.57 C per century so alarming.

Reply to David Appell :-

1. I did search for temperatures and CO2 over the last 2000 years, but didn't find anything quantitative. As I mentioned, many alarmists dismiss proxy data, so I was hoping that you would suggest one or more data sets that you personally believe are reliable. For example, I was told elsewhere that Greenland ice core data was not acceptable, because it only referred to Greenland, and was not applicable to the globe as a whole.

2. I just wondered why you appear to dismiss the arguments of those 60 scientists out of hand. I do not feel that it is incumbent on me to present the arguments of those 60 scientists. I just wondered why you find those arguments unconvincing.

3. (a) The two papers on rainfall extremes are paywalled, and I am not prepared to pay for access just to see if they support your arguments, sorry.

Do you agree that the IPCC have backed away from the argument that increased temperature (if it continues) will cause more extreme events ? I seem to remember reading that.

3. (b) the paper on crop production was very interesting. Obviously they mention a number of caveats in their conclusion, so more research needs to be done on this. For example, some areas of the world will benefit from increased temperatures and CO2 by allowing crops to be grown in areas where it would have been impossible before.

Apologies if I have missed anything in my rewrite, after my original reply disappeared when I tried to edit it in preview mode without clicking on the edit link first.

Layzej said...

Hi Richard,

1) Try reading the references in AR5 chapter 8.

2) You should ask some alarmists I guess.

Layzej said...

If you are interested in impacts of rising temps then I would recommend AR5 WG2: https://www.ipcc.ch/report/ar5/wg2/

Layzej said...

I'll take a stab at some of the questions directed at our host.

1) If you're interested in Greenland then a Greenland core should be fine for temp. If you're interested in the globe then obviously it would not. CO2 is a well mixed gas so a core from anywhere is probably fine.

2) What arguments?

3) If you're interested in the science then you'll need to read the literature.
b) see https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter12_FINAL.pdf

Richard Mallett said...

Reply to Layzej :-

1. So after reading a 62 page paper, you want me to track down 20 pages of references, and read all those as well, in order to find the answer to why there are so many periods of warming and cooling, particularly in the period before anthropogenic effects ? Is that it ?

2. So now you want me to read 30 chapters and 4 appendices to see if any of those explain why the alarmists are so alarmed over the impact of rising temperatures ?

You would not make a good press spokesman :-)

More to follow.

Richard Mallett said...

Reply to Layzej :-

1. (Point 2 at 10:21)

As you suggest that I ask some alarmists why they find the anthropogenic effect of +0.57 C so alarming, I presume that you don't find this alarming. Nor do I.


2. (Point 2 at 11:16)

If you don't know the arguments of the 60 scientists who are sceptical, it is not up to me to present them all to you. If you are not familiar with those arguments, then you have no basis on which to criticise them. Every scientist (if you are one you will know this) has the responsibility to address those professional critics of their own work, and to explain why your theory is better than theirs.

3. (Point 1 at 11:16)

Since you take the view that Greenland ice core measurements are not an appropriate proxy for global temperatures, please suggest some proxies for global tenperatures that you consider are appropriate. Many thanks in advance.

4. (Point 3 at 11:16)

Now you want me to read a 108 page chapter to see if it (or some part of it) answers the two simple questions that I posed originally. It has been reported that :-

Einstein, having a final discussion with de Broglie on the platform of the Gare du Nord in Paris, whence they had traveled from Brussels to attend the Fresnel centenary celebrations, said "that all physical theories, their mathematical expressions apart ought to lend themselves to so simple a description 'that even a child could understand them.' "

Layzej said...

1) ok. So what?

2) What are you on about? I never criticized 60 scientists. We can all have a good laugh at Judy though for the subject of this post.

3) You'd need to find a way to combine multiple proxies. I think there's literature on that. You may want to start with AR5 WG1 chapter 5: http://www.ipcc.ch/report/ar5/wg1/

4) You don't need our opinion on the current IPCC position on this or that. The papers are freely available. I even provided a link.

Richard Mallett said...

1. If you just laugh at Professor Judith Curry, who has presented her arguments before the US Congress (I would guess that you have not, since your answers to my questions here are so obtuse) then perhaps I'm being too kind to you when I say that you criticise the 60 scientists who are sceptical of catastrophic anthropogenic global warming.

Perhaps you merely laugh at them also. Anyone can laugh instead of providing cogent arguments supported by evidence, which Professor Curry does.

2. No, I don't need to find a way to combine multiple proxies. I need to know which of the multiple proxies you find acceptable. It is no use me posting information from this or that proxy when you could just reject it.

3. Yes, you have provided links to dozens / hundreds of papers and IPCC reports, each of dozens / hundreds of pages, without saying where in those hundreds / thousands of pages there is evidence that supports your position. Maybe your evidence is nowhere in those hundreds / thousands of pages. Nobody would ever know.

It is interesting that you have started to use the plural pronoun 'we' - is that you and David Appell ?

Are you the only ones who just laugh at Professor Curry, or are there others ?

Why don't you try to engage her in debate, rather than merely laughing at her ?

She does't laugh at you for providing links to dozens / hundreds of papers and IPCC reports consisitng of hundreds / thousands of pages as your sole argument.

Layzej said...

1) Her argument is that closer scientific agreement is evidence of a lack of evidence. That is laughable.

2) If you have a question about a proxy then ask it. There are many. I've given you a resource for finding them.

3) You asked "Do you agree that the IPCC have backed away from the argument that increased temperature (if it continues) will cause more extreme events ?"

You are asking us to review the IPCC position now and compare it to the IPCC position before. You are asking us to review all of the pages that you yourself will not review and provide a summary of the differences. You haven't contracted us for this work.

Please review the material and if you have something interesting to say about it then feel free to post it.

Richard Mallett said...

I'm tired of your obtuseness when asked simple questions, so I have no confidence in your ability to answer more complex questions.

1. You totally misunderstand Professor Curry's argument. Not surprising really.

2. I have asked you which temperature proxies you would deem acceptable, and you have refused to answer.

3. I'm asking you for your opinion, not contracting you to do research. If you are as familiar with the IPCC reports as you claim to be, you could give an opinion straight away.

Once again you use the pronoun 'we' - for whom are you acting as spokesman ? Whoever it is, you are doing an extremely poor job in that role, and should be dismissed immediately.

Layzej said...

1) Whatever.
2) They're all good I'm sure.
3) Who cares about your or my opinion on a fact? It doesn't change the fact. The IPCC position is easy to confirm since they published it and made it freely available.

David Appell said...

Richard M wrote:
"If you just laugh at Professor Judith Curry, who has presented her arguments before the US Congress...."

Oh please. Curry was selected by climate deniers because she was a denier. It was a rigged selection.

Don't forget, the same Congresspeople also chose Mark Steyn to appear for his climate expertise.

Let's not pretend like being asked to appear before Congress is some kind of ruling on her science. It was 100% political and you know it.

David Appell said...

Richard M wrote:
"Since you take the view that Greenland ice core measurements are not an appropriate proxy for global temperatures...."

Please explain, analytically, how measurements at one point on a planet are a proxy for that planet's global temperature.

Layzej said...

Here's a great resource for ice core datasets by the way: https://www.ncdc.noaa.gov/cdo/f?p=517:1:0:::APP:PROXYDATASETLIST:7

Richard Mallett said...

Reply to David Appell :-
1. What does Professor Curry specifically deny ? she does not deny that the recent warming has an anthropogenic component, so what does she deny ?

2. I have now found the temperature proxies from many parts of the world (year AD 16 to 1980) by Craig Loehle, and the Law Dome CO2 data from Year AD 1 to 2004.

Reply to Layzej :-

2. If 'all proxies are good' then I will use the data from Craig Loehle's paper in Energy & Environment, which covers AD 16 to 1980. The correlation with the Law Dome CO2 data from AD 16 to 1980 is 0.099743 which is negligible correlation.

3. Working Group II AR5:

“Economic growth, including greater concentrations of people and wealth in periled areas and rising insurance penetration, is the most important driver of increasing losses.” (AR5 10.7.3)

“Apart from detection, loss trends have not been conclusively attributed to anthropogenic climate change; most such claims are not based on scientific attribution methods.” (AR5 10.7.3)

“…increased probabilities of upward shifted accumulated loss [from tropical cyclones] might be detectable by 2025 at earliest, whereas a significant loss trend might emerge much later (Emanuel, 2011); (Crompton et al., 2011).” (AR5 10.7.3)

“The observed rise in US normalized insured flood losses (Barthel and Neumayer, 2012) may partly correspond to very likely increased heavy precipitation events in central North America (WG1-2.6.2.1), while the evidence for climate driven changes in river floods is not compelling (WG1-2.6.2.2)” (AR5 10.7.3)

JoeT said...

"If 'all proxies are good' then I will use the data from Craig Loehle's paper in Energy & Environment, which covers AD 16 to 1980. The correlation with the Law Dome CO2 data from AD 16 to 1980 is 0.099743 which is negligible correlation."

Richard,

Do this problem and post your answer here. Take the Law Dome data from 1850, combine it with the Keeling data to get a CO2 signal from 1850 to 2015. Then take the Berkeley Earth data set from 1850. Now do the correlation. What do you get?

Second problem: Plot the Temperature data from Berkeley Earth versus the log2(CO2). Do a linear regression on the data and find the slope. That gives you a rough approximation of the transient climate sensitivity. What do you get?

Richard Mallett said...

I shall assume that by 'Keeling data' you mean Mauna Loa data, which runs from 1959 to 2015. I shall also assume that by 'Berkeley Earth' you mean Berkeley Earth Global Land and Ocean (average of two data sets) from 1850 to 2015.

1. For the overlap period (1959 to 2004) I will use the average of Mauna Loa and Law Dome.

So the combined CO2 data set comes from :-

1850-1958 Law Dome
1959-2004 Average of Law Dome and Mauna Loa
2005-2015 Mauna Loa

Then the correlation coefficient (temperature : CO2) = 0.9147 over the period 1850-2015.

2. I presume that by log2(CO2) you mean the log to base 2.
Then slope (temperature : log2(CO2)) = 2.17 and correlation coefficient = 0.916 over the period 1850-2015.

JoeT said...

Good.

Is there any conclusion you come to from this little exercise?

Richard Mallett said...

Reply to JoeT :-

There is a much stronger correlation between CO2 and global temperature since 1850 than there was before 1850, even though CO2 growth rate didn't really start to increase dramatically until around 1945; so that if we were to say 'a rise in CO2 causes a rise in temperature' then that would need to be qualified somewhat.

JoeT said...

OK.

Although I'm not sure what your qualification means. There isn't a climate scientist out there who claims that CO2 is the only forcing. You see it in your plot of temperature versus log2(CO2) since 1850. Sometimes there are intervals where the trend is even negative. One sees it in your 2000 year time span where orbital variation and volcanic aerosols dominate the forcing. However, as one can see from the plot we both made, since 1970 the dominant forcing is CO2. And what's nice about the slope of the curve is that even back to 1850 or so it shows a fairly consistent rough transient climate sensitivity of around 2.2 C per doubling of CO2.

Richard Mallett said...

Reply to Joe T :-

So it is difficult for us to tell if the current period of warming (say from 1975 to 2015) will continue, or if it will again be dominated by other factors, as was the cooling from 1943 to 1975.

It is interesting that the Berkeley Earth Global Land average temperature showed a cooling trend before 1850, and then a warming trend since 1850.

It's also interersting that the Mauna Loa CO2 stayed much the same between 2002 and 2014.

JoeT said...

Huh?

2002 373.22
2014 398.61

That's not much the same.

It's not at all difficult to say whether the trend will continue or not. CO2 is going up and although the temperature is still sensitive to natural variability, like the current ENSO, there is no reason to think CO2 is going to come crashing down anytime soon. The cooling in mid-century was due to a combination of negative PDO and aerosols. Unless there are a series of large volcanic explosions or a huge increase in industrial pollution, the long-term temperature trend is only upward.

In any case, I'm done here. You can have the last word.

Richard Mallett said...

Sorry, I meant the annual growth rate seems to have levelled out, not concentration. It seems that the AMO, PDO and TSI are all reducing, so we should have a clearer picture after the current El Nino.

David Appell said...

Richard:
"It is interesting that the Berkeley Earth Global Land average temperature showed a cooling trend before 1850, and then a warming trend since 1850."

Translation: AGW is interesting.

Richard Mallett said...

Reply to David Appell :-

So would you agree that the AGW component of the current rate of increase is approximated by :-

Warming 1815 to 1915 (linear trend) = +0.55 C per century
Warming 1915 to 2015 (linear trend) = +1.12 C per century

Difference = 0.57 C per century ?

David Appell said...

Richard wrote:
"So would you agree that the AGW component of the current rate of increase is approximated by
Difference = 0.57 C per century ?"

Of course not. AGW isn't linear over a time frame of a century.

David Appell said...

Richard wrote:
"...so that if we were to say 'a rise in CO2 causes a rise in temperature' then that would need to be qualified somewhat."

Joe's statement already qualified. He knows what the science says.

Richard Mallett said...

Reply to David Appell :-

So how would you quantify the (non linear) AGW effect over the instrumental period ?

David Appell said...

Richard Mallett wrote:
"So how would you quantify the (non linear) AGW effect over the instrumental period ?"

So then you agree that there is no justification for linear extrapolation surface temperatures over a century?

I would quantify AGW's effects with a climate model.

Layzej said...

Try this: http://phosphorus.github.io/app.html?id=17364672&full-screen=true

On the first screen set CO2 factor to 2. Then skip forward to the fourth tab and set PDO factor to 0.1.

Skip forward one tab to see the result.

This will add PDO and CO2, factoring each according to the selection. You get a fair approximation to the actual temps. Add volcanic activity and you may get closer still.

Richard Mallett said...

Reply to David Appell :-

Climate models have proven to over estimate temperatures when we compare observations with forecasts.

See for example
https://climateaudit.org/2016/04/19/gavin-schmidt-and-reference-period-trickery/
and
https://climateaudit.org/2013/10/08/fixing-the-facts-2/
and
http://www.climate-lab-book.ac.uk/2013/near-term-ar5/
and
http://www.cato.org/blog/climate-models-tendency-simulate-too-much-warming-ipccs-attempt-cover
and
https://judithcurry.com/2013/07/09/climate-model-tuning/
and
https://climateaudit.org/2013/09/30/ipcc-disappears-the-discrepancy/
and
http://www.nature.com/nclimate/journal/v3/n9/full/nclimate1972.html?WT.ec_id=NCLIMATE-201309
and
https://judithcurry.com/2013/08/28/overestimated-global-warming-over-the-past-20-years/
and
http://www.climate-lab-book.ac.uk/2013/comparing-observations-and-simulations-again/
and
https://curryja.files.wordpress.com/2013/04/curry-testimony-2013-il.pdf
and
https://judithcurry.com/2013/02/22/spinning-the-climate-model-observation-comparison/
and
https://judithcurry.com/2013/10/02/spinning-the-climate-model-observation-comparison-part-ii/
and
https://judithcurry.com/2013/10/13/spinning-the-climate-model-observations-comparison-part-iii/
and
https://judithcurry.com/2016/04/05/comparing-models-with-observations/#more-21374

A climate model is only as good as the extent to which it agrees with observations. At the moment, models are over estimating the trend in global temperatures.


Reply to Layzej :-

Again, as I asked you before, where is the underlying data ? What is the correlation coefficient ? Saying it's a 'fair approximation' is not scientific, especially when we cannot see the data.

Layzej said...

http://lmgtfy.com/?q=pdo+data&l=1

Layzej said...

It's possible models are running hot. Then again, maybe not: http://www.nature.com/articles/srep19831

Either way, we're headed in the same direction. The only question is how much time we have to change course.

Richard Mallett said...

1. I am very familiar with the PDO thank you.

a) What exact data and formulae are used in
http://phosphorus.github.io/app.html?id=17364672&full-screen=true

b) which observations were used

c) what is the correlation coeffficient with observations ?

2. No, the only question is if we have to 'change course' - this requires you to answer two questions :-

a) Will the temperature :-

i) continue to increase at the 1975 to 2015 rate of +1.73 C per century

iI) slow down to less than +1.73 C per century, like the +1.16 C per century during the period from 1863 to 1877, or the +1.44 C per century during the period from 1910 to 1943 ?

iii) stay much the same, as it did from 1955 to 1975 when it slightly cooled at -0.06 C per century ?

iv) start a cooling period, like the periods from 1850 to 1861 when it cooled at -1.25 C per century, or from 1943 to 1955 (when atmospheric CO2 concentrations started to increase dramatically) when it cooled at -0.97 C per century ?

b) will the warming or cooling period that will happen in the future be beneficial or detrimental, in different parts of the world ?

Layzej said...

1) use whichever you like
2) depends on what we do.

Richard Mallett said...

1. So this mysterious web page uses any and all data and some unknown formula ?
2. Depends on what nature does.

Layzej said...

1) Just add (log2(CO2)*factorA) and PDO*factorB. You can compare that with any temp data you like.
2) Nature is bound by physics.

Richard Mallett said...

Reply to Layzej :-

1. So this mysterious unknown formula on this anonymous website just uses temperature, CO2 and PDO and ignores all the other factors ?

2. Nature is still unpredictable.

Layzej said...

I gave you the formula. How can you say it is unknown? You can add whatever other factors you'd like. CO2+PDO gets you pretty close to the actual temps.

Richard Mallett said...

No, you only gave me the address of a website with factor A and factor B.

There is no indication of how this anonymous website uses these factors, or what temperature data it uses, over what period of time, or who has produced this, or why it should be more trust worthy than the IPCC forecasts.

You say that it gives a 'fair approximation' but won't tell me the correlation coefficient.

Why should I trust it any more than the IPCC forecasts, which have all forecast a warming rate that is higher than the observations. Is it any better than the IPCC when forecasting temperatures ? Does it even produce forecasts of future tamperatures ? Anybody can produce a model that can be made to agree with past observations. How well does it forecast future temperatures ?

Layzej said...

Don't trust it. Do it yourself: "Just add (log2(CO2)*factorA) and PDO*factorB. You can compare that with any temp data you like."

This is not a forecast. It is meant to be illustrative. You had asked "How does science explain these fluctuations ? Natural variability ?"

If you are at all curious then you can do this and see to what extent CO2 + natural variability can explain the temp over the last century or so.

Richard Mallett said...

Reply yo Layzej :-

So, as I asked before :-

"So this mysterious unknown formula on this anonymous website just uses temperature, CO2 and PDO and ignores all the other factors ?"

Your answer then was :-

"I gave you the formula. How can you say it is unknown? You can add whatever other factors you'd like. CO2+PDO gets you pretty close to the actual temps."

So what you seem to be saying now is that I can create my own formula, when the IPCC (which has much greater resources) has so far failed to come up with a formula that matches the oberved data; or, at best, the low end of their models come close to the observed data ?

In addition to the references that I have already given you, read the comments at
https://www.skepticalscience.com/climate-models.htm

Look especially at http://www.climate-lab-book.ac.uk/comparing-cmip5-observations/
which shows 180 models compared to observations (updated with 2015 observations) where the vast majority of the models are much warmer than observations.

See also http://www.civitas.org.uk/content/files/SingerNIPCCvsIPCC_2011.pdf and
http://www.c3headlines.com/climate-model-chartsgraphs.html which summarises data from many different sources. This shows that the actual temperature observations correspond most closely to Hansen's Scenario C, which would have limited CO2 emissions to the 2000 level.

Models use a small number of possible contributors to global temperatures (which your anonymous website does) and ignore most of the natural variability.

"[Models] are full of fudge factors that are fitted to the existing climate, so the models more or less agree with the observed data. But there is no reason to believe that the same fudge factors would give the right behaviour in a world with different chemistry, for example in a world with increased CO2 in the atmosphere." (Freeman Dyson) - quoted in Skeptical Science.

Layzej said...

The formula is: "Just add (log2(CO2)*factorA) and PDO*factorB. You can compare that with any temp data you like." That's the third time I've posted this so I'm guessing there is a disconnect. How does that not answer your question?

CMIP5 models used by the IPCC do a great job when observed forcings are used. See figure 1 here: http://www.nature.com/articles/srep19831 .

Richard Mallett said...

I see that you have not read any of the references I gave to you, which is why your reply doesn't address them at all, or answer my question. Unless you can demonstrate that your anonymous website can do better than the appalling record of the IPCC models over the past 25 years, there is no basis for discussion.

Layzej said...

They are different things. Please stop confusing them. Remember, This is not a forecast. It is meant to be illustrative. You had asked "How does science explain these fluctuations ? Natural variability ?

If you are at all curious then you can do this and see to what extent CO2 + natural variability can explain the temp over the last century or so.


It turns out that it could explain it quite well. You really should give it a go if you don't trust my web page. But I think you are not actually curious.

Richard Mallett said...

I am curious about the relative effects of CO2 and natural variability. I do not believe that the temperature record since 1850 can be explained by CO2 and the PDO alone. The AMO for example agrees quite well with the global temperature record.

JoeT said...

I’m reading the continuation of this thread with some astonishment. Let me just pick out a few of the many rather odd things that are being written here.

Layzej pointed to a rather neat empirical model and says “set CO2 factor to 2. Then skip forward to the fourth tab and set PDO factor to 0.1” to which Richard replies, “Again, as I asked you before, where is the underlying data ? What is the correlation coefficient? But this is right after Richard already calculated that the correlation coefficient for CO2 versus temperature is 0.91 and the slope of temperature versus log2(CO2) is 2.2. Did it occur to you Richard that you already had the answer to your question and that Layzej is merely asking you to use the number you already calculated?

Let’s go a step further. Richard wrote, “It seems that the AMO, PDO and TSI are all reducing, so we should have a clearer picture after the current El Nino.” Well, if anyone actually looked at the PDO lately, it clearly isn’t “reducing”. The PDO turned positive back in 2014 and while it fluctuates quite a lot, it just hit a local maximum in March, 2016. If you have any foreknowledge of what the PDO is going to be for the rest of the year, perhaps you can share your insight here.

But since you’re very focused on the correlation coefficient Richard, why don’t you do some calculations for us so that we can understand what might happen if indeed the TSI “reduces” as you say.

I’m sure you can find the historical TSI back to 1850 on the internet. (If not, I'll point it out to you.) Calculate the correlation coefficient for the TSI versus the Berkeley Earth global land and sea temperature for the period 1850 – 2015. What do you get? Is that coefficient higher or lower than the one for CO2 and temperature?

One more thing: Since you wrote, “CO2 growth rate didn't really start to increase dramatically until around 1945”, let’s take a look at that. Pick a date in the recent past that you’re happy with. 1945 perhaps or 1975, I don’t care. Now calculate the correlation coefficient. How does that value compare to the one from 1850? Based on this information, what can you conclude as to whether changes in the solar irradiance are having a stronger or weaker effect on the global temperature? If the TSI decreases and CO2 keeps increasing, which one do you think would be the stronger effect? The answer of course depends on the range in which one varies, but let's stipulate that TSI would stay roughly in the bounds of the 11 year cycle and CO2 keep increasing at the same yearly rate.

Richard Mallett said...

Reply to Joe T :-

I don't have the time right now, but I will certainly do what you suggest tomorrow (God willing)

Layzej said...

RM: "The AMO for example agrees quite well with the global temperature record."

Do you get a better fit with CO2 + AMO than CO2 + PDO?

Richard Mallett said...

Reply to Latzej :-

I will examine these things tomorrow.

Layzej said...

This one uses AMO in place of PDO: http://phosphorus.github.io/app.html?id=106945663&full-screen=true

It also has TSI with an 11 year running mean if you are interested in seeing how that may fit.

Layzej said...

I get a pretty good fit with CO2=2.08, nino=0.05 with a 1 month delay, sunspots = 0.01, and AMO=0.44 with a one month delay. I use the standard deviation of the residual to gauge the fit. I get std dev=0.069687. Better than I can get with PDO.

This article is interesting:

http://www.realclimate.org/index.php/archives/2015/02/climate-oscillations-and-the-global-warming-faux-pause/

I should probably add AMO as a tab on the first project so that PDO and AMO can be combined.

JoeT said...

Layzej, you made these apps?

Layzej said...

Yup.

JoeT said...

Nice!

Richard Mallett said...

Reply to Layzej :-

Ah so the anonymous website belongs to you. I prefer to use Excel, which I will do later. Admitttedly I will not be able to calculate the correlation coefficient for more than two variables.

Yes, the article in Real Climate (which I reckon is probably the best 'alarmist' site) indicates that the AMO (which is what I was thinking of) is probably close to maximum, while the PMO (the longer term features of the PDO) and the NMO (which I had not heard of before) are reducing.

I entirely agree with the article that these oscillations should be included in the IPCC models, as well as ENSO.

Layzej said...

I believe these oscillations emerge in the models, but they're not able to predict exactly when AMO will reverse. Most runs will be out of phase with reality over the short term even when the long term trajectory is correct.

Ultimately it doesn't matter because these are osculations and by definition do not have a trend. We may stray towards the lower end of the ensembles one decade and towards the upper end another. They do not impact the long term result.

Richard Mallett said...

Reply to Joe T :-

I have found annual TSI data from 1610 to 2015 from
http://spot.colorado.edu/~koppg/TSI/TSI_TIM_Reconstruction.txt - this has two values for 2003.5 (1361.1014 and 1361.02) so I shall average them to give 1361.0607.

More when I have time.

Richard Mallett said...

Reply to Joe T :-

The correlation of TSI with Berkeley Earth Global Land and Ocean = 0.60635. Of course, a combination of factors may have a correlation with global temperatures greater than each one indivdually. Nevertheless, as I explained before to Layzej, I will compute the correlation of AMO and PDO with temperature also.

David Appell said...

Richard wrote:
"The correlation of TSI with Berkeley Earth Global Land and Ocean = 0.60635."

I am very dubious. TSI has been on a slowly declining trend since the 1960s, while essentially all of warming has come since that time.

JoeT said...

David, that's why I also asked Richard to do the correlation for a more recent period. Say, 1945 or 1975 to 2015. The answer as you may expect is very different. Just plotting TSI versus temperature shows how uncorrelated they are in the recent past.

JoeT said...

Layzej of course is correct. Neither AMO nor PDO is a forcing. They neither increase nor decrease the heat content of the Earth; rather they redistribute it. And yes, these are are natural oscillations that come out of the models contrary to the nonsense that Freeman Dyson wrote. Since they can't be predicted in advance, the models start off with different initial conditions to cover a range of possible outcomes. The conclusion from the recent Fyfe paper (which I find lacks in some areas) is that the difference between the models and actual temperature was due to the Interdecadal Pacific Oscillation. Those simulations that had the right IPO came close to the data.

Layzej said...

The dataset Richard has found seems to indicate that TSI peaked in the late 90's, though the increase has been slow since the 60's.

Richard Mallett said...

Reply to Layzej :-

Yes, there were peaks in 1979-1981, 1989-1991, 2000-2002, and 2013-2015, so we should expect TSI to decrease in the next few years. More tomorrow hopefully.

JoeT said...

This data set http://lasp.colorado.edu/lisird/tss/historical_tsi.csv?
shows the peak TSI in 1958 at 1362.1 as I thought. I'm not sure what accounts for the difference with the one Richard used. If you do the correlation from 1975-2015 for temperature and TSI I get 0.09, which is a lot different than if we did the range from 1850 - 2015.

From this one can conclude that variations in the sun's intensity these days has very little impact on the temperature compared to CO2. As I wrote in the other thread, even if we went back to the Maunder minimum, maybe the temperature would drop back a decade or so. Clearly no Little Ice Age, no matter what the sun does.

JoeT said...

Actually, the surprising thing to me was that the correlation for the more recent time period wasn't negative, which is what I thought it would give.

Richard Mallett said...

Reply toJoe T :-

The reconstruction at http://lasp.colorado.edu/home/sorce/data/tsi-data/#historical_TSI refers to :-

1) Coddington, O., Lean, J.L., Pilewskie, P., Snow, M., Lindholm, D.: 2015, A solar irradiance climate data record, Bull. American Meteorological Soc. doi: 10.1175/BAMS-D-14-00265.12)

2) Kopp, G., Krivova, N., Lean, J., and Wu, C.J., The Impact of the Revised Sunspot Record on Solar Irradiance Reconstructions, Solar Physics, 2016, doi: 10.1007/s11207-016-0853-x

There are peaks at 1948 (1361.3) 1957 (1361.6) 1980 (1361.6) 1989 (1361.6) 2000 (1361.6) and 2015 (1361.4)

More tomorrow.

Richard Mallett said...

Reply to Joe T :-

It looks like your reconstruction only goes up to 2014, while mine goes up to 2015.

Layzej said...

The two TSI indexes are quite different. They agree on cycle 24 and 23, but JoeT's is larger on every other cycle and almost twice as large on cycle 19. If I use an 11 year running mean it looks like JoeT's peaks in the 60s and Richard's peaks in the 90s.

David Appell said...

Richard wrote:
"There are peaks at 1948 (1361.3) 1957 (1361.6) 1980 (1361.6) 1989 (1361.6) 2000 (1361.6) and 2015 (1361.4)"

Are you using these TSI data points for your linear regressions?

If so, that's not valid. Look at the PMOD graph in my post of yesterday:

http://davidappell.blogspot.com/2016/04/is-abdussamatovs-prediction-of-tsi.html

The maximum TSI for each cycle are usually outliers, not representative of total TSI variations.

David Appell said...

I used the PMOD data since 1976. I averaged the daily data for each month, and calculated the anomaly of that month relative to the total average of all the data.

I find a TSI trend, since 1976, of -0.04 W/m2/decade.

But this isn't sufficient either. The trend is going to always going to depend on the date you begin in, and it's unlikely to be one that includes an integer number of the solar cycle, with no remainder.

David Appell said...

Joe wrote:
"As I wrote in the other thread, even if we went back to the Maunder minimum, maybe the temperature would drop back a decade or so. Clearly no Little Ice Age, no matter what the sun does."

I agree. I have this from my notes:

This exact question was studied a few years ago by Feulner and Rahmstorf (GRL 2009) and Song et al (GRL 2010), and it was found that greenhouse gas warming easily swamps any cooling from a Maunder Minimum-like sun. Cooling by 2100 would only be, at most, 0.3 C below IPCC projections. We will not be entering another Little Ice Age.

"On the effect of a new grand minimum of solar activity on the future climate on Earth," G. Fuelner and S. Rahmstorf, Geo Res Lett vol. 37, L05707 2010.
http://www.pik-potsdam.de/~stefan/Publications/Journals/feulner_rahmstorf_2010.pdf

"Increased greenhouse gases enhance regional climate response to a
Maunder Minimum," Song et al, Geo Res Lett vol. 37, L01703 (2010) http://www-cirrus.ucsd.edu/~zhang/PDFs/Song_et_al-2010.pdf

"What influence will future solar activity changes over the 21st century have on projected global near-surface temperature changes?" Gareth S. Jones, et al, JGR v 117, D05103, doi:10.1029/2011JD017013, 2012.
http://www.leif.org/EOS/2011JD017013.pdf

See also:
http://www.skepticalscience.com/what-would-happen-if-the-sun-fell-to-maunder-minimum-levels.html

Richard Mallett said...

Reply to David Appell (10:38 pm) :-

I agree, it's important to take as long a period as possible for all the possible efffects. Here we are limited by the instrumental record, so I started at 1850 rather than the start of the TSI reconstructions at 1610. Starting at a later date may not be as accurate an assessment of the actual effects, but I may calculate the correlation coefficient from 1945 (as Joe T asked) since that's when the rate of increase in CO2 started to increase dramatically, though that's typically about one cycle of the AMO and PDO.

Vahrenholt and Luning identify the Gleissberg cycle, the Suess / de Vries cycle, and the Eddy cycle of the sun, which I assume are covered by TSI (they agree that the next Maunder minimum will not occur before AD 2500 because of the Eddy cycle, but a repeat of the Dalton minimum of 1810 is possible around 2020 to 2040), the PDO (40-60 years) AMO (50-80 years) NAO (about 70 years) and ENSO (using the SOI - every 2 to 7 years)

Richard Mallett said...

Reply to David Appell (10:30 pm) :-

I let Excel 2013 calculate the correlation coefficient from 1850 to 2015 of the TSI with the average of the two series of the Berkeley Earth Global Land and Ocean temperatures.

David Appell said...

Richard wrote:
"I let Excel 2013 calculate the correlation coefficient from 1850 to 2015 of the TSI with the average of the two series of the Berkeley Earth Global Land and Ocean temperatures."

Oh come on, that is hopelessly naive.

http://lasp.colorado.edu/home/sorce/files/2011/09/TIM-TSI-Reconstruction1.jpg

You're not doing science, just mindless curve fitting.

David Appell said...

PS: What is the correlation between TSI and the Dow Jones Industrial Average?

Richard Mallett said...

The correlation of Berkeley Earth Global Land & Ocean temperature with TSI from 1945-2015 = 0.1834.

Just to keep the results together, the corrrelation from 1850-2015 = 0.60635.

AMO unsmoothed, de-trended from
http://www.esrl.noaa.gov/psd/data/correlation/amon.us.long.data

Correlation with Berkeley Earth Global Land & Ocean temperature from 1856-2015 = 0.35042
Correlation with Berkeley Earth Global Land & Ocean temperature from 1945-2015 = 0.42601

PDO from http://research.jisao.washington.edu/pdo/PDO.latest

Correlation with Berkeley Earth Global Land & Ocean temperature from 1900-2015 = 0.0974
Correlation with Berkeley Earth Global Land & Ocean temperature from 1945-2015 = 0.3465

NAO data 1821-1999 (complete years from 1825) from
https://crudata.uea.ac.uk/cru/data/nao/ and 1999-2015 from
https://crudata.uea.ac.uk/~timo/datapages/naoi.htm

Correlation with Berkeley Earth Global Land & Ocean temperature from 1850-2015 = -0.154
Correlation with Berkeley Earth Global Land & Ocean temperature from 1945-2015 = -0.172

SOI data 1876-2016 from http://www.bom.gov.au/climate/current/soihtm1.shtml

Correlation with Berkeley Earth Global Land & Ocean temperature from 1876-2015 = -0.166
Correlation with Berkeley Earth Global Land & Ocean temperature from 1945-2015 = -0.199

So I think that we can discount the NAO and SOI data.

Richard Mallett said...

Reply to David Appell (8:46 am):-

Joe T asked me to calculate correlation coefficients from 1850 and from 1945, so that's what I have done. We could argue that the IPCC models are 'hopelessly naive' since they compare so badly with observations, as have been indicated in the numerous references that I have provided.

David Appell said...

"So I think that we can discount the NAO and SOI data."

You can't discount anything. Or rule anything in. Because you're not doing science.

The problem with Excel is that it lets people do calculations like this, whether the calculations means anything or not and whether the results mean anything or not.

Seriously: what is the correlation between TSI and the Dow Jones Industrial Average? I bet it's decent....

David Appell said...

Richard, what makes you think TSI and surface temperature should be linearly related?

David Appell said...

"We could argue that the IPCC models are 'hopelessly naive' since they compare so badly with observations"

Could you please link to that comment so I know which you are talking about?

I know it's a standard denier meme that climate models fail badly, but it's completely false. Of course, the IPCC 5AR longest chapter is on model verification, and here are a few recent examples:

https://twitter.com/climateofgavin/status/674336477669670912

https://twitter.com/climateofgavin/status/689889733737082880

https://twitter.com/ClimateOfGavin/status/642024749569298432/photo/1

JoeT said...

Richard, As David correctly pointed out, none of this is actual physics, but correlation is the issue that you brought up. So, I'll simply rephrase what you wrote here:

Correlation between Berkeley Earth and TSI:
1850 - 2015 0.6
1945 - 2015 0.2
1975 - 2015 0.09 (I added this one myself)

Correlation between Berkeley Earth and CO2
1850 - 2015 0.91 (fairly independent of time period)

Now let's go back to your quote:
"If 'all proxies are good' then I will use the data from Craig Loehle's paper in Energy & Environment, which covers AD 16 to 1980. The correlation with the Law Dome CO2 data from AD 16 to 1980 is 0.099743 which is negligible correlation."

Since the correlation between the solar irradiance and the global mean temperature is clearly decreasing and for the past 40 years in particular is now negligible (as you would say) and that between CO2 and temperature since 1850 is on the order of 0.9 --- as well as the fact that AMO and PDO are not forcings -- do you now have any conclusion about what is the main factor driving the Earth's temperature?

David Appell said...

Thanks Joe. Sorry, I wasn't able to pay attention to all of the comments and came in late.

Layzej said...

Richard cited the following for evidence that models "compare so badly with observations"

"Look especially at http://www.climate-lab-book.ac.uk/comparing-cmip5-observations/"

...which doesn't really support his case.

David Appell said...

Thanks. You're right, that page doesn't support his claim.

Layzej said...

Richard - it may be that you have expectations for the models that are not realistic.

Model runs will not be in phase with internal cycles like PDO, AMO, ENSO. It would be swell if they could predict the timing and strength of the next El Nino, but they can't.

Models cannot predict how much CO2 we will release. They cannot predict the strength or duration of solar cycles. They cannot predict the timing or strength of the next volcanic eruption. It would be nice if they could, but they cannot.

They're not going to be very useful in predicting the GMT 5 years from now, but they can give you a range of possible outcomes for a set of inputs.

Richard Mallett said...

Reply to David Appell (8:47 am and 9:12 am) :-

The Dow Jones Industrial Average has not been herefore postulated as something that's related to the TSI (nor, for that matter, have the PDO, AMO, NAo or SOI)

Reply to David Appell (9:31 am) :-

Changes in TSI have been postulated as a possible cause (among others) of changes in surface temperature.

Reply to David Appell (9:36 am) :-

See my comment at 4:09 am. It said :-

Reply to David Appell :-

"Climate models have proven to over estimate temperatures when we compare observations with forecasts.

See for example
https://climateaudit.org/2016/04/19/gavin-schmidt-and-reference-period-trickery/
and
https://climateaudit.org/2013/10/08/fixing-the-facts-2/
and
http://www.climate-lab-book.ac.uk/2013/near-term-ar5/
and
http://www.cato.org/blog/climate-models-tendency-simulate-too-much-warming-ipccs-attempt-cover
and
https://judithcurry.com/2013/07/09/climate-model-tuning/
and
https://climateaudit.org/2013/09/30/ipcc-disappears-the-discrepancy/
and
http://www.nature.com/nclimate/journal/v3/n9/full/nclimate1972.html?WT.ec_id=NCLIMATE-201309
and
https://judithcurry.com/2013/08/28/overestimated-global-warming-over-the-past-20-years/
and
http://www.climate-lab-book.ac.uk/2013/comparing-observations-and-simulations-again/
and
https://curryja.files.wordpress.com/2013/04/curry-testimony-2013-il.pdf
and
https://judithcurry.com/2013/02/22/spinning-the-climate-model-observation-comparison/
and
https://judithcurry.com/2013/10/02/spinning-the-climate-model-observation-comparison-part-ii/
and
https://judithcurry.com/2013/10/13/spinning-the-climate-model-observations-comparison-part-iii/
and
https://judithcurry.com/2016/04/05/comparing-models-with-observations/#more-21374

A climate model is only as good as the extent to which it agrees with observations. At the moment, models are over estimating the trend in global temperatures."

If you want to discuss the IPCC reports, let's see :-

a) 1990 IPCC First Assessment Report Working Group 1 predicted 0.2-0.5 C/decade
Actual increase from 1990 to 2014 (mean of HadCRUT4, NCDC and GISS) = 0.12 C/decade

b) 1995 IPCC Second Assessment Report Working Group 1 predicted 0.1-0.35 C/decade
Actual increase from 1995 to 2014 (mean of HadCRUT4, NCDC and GISS) = 0.14 C/decade

c) 2001 IPCC Third Assessment Report Working Group 1 predicted 0.13-0.43 C/decade
Actual increase from 2001 to 2014 (mean of HadCRUT4, NCDC and GISS) = 0.11 C/decade

d) 2007 IPCC Assessment Report 4 Working Group 1 predicted 0.11-0.64 C/decade
Actual increase from 2007 to 2014 (mean of HadCRUT4, NCDC and GISS) = 0.12 C/decade

The increase from 2007 is only provisional since we have not completed a full decade yet.

Reply to Joe T (9:39 am) :-

Yes, CO2 is clearly the major effect at the moment. Remember, some time ago, I asked :-

"If we look at the last 100 years, from 1915-2015, compared to earlier periods, we can look at HadCRUT4 from 1850 and Berkeley Earth Land and Ocean from 1850. Taking the average of these temperature data sets. we find :-

Cooling from 1850 to 1861 at -1.25 C per century
Warming from 1861 to 1877 at +1.16 C per century
Cooling from 1877 to 1910 at -0.66 C per century
Warming from 1910 to 1943 at +1.44 C per century
Cooling from 1943 to 1955 at -0.97 C per century
Stasis from 1955 to 1975 at -0.06 C per century
Warming from 1975 to 2015 at +1.73 C per century

How does science explain these fluctuations ? Natural variability ?"

Apologies if I have missed anything.

Layzej said...

Richard,

You end your post by asking "How does science explain these fluctuations ? Natural variability ?"

Haven't you answered that question by comparing AMO+CO2 and PDO+CO2 to the records? I really think it is important for you to get this before we can move on to discuss models.

David Appell said...

Richard wrote:
"Changes in TSI have been postulated as a possible cause (among others) of changes in surface temperature."

But what is your justification for assuming they are linearly related?

Richard Mallett said...

Reply to Layzej :-

Well, I have not compared AMO+CO2 and PDO+CO2 to the records. I have found that, over the 1850-2015 period, during which there have been warming, cooling and stasis periods, there is a correlation between temperature and :-
CO2 of 0.915 since 1850
TSI of 0.606 since 1850
AMO of 0.350 since 1856
PDO of 0.097 since 1900 so that can be discounted.

So (on that basis) the major influences seem to be CO2, TSI and AMO (as I suspected). This does not attempt to determine the reasons for the fluctuations, which is what I was (and am) also interested in.

The models only started in 1990, so they would not answer the question of the cause of the fluctuations since 1850.

Richard Mallett said...

Reply to David Appell :-

I did not assume (and did not expect) changes in TSI and changes in temperature to be linearly related. That's why I asked :-

"How does science explain these fluctuations ? Natural variability ?"

Layzej said...

You really should add AMO+CO2 and compare with temps. Or possibly detrend the temps and compare with AMO. Checking correlation between temps and AMO will not help you answer this question.

David Appell said...

Richard wrote:
"I did not assume (and did not expect) changes in TSI and changes in temperature to be linearly related."

I thought you were doing a linear regression between TSI and T_surface.

If anything I would think T_surface is approximately proportional to TSI^(1/4). But that's not a very good model either.

"How does science explain these fluctuations ? Natural variability ?"

Richard, there are many things that determine T_surface besides atmospheric CO2. Natural forcings (solar, volcanoes), cycles like ENSO, AMO, PDO etc, and feedbacks like ice melt and greener vegetation. And, yes, sometimes, somewheres, heat just fluctuates because a butterfly flapped its wings and climate is a very complex system.

Remember, the surface is 2-dimensional -- it really can't hold any heat. The actual volume of a thermometer is tiny -- so all the thousands of temperature sensors around the world that are used to calculate T_surface measure and almost infinitesimal volume of the atmosphere. So, every time the wind blows -- literally -- T_surface(x) changes. Yes, the global average is more stable to fluctuations, but hardly immune from them, as we're seeing right now with ENSO.

Meanwhile the ocean is, by comparision, an humongous heat sink, so much less prone to random fluctuations, but heat moves around there too, there are lags, etc. If you want to explain something with a very simple model, try explaining ocean heat content:

http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/

David Appell said...

Richard wrote:
"How does science explain these fluctuations ? Natural variability ?"

Perhaps you should learn more about climate and climate change before trying to quantatively analyze it.

Richard Mallett said...

Reply to David Appell :-

Thank you, that's exactly what I expected.

Reply to Layzej :-

AMO and CO2 cannot be added together. They are different units.

JoeT said...

David, certainly T ~ I^1/4, but as we were discussing on another thread, in the limit of small changes in the intensity -- which is characteristic of the 11 year solar cycle ---- then delta_T = T/4 delta_I/I, so delta_T is proportional to delta_I. From that and feedbacks you get a climate sensitivity of roughly 0.8 C/(W/m2)

We're only doing back-of-the-envelope estimates here, not full blown modeling. But, as we saw for the Maunder minimum problem, the BOE gives roughly the same order as the full blown code calculation.

Layzej said...

Here's a tool that let's you add (log2(CO2)*factorA) and PDO*factorB and compare with temps: http://phosphorus.github.io/app.html?id=17364672&full-screen=true

On the first screen set CO2 factor to 2.2. Then skip forward to the fourth screen and set PDO factor to 0.1.

This is for illustrative purposes only, but it does provide a "sniff test" for your hypothesis that natural variability explains the wobbles around the secular warming trend.

Richard Mallett said...

The result does not match.

Layzej said...

No, but most of the broad features are present. You will note:

Warming from 1910 to 1943 at about +1.44 C per century
Cooling from 1943 to 1955 at about -0.97 C per century
Stasis from 1955 to 1975 at about -0.06 C per century
Warming from 1975 to 2015 at about +1.73 C per century

Any thoughts on whether natural variability + a secular warming trend could explain most of the temperature record?

Richard Mallett said...

How does one deduce those numbers from your program ?

Yes, of course there is a secular warming trend since 1850 (average of BEST and HadCRUT4) of +0.53 C per century, plus considerable natural variability from +1.73 C per century to -0.97 C per century, as you agree; so a range of 2.7 C per century super-imposed on the secular trend of +0.53 C per century, so a ratio of about 5:1.

Richard Mallett said...

Reply to Layzej (11:12 am) :-

Yes, I gave the range of possible outcomes in my reply at 11:12 am to David Appell. Here they are again :-

a) 1990 IPCC First Assessment Report Working Group 1 predicted 0.2-0.5 C/decade
Actual increase from 1990 to 2014 (mean of HadCRUT4, NCDC and GISS) = 0.12 C/decade
[less than the lower bound]

b) 1995 IPCC Second Assessment Report Working Group 1 predicted 0.1-0.35 C/decade
Actual increase from 1995 to 2014 (mean of HadCRUT4, NCDC and GISS) = 0.14 C/decade
[much closer to the lower bound than to the upper bound]

c) 2001 IPCC Third Assessment Report Working Group 1 predicted 0.13-0.43 C/decade
Actual increase from 2001 to 2014 (mean of HadCRUT4, NCDC and GISS) = 0.11 C/decade
[less than the lower bound]

d) 2007 IPCC Assessment Report 4 Working Group 1 predicted 0.11-0.64 C/decade
Actual increase from 2007 to 2014 (mean of HadCRUT4, NCDC and GISS) = 0.12 C/decade
[much closer to the lower bound than to the upper bound]

The increase from 2007 is only provisional since we have not completed a full decade yet.


Reply to David Appell (12:41 pm) :-

I was hoping to learn more about climate and climate change by asking those questions.

Layzej said...

Using GISS (but I'm happy to use any other you prefer):

a) Temp rise since 1990 was 0.184 ±0.070 °C/decade (2σ) so I suspect we can reject the upper end of the FAR projection - anything over about 0.25 °C/decade.

b) Temp rise since 1995 was 0.172 ±0.092 °C/decade (2σ) so I suspect we can reject the upper end of the SAR projection - anything over about 0.26 °C/decade.

c) Temp rise since 2001 was 0.156 ±0.149 °C/decade (2σ) so I suspect we can reject the upper end of the TAR projection - anything over about 0.3 °C/decade.

d) Temp rise since 2007 was 0.317 ±0.334 °C/decade (2σ) so it looks like the IPCC may have been a bit conservative on this one.

Richard Mallett said...

Reply to Layzej :-

Obviously your figures are very different from mine, so let's agree on HadCRUT4 and use the ranges :-

1990-2014
1995-2014
2001-2014
2007-2014

so that they don't include the 2015-16 El Nino.

Go to http://www.metoffice.gov.uk/hadobs/hadcrut4/data/current/download.html and choose "Global (NH+SH)/2 annual"

http://www.metoffice.gov.uk/hadobs/hadcrut4/data/current/series_format.html gives the data format. You can see that :-

"Column 1 is the date.
Column 2 is the median of the 100 ensemble member time series."

"Columns 11 and 12 are the lower and upper bounds of the 95% confidence interval of the combined effects of all the uncertainties described in the HadCRUT4 error model (measurement and sampling, bias and coverage uncertainties)."

so you can use columns 11 and 12 to give upper and lower bounds for the anomalies (relative to 1961-1990) in column 2.

I hope that you will agree that this is a useful temperature record to use.

Layzej said...

Subtracting the most recent El Nino but leaving those at the start of the record will give you a very skewed perspective. You don't want that. What you want to do is subtract ENSO: http://assets.carbonbrief.org/wp-content/uploads/2016/01/correcting-gistemp-for-enso.png

I believe you could do this in Excel.

Another consideration is how did natural forcings such as solar output and volcanic activity affect the temperatures of the last few decades? These cannot be predicted in advance. Also, how did natural cycles such as PDO or AMO affect the temperatures of the last few decades? these are also not predictable (although see http://onlinelibrary.wiley.com/doi/10.1002/2016GL068159/abstract?campaign=woletoc referenced in our hosts most recent post).

If you include these actual forcings and cycles you get this from the very same models used in AR5: https://pbs.twimg.com/media/CbElthfUAAA1DVS.jpg

It's bang on. What does that tell you?

JoeT said...

Richard wrote:

"a) 1990 IPCC First Assessment Report Working Group 1 predicted 0.2-0.5 C/decade
Actual increase from 1990 to 2014 (mean of HadCRUT4, NCDC and GISS) = 0.12 C/decade
[less than the lower bound]"

Here's what FAR actually says:

"Based on current model results we predict:

An average rate of increase of global mean temperature during the next century of fabout 0.3° C per decade(with an uncertainty range of 0.2—0.5° C per decade) assuming the IPCC Scenario A (Business-as-Usual) emissions of greenhouse gases; .... The rise will not be steady because of other factors.

Under the other IPCC emissions scenarios which assume progressively increasing levels of controls, rates of increase in global mean temperature of about 0.2° C per decade(Scenario B), just above 0.1° C per decade (Scenario C) and about О.1 С per decade (Scenario D). The rise will not be steady because of other factors."

Seems to me that you just went with Scenario A. Did you make any attempt at all to see which Scenario actually came closest to reality?

Richard Mallett said...

Reply to Layzej :-

SOI is a pressure index, and so cannot be subtracted from temperature anomalies. My object is to determine how well the forecasts as published in the various IPCC Assessment Reports compare with the actual temperature measurements since those reports were published.

Reply to Joe T :-

No, please tell me how to find the predictions for various scenarios in the FAR, SAR, TAR, AR4 and AR5, and what the various scenarios mean. Many thanks in advance.

Have the scenarios stayed the same in the various assessment reports ? I know that Hansen had scenario A (what we're doing now) to scenario C (which he regarded as very unlikely, and not what we are doing now) but I had never previously heard of scenario D; so I suspect that these scenarios are different from Hansen's. Do they also range from 'what we're doing now' to 'least likely' ? If so, then it would seem that we are currently following scenario A.

Layzej said...

It looks like we've probably warmed at about the rate projected by scenario B, or possibly somewhat less.

On page VIV of https://www.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_full_report.pdf there
doesn't appear to be much difference in the two scenarios before 2020 where they really start to diverge. At least not as far as CO2 goes.

It looks like scenario A has us hitting 400 ppm by 2015 and scenario B has us hitting 400 ppm by 2020.

By that measure I'd say we're on the scenario A track. Let me know if there is something I'm overlooking. Possibly CH4 and CFC output?

Layzej said...

Richard, of course you can subtract the effect of ENSO from the temperatures. I included a graph where exactly that was done.

Have you considered my question to you:

If you include these actual forcings and cycles you get this from the very same models used in AR5: https://pbs.twimg.com/media/CbElthfUAAA1DVS.jpg

It's bang on. What does that tell you?


Layzej said...

Richard, you said "No, please tell me how to find the predictions for various scenarios in the FAR, SAR, TAR, AR4 and AR5, and what the various scenarios mean. Many thanks in advance.

Have you considered looking in the various IPCC reports? I very much suspect you'll find your answer there.

Layzej said...

Looking closer at the FAR scenarios, it looks like CH4 is the only gas where there is a real divergence between scenario A and B prior to 2015. We're at about 1834 ppm CH4. (http://cdiac.ornl.gov/pns/current_ghg.html). Below even scenario B.

In that case it looks like the FAR was right on the money; even though waning solar output and natural cycles have likely reduced the trend over the last few decades.

I'm somewhat surprised. Is there anything I'm overlooking?

JoeT said...

"No, please tell me how to find the predictions for various scenarios in the FAR, SAR, TAR, AR4 and AR5, and what the various scenarios mean. Many thanks in advance."

So what you're telling me is that you didn't actually look at these reports to determine what they said. If you're asking where to find the various scenarios, then it appears you simply lifted these results from someone else.

This isn't physics.

JoeT said...

Layzej

I don't have the time to hunt through these reports myself, but it appears that your comment about the lower level of CH4 than Scenario B is at least consistent with this post that claims the actual radiative forcing was lower than all of the scenarios.

http://www.skepticalscience.com/lessons-from-past-climate-predictions-ipcc-far.html

Richard Mallett said...

Reply to Layzej (9:44 am) :-

That graph doesn't tell me anything, except that it is very different from the graphs that I referred you to.

What I'm interested in at the moment is how well did the published forecasts compare with the actual global temperatures (not how some modified graph agrees with the global temperatures) - I will do that with HadCRUT4 when I have the time.

Reply to Layzej (9:44 am) and Joe T (10:13 am) :-

If the different scenarios in the five assessment reports range from 'what we're doing now' to 'very unlikely' then it makes sense to me to first look at the scenario 'what we're doing now' - I don't often have the time to look through all the IPCC assessment reports, sorry.

JoeT said...

"If the different scenarios in the five assessment reports range from 'what we're doing now' to 'very unlikely'"

They are not. They are scenarios. You need to look at each scenario and see how it compares with the data. Otherwise, all you're doing is reciting talking points.


"I know that Hansen had scenario A (what we're doing now)"

As we went through, even this is wrong. Scenario A from Hansen had a much larger forcing than reality.

David Appell said...

Richard: climate models don't make "forecasts" -- they make projections, based on a set of assumptions that never represent what actually transpires.

Layzej said...

Hi Richard,

You may want to read this paper to understand what that graph is showing. It is pertinent to understanding how well the projections are doing.

If you are just interested in how well the projections are doing, it looks like they are doing quite well.

We appear to have followed something just south of scenario B from the FAR. Our temps are something just south of the projected temps for scenario B.

Richard Mallett said...

Reply to Layzej :-

At the moment, I am interested in how the forecasts of the five assessment reports (at the time that they were made) compare with actual temperatures since then, not how they can be adjusted in 2016 to make them better conform to what we know today.

Reply to Layzej and Joe T :-

I will take a look at the different forecasts for the different scenarios when I have time.

Reply to David Appell :-

It is the forecasts made by Hansen (so called by Hansen) and those made by the IPCC
in its five assessment reports, and how they compare with observations since then, that the average man in the street is interested in (to the extent that they are interested in the subject at all)

Layzej said...

Not adjusted. The very same models. Read the paper.

Richard Mallett said...

He uses 'the latest (CMIP5) model simulations' not those used in 1990,1995, 2001 and 2007.

Richard Mallett said...

Reply to David Appell :-

If climate models "make projections, based on a set of assumptions that never represent what actually transpires" then what is the point ?

Richard Mallett said...

Reply to Layzej (3:09 am) :-

HadCRUT.4.4.0.0 1850-2015 trend +0.049 C per decade

HadCRUT.4.4.0.0 1990-2015 trend +0.160 C per decade
HadCRUT.4.4.0.0 1995-2015 trend +0.131 C per decade
HadCRUT.4.4.0.0 2001-2015 trend +0.083 C per decade
HadCRUT.4.4.0.0 2007-2015 trend +0.237 C per decade

which is considerably less than yours.

David Appell said...

Richard, what are the error bars on these HadCRUT4 trends?

Richard Mallett said...

Reply to Savid Appell :-

If I'm interpreting columns 11 and 12 correctly, the uncertainties are :-

1850-2015 trend of lower bound 0.056 trend of upper bound 0.042 C per decade

1990-2015 trend of lower bound 0.158 trend of upper bound 0.162 C per decade
1995-2015 trend of lower bound 0.131 trend of upper bound 0.133 C per decade
2001-2015 trend of lower bound 0.084 trend of upper bound 0.084 C per decade
2007-2015 trend of lower bound 0.023 trend of upper bound 0.024 C per decade

Reply to Layzej (10:00 am) and David Appell (10:16 am) :-

Why did you say "http://www.climate-lab-book.ac.uk/comparing-cmip5-observations/

... doesn't really support his case [or claim]." ?

Why did you pick out that page in particular, out of the several references that I cited ?

JoeT said...

Richard,

The answer you gave to David's question about the uncertainty is the wrong answer to the wrong calculation.

First of all, you don't get the 2 sigma uncertainties in the slope by plotting the lower bounds and the upper bounds of each data point and fitting those individually. I can't even begin to tell you how wrong this is.

You need to start with a basic book on statistics. And second, the answer you gave wasn't even per decade. It was per year. As I said, the wrong answer to the wrong calculation.

On a different topic, no matter how many times you call these forecasts, they are not. You want them to be forecasts which is why you only use the scenario that gives the highest temperature trend. A forecast is tomorrow will be partly sunny in the morning turning cloudy in the afternoon with s high of 59 and a low of 47. It's not a list of forcings due to numerous greenhouse gases, estimates of what the aerosol concentrations and total solar irradiance are going to be plus the chaotic behavior inherent in the natural variation. Not to mention the occasional volcano explosion.

The only reason the average man on the street may think the IPCC projections are forecasts is if they are being deliberately misled.

Richard Mallett said...

Reply to Joe T :-

Please recommend a suitable book on statistics. I am not well enough to read a book all the way through, sorry, but I can look things up.

The uncertainties are per decade, not per year. The figures per year are :-

1850-2015 lower bound 0.0056 upper bound 0.0042

1990-2015 lower bound 0.0158 upper bound 0.0162
1995-2015 lower bound 0.0131 upper bound 0.0133
2001-2015 lower bound 0.0084 upper bound 0.0084
2007-2015 lower bound 0.0235 upper bound 0.0241

Hansen calls them forecasts, the IPCC FAR overview / WG1 SPM call them predictions.

I really don't have the time to trawl through all the five IPCC reports (plus the FAR supplement) to find all the places where they make these forecasts / predictions / projections for all the four different scenarios, sorry. You seem to be saying that they are of little to no value anyway.

JoeT said...

I checked your 2007-2015 uncertainty just to make sure I understood what you were doing. As you just showed us, you gave it in terms of degrees/year. It's irrelevant anyway, because it's a completely wrong estimate of the uncertainty.

I grew up on Bevington, Data Reduction and Error Analysis. There are probably much better books out there since I was in school.

The only thing that constitutes a forecast in Hanson's paper is that it was going to get warmer, no matter what the scenario. That's the extent of his forecast. Otherwise, he gave a set of very specific scenarios using a very primitive model that still agreed reasonably well with the temperature data.

I absolutely don't believe they are of little to no value. This is complete nonsense. Over, a long enough time period they give a range of possible temperature outcomes based on the forcings. On a shorter time scale, they also give a range of outcomes but are much more dependent on the chaotic behavior of the natural variation. It's why the start off each simulation with different initial conditions and then average them to get a long term response.

As Ed Hawkins is showing now the actual mean global temperature is right smack in the middle of the simulations.

Richard Mallett said...

If "the actual mean global temperature is right smack in the middle of the simulations" from 1990, then why are there so many websites showing the actual observations either at the bottom or well below the simulations. They apply the models from 1990 to 2007 and that's what they get. Here they are again :-

See for example
https://climateaudit.org/2016/04/19/gavin-schmidt-and-reference-period-trickery/
and
https://climateaudit.org/2013/10/08/fixing-the-facts-2/
and
http://www.climate-lab-book.ac.uk/2013/near-term-ar5/
and
http://www.cato.org/blog/climate-models-tendency-simulate-too-much-warming-ipccs-attempt-cover
and
https://judithcurry.com/2013/07/09/climate-model-tuning/
and
https://climateaudit.org/2013/09/30/ipcc-disappears-the-discrepancy/
and
http://www.nature.com/nclimate/journal/v3/n9/full/nclimate1972.html?WT.ec_id=NCLIMATE-201309
and
https://judithcurry.com/2013/08/28/overestimated-global-warming-over-the-past-20-years/
and
http://www.climate-lab-book.ac.uk/2013/comparing-observations-and-simulations-again/
and
https://curryja.files.wordpress.com/2013/04/curry-testimony-2013-il.pdf
and
https://judithcurry.com/2013/02/22/spinning-the-climate-model-observation-comparison/
and
https://judithcurry.com/2013/10/02/spinning-the-climate-model-observation-comparison-part-ii/
and
https://judithcurry.com/2013/10/13/spinning-the-climate-model-observations-comparison-part-iii/
and
https://judithcurry.com/2016/04/05/comparing-models-with-observations/#more-21374

They have tested the models since 1990 and compared them with observations, and they are nowhere near 'right smack in the middle of the simulations'

Bevington on order, trhank you for the recommendation.

Richard Mallett said...

I made one small mistake with the last line. As you say, it does not matter if you don't want me to use the HadCRUT4 uncertainties; but just for the record the last line should read :-

2007-2015 trend of lower bound = 0.02345 C per year = 0.2345 C per decade (not 0.023 C per decade)
2007-2015 trend of upper bound = 0.02410 C per year = 0.2410 C per decade (not 0.024 C per decade)

The rates per year are correct.

JoeT said...

You're misunderstanding what I'm saying, whether on purpose or not I don't know. It's not that I don't want to use the HadCRUT4 uncertainties. I trust that they are correct, but those are the uncertainties for each data point. From the data and the error in the data one then calculates the error in the slope. That you did not do correctly. You'll find the right way to do it in Bevington. However, even Bevington doesn't discuss the problem of autocorrelation in the data. That's a whole different level of uncertainty in the trend.

You can list the same websites another 10 times to claim that models overestimate the warming trend and it won't matter. Science isn't done by a vote of blog posts. Let's break it down. You list multiple posts from Judith Curry and Steve McIntyre. I couldn't care less what McIntyre says because the one time I did track down a paper he wrote he committed outright fraud by cutting off the top eigenvalues in a principle component analysis. That is to say, he claimed there was no warming because he threw out the term that actually contained the warming.

I have little use for ex-scientist Judith Curry either. As was the original post by our host, she writes nonsense. Then you have something there by Patrick Michaels who doesn't publish papers but writes editorials instead. You can examine Michaels track record from this article: http://www.skepticalscience.com/patrick-michaels-history-getting-climate-wrong.html.

Most of your references are to blog posts from 2013. A lot has happened since then. It's curious that you seem to want to stop in 2013 and not see what's happened since. You're perfectly willing to cite Ed Hawkins in 2013, but Ed Hawkins in 2016 is off-limits.

Finally, the one paper you did cite is by John Fyfe. But it's from 2013 again. Yes, we all recognize that in 2013 mean global temperatures were at the bottom of the model simulations. However, what you should be reading is John Fyfe in 2016:
http://tinyurl.com/gwetwoa where they show that the disagreement between models and data is due to the not getting the correct phase of the Interdecadal Pacific Oscillation. The simulations that got the phase correctly were in good agreement with the temperature. Unfortunately you probably don't have access to the paper. The unfortunate thing about the title, "Making sense of the early-2000s warming slowdown" is that they never actually do a statistical analysis to show that there was any kind of slowdown, just that the recorded temperatures were on the low end of the simulations.

So, to sum up, as Ed Hawkins has shown, right now the temperatures are right smack in the middle of the simulations. As Layzej already told you, natural variation cannot be predicted in advance so it is understandable that sometimes the models will run along the bottom, sometimes they will hit the top. The one thing the simulations do not show is that even including natural variation -- AMO, PDO, IPO, ENSO etc --- they do not indicate cooling in the next few decades. There is a very high likelihood that 2016 will again show a record hot year and then in 2017 it will drop back a bit. However, over the next decade or so it's a safe bet that temperatures will continue to climb. I'd even call that a forecast --- except if there is a massive volcanic eruption. Then all bets are off.

Richard Mallett said...

Bevington will take a while to arrive.

Ed Hawkins 2016 is fine with me. See
http://www.climate-lab-book.ac.uk/2016/making-sense/ and
http://www.climate-lab-book.ac.uk/comparing-cmip5-observations/

You say "As Ed Hawkins is showing now the actual mean global temperature is right smack in the middle of the simulations." I don't see it like that. I see the data in the lower half of the simulations.

I also see the models rising much faster in the future in his figures than the 1.138 C per century since 1950, according to HadCRUT.4.4.0.0. So the models are predicting / projecting / forecasting an acceleration in global warming, when TSI is probably near its peak and is about to decline, PDO is probably near its peak and is about to decline, and AMO (detrended) is already declining from a broad peak.

So "in 2013 mean global temperatures were at the bottom of the model simulations" - that's only two years before the latest global temperature data, during which we have had a warming El Nino, which may well be followed by a cooling La Nina.

Also you say that the paywalled paper admits that there is "disagreement between models and data" - this is not the same as "right smack in the middle of the simulations."

JoeT said...

'You say "As Ed Hawkins is showing now the actual mean global temperature is right smack in the middle of the simulations." I don't see it like that. I see the data in the lower half of the simulations."

Yup, pretty much right smack in the middle of the simulations. Plus this data point is only for 2015. This is a year which would have been a record warm year even if there wasn't an El Nino. We know this because the El Nino didn't show up in the records until October, 2015. If we look at what is happening now, April looks like it will come in somewhere around 1.14C above the 1951-1980 mean, making this the warmest April by far, a full 0.27C over second place. (I'm using NASA GISS). If we do the running mean for 2016 so far, we get 1.22C, which is 0.36 C higher than 2015. While the latter part of the year will probably have lower anomalies, we can expect 2016 to be right up there at the top of the simulations.

"I also see the models rising much faster in the future in his figures than the 1.138 C per century since 1950, according to HadCRUT.4.4.0.0."

I still don't understand why you insist on writing temperatures per century. In any case, your starting year is wrong. If you look at the caption of Figure 2 in the post by Ed Hawkins here, you'll see he puts the start of the current warming at 1972. Or if you look at Figure 3 of this paper by Mann et al., you'll see that the forcing due to greenhouse gases didn't overcome natural variation until the 1970s.

From this we understand using any of the databases that the warming trend since 1970 has been on the order of 0.17-0.18C/decade. This is on the order of what the simulations show for the next few decades.

"So the models are predicting / projecting / forecasting an acceleration in global warming"

Nope, they do not. There is no acceleration seen in the model projections.

"TSI is probably near its peak and is about to decline, PDO is probably near its peak and is about to decline, and AMO (detrended) is already declining from a broad peak."

What you consistently neglect is the most important forcing of all which are greenhouse gases. I can understand that you may not know how to get the 2 sigma uncertainty in a trend. But here you're not understanding basic physics. CO2 is the major driver of the current warming and there is just no getting around the fact that the planet will keep on warming because CO2 keeps increasing.

TSI as we've already shown has a negligible correlation with surface temperature. Go to this post by our host and look at David's 3rd figure. The solar minimum is typically around 1360.5 w/m2. It's now around 1361. From this you can calculate what the expected drop in temperature would be. Previously you calculated what the trend is for temperature versus log2(CO2). How much does CO2 have to rise to cancel out the solar minimum?

Secondly PDO is definitely not at its peak. It only turned positive in 2014. No one knows what AMO is going to do. If anything, natural variation is going to add to the warming, not subtract from it.

"Also you say that the paywalled paper admits that there is "disagreement between models and data" - this is not the same as "right smack in the middle of the simulations.""

Do you really not understand that a paper entitled "Making sense of the early-2000s warming slowdown" is about the early 2000s? Ed Hawkins was a co-author on the paper and his blog post, referred to above, is about his views on the paper. It does not contradict the fact that in 2015 Ed has the temperature for that year 'right smack in the middle of the simulations' to quote myself.

Richard Mallett said...

Once again, my reply disappeared when I followed your links, so this will have to be an abbreviated version.

1. We will have to wait and see if 2016 is "right up there at the top of the simulations."

2. I find degrees per century more meaningful than degrees per decade. I can read +1.138 C (per century) on my LIG thermometer more easily that +0.1138 C (per decade)

3. Yes, I believe that the current warming period started in 1975. However, if we look at the "Updated version of IPCC AR5 Figure 1.4" in
http://www.climate-lab-book.ac.uk/comparing-cmip5-observations/ it starts in 1950, so I'm comparing obervations from 1950 with the models, which in the figure start in 2000.

4. If we look at the "Updated version of IPCC AR5 Figure 1.4" we see the rate of warming from 2000 to 2035 ranging from (these are very rough estimates because there are no grid lines) :-

Lower bound 0.25 C anomaly in 2000 to 0.5 C anomaly in 2035 = 0.25 C in 35 years
Upper bound 0.25 C anomaly in 2000 to 2.0 C anomaly in 2035 = 1.75 C in 35 years

So the rate of increase is :-

Lower bound = 100 * 0.25 / 35 = 0.71 C per century
Upper bound = 100 * 1.75 / 35 = 5.00 C per century

So 'smack in the middle' would then be +2.85 C per century, compared to the current rate of +1.138 C per century.

So your 0.17 to 0.18 C per decade is definitely in the lower half of the rate of warming in the figure. So what the figure is ahowing is an acceleration if one uses the 'smack in the middle' position.

5. No, I have looked on the web, and I'm still not sure how to get the +/- 2 sigma figures for each point in a sample taken from a larger population, or if (and how) to correct for auto-correlation, sorry.

6. Yes, I have found that :-

CO2 has 0.91473 correlation coefficient with temperature from 1850 to 2015
TSI has 0.60635 correlation coefficient with temperature from 1850 to 2015
AMO has 0.35042 correlation coefficient with temperature from 1850 to 2015
PDO has 0.09742 correlation coefficient with temperature from 1850 to 2015 (so negligible)

7. Yes, the linear trend is 2.17 C per log2(CO2) - we don't know if the next solar minimum or successive solar minima between now and 2035 (approximately 2021 and 2032) will be similar to 2010 or successively lower than 2010.

8. PDO effect is negligible (correlation coefficient with temperature = 0.09742)

AMO (correlation coefficient with temperature = 0.35042) reached a peak in 1998, and a lesser peak in 2010. The previous meximum had peaks in 1944, 1952 and 1960. This is correlated with the cooling period from about 1943 to 1975.

9. So in the early 2000s there was "disagreement between models and data" and now in the figure in http://www.climate-lab-book.ac.uk/comparing-cmip5-observations/ the black and green lines are at about 0.5 C anomaly, while the range of the models is about 0.25 C to 0.75 C. So, that is 'right smack in the middle of the simulations' as you say.

As I mentioned above, the models show a rate of warming of about 0.71 to 5.00 C per century from 2000 to 2035. So we shall see if the observations stay 'right smack in the middle of the simulations'

JoeT said...

1- C/century is meaningless, because there is no reason to expect the temperature change to have the same linear slope over periods of a century

2- What you should be doing is comparing the warming rate since greenhouse gases prevailed over natural variability. 0.17-0.18 C/decade is the right number to use.
You are extending it back to 1950 to artificially lower the warming.

3- You wrote: "Lower bound = 100 * 0.25 / 35 = 0.71 C per century. Upper bound = 100 * 1.75 / 35 = 5.00 C per century."

This is simply wrong. You're making the exact same mistake that you made when David asked you to give the uncertainty in the trend. This is the kind of mistake undergraduates make. The trend given in the simulations is roughly the same as the what has been observed since 1970. There is no acceleration shown over the next few decades.

5- The PDO definitely plays a key role in natural variability. Go back and read Ed Hawkins:
"This period also corresponds to when the Pacific Decadal Oscillation was in its positive phase, suggesting that these variations in the Pacific have caused a large part of the difference between models and observations. As further evidence, model simulations which produce a fluctuation in their Pacific variability similar to that observed (either by chance or by design – see Fig. 1e) also better reproduce the observed fluctuations in global temperatures."

6- You can look at the solar variation and estimate the temperature change and compare that to the change due to increasing CO2. You either don't know how to do it or won't.

7- You are consistently ignoring the physics.

Richard Mallett said...

1. I am not implying that the rate is the same over a century, or over a decade.
2. I am using the whole period used in the graph.
3. The slope of the graphs become clearly steeper after 2000.
5. We shall see.
6. I have already said that the correlation of temperature with CO2 is greater than the correlation with TSI.

Richard Mallett said...

7. We shall see.

JoeT said...

This is as good as time as any to take this thread off life support and send it off for hospice care so that it can finally die in dignity.

Richard Mallett said...

No, I cannot find a list of the various IPCC forecasts / predictions / projections of global temperature under the various scnarios from the IPCC FAR, SAR, TAR, AR4 and AR5, so we might as well leave it there.

Richard Mallett said...

Actually, I have found the IPCC FAR Overview at http://www.ipcc.ch/ipccreports/1992%20IPCC%20Supplement/IPCC_1990_and_1992_Assessments/English/ipcc_90_92_assessments_far_overview.pdf and IPCC FAR WG1 SPM at
http://www.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_spm.pdf which both say that (text from Overview) :-

"We predict :-

An average rate of global mean temperature during the next century of about 0.3 C per decade (with an uncertainty range of 0.2-0.5 C per decade) assuming the IPCC Scenario A (Business as Usual) emissions of greenhouse gases."

"Under the other IPCC emissions scenarios which assume progressively increasing levels of controls, rates of increase in global mean temperature of about 0.2 C per decade (Scenario B), just above 0.1 C per decade (Scenario C) and about 0.1 C per decade (Scenario D)"

So we can say that the predictions (so called by the IPCC) are :-

Scenario A (Business as Usual) 0.3 C (0.2 to 0.5 C) per decade
Scenario B (Low Emissions Scenario) about 0.2 C per decade
Scenario C (Control Policies Scenario) just above 0.1 C per decade
Scenario D (Accelerated Policies Scenario) about 0.1 C per decade

Since 1990, the rate of increase in HadCRUT4 has been 0.1595 C per decade.
So we can say that we are somewhere between Scenario B (Low Emissions Scenario) and C (Control Policies Scenario) - not bad.