Climate Change Banter

[StudentOfClimatology]

That would be borderline mid Pliocene temps. I want what your smoking.

Pliocene? Again, this is why a formal education would suit you well. Technically, the mid/late Pliocene was a glacial era.

The majority of the proxy data is fairly clear regarding the Holocene climate optimum. Paleoclimate is my area of study.

[AvantHiatus]

Pliocene? Again, this is why a formal education would suit you well.

The majority of the proxy data is fairly clear on this. Paleoclimate is my area of study.

I love being brainwashed. Warm era of the Pliocene is a range of 3.8-1.8C, besides the Eemian interglacial peak, this approaching 1.5-2.0C range has been unchallenged territory for millions of years.

 

We are starting from 0.85C so subtract that. Do you not know what the Pliocene is? This graph is the most accurate big picture view we have, some of the datapoints are coarse but good enough.

 

Sad to see you go down that path. Trying to get at my lack of credentials to make my post look discreditable. I have a formal education, just not a PHD by the way.

 

We can still be warm during glacials, not sure of the official definition but since interglacials are unique to the Pleistoscene transition, our interglacials are probably like the glacials of the Pliocene if you move the baseline up.

[AvantHiatus]

Opps, it is 1960-1990 baseline. So we are starting from about 0.55C.

[StudentOfClimatology]

I love being brainwashed. Warm era of the Pliocene is a range of 3.8-1.8C, besides the Eemian interglacial peak, this approaching 1.5-2.0C range has been unchallenged territory for millions of years.

This is wrong. Three of the last five interglacials peaked at or above 1.5 degrees centigrade warmer than post-modern era. This is undisputed in the literature. The Holocene optimum wasn't quite as warm, but still peaked early in both the borehole data and the ice core data, well above current/post-modern era temperatures.

[AvantHiatus]

You are downplaying the 20th century warming too much. We need to warm by about 0.9C to surpass everything in the last 2.5 million years except the Eemian. I am using Hansen's (2013) dataset to formulate these numbers.

[StudentOfClimatology]

You are downplaying the 20th century warming too much. We need to warm by about 0.9C to surpass everything in the last 2.5 million years except the Eemian. I am using Hansen's (2013) dataset to formulate these numbers.

Please stop inventing crap like this. It's honestly annoying.

No one is downplaying the 20th century warming..we know how much the planet has warmed since 1850..about 0.85C, +/- 0.2C. It was a very rapid warming, largely an anthropogenic signal. But it's nowhere near the levels seen during the Holocene climate optimum (yet).

[AvantHiatus]

Mindblown. Can we agree that the sky is blue? Where did you get that 1.5C number from? The difference between the Eemian and early Pliocene is that the latter is more persistent and less transient in regards to warming. 

[StudentOfClimatology]

Mindblown. Can we agree that the sky is blue?

We can agree that Rayleigh Scattering causes it to appear blue in the presence of solar radiation.

[AvantHiatus]

Probably 0.1-0.25C away from the HCO....exciting times indeed.

[StudentOfClimatology]

Probably 0.1-0.25C away from the HCO....exciting times indeed.

You're way out of the mainstream with this one, but it's not my job to govern your opinions. Good luck with your research.

[PhillipS]

That Marcott et al study depicting Holocene climate variability is at odds with ~80% of the peer reviewed literature in the paleoclimate arena. The consensus is the globe was at least 1 degree centigrade warmer during the Holocene climate optimum than it is now.

The best global climate proxies are in fact the isotope ratios found in ice cores. Not only are they preserved better via the lack of biological decay, but they represent a process that takes place from the equator to the pole itself.

 

Well, if you are correct about the 80% then you should find it easy to share four recent peer-reviewed papers that refute Marcott et al 2013.  Otherwise, we can confidently assume you're just making things up again.

[AvantHiatus]

Negative feedback city.

[StudentOfClimatology]

Well, if you are correct about the 80% then you should find it easy to share four recent peer-reviewed papers that refute Marcott et al 2013. Otherwise, we can confidently assume you're just making things up again.

I could link 50 studies that reach a vastly different conclusion regarding the Holocene climate optimum and subsequent millennial variability. Is that what you want?

[AvantHiatus]

 

 

The initial meltwater pulse caused between 0.5 and 4 m (1 ft 8 in and 13 ft 1 in) of sea-level rise. Based on estimates of lake volume and decaying ice cap size, values of 0.4–1.2 m (1 ft 4 in–3 ft 11 in) circulate. Based on sea-level data from below modern deltas, 2–4 m (6 ft 7 in–13 ft 1 in) of near-instantaneous rise is estimated, in addition to 'normal' post-glacial sea-level rise.^[15] Meltwater pulse sea-level rise was experienced fully at great distance from the release area. Gravity and rebound effects associated with the shifting of water masses meant that the sea-level fingerprint was smaller in areas closer to the Hudson Bay. The Mississippi delta records ~20%, NW Europe records ~70% and Asia records ~105% of the global averaged amount.^[16] The cooling of the 8.2 kiloyear event was a temporary feature; the sea-level rise of the meltwater pulse was permanent.

[StudentOfClimatology]

Yep, and that's the risk we face going forward. We can handle a gradual AGW, but if the system decides to go into one of its feedback loops (as it often does, geologically speaking), then we have a problem.

[AvantHiatus]

Yep, and that's the risk we face going forward. We can handle a gradual AGW, but if the system decides to go into one of its feedback loops (as it often does, geologically speaking), then we have a problem.

In the grand scheme of things, the system has a larger CO2 buffer now, to prevent it from sliding too deep into melt feedbacks. That does not rule-out dangerous melt tho.

 

It is why Hansen has warming peaking in the 2045-2060 range and then stabilizing due to massive negative feedbacks associated with meltwater pulsing that were overwhelming CO2 levels as high as 600ppm.

 

http://www.columbia.edu/~jeh1/mailings/2012/20121226_GreenlandIceSheetUpdate.pdf

[StudentOfClimatology]

I agree on an (eventual) stabilization, but I think it'll occur much later. Eventually, Antarctica will begin to warm as AGW overwhelms the stratospheric processes that are currently keeping that domain relatively cold.

There's also evidence for rapid changes to the Hadley Cells in the paleoclimate data, in response to various stimuli that include some of the forementioned processes. That alone could have enormous consequences in the future, if it occurs again.

[PhillipS]

I could link 50 studies that reach a vastly different conclusion regarding the Holocene climate optimum and subsequent millennial variability. Is that what you want?

 

All I want are four peer-reviewed global (not regional) Holocene temperature reconstructions that refute the Marcott et al 2013 by showing that the peak global Holocene temperatures were warmer than current global temperatures.  That should be a breeze for you, right?

 

Or possibly not.  I did a cursory scan of the 198 papers that have cited Marcott et al 2013 since its publication and not one of your alleged 80% have published a rebuttal, or response, or critique, of the Marcott paper.  Surely if it were as flawed as you claim at least one of your multitude would have pointed out the errors, if only to prevent others from being misled.  Agree?

[StudentOfClimatology]

All I want are four peer-reviewed global (not regional) Holocene temperature reconstructions that refute the Marcott et al 2013 by showing that the peak global Holocene temperatures were warmer than current global temperatures. That should be a breeze for you, right?

Or possibly not. I did a cursory scan of the 198 papers that have cited Marcott et al 2013 since its publication and not one of your alleged 80% have published a rebuttal, or response, or critique, of the Marcott paper. Surely if it were as flawed as you claim at least one of your multitude would have pointed out the errors, if only to prevent others from being misled. Agree?

If you had read Marcott et al 2013, you'd know that he himself notes that we have not yet reached peak interglacial warmth. That RealClimate.com graph is misleading for obvious reasons.

But sure, I'll link you your studies.

[AvantHiatus]

Here, I fixed the baselines for you SOC. WOW I feel so much better now.. the graph looks totally different!!!! Oh wait, nothing changed.

[FloridaJohn]

I build arguments and if it doesn't fit your preconceived notions about the climate system you folks hurl insults ad hominem attacks etc.

The skeptical side in me is the scientist in me. None of what you folks on this forum have presented anything that would convince a skeptic like me that the world is in trouble from rapid climate change. I have said this before...I can see a maybe another 1c of warming spread out over at least 100 years or more....TCR. This would have minimal impact on the climate system. There is not enough land ice...glaciers... to abruptly change ocean currents which abruptly change climate. Below is a graph of the ice accumulation rate over Greenland from the ice core. The climate system was chaotic until the Holocene when the land ice disappeared.

 

GISP220k.png

 

To think a trace gas that is a minor GHG will somehow throw this whole system out of balance is a stretch. Computer models give us an idea that if you increase an external forcing like CO2 you will get some warming. I agree with that. But the feedbacks?? Models are horrible with feedbacks....I use models almost everyday. I understand NWP well.... So to bet the farm on these climate models is like in winter putting forecast out for a major snowstorm 15 days from now for a major nor'easter because the models are indicating it. And then having making people prepare NOW!!!  This is why so many METS are skeptical of climate science forecasts.

 

[An aside: Boy, this forum software is really hard to work with. I was trying to do this reply as a multi-quote post, but never got it to work.]

 

I have yet to see you build an argument on any topic. Usually it is unsubstatiated, unreferenced charts. Where are the links to the papers that back up your positon? Where are the rebuttals to counter-arguments from fellow board members?

 

In order to be a skeptic, you need to be skeptical of other positions as well as your own. If you aren't willing to examine your own biases and pre-concieved notions, then you are a contrarian, not a skeptic. When you say "None of what you folks on this forum have presented anything that would convince a skeptic like me" that sounds to me like someone who has already made up their mind as is not open to new data or ideas. Very unskepic-like.

 

Regarding your idea that "There is not enough land ice...glaciers... to abruptly change ocean currents which abruptly change climate," I guess it depends on what you call "abrubt" climate change. If you think people are contending that there is an upcoming "Day After Tomorrow" scenario in the works, then you are mistaken on what "abrubt climate change" is. We are already experiencing abrubt climate change, as multiple records show there are very few analogs to the radipdly changing temperature which we are currently experiencing. Our society is highly optimized to live in our current climate. Large changes to this will cause a major disruption to our lifestyle. Miami, for example, has already had nine inches of sea level rise in the last century. This was fairly easy to cope with. The next nine inches will not be as easy, and the nine inches after that will be even less so. And each increment of nine inches of rise will come in less time. So 100 years for the first, maybe 80 for the next, 50 for the one after that, and maybe 20 after that. There comes a point when you can't hold the ocean back anymore, and the city has to be abandoned. How disruptive do you think that will be?

 

How about animal and plant species that have evolved for a certain range of climates? As the world warms, they can safely move to higher elevations. But eventually, they run out of mountain, and then die off. There is evidence that this is already happening.

 

We, as a society, are already using the ideal locations to grow crops to feed the population. If those become less ideal due to reduced rain, excessive rain, warmer temperatures, etc. feeding people will become more difficult and more expensive. There are lots of other examples where even moderate climate change has negative consequences for our society.

 

Calling CO2 a "trace gas" shows a lack of understanding about the chemistry of our atmosphere. CO2 has unique properties that makes it's influence outweigh it's proportion of the atmosphere. This can be proven in lab experiments, so I don't understand you "skepticism" on the mechanics of it's influence on our climate.

 

The models you use every day are not the same models the climate scientists are using. Your models are highly tuned to return useful information in extremely short timescales. Timescales that have no influence on long-term climate. So your experience with short-term models is not really applicable to long-term models.

 

For example, I could use the model y=mx+b. This is a really good model that describes a line. But it is a lousy model for describing a sine wave, which is better modeled by the function y=sinx. Now, depending on what values I pick for m and b in my model of a line, I can have several values of y that will fit both the line model and the sine wave model. But that doesn't mean that my line model is somehow flawed, or that my sine wave model is not accurate. They are modeling different things, so they react differently, even if they share the same x and y values. This is how you have to think about climate models. They are not the same thing you work with every day.

 

Anyway, I look forward to your rebuttal to why you chose that particular graph to illustrate your point.

[nflwxman]

I always love the "trace gas" argument.  I wonder if these same people would be okay with ingesting a "trace" amount of cyanide every other day.  It's really a silly point to make.

[Polar Vortex 2014]

Please stop inventing crap like this. It's honestly annoying.

No one is downplaying the 20th century warming..we know how much the planet has warmed since 1850..about 0.85C, +/- 0.2C. It was a very rapid warming, largely an anthropogenic signal. But it's nowhere near the levels seen during the Holocene climate optimum (yet).

 

I would trust Drs. Hansen and Sato over you.

 

 

We conclude that Pliocene temperatures probably were no more than 1-2°C warmer on global average than peak Holocene temperature. And regardless of the precise temperatures in the Pliocene, the extreme polar warmth and diminished ice sheets are consistent with the picture we painted above. Earth today, with global temperature having returned to at least the Holocene maximum, is poised to experience strong amplifying polar feedbacks in response to even modest additional global mean warming.

 

 

 

Source: http://www.columbia.edu/~jeh1/mailings/2011/20110118_MilankovicPaper.pdf

[AvantHiatus]

^If not we will hit the HCO this year or before 2020. Yes, that's how important 2015 is. The red meat effects of AGW are about to kick into high gear. Tho I would argue we're already there due to the California situation alone.

 

Stuff like that cannot be 100% natural variability, especially when you run East Pacific SSTA against the sediment records.

[HailMan06]

I'm curious about those peer-reviewed papers refuting Marcott et al. 2013, SOC.

[StudentOfClimatology]

I would trust Drs. Hansen and Sato over you.

Source: http://www.columbia.edu/~jeh1/mailings/2011/20110118_MilankovicPaper.pdf

Did you even read my post? That's exactly what I said.

[StudentOfClimatology]

http://www.pages-igbp.org/calendar/127-pages/904-holocene-climate-change

Near the beginning of the current interglacial, global temperatures rose considerably about 10,000 years ago to usher in a period of time referred to as the Holocene. On the basis of temperature reconstructions derived from studies of latitudinal displacements of terrestrial vegetation (Bernabo and Webb, 1977; Wijmstra, 1978; Davis et al., 1980; Ritchie et al., 1983; Overpeck, 1985) and vertical displacements of alpine plants (Kearney and Luckman, 1983) and mountain glaciers (Hope et al., 1976; Porter and Orombelli, 1985), it has been concluded (Webb et al., 1987; COHMAP, 1988) that mean annual temperatures in the Midwestern United States were about 2 °C warmer than those of the past few decades (Bartlein et al., 1984; Webb, 1985), that summer temperatures in Europe were 2 °C warmer (Huntley and Prentice, 1988), as they also were in New Guinea (Hope et al., 1976), and that temperatures in the Alps were as much as 4 °C warmer (Porter and Orombelli, 1985; Huntley and Prentice, 1988). In the Russian Far East, temperatures are also reported to have been from 2 °C (Velitchko and Klimanov, 1990) to as much as 4-6 °C (Korotky et al., 1988) higher than they are today; while the mean annual temperature of the Kuroshio Current between 22 and 35 °N was 6 °C warmer (Taira, 1975), and the southern boundary of the Pacific boreal region was positioned 700 to 800 km north of its present location (Lutaenko, 1993). 10,000-year temperature history A graphical representation of the mean global air temperature that results from the amalgamation of these several records, as prepared by the Intergovernmental Panel on Climate Change (Houghton et al., 1990) indicates that temperatures during the Holocene maximum were warmer than those of the past few decades for a period of time on the order of several thousand years.

Bartlein, P.J., Webb, T., III. and Fleri, E. 1984. Holocene climatic change in the northern Midwest: Pollen-derived estimates. Quaternary Research 22: 361-374.

Bernabo, J.C. and Webb, T, III. 1977. Changing patterns in the Holocene pollen record of northeastern North America: A mapped summary. Quaternary Research 8: 64-96.

Bryson, R.A., and Swain, A.M. 1981. Holocene variation of monsoonal rainfall in Rajasthan. Quaternary Research 16: 135-145.

Ciais, P., Petit, J.R., Jouzel, J., Lorius, C., Barkov, N.I., Lipenkov, V. and Nicolaiev, V. 1992. Evidence for an early Holocene climatic optimum in the Antarctic deep ice-core record. Climate Dynamics 6: 169-177.

COHMAP Members. 1988. Climatic changes of the last 18,000 years: Observations and model simulations. Science 241: 1043-1052.

Crowley, T. J. and North, G.R. 1991. Paleoclimatology, Oxford University Press, New York, NY.

Davis, M.B., Spear, R.W. and Shane, L.C.K. 1980. Holocene climate of New England. Quaternary Research 14: 240-250.

Fabre, J. and Petit-Marie, N. 1988. Holocene climatic evolution of 22-23 °N from two palaeolakes in the Taoudenni area (Northern Mali). Palaeogeography, Palaeoclimatology, Palaeoecology 65: 133-148.

Hope, G.S., Peterson, J.A., Radok, U. and Allison, I. 1976. The Equatorial Glaciers of New Guinea. Balkema, Rotterdam.

Houghton, J.T., Jenkins, G.J. and Ephraums, J.J. (Eds.). 1990. Climate Change: The IPCC Scientific Assessment. Cambridge University Press, Cambridge, UK.

Huntley, B. and Prentice, C. 1988. July temperatures in Europe from pollen data 6000 years before present. Science 241: 687-690.

Kearney, M.S. and Luckman, B.H. 1983. Holocene timberline fluctuations in Jasper National Park, Alberta. Science 221: 261-263.

Korotky, A.M., Pletnev, S.P., Pushkar, V.S., Grebennikova, T.A., Raszhigaeva, N.T., Sahebgareeva, E.D. and Mohova, L.M. 1988. Development of Natural Environment of the Southern Soviet Far East (Late Pleistocene-Holocene). Nauka, Moscow, USSR.

Lambin, E.F., Walkey, J.A. and Petit-Marie, N. 1996. Detection of Holocene lakes in the Sahara using satellite remote sensing. Photogrammetric Engineering & Remote Sensing 61: 731-737.

Lutaenko, K.A. 1993. Climatic optimum during the Holocene and the distribution of warm-water mollusks in the Sea of Japan. Palaeogeography, Palaeoclimatology, Palaeoecology 102: 273-281.

MacCracken, M.C., Budyko, M.I., Hecht, A.D. and Izrael, Y.A. (Eds.). 1990. Prospects for Future Climate: A Special US/USSR Report on Climate and Climate Change. Lewis Publishers, Chelsea, MI.

Overpeck, J.T. 1985. A pollen study of a late Quaternary peat bog, south-central Adirondack Mountains, New York. Geological Society of America Bulletin 96: 145-154.

Petit-Marie, N. (Ed.). 1991. Paléoenvironnements du Sahara Lacs Holocenes a Taoudenni (Mali), Editons du CNRS, Paris, France.

Porter, S.C. and Orombelli, G. 1985. Glacial concentration during the middle Holocene in the western Italian Alps: Evidence and implications. Geology 13: 296-298.

Ritchie, J.C., Cwynar, L.C. and Spear, R.W. 1983. Evidence from north-west Canada for an early Holocene Milankovitch thermal maximum. Nature 305: 126-128.

Ritchie, J.C. and Haynes, C.V. 1987. Holocene vegetation zonation in the eastern Sahara. Nature 330: 645-647.

Taira, K. 1975. Temperature variation of the "Kuroshio" and crustal movements in eastern and southeastern Asia 7000 years B.P. Palaeogeography, Palaeoclimatology, Palaeoecology 17: 333-338.

van Zinderen Bakker, E.M. and Coetzee, J.A. (Eds.). 1980. Palaeoecology of Africa, v. 12. A.A. Balkema, Rotterdam, The Netherlands.

Velitchko, A.A. and Klimanov, V.A. 1990. Climatic zonality of the northern hemisphere 5 or 6 thousand years B.P. Proceedings of the USSR Academy of Sciences, Geographical Series, 5: 38-52.

Webb, T. 1985. Holocene palynology and climate. In: Paleoclimate Analysis and Modeling. A.D. Hecht (Ed.). Wiley-Interscience, New York, NY, pp. 163-196.

Webb, T., Bartlein, P.J. and Kutzbach, J.E. 1987. Climatic change in eastern North America during the past 18,000 years: Comparisons of pollen data with model results. In: North America and Adjacent Oceans During the Last Deglaciation. W.F. Ruddiman and H.E. Wright, Jr. (Eds.). The Geology of North America, v. K-3. Geol. Soc. Am., Boulder, CO, pp. 447-462.

Whyte, I.D. 1995. Climatic Change and Human Society. Arnold, London, UK.

Wijmstra, T.A. 1978. Paleobotany and climatic change. In: Climatic Change. J. Gribbin (Ed.). Cambridge University Press, New York, NY.

[AvantHiatus]

Why are those papers so ancient? Houghton came out before the big 90's warm-up. We are not 1.0C from the HCO, no way my man.

[StudentOfClimatology]

Why are those papers so ancient? Houghton came out before the big 90's warm-up. We are not 1.0C from the HCO, no way my man.

You sure don't understand context. Instrumental data is usually tuned to the proxy resolution used in the study. The best early/mid proxy resolutions are on the order of 50-200 years.

Most of the early/mid Holocene work was done from the 1970s to the 1990s. I can link more recent papers if you'd like, but they'll reiterate the same thing.

[HailMan06]

You sure don't understand context. Instrumental data is usually tuned to the proxy resolution used in the study. The best early/mid proxy resolutions are on the order of 50-200 years.

Most of the early/mid Holocene work was done from the 1970s to the 1990s. I can link more recent papers if you'd like, but they'll reiterate the same thing.

Please do.