Medieval Warm Period/Little Ice Age

[steve]

Apr 26, 2013 2:02:49 GMT icefisher said:

Apr 25, 2013 16:45:05 GMT steve said:

Indeed not! Which is why Steve McIntyre would quite often be able to find a questionable looking surface station dataset to place before his minions - until the surfacestations project hit the Muller buffers that is.

That is why you have to look at lots of pieces of evidence, not just a few.

And if you are, for example, trying to compare with the recent 30-50 years, you should look at each 30-50 year period of the past in isolation (as far as can be managed given the resolution of some proxies).

There is a tendency to compare the recent 30-50 (or even 100 year) average with the *peak* of any Medieval reference.

In short, this is the point I am making.

Its not clear the extent of what you are saying Steve. Should we never compare current temperatures to past proxies that entail a great deal of averaging over a significant period of time? If so I disagree. The proxies for the MWP clearly sets a minimum standard. Perhaps even if it stays at the current temperature in a couple of hundred years, our worldit will look much closer to the world of the MWP. I would suggest that since we just rose from the LIA the warmth is not currently significant because it has not been around long enough to be something of great enough endurance to have confidence it will show up in a proxy a thousand years from now as does the MWP. What I see is in just the ocean oscillation record a rather clear pattern of about .7degC from natural variation (and I don't care if you use the recent one or the one at the beginning of the 20th century!). I don't see that pattern in the proxies and the reason might be that they are not sensitive enough to capture less than 100 year averages. Thats pretty significant because after that what left? About a half degree of modern warming?

[/quote]

Icefisher,

If the current warming was not in line with expectations, and in line with predictions that have been on the table for many decades, then you may have a point.

But it is, so you don't.

[magellan]

Icefisher,

If the current warming was not in line with expectations, and in line with predictions that have been on the table for many decades, then you may have a point.

But it is, so you don't.

I remember the predictions from decades ago because it seemed plausible and after all, "scientists" can't be wrong because they are soooo smart. It is in no way in line with reality and why I began questioning the AGW meme. Stop making up stuff, first produce the predictions and what fulfilled those predictions. Then produce the models/scientists from "many decades" ago that predicted 15+ years of no warming/cooling, particularly the FAILED warming of the atmosphere.


Why is it we can find dozens if not hundreds of failed AGW predictions complete with the charts and data but you seem to only give speeches, make up excuses and form new hypotheses to cover for the failed old ones? That is not a prediction. All you folks are doing is making it up as it goes along.

Here's one from Hansen 1986. His 1989 Congressional testimony was my first real exposure to hearing a scientist explain and make predictions. There was no internet back then to counter the "consensus". I bought it hook line and sinker for several years.

Hansen 1986


Oh yes steve, I remember what was on the table.

[icefisher]

Apr 27, 2013 12:59:34 GMT steve said:

Apr 26, 2013 2:02:49 GMT icefisher said:

Indeed not! Which is why Steve McIntyre would quite often be able to find a questionable looking surface station dataset to place before his minions - until the surfacestations project hit the Muller buffers that is.

That is why you have to look at lots of pieces of evidence, not just a few.

And if you are, for example, trying to compare with the recent 30-50 years, you should look at each 30-50 year period of the past in isolation (as far as can be managed given the resolution of some proxies).

There is a tendency to compare the recent 30-50 (or even 100 year) average with the *peak* of any Medieval reference.

In short, this is the point I am making.

Its not clear the extent of what you are saying Steve. Should we never compare current temperatures to past proxies that entail a great deal of averaging over a significant period of time? If so I disagree. The proxies for the MWP clearly sets a minimum standard. Perhaps even if it stays at the current temperature in a couple of hundred years, our worldit will look much closer to the world of the MWP. I would suggest that since we just rose from the LIA the warmth is not currently significant because it has not been around long enough to be something of great enough endurance to have confidence it will show up in a proxy a thousand years from now as does the MWP. What I see is in just the ocean oscillation record a rather clear pattern of about .7degC from natural variation (and I don't care if you use the recent one or the one at the beginning of the 20th century!). I don't see that pattern in the proxies and the reason might be that they are not sensitive enough to capture less than 100 year averages. Thats pretty significant because after that what left? About a half degree of modern warming?

Icefisher,

If the current warming was not in line with expectations, and in line with predictions that have been on the table for many decades, then you may have a point.

But it is, so you don't.
[/quote]


You need to describe how you are differentiating expectations and predictions.

All I can say is robust 2+ degree variation is observable in basically all proxies. It only disappears when mathematical smoothing is applied. One cannot pontificate on the meaning of something you are hiding and then claim that pontification to be science.

[steve]

Apr 27, 2013 13:54:48 GMT magellan said:

Icefisher,

If the current warming was not in line with expectations, and in line with predictions that have been on the table for many decades, then you may have a point.

But it is, so you don't.

I remember the predictions from decades ago because it seemed plausible and after all, "scientists" can't be wrong because they are soooo smart. It is in no way in line with reality and why I began questioning the AGW meme. Stop making up stuff, first produce the predictions and what fulfilled those predictions. Then produce the models/scientists from "many decades" ago that predicted 15+ years of no warming/cooling, particularly the FAILED warming of the atmosphere.


Why is it we can find dozens if not hundreds of failed AGW predictions complete with the charts and data but you seem to only give speeches, make up excuses and form new hypotheses to cover for the failed old ones? That is not a prediction. All you folks are doing is making it up as it goes along.

Here's one from Hansen 1986. His 1989 Congressional testimony was my first real exposure to hearing a scientist explain and make predictions. There was no internet back then to counter the "consensus". I bought it hook line and sinker for several years.

Hansen 1986


Oh yes steve, I remember what was on the table.

That news article was clearly an error. As you are such an expert, you know this. Therefore your aim is to be deceptive.

From the contemporaneous publication (I couldn't find the testimony):

Another conclusion is that global warming to the level
attained at the peak of the current interglacial and the
previous interglacial appears to be inevitable; even with the
drastic, and probably unrealistic, reductions of greenhouse
forcings in scenario C, a warming of 0.5øC is attained
within the next 15 years. The eventual warming in this
scenario would exceed 1øC, based on the forcing illustrated
in Figure 2 and the feedback factor f • 3.4 for our GCM
[paper 2]. The 1øC level of warming is exceeded during the
next few decades in both scenarios A and B; in scenario A
that level of warming is reached in less than 20 years and
in scenario B it is reached within the next 25 years

www.fas.harvard.edu/~eps5/writing_assignment/CLIMATE_BKGD/Hansen_1988_keypaper.pdf

The warming figures are relative to the 1951-1980 mean.

The actual forcing was closest to Scenario B.

The actual warming in the 27 years since the testimony is 0.6C



Given the status of modelling then, a 40% error in the estimate is pretty good. A big chunk of that error has been understood for over 15 years - since calculations of CO2 forcing were improved and forcing was found to be a bit less than what Hansen thought.

I guess people who buy into hype will always buy into hype and tend to go from one extreme to the other. If your original assessment was more measured (like mine was and is) you might have not felt the need to make up for your previous mistakes.

[icefisher]

Apr 28, 2013 14:03:10 GMT steve said:

The warming figures are relative to the 1951-1980 mean.

The actual forcing was closest to Scenario B.

The actual warming in the 27 years since the testimony is 0.6C



Given the status of modelling then, a 40% error in the estimate is pretty good. A big chunk of that error has been understood for over 15 years - since calculations of CO2 forcing were improved and forcing was found to be a bit less than what Hansen thought.

I guess people who buy into hype will always buy into hype and tend to go from one extreme to the other. If your original assessment was more measured (like mine was and is) you might have not felt the need to make up for your previous mistakes.

Steve where do you get: "The actual warming in the 27 years since the testimony is 0.6C"?

The chart (Hansen's modified temperature record) shows a mean about .58degC above the 1951-1980 mean (mean of the cold phase of the PDO). In 1988 the mean appears to be a bit above .33degC. That suggests that Hansen's GISTEMP suggests about .25 warming since the testimony.

We also know that Hansen's temperature record (odd using his to defend his predictions) is the most aggressive of the pool of records.

He accomplishes that through various biased smoothings like smoothing land trend temperatures 60 miles to sea to fill data gaps. Fact is the sea has far more influence on the land than the land has on the sea. Why would he do that in the face of science that suggest the opposite? I recently drove 60 miles to the sea from inland on a warming morning 10:30 am to 11:30am and found more than a 10c difference from the ocean influence. 10c to 60 miles to sea differences just don't exist no matter which direction or how hard the wind is blowing.

No doubt the reason he does it is because the land temperature trend is so much steeper than the ocean temperature trend so he can pump up his temp record as much as possible. Its not the only odd thing he does, extrapolating from arctic land stations over ice is another. His bias is palpable and he will disregard any science he chooses to acheive his aims.

So maybe you could look at Hadcrut 3 (before Phil Jones polluted Hadcrut with weak science temperature trends in the arctic), keeping in mind the prediction came well before trends in the arctic had been identified. At first those trends were offered up as "worse than we previously thought", today they are used as backfill.

The only honest way to look at trends is use the same methodology as originally used. Not "corrected" data, or modified methods. In accounting it is a "standard" to ensure any and all trends are consistent in the application of accounting principles throughout the presentation. You can calculate new trends with new principles but only with disclosure of the effect of the change. The purpose of this standard is to prevent management from dressing up their results after the fact. Of course climate science has no accountability so they do it as a regular business practice.

[glennkoks]

It would seem that the winter of 1609-1610 was pretty bad.

www.bloomberg.com/news/2013-05-01/cannibalism-evidence-found-at-jamestown-settlement-by-scientists.html

[sigurdur]

Glenn: The winter that Lewis and Clark were in Mandan, temps there were 40+F below zero. For our celcius friends, that is about -50c?

Watched an excellent doc on the expedition, not done watching it yet as it is three hrs+ long, but that musta been one cold winter!

[trbixler]

sig
I wrote a college paper on Lewis and Clark. They were true adventurers and explorers.

[sigurdur]

Ice age.....it would seem.

www.facebook.com/photo.php?fbid=10151396053093093&set=a.309486388092.149605.46959023092&type=1&ref=nf

[sigurdur]

May 2, 2013 1:15:11 GMT trbixler said:

sig
I wrote a college paper on Lewis and Clark. They were true adventurers and explorers.

They were amazing men. From their papers, how they drew new species, plants etc.

Scientists in the true sense of the word.

[glennkoks]

Public TV had a great serious on their expedition. I think the mercury dropped down as low as -43F when they were in Mandan. The amount of ground they covered in the amount of time they did it in was truly amazing.

[steve]

Icefisher,

Steve where do you get: "The actual warming in the 27 years since the testimony is 0.6C"?

Correction: The testimony said there was a possibility of 1C warming by now relative to 1951-1980. The actual warming was 0.6C

[icefisher]

May 4, 2013 7:55:00 GMT steve said:

Icefisher,

Steve where do you get: "The actual warming in the 27 years since the testimony is 0.6C"?

Correction: The testimony said there was a possibility of 1C warming by now relative to 1951-1980. The actual warming was 0.6C

That is incorrect Steve. this should fix your error for you.

Here is Hansen's testimony.

www.skepticalscience.com/pics/ClimateChangeHearing1988.pdf

In the testimony there is a chart of current and predicted temperatures (page 48 of the congressional record - page 39 is the first page where his testimony starts)

In the testimony and noted on the chart is a current anomaly of .4 degrees and a predicted anomaly if emissions were capped in 1988 at the 1988 level of 1.0 degrees (and a somewhat higher prediction for no capping of emissions).

So the .6 degree warming prediction is additional warming from 1988 for a total anomaly of 1.0+ degrees

Looking at his current temperature record above (Hansen has enhanced the warming since 1988 by both reducing the anomaly he estimated in 1988 (by .07 degrees)and being more aggressive than his peers with current temperature anomalies.

And with all that fudging his current chart shows only about .25 degree warming since 1988. His fudging makes up probably half of that.

[cuttydyer]

This may have been posted before, bust just in case it hasn't:

CO2 Science's Medieval Warm Period Project:

What is it?
Our Medieval Warm Period Project is an ongoing effort to document the magnitude and spatial and temporal distributions of a significant period of warmth that occurred approximately one thousand years ago. Its purpose is to ultimately determine if the Medieval Warm Period (1) was or was not global in extent, (2) was less warm than, equally as warm as, or even warmer than the Current Warm Period, and (3) was longer or shorter than the Current Warm Period has been to date.

Link: www.co2science.org/data/mwp/description.php

Link to interactive map (don't forget to allow pop-ups): www.co2science.org/data/timemap/mwpmap.html

[steve]

cuttydyer,

Yes the co2"science" project has been mentioned many times before.

Basically, they look at proxy papers. If the paper says it may have been warmer or drier than some period in the 20th Century for a short period some time between 850 and 1450AD they will say "aha!!! this proves the MWP was present in this location".

Given that many of the proxies also show large periods of time when temperatures were similar or cooler, and given that the late 20th Century and early 21st Century warming is not picked up by many proxies, the average of the proxies tend to back up the findings of folk such as Esper, Mann and Marcott - that temperatures now are globally as warm or warmer than any time in the last millennium.