Medieval warming WAS global – new science contradicts IPCC

[FarCenter]

A proper temperature record for Antarctica is particularly interesting, as it illuminates one of the main debates in global-warming/climate-change: namely, were the so-called Medieval Warm Period and Little Ice Age merely regional, or were they global events? The medieval warmup experienced by northern Europeans from say 900AD to 1250AD seems to have been at least as hot as anything seen in the industrial era. If it was worldwide in extent that would strongly suggest that global warming may just be something that happens from time to time, not something caused by miniscule concentrations of CO2 (the atmosphere is 0.04 per cent CO2 right now; this figure might climb to 0.07 per cent in the medium term).

The oft-mentioned "scientific consensus", based in large part on the work of famous climate-alarmist scientists Michael Mann and Phil Jones and reflected in the statements of the Intergovernmental Panel on Climate Change (IPCC), says that isn't true. The IPCC consensus is that the medieval warming – and the "Little Ice Age" which followed it – only happened in Europe and maybe some other northern areas. They were local events only, and globally the world was cooler than it is now. The temperature increase seen in the latter half of the 20th century is a new thing caused by humanity's carbon emissions.

Lu and his colleagues' new work, however, indicates that in fact the medieval warm period and little ice age were both felt right down to Antarctica.

http://www.theregister.co.uk/2012/03/23/warm_period_little_ice_age_global/

[tabatha]

1. Extremely vague statement

"If it was worldwide in extent that would strongly suggest that global warming may just be something that happens from time to time"

All natural phenomena have a scientific basis. This needs to be determined.

CO2 is a greenhouse gas - if there were none in the atmosphere, the planet would be uninhabitable. Approximately 300 ppm is enough to change it from an uninhabitable to a inhabitable one.

The paper may be valid scientifically - however the conclusion drawn in that sentence is not scientific at all.

[ProfessorGAC]

2. +1

Well said.

[SidDithers]

3. "warming-alarmist" in the first sentence immediately colours whatever this article is saying...

Sid

[ljm2002]

9. Precisely. n/t

[mmonk]

12. Agreed.

Dead give away.

[Bohunk68]

18. That's what

I thought, too.

[JBoy]

4. More junk science from denier Lewis Page

In 2010 he was claiming evidence showed that changing energy output from the sun was a major cause of temperature increases on earth.

http://hockeyschtick.blogspot.ca/2010/10/paging-ipcc-much-of-recent-global.html

New data indicates that changes in the Sun's output of energy were a major factor in the global temperature increases seen in recent years. The research will be unwelcome among hardcore green activists, as it downplays the influence of human-driven carbon emissions.

[G_j]

19. he has quite a record...,

http://www.guardian.co.uk/environment/blog/2010/dec/17/register-climate-myths

[fascisthunter]

5. LOL... good lawd

[pscot]

6. Lewis page also believes

that a new ice-age is just around the corner.

[Boojatta]

8. The term "climate change" is vague enough to allow for an ice age.

It's a term that is being used:
"United Nations Framework Convention on Climate Change"
http://unfccc.int/2860.php

[hootinholler]

34. My understanding is that if the Gulf Stream fails

Then it will be so.

[mmonk]

7. How quickly did the warming occur?

[ProdigalJunkMail]

10. while the author of the article is a bit of a kook...

the scientist who authored the paper come from all around. Instead of trashing the study due to the author of the article...maybe the study has some merits. why does everyone assume the study is done by hacks just because the article is written by one?

sP

[Viking12]

14. The study probably does not say what the reporter/columnist asserts it says

Lewis, along with most other deniers, has a track record of blatant misrepresentation of scientific information. If I can make some time, I'll read the actual piece. I'd bet it does not lead to the types of conclusions made on the serial denier website.

[ProdigalJunkMail]

16. The study does claim in the abstract

that the MWP extended to Antarctica...and if there is quantitative data that shows this (and I suspect it would or it would not be in the abstract) then why are people here reacting with such venom?

sP

[Viking12]

20. "This ikaite record qualitatively supports..."

Do you know the difference between qualitative and quantitative?

From the article:
"At this stage, the geochemistry of ikaite serves as a qualitative, rather than a quantitative, climatic proxy, because it remains challenging to account for kinetic effects on uptake of δ18O into the carbonate during crystallization and any post-crystallization exchange of δ18Ohydra signal."

[ProdigalJunkMail]

21. yes...that is why i said IF...

i am not plopping down $40 to be a member so i can read the whole thing...

sP

OnEdit for your addition from the study : Is that the only measure that is in the study? If so, then I guess there IS no quantitative data and we can wait from something more...if it were ever to be forthcoming. My assumption is that there would be more quantitative data deeper into the study...

[Viking12]

24. Nope. No quantitative data at all.

It is an interesting paper that identifies the potential of a new paleoclimate proxy. There's much more work to be done before it can be successfully used to infer actual temperatures. It certainly does not contradict previous multiproxy studies as the lying liar from the register asserts.

[ProdigalJunkMail]

25. so, would it then contradict the other data

were it found to be a valid climate proxy? i would think that it would not be able to be considered valid if it were contradictory to the other accepted proxies.

thanks for the info...quick question though...you copied and pasted some text from 'the article' but i don't see it in the OP posted article. where did it come from? would love to do some more reading when time permits.

sP

[Viking12]

26. My super-fast reading is that it is in line withing existing proxy analyses back to at least the LIA

Specifically, the study refers frequently to;
Bentley, M.J., et al., 2009. Mechanisms of Holocene palaeoenvironmental change in the
Antarctic Peninsula region. Holocene 19 (1), 51–69.


The authors appear to have made a large leap to infer the MWP signal from the absence of the crystals.

I have access to the article because I have a subscription to ScienceDirect through my employer.

[ProdigalJunkMail]

28. ahhh, that would 'splain it

i thought my reading skills were severely deteriorated beyond my previous assessments

thanks again for the info...very interesting.

sP

[Codeine]

11. If that story were any more slanted the words would slide right off my screen. nt

[Bandit]

13. What complete Bunk

Core samples have been taken from Antartica and greenland and other Arctic regions for more than a half century now.. At no time in the last six hundred thousand years have Carbon Dioxide concentrations been even half as high as they currently are and they are still spiking...

[FarCenter]

15. This is about temperature, not carbon dioxide

The IPCC basically tried to minimize the Medieval Warm Period, at least in its earlier reports, as being a local European phenomena, and then not very warm at all.

This study shows that the Medieval Warm Period of relatively elevated temperatures extended to Antarctica.

So the problem for global climate modelers is to be able to run climate simulations that reproduce a global MWP, rather than a local minor one.

http://www.sciencedirect.com/science/article/pii/S0012821X12000659

Calcium carbonate can crystallize in a hydrated form as ikaite at low temperatures. The hydration water in ikaite grown in laboratory experiments records the δ18O of ambient water, a feature potentially useful for reconstructing δ18O of local seawater. We report the first downcore δ18O record of natural ikaite hydration waters and crystals collected from the Antarctic Peninsula (AP), a region sensitive to climate fluctuations. We are able to establish the zone of ikaite formation within shallow sediments, based on porewater chemical and isotopic data. Having constrained the depth of ikaite formation and δ18O of ikaite crystals and hydration waters, we are able to infer local changes in fjord δ18O versus time during the late Holocene. This ikaite record qualitatively supports that both the Medieval Warm Period and Little Ice Age extended to the Antarctic Peninsula.

--------------------------------------------------------------------------------

Scientists use rare mineral to correlate past climate events in Europe, Antarctica

http://www.syr.edu/news/articles/2012/ikaite-03-12.html

To understand the present, scientists look for ways to unlock information about past climate hidden in the fossil record. A team of scientists led by Syracuse University geochemist Zunli Lu has found a new key in the form of ikaite, a rare mineral that forms in cold waters. Composed of calcium carbonate and water, ikaite crystals can be found off the coasts of Antarctica and Greenland.

...

Ikaite crystals incorporate ocean bottom water into their structure as they form. During cooling periods, when ice sheets are expanding, ocean bottom water accumulates heavy oxygen isotopes (oxygen 18). When glaciers melt, fresh water, enriched in light oxygen isotopes (oxygen 16), mixes with the bottom water. The scientists analyzed the ratio of the oxygen isotopes in the hydration water and in the calcium carbonate. They compared the results with climate conditions established in Northern Europe across a 2,000-year time frame. They found a direct correlation between the rise and fall of oxygen 18 in the crystals and the documented warming and cooling periods.



“We showed that the Northern European climate events influenced climate conditions in Antarctica,” Lu says. “More importantly, we are extremely happy to figure out how to get a climate signal out of this peculiar mineral. A new proxy is always welcome when studying past climate changes.”

[DCBob]

22. There are numerous methodologies to determine past climate changes.

Most of them show the current warming is more extreme than anything seen in at least 1200 years.

From NOAA..



In summary, it appears that the late 20th and early 21st centuries are likely the warmest period the Earth has seen in at least 1200 years. For a summary of the latest available research on the nature of climate during the "Medieval Warm Period", please see Box 6.4 of the IPCC 2007 Palaeoclimate chapter. To learn more about the "Medieval Warm Period", please read this review published in Climatic Change, written by M.K. Hughes and H.F. Diaz. (Click here for complete review reference). Discussion of the last 2,000 years, including the Medieval Warm Period, and regional patterns and uncertainties, appears in the National Research Council Report titled "Surface Temperature Reconstructions for the Last 2,000 Years", available from the National Academy Press.

http://www.ncdc.noaa.gov/paleo/globalwarming/medieval.html

[FarCenter]

29. The statement that is being contested is the following:

From page 28 of:
http://www.grida.no/climate/ipcc_tar/wg1/pdf/WG1_TAR-FRONT.pdf

There has been a considerable
advance in understanding of temperature change that occurred
over the last millennium, especially from the synthesis of
individual temperature reconstructions. This new detailed
temperature record for the Northern Hemisphere is shown in
Figure 5. The data show a relatively warm period associated
with the 11th to 14th centuries and a relatively cool period
associated with the 15th to 19th centuries in the Northern
Hemisphere. However, evidence does not support these
“Medieval Warm Period” and “Little Ice Age” periods, respectively,
as being globally synchronous. As Figure 5 indicates, the
rate and duration of warming of the Northern Hemisphere in
the 20th century appears to have been unprecedented during the
millennium, and it cannot simply be considered as a recovery
from the “Little Ice Age” of the 15th to 19th centuries.

This was from the 2004 IPCC report. The discussion in 2007 is more complicated and nuanced. See http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch6s6-6.html

[Viking12]

30. The article referenced in the OP does nothing to 'contest' the IPCC

The Register lies about the significance of the article. You parrot those lies.

[FarCenter]

32. The lead researcher was quoted in the Syracuse University release as saying:

“We showed that the Northern European climate events influenced climate conditions in Antarctica,” Lu says. “More importantly, we are extremely happy to figure out how to get a climate signal out of this peculiar mineral. A new proxy is always welcome when studying past climate changes.”

[Viking12]

33. So? That says NOTHING about your false assertions about the MWP and the IPCC.

You haven't read the paper but I have. It says nothing that supports your false assertions. Read the paper and get back to me.

[Lydia Leftcoast]

17. The Medieval Warm Period was actually cooler than what we considered "normal" temperatures

in the 20th century.

I've heard a theory that says that the sharp drop in global temperatures around 1400 was precipitated by the Black Death, which killed about 1/3 of the population worldwide beginning around 1340.

That meant 1/3 fewer cooking fires, 1/3 fewer heating fires, 1/3 fewer torches or candles being lit, 1/3 fewer industrial processes, 1/3 less carbon dioxide being pumped into the air.

The population of Europe took 200 years to recover its pre-plague size.

The low point of the Little Ice Age is around 1600, or about 200 years after the original drop. The Earth begins warming up gradually.

Then, as Europe and North America begin to industrialize in the nineteenth century, the temperatures start to shoot up.

It's worth thinking about.

[FarCenter]

23. I doubt that pre-fossil fuel populations would have influenced climate due to biofuel burning

See link for graph of population of China from 0 to present of current era. http://www.iiasa.ac.at/Research/SRD/ChinaFood/data/pop/pop_21_m.htm

Population collapse after the Song dynasty is a little early for your theory. Also bear in mind that during this period China and India, as well as other parts of Southeast Asia consisted of the bulk of humanity.

The graph is interesting because it gives one an idea of the steady state carrying capacity of China in the pre fossil fuel era (and probably in the post fossil fuel era), i.e. something less than 10% of the current population.

[Tikki]

27. Medieval Bikini Babe...

When the weather is right...


Tikki

[intaglio]

31. It's F'n Lewis Page exagerating - again

Lewis is a long time climate change denier and a BIG fan of nuclear power.

I note he give no link to the study he is purportedly citing and seems to quote selectively.

Clues to climate from rare cold water mineral: Futurity dot org
The scientists analyzed the ratio of the oxygen isotopes in the hydration water and in the calcium carbonate. They compared the results with climate conditions established in Northern Europe across a 2,000-year time frame. They found a direct correlation between the rise and fall of oxygen 18 in the crystals and the documented warming and cooling periods.

“We showed that the Northern European climate events influenced climate conditions in Antarctica,” Lu says. “More importantly, we are extremely happy to figure out how to get a climate signal out of this peculiar mineral. A new proxy is always welcome when studying past climate changes.”

Note that the important parts of this are these quotes
1) “We showed that the Northern European climate events influenced climate conditions in Antarctica,” it says nothing about Antarctica being warmer just that a North European climate had some undesignated effect upon the Antarctic
2) “More importantly, we are extremely happy to figure out how to get a climate signal out of this peculiar mineral. A new proxy is always welcome when studying past climate changes.” i.e. there was a detectable signal from an North European event in Antarctica.

Please treat Mr Page with extreme caution because he specialises in deceit, mainly of himself.