Glaciers in the Swiss Alps

[Mike Davis]

I found this research paper for Q. It is a follow up on other reports I read some years ago.:
http://pgosselin.wordpress.com/2010/04/ ... m-periods/
I do not speak the original language so will rely on this translation until it is published in English.
Excerpt:
Christian Schlüchter, Professor of Geology, and his team of researchers are studying remnants of ancient trees and peat that have been exposed by melting glaciers high in the Swiss Alps. At first sight, these pieces of wood may not look spectacular, but they are up to 10,000 years old and have a story to tell.

These tree remnants include complete tree trunks that were scraped and twisted by the massive ice sheets that once covered them. Over time these chunks of wood were transported by the glaciers partway down the Alps, and it was not exactly sure from what elevation they originated. But the wood chunks and peat prove one thing: Today, where one now only finds bare rock and gravel, and even where there is still ice, trees once grew there thousands of years ago.

In fact, entire forests must have existed there because in some places the wood remnants were found in piles. By looking at flow and glacial movement patterns of the individual glaciers, Prof Schlüchter and his team have been able to reconstruct the path the wood chunks and peat must have taken, and thus they were able to pinpoint their original location of growth

[Philip]

Mike: That is another good find, thank you. A similar story was reported a couple of years ago on the dear old Beeb:

http://news.bbc.co.uk/1/hi/sci/tech/7580294.stm

Interesting to notice the following curious statement from one Martin Grosjean (half way down opposite the picture of some Roman coins): "But what we do know is that the climate has fluctuated throughout history; in the past the driving force for the changes was the Earth's orbital pattern, now the driving force is green house gas emissions." Now we know .

[Mike Davis]

Philip:
You and I both know there was NO Magic bullet that caused nature to step aside so Humans can interfere with the climate.

[glenncz]

This is one one of my favorite glacier pictures.
http://www.cseg.ca/publications/recorde ... w-nuna.pdf
Scroll through the jibberish to page 3. Geologically speaking, just a very short time ago there were trees growing at this spot in Alaska, 1000 BC, then giant glaciers forms, and now the cycle has returned, the glaciers have receded, but not nearly enough to grow trees yet. 3,000 years is just a heartbeat in the timeline for planet earth. yet the wackos, group-thinkers that are running this conference, completely ignore this simple data in promoting their conference.

[Mike Davis]

Glenncz:
Just one more region that shows we are experiencing a little bit of warming on the slide into the next glaciation. It would take 500 to 1000 years of current or warmer temperatures to achieve the same forest canopy that was experienced 5000 years ago at high latitudes and high altitudes. It would probably take an additional 1000 years to achieve the biomass age that is evident under glaciers and in permafrost tundra.
Thank you for the link!

[questioner]

The argument you are making is rubbish. There is no logic to it. The driver for the warm period thousands of years ago is believed to be the sun. There were of course no industrial emissions of GHG's at that time. The existence of prior eras that were as warm as today does not constitute proof that GHG's produced by human industry are not producing the warming today. The two sources of warming are totally independent. The existence of one does not have any bearing on the existence of the other.
In fact one of the scientists interviewed in connection with the BBC said the following:

For Martin Grosjean, the leather items found on the Schnidejoch, dated at over 5,000 years old, are proof, if any more were needed, that the Earth is now warming up.

"The leather is the jewel among the finds," he says. "If leather is exposed to the weather, to sun, wind and rain, it disintegrates almost immediately.
Tool reconstruction (University of Berne)
Bit by bit, the Neolithic way of life is being revealed

"The fact that we still find these 5,000-year-old pieces of leather tells us they were protected by the ice all this time, and that the glaciers have never been smaller than in the year 2003 and the years following."

[Philip]

Fabulous response, Q. However, irrespective of any arguments over the details, the glaciers tell us that temperatures have been higher than today during the Holocene, and we know for a fact that this did not lead to catastrophic warming.

[questioner]

Fabulous response, Q. However, irrespective of any arguments over the details, the glaciers tell us that temperatures have been higher than today during the Holocene, and we know for a fact that this did not lead to catastrophic warming.

The presumed increase in solar energy responsible for the holocene warm period thousands of years ago is indeed a cyclical process. The emissions of GHG's are not a cyclical process and there is no logical reason to believe that they would go away like the increase in solar energy did. So it is illogical to rely on experience of the past retreat of the glaciers to claim that the current problem is a symptom of transient warming that will go away in the future.

[Philip]

So it is illogical to rely on experience of the past retreat of the glaciers to claim that the current problem is a symptom of transient warming that will go away in the future.

I didn't suggest that. Past retreat of the glaciers indicates that past Holocene temperatures have been higher than today. For existential reasons we know that this didn't lead to catastrophic warming. The feedbacks proposed as the cause of catastrophic warming operate independently of the cause of warming. Why therefore should we therefore expect that catastrophic warming would result today from a 1 degree C02 forcing?

[questioner]

So it is illogical to rely on experience of the past retreat of the glaciers to claim that the current problem is a symptom of transient warming that will go away in the future.

I didn't suggest that. Past retreat of the glaciers indicates that past Holocene temperatures have been higher than today. For existential reasons we know that this didn't lead to catastrophic warming. The feedbacks proposed as the cause of catastrophic warming operate independently of the cause of warming. Why therefore should we therefore expect that catastrophic warming would result today from a 1 degree C02 forcing?

What was the forcing that caused those past temperatures and the time scale of the feedbacks?
In fact estimates of climate sensitivity based on the orbital wobbles with albedo and CO2 emissions as feedback factors show huge temperature changes over long periods of time. The climate sensitivity depends on the time scale that is considered. For decades to centuries, the value of 3C for doubling of CO2 seems reasonable. For longer time periods, the slow process of emission of CO2 from the oceans must be considered. This slow process increases the climate sensitivity substantially.
http://climateprogress.org/2007/10/01/a ... ubled-co2/

Here is what Hansen says on the subject (though when you read it you may wonder why Hansen is more optimistic than I am, rather than less):


"The implied climate sensitivity, ¾°C per W/m2 (equivalent to 3°C for doubled CO2), is consistent with climate model estimates, but of greater precision. We can never be certain that climate models accurately include all relevant processes. But we know that the real world included all changes of clouds, water vapor, sea ice and any other such fast ‘feedbacks’ that exist.

It must be recognized that the specific climate sensitivity derived in this way includes only ‘fast’ feedbacks. We call this the Charney climate sensitivity, because it is essentially the case considered by Charney (1979), in which water vapor, clouds and sea ice were allowed to change in response to climate change, but GHG (greenhouse gas) amounts, ice sheet area, sea level and vegetation distributions were taken as specified boundary conditions. We would expect the Charney climate sensitivity to be most relevant on decadal time scales. On longer time scales as the quantities assumed to be fixed can change in response to climate change, thus becoming powerful climate feedback mechanisms.

Important insight emerges from close examination of the temperature and forcing curves: the temperature change leads the forcings by several hundred years. Thus the greenhouse gas and ice sheet changes, although they are the principal direct mechanisms for the climate change, are changing as feedbacks. The pacemaker and instigator of the changes is cyclic variation of the Earth’s orbit (Hays et al. 1976), which alters the seasonal and geographical distribution of solar radiation. Insolation changes by a significant amount over several thousand years.

Variations of atmospheric CO2 occurring as a climate feedback on the time scale of the ice ages (Figure 3) can be ~100 ppm in 5000 years, or 0.02 ppm/year. This atmospheric change is due to a shifting of carbon among the atmosphere, ocean, soil and biosphere compartments within the surface carbon pool, a warmer climate driving more CO2 into the air. This natural glacial-interglacial variation of atmospheric CO2 is quite rapid in comparison with the geologic cycling of carbon between the Earth’s crust and the surface carbon pool, which amounts to ~10**(-4) ppm/year of CO2, as discussed above.

These natural rates of atmospheric CO2 change must be compared with the human-caused growth of atmospheric CO2, which is now ~ 2 ppm/year (see below). Humans, indeed, are now in control of long-lived atmospheric GHGs. As a result it is important to investigate climate sensitivity for the case in which GHGs are specified as the forcing. The Charney climate sensitivity applies to this case under the assumption that slow feedbacks such as ice sheet area, vegetation distribution, and climate-induced GHG changes are not allowed to operate.

As a complement to the Charney climate sensitivity, let us derive the climate sensitivity that applies if these slow feedbacks are allowed to operate: we call this the ‘long-term’ climate sensitivity. We can obtain this ‘long-term’ climate sensitivity from paleoclimate data by finding the scale factor that causes the GHG forcing to match the paleoclimate temperature change as accurately as possible. Figure 4 shows that multiplying the climate forcing due to long-lived GHGs (CO2 + CH4 + N2O) by 3.02°C per W/m2 yields remarkably good agreement with Antarctic temperature. Given that glacial-interglacial global temperature change is about half of Antarctic temperature change, this implies a ‘long-term’ climate sensitivity of ~1.5 W/m2 or about 6°C for doubled CO2."

So paleo climatology data indicates the long term climate sensitivity is twice the often quoted Charney factor, of 3C, when emissions of GHG's over time are taken into account.