Comments on: Historical video perspective: our current “unprecedented” global warming in the context of scale

By: Smokey

Smokey — Mon, 01 Feb 2010 12:25:51 +0000

foinavon (05:56:52)…

…actually believes that temperatures can be determined through century old proxies, to within 0.1°C.

This is the kind of ridiculous “evidence” that the alarmist contingent always trots out when they have nothing credible to go on. foinavon really believes that a temperature of exactly 31.6°C can be determined through proxies for the year 1900. Extreme cognitive dissonance.

By: san diego audio video

san diego audio video — Wed, 30 Dec 2009 22:01:17 +0000

how can this be screamed in the ears of the governments, they are the source of all pollutions

By: David Ball

David Ball — Fri, 18 Dec 2009 04:32:50 +0000

Colin, present some reasonable length of data that doesn’t just show what we would like them to show, but the entire time span, and you may have something. To use starting and ending points that confirm our delusion is not “good science”. Please define “good science” for me.

By: David Ball

David Ball — Fri, 18 Dec 2009 04:28:46 +0000

The graphs are not making any attempt to show the comparisons between current temps and the MWP. The graphs show us the place we happen to be on the timeline of earth’s temperature fluctuations. You seem to be making up your own discussion. To provide data to one Greenland station to show how the “hockey stick” in comparison to the paleo record is wrong convinces me of nothing. I’m sorry, but I guess I must be a little slow to see the connection. “Enhanced melting is from sea level upwards as glacier discharge to the sea accelerates and summer melt reaches to higher altitudes”. How many times in the history of earth do you suppose this has happened? What is the cause of this warmth? Is it unprecedented? Showing 100 years of data from one point on the earth does little to clear up my queries. Most of which you conveniently chose not to address. The whole point of these graphs is to show how futile it is to claim know what has caused the recent warming, when it is clearly within the bounds of what the climate does naturally. You have not convinced me in any way that these graphs are wrong.

By: foinavon

foinavon — Thu, 17 Dec 2009 17:17:10 +0000

David Ball (22:37:50) :

Not really hand-waving David. It’s pretty simple. If one is attempting to make a point about temperature comparisons at the MWP and now, from a single site on the Greenland summit, and the proxy data from the ice core at the site only goes up to 100-150 years ago, one can’t just “fill in” the intervening temperature trend with some arbitrary truncated global temperature, that bears rather little relationship to what the temperature change has been at that site in the intervening period.

One should at the very least use the Northern hemisphere temperature data (around 1.3-1.4 oC of temperature rise since the last point in the ice core).

But why not use the temperature data from the Greenland summit 1.5-2.0 oC temperature rise or more in the last 100-150 years, since we have this [see Box et al (2009) citation in my post above [foinavon (05:56:52)]

The fact that the Greenland summit at 3 km high is very cold is not the issue. The Greenland ice sheet can’t melt from the summit down. Enhanced melting is from sea level upwards as glacier discharge to the sea accelerates and summer melt reaches to higher altitudes.

For some reason the link to the NCDC data repository link didn’t paste here properly. Here it is again.

ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/isotopes/gisp2_temp_accum_alley2000.txt

By: colin

colin — Thu, 17 Dec 2009 14:57:02 +0000

The problem with this presentation is that it compares temperatures on Greenland with Michael Mann’s global temperature record – the hockey stick. But warming on Greenland since 1900 was significantly more than in the global record, as is evident too from the Arctic record. Relative to the 1961-1990 average, Arctic temperatures were down -0.8C in 1900 and up +1.5C by 2003, a range of 2.3C in total, and much more than suggested in the graphs used here. So, who is kidding who? Why can’t we have some good science for a change?

By: kwik

kwik — Thu, 17 Dec 2009 06:48:12 +0000

One thing I have nothiced with this site, is that time ; Local and Regional time, is messed up. This post for example, was posted 07:48 Oslo time. [I've noticed that too. It must be a WordPress glitch. ~dbs, mod]

By: kwik

kwik — Thu, 17 Dec 2009 06:42:08 +0000

Now THAT is interesting! Coincides with Callion et. al.

By: David Ball

David Ball — Thu, 17 Dec 2009 06:37:50 +0000

Foinavon, a ton of hand waving. Very impressive. To what do you attribute the warming at the GISP 2 site? Natural Variability? Co2? The Sun? -30.5 oC wow. Is that “adjusted data” or “unadjusted”? Either way, I guess we don’t have to worry about that melting anytime soon. But I must not have proper recourse to the science. Thanks for mentioning the Milankovitch cycle though. I can’t remember, but are those even factored into the models? The cycles explain some of the aspects of the ice ages, but not all. Could you fill in the blanks for us on that since it is so well understood? Could not get your links to work and the GISS map would not input the years you have indicated. Maybe you could help me further with these things. I must point out that I think the graphs are very clearly telling us that we have nothing to fear from catastrophic human induced climate change. Does not take a PhD to understand that.

By: Pete

Pete — Thu, 17 Dec 2009 05:43:06 +0000

Sorry, I meant to say that “… maybe the Team has realized this lag between rise of temp and rise of CO2 and is therefore…”

By: Pete

Pete — Thu, 17 Dec 2009 05:40:38 +0000

The really mindblowing observation in terms of the Vostok was made in JoNova-blog
http://joannenova.com.au/2009/12/carbon-rises-800-years-after-temperatures/
by a reader suggesting that since there always seems to be a lag between the rise of climate temp and CO2 (based on the Vostok ice cores seems the lag seems to be about 800 years) the current rise of CO2 might actually be caused by MWP. Maybe the has realized this and is therefore so scared of accepting the MWP? Maybe it’s the changing ability of the oceans to store CO2 (and not the humans) that causes the rise of CO2? The lag was also discussed in the latest news of the CO2 Science-blog: http://www.co2science.org/

By: foinavon

foinavon — Wed, 16 Dec 2009 13:56:52 +0000

David (21:30:57), the graphs are obviously wrong. They’re specifically wrong in ignoring the relevant Greenland temperature data for the past 100 years, and tacking an incorrect global temperature stick onto a local proxy series obtained from a region known to have undergone very large warming during the last 100 years.

Inspection of Alley’s data in the NCDC archive [*] shows that the most recent temperature data point for the GISP 2 core is for around 100 years before 2000.

According to the temperature reconstruction from the ice sheet this temperature was -31.6 oC.

In the intervening period, the Greenland ice sheet temperature (2 metre surface height) has risen by around 1.5 oC, averaged over the whole ice sheet [**]. It’s likely that the ice sheet summit area where GISP 2 is, has warmed more than this (NASA GISS analysis puts the warming at the Greenland summit where the GISP 2 core was drilled to more than 2 oC [***])

So if we are comparing like with like [i.e. the temperature at the Greenland ice sheet summit at GISP 2 at the “height” of the MWP (-30.5 oC), and the temperature at the Greenland ice sheet summit at GISP 2 at the turn of the 20th century (-31.6 oC)], we should really consider the temperature change since then at the same location. The evidence indicates this is at least 1.5 oC warmer and likely 2 oC or more warmer.

So analysis of the Alley GISP-2 ice core temperature proxies with the temperature rise at the GISP 2 site during the last time point in the core around 100 years before 2000, indicates that the local temperatures at the GISP-2 site are already well above those of the MWP, even in this locale where the MWP was very strongly represented. However one would only know that by proper recourse to the science….

On your query about the ice age interglacial to glacial transition, that is indeed rather well understood. Google “Mil.ankovitch cycles”….

[*] ftp://ftp.ncdc.noaa.gov/pub/data/…gisp2_temp_accum_alley2000.txt

[**]
Box JE et al. (2009) Greenland Ice Sheet Surface Air Temperature Variability: 1840-2007 J. Climate 22, 4029-4049

[***]
http://data.giss.nasa.gov/gistemp/maps/

By: David Ball

David Ball — Wed, 16 Dec 2009 05:30:57 +0000

Gazzer(09:51:11) Just empty words until you can back them up. Intellectually lazy to dismiss the graphs used here without showing why they are wrong. I suspect that you can not. I’ll give you one that by your logic should be easy. Explain the plunge into the ice ages from the interglacial high point if all this has been cleared up and explained. I am at least humble enough to admit that what we don’t know far outweighs what we do know. Humble thyself.

By: solarity

solarity — Wed, 16 Dec 2009 03:40:40 +0000

The attitude displayed by Gazzer is epidemic throughout the climate change community. Climatologists and related specialists are in a somewhat unique position. By subtle distortions or misinterpretations of the scientific record (intentional or not) they are able to make themselves and their work seem very important because they are in a position to warn humanity of a pending disaster. Seismologists probably would do the same if they could but earthquakes are short and largely unpredictable events. In the realm of the earth sciences, it is only the climatologist who can plausibly attract attention and money by claiming impending disaster. Do not underestimate the need of obscure professionals to manufacture data if by doing so they can get favorable attention and attract grant money. It is simple human nature to want one’s life work to be important. Crying wolf about global warming accomplishes that goal.

By: Dan Pangburn

Dan Pangburn — Wed, 16 Dec 2009 02:04:47 +0000

Gazzer, Bart, Apparently the research that “accurately predicts average global temperatures since 1895″ in the October 16 pdf at http://climaterealists.com/index.php?tid=145&linkbox=true is too complex for you to grasp. So you will just have to continue to wonder (along with Trenberth et. al.) why the cooling trend is down while the CO2 level continues to go up.