Comments on: Welcome words from a politician

By: Phil Scadden

Phil Scadden — Wed, 03 Feb 2010 01:00:59 +0000

C3PO. If you want further info on Cook et al and SH temperature reconstruction then can I recommend section 6.6.2 in IPCC AR4 WG1?
Cook is contributing author. The whole discussion on proxies, past reconstructions and relevance to current climate in the chapter is a hell of a lot more enlightening then the drivel on the blogs.

By: Phil Scadden

Phil Scadden — Wed, 03 Feb 2010 00:41:29 +0000

Phil Sage – why would believe that warmer temperatures in earlier times invalidates AGW? Climate forcing are sun, aerosols, albedo and GHG all varying in the past. Its just the GHG is the forcing at the moment. AGW is founded on physics not paleoclimate. Paleo studies suffer from poor sampling, limitations on dating, and variable proxies leading to uncertain forcings determining uncertain temperatures. This is not to say paleoclimate isnt extremely valuable for constraining parameters and validation. Skeptics rabbit on about paleoclimate simply because they can – uncertainty is a happy hunting ground.

By: Gareth

Gareth — Wed, 03 Feb 2010 00:00:56 +0000

Another revealing post… So you only believe in a global picture when it suits? Greenland’s ice cores are an incredible record of part of the northern hemisphere and a lot of useful information can be inferred from them, but they are not a proxy for the entire NH! Look again at the maps in the Skeptical Science article, and in particular at the map showing current temps compared to MWP and LIA. Warming was patchy in the MWP. It’s not now.

And, for the record, I do not claim to be a scientist. I am a writer specialising in climate science (amongst other things). I have a science background (degree level), and have worked with scientists on research projects, managing one of them.

By: Phil Scadden

Phil Scadden — Tue, 02 Feb 2010 23:40:49 +0000

Mann 2004 gives his reason for not including Cook et al 2002 – data as poor local box correlation. I hardly think though that the paper contradicts Mann.

For much more detail on NH and SH correlations see
http://www.sciencemag.org/cgi/content/full/324/5927/622?ijkey=602f2e25a09fcda4e4ad6d8922587742bc18f92b
It would also have say cool here in line with other data.

(though I know from a coauthor in next office that more data and analysis coming. Doesnt effect MWP discussion though but more on larger issue of NH/SH connections)

Cook et al 2006 with comparisons with Tasmania might be worth a look. You might also want to consider that Cook and Mann have collaborated on a number of papers so hardly unaware of what each other is doing.

Good to see some discussion based on published research however. Explain to me why this discussion of MWP is relevant to current climate please though. What do YOU think is wrong with the model data in Mann 2009 that represents a challenge to AGW?

By: Phil Sage

Phil Sage — Tue, 02 Feb 2010 23:38:22 +0000

Gareth. If your faith allows you to ignore such evidence or consider it irrelevant to the question of whether temperatures have been higher in the past then I give up. I thought you called yourself a scientist.

Constant wittering about “global” temperatures from the true believers ignores that the globe is made up of individual places that have a correlation to each other in climate terms. Greenland is an incredible record of the northern hemisphere. and the north is half of the globe. But that does not suit your belief structure so rationalise it out of relevance.

I guess you must believe in the magical warm aliens who landed only in Greenland and warmed their environment. Whatever. End of my welcome here.

By: Gareth

Gareth — Tue, 02 Feb 2010 22:14:34 +0000

Phil: that is a graph of central Greenland temperatures derived from ice core data. It can’t cover temps over the last 70-odd years (because that’s how long it takes the firn layer to consolidate), and so has nothing to say about modern temps in the longer term context. Was it warmer than now in the early Holocene? Certainly possible. But that tells us nothing about the global temperature at the time. It’s certainly of interest in considering the history of Greenland’s ice cap…

By: Gareth

Gareth — Tue, 02 Feb 2010 22:09:49 +0000

The MWP was not “comparable in magnitude or warmer” than today. Take a look at the series of maps on Skeptical Science, linked above.

Keller was writing in 2001. Seems to me he was asking for a mechanism that could explain all the variability in the various records. Mann’s latest paper could be seen as an attempt to do that. But it’s worth noting one thing: we’ll never have perfect knowledge of past temperatures, we can only improve our understanding. Surfers as a proxy? Frequency of wet suit use might indicate changes in sea temps…

By: RW

RW — Tue, 02 Feb 2010 21:43:42 +0000

Sigh – idiots still maundering on about the NZ temperature series I see. Time to beam up again.

By: C3P0

C3P0 — Tue, 02 Feb 2010 20:40:56 +0000

Dappled, I was refering to reported modern warming in Hokatika. Your diversion to regional cooling 1000 years ago is weak, if I found an area that cooled during the current warming would than mean 20th century warming was false?

Back to the point….

By looking at glaciers current trend you are preferring a bad proxy over an OK proxy because it gives you the result you want.

So why did the tree ring proxy recon not show 20th century warming? Is it scientifically robust to compare current instrumental records to historical proxy data?

By: Dappledwater

Dappledwater — Tue, 02 Feb 2010 12:29:54 +0000

“but I donâ€™t see it as being a proof that warming will cause less precipitation in Amazonia” – Phil Sage

It is generally accepted that current warming trend will lead to the oceans ability to store heat to diminish and therefore give up more of it’s heat to the atmosphere i.e. more El Nino’s and less La Nina’s. This is bad news for the Amazon as there is a connection with El Nino, it’s effect on tropical Atlantic waters and drought in the area.

http://mudancasclimaticas.cptec.inpe.br/~rmclima/pdfs/publicacoes/2008/Zengetal2008.pdf

“A rare drought in the Amazon culminated in 2005, leading to near record-low streamï¬‚ows, small Amazon river plume, and greatly enhanced ï¬re frequency. This episode was caused by
the combination of 2002â€“03 El Ni Ëœ no and a dry spell in 2005 attributable to a warm subtropical North Atlantic Ocean.”