I'm sure you have Grendel, but that is not what interests me. What interests me is why you have suddenly become so shy about it. Is it simply because you cannot respond to the criticism that the evidence you posted does not support your position? Muso also picked up on it, so maybe there is more to it. It simply does not make sense for someone who believes in themself to go to such effort to avoid giving a simple explanation of their position, while posting so much else.

Soren wrote on May 30^th, 2009 at 6:31pm:



Well done Soren, you at least made a good point, although you have not supplied any data to support this yet. I'll try to answer you as well as I can.


The CO2 concentration in the atmosphere and temperature are interdependent. Arrhenius demonstrated that increasing CO2 levels would increase temperature via the greenhouse effect way back at the beginning of the 20th century.

This plot of CO2 versus temperature shows that current atmospheric CO2 levels are higher than they have been for 800,000 years:

So something tells me we're not in Kansas any more, to quote Dorothy from the Wizard of Oz.



To go much beyond that requires the use of proxies that are increasingly unreliable.

However, work carried out in 2006-2007 show that the climate sensitivity has actually remained roughly about the same as far back as 420 Million years.

Climate sensitivity constrained by CO concentrations over the past 420 million years

Ref: Robert A. Berner, Jeffrey Park, Dana L. Royer
Nature 446, 530-532 (29 March 2007) doi:10.1038/nature05699 Letter

Here's an abstract of that study:

http://www.nature.com/nature/journal/v446/n7135/full/nature05699.html

I think what you are probably referring to is the end of the Ordovician period,  443 Million years ago, at which stage there was a period of glaciation. We really don't have enough reliable data on that period to conclude anything.

While we have a reasonably good measure of solar activity over fairly recent times, we have very little idea of how 'hot' the sun was during that period. For all we know, the solar irradiance may have dropped resulting in glaciation.

Ah, but you say - so how could this be when CO2 levels were so high?
During geological time, CO2 levels have fluctuated enormously. Prior to the blooming of photosynthesising cyanobacteria (blue green algae), the atmospheric CO2 was in the two figure percent range, but of course, the sun was not as luminous back then.

The main thing about these geological periods was that other conditions were different from today. With greater 'buffers' such as ocean life and in some cases, vast areas of rainforest, the actual CO2 to temperature relationship has varied somwhat.

There have been periods within the last 420 million years where CO2 levels have changed sharply for different reasons, but generally these have been coincident with species extinction.

Our best guide to climate sensitibity is the most recent geological periods. The main change in the last 150 years or so has been the dramatic reduction in tropical rainforest, which acts as a buffer, effectively removing excess CO2 and smoothing out any spikes.  

So it's important to compare apples with apples.

muso wrote on May 31^st, 2009 at 8:45am:



So that is the long version of the answer, which is " well, yes, but long term data is not supportive of man made climate change so it's best not to look at it for some reason or another."

VAGUE...  yep that's you fd.

And wrong and idiotic.  but hey, no ones perfect right.

DWMT

funnily enough that has no effect on me and only makes me wish you would. 

In fact, here's quite an old paper that may have some answers:

http://adsabs.harvard.edu/abs/1999PalOc..14..542P

The analysis of the geologic record has revealed a question concerning how the Late Ordovician glaciation could have occurred simultaneously with high CO2 levels (10-18x). Sensitivity studies using a coupled atmosphere-ocean-sea ice model show that it is possible to maintain a permanent snow cover (which corresponds to 60% of all the glacial deposits found on Gondwana) under 10x CO2 levels, warm fall/cool spring orbital parameters, a 4.5% reduction in solar luminosity, a length of day of 21.5 hours, and an enhanced snow/sea ice albedo of 0.3. A cold summer orbit experiment with 10x CO2 and a reduced snow/sea ice albedo of 0.1 also sustains a permanent (albeit less extensive) snow cover. The geographic configuration of the Late Ordovician results in an up to ~42% increase in the global ocean poleward heat transport in the Southern Hemisphere relative to present-day and a significant asymmetry relative to the equator.

In summary - the glaciation was probably driven mostly by the movements of continents toward the poles.

So all you need to do is to shuffle the positions of the continents around - and hey presto! - Global Warming solved.  

(If you speak to somebody regularly who is into the rapid migration of continental landmasses, maybe you could suggest it if He is willing to intervene.)

Grendel wrote on Jun 2^nd, 2009 at 8:23pm:



About moving continental landmasses - yes I was - That was 'irony' Grendel. You were not meant to take it literally.

You ever watch the Vicar of Dibley? Especially where the vicar tells the dumb blonde woman a joke and she just doesn't get it. The actress (Emma Chambers) plays that part that very well.

But you'd do it even better!