locutius wrote on Jan 29^th, 2010 at 9:09am:



Thank you for the vapid condescention. Like Abu's tireless work to highlight the dangers of Islamic politics, this kind of breezy, limp-wristed moan does more for climate scepticism than you realise.

Neither you nor Mozz have been able to say anything about this AGW discussion except relentlessly chip in to tell the world how miffed you are. Not sufficient for an argument, only enought to make people think 'I don't want to be like that.'

Muso, to his great credit, is not limited to merely posing and preening.

Soren wrote on Jan 29^th, 2010 at 12:38pm:


You just put your foot fairly and squarely in it again, Soren, and I'll explain why in a moment.  Let's take the PETM. It was caused by a build up of another Greenhouse gas - a methane release from sea floor clathrates. The evidence for this is to be found even today in vast areas of the sea bed that were ripped off by this release, particularly in the NW Atlantic and the North Sea just West of the Norwegian continental shelf.

A doubling of Carbon Dioxide from  250 to 500ppm will result in a 3 degree warming.

The Global Warming potential for methane (based on a 25 year horizon) is 25 times that of CO2 (7.6 times for a 500 year horizon). The logarithmic relationship with warming still holds.

Now methane gradually decomposes to carbon dioxide in the atmosphere, but it was a much much lower concentration of methane that caused the PETM warming, which increased temperatures to about 8-10 degrees warmer than today.

To illustrate this, the actual release of methane during that entire period was around 1500 to 2000 Gt. Compare that to about 8000 Gt of CO2 being released from fossil fuel combustion every year.

We're not talking about 0.0388 percent methane here, we're talking about an increase from 735ppbv to about 1600ppbv at the peak of the PETM. In percentage terms, which you prefer,  that's an increase from from 0.0000735 to 0.00016 % percent. So much for trace gases.

Your whole argument about trace gases just went out the window. A great deal of work on the PETM was carried out by workers from the Université Catholique de Louvain, Belgium, and this is corroborated by other studies.  

I have a nice pdf version from a poster session by Drs Fichefet, T and   Goosse, H which explains this better that I could, but it's in pdf format, and it's not available on the web. I'll try to convert it to jpg and attach it.

Here is part of the paper. It's difficult to get it below 250kb and keep it readable.

Different paper, although the work is similar. The one I cited was from a poster session at an environmental conference I attended a few years ago.

So you don't accept that any models could possibly be accurate? - even though the atmospheric temperatures of the modelled response matched the proxies pretty well ? Note - no iterative approach - no multi variable hill climbing approach, just a straight run. 

In that case, I suggest that you never fly, because most of the work done on aircraft design is done using models with about the same level of sophistication.

Testing?

Great idea Soren, your new career awaits.

locutius wrote on Jan 29^th, 2010 at 9:09am:


Exactly. Just substitute radiocarbon dating and other dating methods for climate models. They come up with an infinite set of arguments to say that models/ radiocarbon dating is just a crock.

It doesn't have to be scientifically based arguments either. It just needs to sound convincing. For example - that the nuclear detonations of the 20th century invalidates RCD, and the Earth is really 7000 years old.

muso wrote on Jan 30^th, 2010 at 9:07am:



Who said this?

"There is a fundamental uncertainty about climate change prediction that can't be changed...Certain unqualified statements have been unfortunate. We have a problem in communicating uncertainty. There's definitely an issue there. If there wasn't, there wouldn't be the level of scepticism. All of these predictions have to be caveated by saying, `There's a level of uncertainty about that'."