Q&A,

Yes, those 4 questions.

Eclipse,

I watched the 4 corners peak oil program. I am aware of the peak oil issue, but this is primarily an economic issue. What I'm interested in is the anoxic ocean CO2 threshold hypothesis described in the Crude series. Have to say that my modest web searches revealed virtuallly nothing to back it up. The Nasa link you provided discussed the apparent anoxic oceans of a couple of billion years ago and the role they played in stalling multicelled life, but did not mention any hypothesis along the lines of the doomsday Crude predictions. Leaves me annoyed at yet another alarmist and sensationalist program, which, as presented by the ABC, is misleading.

Mem's euphoria over recent cooling trends in the US is plainly unwarranted given the relatively high levels of recent tempeartures as indicated in Mem's data set, however, the recent trend is still modest evidence that the present trend is cooling.

Yes, you all get stuck into Mem for referring to US data, but until the advent of satelite data (whic I think began in the 70s, very little reliable data is available outside the western world. In other words, most of the last hundred years of global temperatures that are used to 'prove' warming do not capture a global picture, but rather a few local trends.

Whilst increased CO2 levels must have a warming effect, none of the links I've seen here, or my own wider reading indicate that that a 30% increase in the concentration of CO2 has a strong enough impact, relative to the poorly understood effects of clouds to provide a sound mathematical basis for attributing warming to CO2 emmissions rather than to other variables in the system.

That of course doesn't mean there aren't other excellent reasons to break ourselves of our carbon addiction.

Anyway, I look forward to any further reading/viewing any of you can provide.

"Whilst increased CO2 levels must have a warming effect, none of the links I've seen here, or my own wider reading indicate that that a 30% increase in the concentration of CO2 has a strong enough impact, relative to the poorly understood effects of clouds to provide a sound mathematical basis for attributing warming to CO2 emmissions rather than to other variables in the system."

Really?
http://en.wikipedia.org/wiki/Radiative_forcing#Examples_of_radiative_forcing_calculations

Eclipse,

There you go again. What you have linked to only shows that CO2 has a warming effect but does not deal with this question relative to the overall greenhouse effect and the other variables.

According to the graph on your link a doubling of CO2 levels from 300 to 600 ppm will increase radiative forcing from CO2 by 3.39 w/m2 (and we are many decades away 600ppm CO2 levels), which is about a 1% increase in radiative forcing due to CO2, but according to the wikipedia link:

"When these gases are ranked by their contribution to the greenhouse effect, the most important are:

* water vapor, which contributes 36–70%
* carbon dioxide, which contributes 9–26%
* methane, which contributes 4–9%
* ozone, which contributes 3–7%

The major non-gas contributor to the Earth's greenhouse effect, clouds, also absorb and emit infrared radiation and thus have an effect on radiative properties of the greenhouse gases."

and plainly there are other variables like in solar output, orbital, and inclination cycles, aerosols, and atmospheric particulates.

Only when the range of variations in these factors (or at least the major players) are identified and comparable radiative forcing figures are calculated can the significance of CO2 radiative forcing be understood. Some of the figures are probably out there, but I haven't been able to find them.. any ideas?

Also, the radiative forcing in your link does not state whether it is the radiative forcing stated excludes the overlaping effects of the other greenhouse variables or whether it takes these into account. If the former (as I suspect given the precision of the calculation), then the CO2 forcing described is greatly overstated, since it does not take into account that much of the stated increased radiative forcing was already present due to the other 'overlaping' greenhouse gases/variables.

With a clear picture of the relative forcings of all the variables, and a sense of how much they vary, we'd all be in a position to rationally assess the significance of CO2 levels to warming. Without these, we are not.

In the meantime, my strong doubts linger on.

"Only when the range of variations in these factors (or at least the major players) are identified and comparable radiative forcing figures are calculated can the significance of CO2 radiative forcing be understood. Some of the figures are probably out there, but I haven't been able to find them.. any ideas?"

Ever read the IPCC reports? You're acting as if you're the only one who has ever had the thought, "Gee, I wonder if other gases or solar variations affect our climate".

My humble layman's understanding from flicking through their enormous, is that they really *have* counted every forcing and variable ever postulated by the sceptics, and each has been studied by multiple organisations and individuals. You've got a few questions which sound quite uninformed about the state of climate research, and yet act as if your questions trump decades of research by the world's leading climate bodies.

You can try reports linked to at the following websites.
http://www.ipcc.ch/

http://en.wikipedia.org/wiki/Intergovernmental_Panel_on_Climate_Change

Note: I'm not claiming climatologist know everything, but that they are "up to date". I hope the genuine climatologist DO discover some previously unknown "safety valve", so then we'd only have peak oil, peak soil, peak fisheries, peak fresh water, overpopulation, peak metals and many other resource depletion and toxic overload issues to worry about. But any "safety valve" would have to be peer reviewed for me to take seriously.

My final comment.
I do not believe in the Global Warming Theory. It's a natural Earth Cycle.
I do believe in reducing Carbon based energy systems in favour of increasing Alternate Energy Systems. If only to have a broarder spread of way to generate energy & a shift away from a single energy source.
Oh, & to kill the monopoly of the Carbon Based Barons.

Kalin, I just lobbed in to answer your previous questions and see you are throwing out more.

I was prepared to do some homework for you, but now I'm not so sure.

You just seem to be creating noise on a word & post limited opinion site, why?

Tell you what, go to google scholar, type some keywords (e.g. earth radiative budget, whatever) and do your own stuff.

Alternatively, do the hard yards - enroll in post-grad science and do some real research.

Elipse just popped up - he's right, have you looked at AR4, or even some of the papers that are referenced? There's heaps.

_________

Eclipse
We don't know everything - but there's a lot we do know and it's getting better all the time. In the interim, I am going to adapt to a warmer and wetter world, and live in a more environmentally sustainable way.