oops, more typos!

@ Grim,
<< As an early Arab OPEC minister put it, about life before oil: “we were very poor. It was common practice for families to have 6 or 7 children, in the hope that one might survive”.>>

Guess, what, Grim ? they now have lots and lots and lots of oil, but many are still having close to 6-7 children per family:

Here’s how the big daddy of OPEC stacks up:

Saudi Arabia 5.8

And, here’s another OPECian

Nigeria 5.2

And then, there’s this non-OPEC heavy weight champ

Yemen 7.6

http://www.pregnantpause.org/numbers/fertility.htm

and there’s is also no relationship between infant mortality and fertility .

But you are right about one thing. There is a relationship between oil revenue and population.
When the oil money runs out and they can no longer sponsor bread and circuses.
There will be hordes of them running to the West (even more than there are currently) all singing

We are [refugees] if you please
We are [refugees] if you don't please
Now we're looking over our new domisile
If we like we stay for maybe quite a while

And then, you can get on your other hobby horse –open borders –and lobby to have them all let in!

Now it's looking really sick - well done!

@SPQR: it is a little hard to believe that a whopping 6000-7000ppm of CO2 ... took millions of years to erode ... a thick planet wide crust

Here is a a some quick quiz:

1. What is the effect on global warming of increasing the CO2 concentration by a factor or say 10? Does it increase by 10?

2. What substance in the air currently causes most of the green house warming?

If you know the answer to those two questions, then with a little thought 25 million years to melt snowball earth doesn't seem so implausible. At least it didn't to me.

It's not difficult to understand if you take the time. It looks to like you haven't taken the time at least come to grips with the basic science, preferring instead to take pot shots from the sidelines at something that threatens your world view.

The problem I have with this brand of scepticism the science we are discussing here is pretty simple stuff compared to what they actually do to model climate. I don't understand it. It's not for lack of trying in my spare time. I suspect to understand it and get some confidence in what they are doing I would have to literally take time off for weeks, understand the equations they are using, design my own models, compare the output of the models to real world data sets. Admittedly this is not helped by the lousy way they publish their data sets, models and results. The way they do it is appropriate for the pre-internet 20th century, not now.

Anyway, the point is I am judging your attitude not by what you think of things that are very difficult to understand. I confess the fact that almost all people who study the climate think the models are accurate if not enough to remove all lingering doubts for me. But this refusal to look at and understand the simple science before criticising it - this betrays healthy scepticism. If you don't evaluate simple stuff apolitically, your pot shots at the complex stuff are just noise.

SPQR,

"...over the comparatively short 100-200 years span since industrialisation...."

Short time span, historically speaking - a major alteration, however, in the mode of human activity. It's a monumental departure from the previous state of affairs.

It's called cause and effect.

@GrahamY: The entry lays a fair part of the blame on fertilisation of the oceans, not by CO2 but by erosion.

Oh for pete's sake. What caused the erosion? Answer: heavy rainfall, not doubt lasted with liberal serving of the carbolic acid that drives the geological carbon cycle. What caused the heavy rainfall: higher temperatures. And what caused the higher temperatures: the greenhouse effect. And what caused the greenhouse effect ...?

@GrahamY: If anoxic episodes are caused by higher temperatures caused by CO2 how do you explain the fact that the oceans weren't anoxic for most of pre-history.

The fundamental driver is an explosion of life in the sea. Yes, that requires CO2 and higher temperatures. But it isn't the only thing life requires, so it is not surprising the geological carbon cycle nipped the process in the bud on occasions.

Your argument that we are a long long way away from these events seems true on the surface. But what seems far becomes much closer in the face of exponential growth. Currently doubling time of CO2 concentrations seems to be around 50 years. If that continued for 200 years we would be in deep trouble indeed. The current levels of just under 400ppm would rise to 6400ppm.

My problem is I can't see that happening. The IEA and USGS predicted it would be possible in the Bush era, but now we have more sober predictions which show both oil and coal peaking this century.

But here is the thing: peak carbon could be even more challenging to us than AGW. A sudden, force transition to other energy sources would be very difficult indeed, almost certainly involving famines and death for swathes of humanity. A carbon tax, which essentially what the article is arguing against, happens to address both AGW and peak carbon. Being on top of things in a post carbon world would be a very good thing for Australia, economically. Sometimes you can get lucky.