The company geodynamics (hot rocks) http://www.geodynamics.com.au claims to install generating capacity for $2500 per kw. Coal fired stations can be built for $1500 per kw. Coal's running costs is 2 cents per kwh. Geodynamics running cost is 1 cent per kwh. Assume both technologies have the same life of 30 years. A discount rate of 5% will give both the same economic return. A 20% discount rate gives at least 3 times the return on a coal investment than hot rocks and paradoxically if we introduce emissions trading it gives an even higher return for coal.
When you go to investors for money they want at least 20% or more return on investment and so "hot rocks" does not get the investment because the time value of money dominates the investment decisions.
There are "other economic worlds" where the time value is not so dominant. We cannot experiment with the planet because we only have one. We can experiment with economic worlds because they are our creation. Another way of tackling climate change is to create an economic world that results in less emissions but where the economy expands and we all get wealthier. It can be done.

Don't you ignorant buggers realise universal history has never had man and his modern technology on this earth before to stuff up nature.

For example, as herbage is said to be nature's way of clearing or exorbing injurious carbon from the atmosphere, what would be the outcome if all the tropical forests were cleared for agriculture?

Maybe we need to think more deeply and sensibly about it?

There is a saying that modern means of natural deep thought has been destroyed by computers etc, taking place of the most important part of the human brain - the deeper recesses of the brain - which work best when humans become deep in thought in a trance-like situation - technology now sadly having taken its place, which includes the lulling exciting music we now have the choice of on Foxtel TV, including human activity.

The above is not the ravings of a old maniac, seeing that such philosophy was written about by the Australian historian Geoffrey Serle, when he wrote about how the real creative spirit of Australia originally coming from the Australian outback, where people though under the stress of so-called hardship and loneliness, did have more time to create and analyse, thus the cover of his popular publication so bearing the title - From Deserts the Prophets Come.

Ah, bushbred – “From deserts the prophets come” – you malign the aspects of society from whence I was spawned.
One where there was time during the October storm period to wander into the rainforest and pillage an egg or two from a Scrub-turkey nest; during winter’s sunny days to scramble down into an open-forest patch in the gorge and count Amethystine Pythons - emerged from the scrub to sun themselves.
Three-score-years-and-ten from those free-ranging days - of togetherness with the local ecology - maybe I don’t need such crap, as I can watch it all on “reality TV” or a filmed documentary; while diabetically fixed to the lounge chair- propelled to that position with the assistance of McDonalds, Coke, and fast-processed meals.
We have progressed to such an era, past the silent movies, through the talkies – but thankfully not yet to the smellies.
More likely it is not just I, that has such need, but society in general.
Yes, it is essential to re-engage mentally and physically with our planet’s seething biological mass. A mass of which we are, as a temporary component during a fleeting millisecond of its geological time scale, in plague proportions.
If we do re-engage and get some common sense in relation to our society’s behavior, we will become cautious in this rush to shorten our fleeting geological millisecond of comfortable existence.
For two million years, geological imperatives have favored the genus Homo. For just a hundred thousand years it has favored Homo sapiens. Only in the fleeting past ten thousand has it enabled agriculture to develop and thrive.
Only in the last hundred years has our species multiplied at such vast rates – like lemmings or mice; expanding our numbers four-fold – in less than four generations. At the same time we have escalated our ability to throw our wastes into the oceans and air; unlocking, in a geological instant, millions of years of the earth’s stored carbon (coal, oil, vegetation, soil-embedded mycology) to active participation in climate matters.

What scientists worth their salt would tell us not to worry.

I wonder if Carter bothered to read Trenberth article (which he didn't link to, the article is here: http://blogs.nature.com/climatefeedback/2007/06/predictions_of_climate.html)
because, for my money, he misrepresents the article totally.

For one, Carter made much of the following:

"In fact there are no predictions by IPCC at all. And there never have been. The IPCC instead proffers “what if” projections of future climate that correspond to certain emissions scenarios"

This shouldn't come as news to anyone. We cannot accurately guess how much CO2 we will emit in 50 years. Stock-market crash? Breakthrough in some technology? All these could change CO2 emissions. As Trenberth says:

"They are intended to cover a range of possible self consistent “story lines” that then provide decision makers with information about which paths might be more desirable."

The article Trenberth wrote was primarily about the lack of long term, regional forecast models. We don't yet have models that work on short enough time or space scales. Real climate has a good post on the limits of the models:

http://www.realclimate.org/index.php/archives/2007/05/climate-models-local-climate/

"Global climate statistics, such as the global mean temperature, provide good indicators as to how our global climate varies. However, most people are not directly affected by global climate statistics. They care about the local climate; the temperature, rainfall and wind where they are. When you look at the impacts of a climate change or specific adaptations to a climate change, you often need to know how a global warming will affect the local climate."

There is a lot of work going on in this area, and the models have recently been able to represent El-Nino cycles, and a lot of other stuff they couldn't 5 years ago. But Trenberth's criticism is valid. He is not making a "confession" that the models are useless. They provide useful projections on what the global climate will be like under a range of senarios

Carter also engages in cherry picking. For instance, he neglects the following:

So if the science is settled, then what are we planning for and adapting to? A consensus has emerged that “warming of the climate system is unequivocal... and the science is convincing that humans are the cause. Hence mitigation of the problem: stopping or slowing greenhouse gas emissions into the atmosphere is essential. The science is clear in this respect.”

He should really present his own arguments, not misrepresent other's.

So how did the climate models do? A recent paper by James Hansen tested his (primitive by today's standards), 1988 model against the observed. It didn't do too badly. The paper can be found here:

http://pubs.giss.nasa.gov/abstracts/2006/Hansen_etal_1.html


Keep in mind that 20 years is not enough time to validate the model. But also keep in mind that the models have improved out of sight since then, and the essential nnumbers are unchanged.

Also keep in mind that the theory of Anthropogenic Global Warming doesn't rely on models, it is mearly suplemented by them. The basic physics is clear in this case.

"They are intended to cover a range of possible self consistent “story lines” that then provide decision makers with information about which paths might be more desirable."
Story lines is a very apt term...no wonder Hollywood loves it.

"So how did the climate models do?"
Comparing to the satellite measurements of global temperature all three of Hansen's scenarios predicted the amount of warming to be greater than what was actually seen. If he is a little bit wrong in 20 years, he will be massively wrong in 100 years.
If instead comparisons are done to the surface temperature record, the closest match is Scenario C. Temperatures in Scenario C rise until 2005 and then begin to slowly decline.
Either way there is not much to worry about. Personally I'd go for the satellite measurements due to the bias in the surface temperature record (guess who is in charge of the surface temperature record).

"keep in mind that the models have improved out of sight since then, and the essential nnumbers are unchanged"
Bigger and bigger computers runing more and more complex models all based on dodgy assumptions. No wonder the results are unchanged.

"mammalian embryos is currently being destroyed on a global scale by
greenhouse/embryo coupling"
By 0.6 degrees? Yeah right dickie.

"Of course humans (and other life forms) will only witness part of this event as they are slowly eliminated by being cooked to a crisp"
I think you're done...bing!