I much appreciated the (mostly) supportive comments from PhillipM, Daviy, Taswegian, rpg, cohenite and davey.

My article concentrated on black-coal power stations. But let’s not forget that black coal currently accounts for only about 35 per cent of anthropogenic generated CO2. The balance of the estimated 50 per cent from all stationary sources comes mainly from lignite, cement manufacture and iron smelting. Not hard to calculate the extra CO2 to sequester.

If by some miracle the fossil-fuel power generators were replaced by wind, solar or nuclear, you are still left with cement and iron (for steel), which are responsible for 20-25 per cent of anthropogenic CO2. You cannot smelt iron without coke and cannot avoid roasting limestone (CaCO3), which is the main constituent in cement, thus emitting CO2. We will still continue mining coal for steel and roasting limestone, until they are exhausted or until the sustainability zealots get steel and concrete banned.

Comments from davey (17/1) were great. Re the much improved efficiencies of new-generation IGCC power stations, a report in London Telegraph (21.12.08), mentioning that the UK government aims to save about 200 Mt of CO2 emissions by 2020, by generating 15 per cent of the country’s electricity from wind power. Instead of new-generation stations, that 15 per cent equates to around 100,000 wind turbines. Currently there are “only” 198 onshore and offshore farms, or 2,389 turbines – only about 97,000 to go! And the warmers call wind farms sustainable development! What about the colossal amount of energy, concrete, steel and other resources needed to build them (and they do have a use-by date), not to mention the blight on the landscape? Not only that, but five-sixths of the current lot of wind farms in UK were idle during Britain’s recent severe cold snap – no wind.

My reference to contamination of potable/brackish aquifers was simply to highlight a potential hazard. Near-liquid CO2 in water is much more reactive and much more concentrated than gaseous CO2 in water (i.e. carbonic acid). The latter is only weakly ionic and therefore mild, as in fizzy drinks.

Another post awaiting.

Among the many sceptics and warmers I know, none has any liking for CCS.

That said, I turn my attention to comments from tonykevin 1, Manorina and kulu, who dwelt on my being an AGW sceptic and on sustainability. My responses:
• The outputs of GCMs are only as reliable as the inputted data – GIGO. IPCC’s AR4 stated bluntly that their climatologists’ knowledge of the effects of aerosols and cloud dynamics was low, and yet they were rash enough to base their catastrophic climate projections till 2100 on incomplete data. As an analogy, if your PC were carefully programmed with all sorts of data to forecast the winner of this year’s Melbourne Cup, you might be astounded to find your horse ran poorly, simply because you failed to input data on the little-known scare effect of a bird flock on the turf. Climate is extremely complex and poorly understood.
• Warmers cannot seem to comprehend that the anthropogenic CO2-causes-global-warming link has not been established beyond the fact that, yes, CO2 has been steadily rising from the 285 ppm pre-industrial level (IPPC value), and so has temperature – but in decades-long fits and starts. However, that doesn’t prove that CO2 is driving warming. Oh yes, there are heaps of papers saying so, but most are hypothetical (on positive feedbacks and the like) and none has yet produced the proof positive – no “smoking gun”. The IPCC’s projections are based purely on untestable hypotheses. Sceptical scientists do agree that the 100 ppm of anthropogenic CO2 (plus 20 ppm or so more of CO2e) has caused about 0.2°C of the rise during last century.

Wrt tonykevin1’s first post, I would point out that climate change is not a brand-new phenomenon – it’s been happening for millennia. Ice-melts are nothing new. How did Greenland get its name in the tenth century, unless the ice had melted beforehand? And anthropogenic CO2 was definitely not the cause! In the past few days it has been reported that current sea-ice levels (satellite measured) are as they were in 1979. IPCC AR4 didn’t anticipate that setback either.

JohnH,

There is a difference between denying or undermining the science behind the general acceptance of the anthropogenic causes of accelerated climate change and questioning the world's ability to deal with it.

I, like you don't for a moment believe that renewable energy such as wind and solar energy are likely to come close to fixing the problem although of course they can make some contribution to reducing GHG emissions along with reforestation, perhaps a little bit of CCS and whatever else turns up.

I am not a scientist myself but have read enough literature about climate change to make me believe that there is an extremely strong probability that our GHG emissions have caused some global warming already and that this will escalate as time goes by. I will think again when enough evidence comes out to satisfactorily explain what is causing the global warming trend if it is not GHG and to explain why increased GHG in the atmosphere should not lead to increased warming in the future.

I am not a scientist but I have become a conservationist over the last 10 years as I have become increasingly aware of the continual damage being done to the environment both at a local level and on a global scale. Climate change is just one of the problems facing us, perhaps the worst one, but the one environmentalists have grabbed onto as a focus for their efforts to bring about change in the way the world uses its resources.

Wind and solar energy will not in themselves fix the climate change problem let alone all the other environmental problems that the world will have to face. I, like James Lovelock (I think) actually believe it’s already too late to prevent a collapse of society as it has evolved but if anything effective IS to done it must start by addressing the ultimate problems of population growth and growth in per capita consumption.

Mike Pope, I have great difficulty in comprehending the enormity of CCS in the Australian situation, given its seemingly insurmountable difficulties and the lack of suitable injection rock. I can only surmise that Mr Rudd has been poorly advised on the promise of CCS, as he has on the AGW religion, because he has listened only to IPCC adherents.

On 21/1 kulu wrote: “There is a difference between denying or undermining the science behind the general acceptance of the anthropogenic causes of accelerated climate change and questioning the world’s ability to deal with it”. I have extreme difficulty in agreeing with any of that statement. “General acceptance” equates to “consensus”; AGW “science” is hypothetical and unproven – shonky even – the best example is Mann’s hockey stick, but many others have been identified by sceptical scientists. Why is it that James Hansen prefers to use questionable surface-based temperature readings, rather than those from balloons and satellites (even though he administers NASA’s satellite measurements)? Why do GISS’s temperature curves not concur with those from other satellite sources, when they all measure the same, or very similar, thing? Why does Hansen edit GISS’s curves, to his advantage? “Accelerated climate change” – accelerated compared with what and when? Surely, you don’t call a 0.7°C increase over 100 years “accelerated”. Temperatures have been rising overall ever since the Ice Age. Since anthropogenic CO2 has accounted for about only 0.2°C of that 0.7°C, what effect would there be in eliminating anthropogenic CO2 from the air? Activists seem to think it possible to stop climate change – which only shows their lack of grey matter.

Have you read Prof Charles Birch’s book “Confronting the Future”? Published in 1975, its 360 pages expounded exactly the same philosophies that our current environmental activists do – close down fossil-fuel power stations; limit population growth; sustainable development; etc (except that he reckoned the world would largely grind to a halt before 2000). BUT WITH TWO EXCEPTIONS – he didn’t mention climate change or CO2. Yes, I too believe that environmentalists have grabbed onto climate change to promote their cause.

Excellent analysis John, and very useful for combatting the CCS proponents (i.e. the coal industry and their political servants).

There's nothing to be gained in debating climate change theory. I accept the evidence for AGW - in fact, I think the situation is far more dire than the IPCC4 suggests, and I think we're already past the point of irreversible and catastrophic climate change - but nothing I say will change the minds of AGW denialists.

But agreement on climate change theory isn't necessary for the current discussion, which is on "clean coal". All posts so far have been unanimous in challenging CCS as a viable means of addressing the massive pollution of coal-fired power stations.

Let's ditch the phrase "clean coal": it's simply a nonsequitur, and a deliberate greenwash by the coal industry. Coal is *dirty*. If it's used as a fuel, there's no getting around the fact that extracting energy from it produces not only CO2, but also highly toxic wastes (as the Tennessee disaster has demonstrated). The CO2 and toxic wastes are all pollutants, and have to be disposed of somewhere - and until recently, that "somewhere" has been the atmosphere.

Do we want to continue using coal as a cheap energy source, and live with the inescapable pollution it causes? I haven't heard anyone advocate this view, not even the coal industry. So this leaves us with three options: we pay a lot more for coal-fired energy so that the pollution is collected and disposed of more carefully (the coal industry's self-interested preference); we build nuclear power plants to displace fossil-fueled plants, and give ourselves an even more intractable pollution problem; or we pay the extra for non-polluting renewable energy, including the cost of weaning ourselves off dirty coal.

My choice is to pay the extra for renewable energy and a cleaner environment. AGW is simply an additional reason to do this, and creates some urgency to make the switch as quickly as possible.

JohnH,

Since your reply to my last post I have read up on the "controversy" generated on the science behind Mann's hockey stick graph. I found the following amongst other things that has me convinced that the criticisms of Mann's science has been hyped up to serve only the purpose of skeptics and not science.

From the US based National Research Council's Board on Atmospheric Sciences and Climate...

"The Committee consisted of 12 scientists from different disciplines and was tasked with explaining the current scientific information on the temperature record for the past two Millenia, and identifying the main areas of uncertainty, the principal methodologies used, any problems with these approaches, and how central the debate is to the state of scientific knowledge on global climate change."

And..

"The panel published its report in 2006.[28] The report agreed that there were statistical shortcomings in the MBH analysis, but concluded that they were small in effect."