Hot air

Damn it you frustrate me! :) What do you propose instead?

[I'm not sure. But the present process has no benefits at all, and several disbenefits (the pretence of progress, and the vast cost and CO2 involved) -W]

They talk and then sometimes they agree, and then they do whatever they were going to do anyway.

In my opinion the only solutions will either be entirely new energy sources which are cheaper than current CO2 emitting energy. Or some type of mechanism that removes CO2 from the atmosphere.

NN, I think that is too pessimistic. How about incremental increases in efficiency of the main suspects (eg solar, wind, tide, some biofuels) combined with increased pressure for energy security and independence, volatility of fossil fuel prices (even if not steadily increasing prices)...I can easily imagine a "soft landing" towards lower CO2 intensity, and it doesn't even necessarily require international agreements (although they could help). Of course imagining something doesn't make it happen, but it is certainly an outcome we can aim for!

JA, I think those changes are very likely in the developed countries. Decreased CO2 intensity is already happening I believe. But referring to page 824 of the IPCC physical basis even a reduction of output of 50% from current levels results in continued rising atmospheric CO2. (It is interesting that they don't even explain what level between 50 and 100 percent would be required to cause a long term stabilization of atmospheric CO2 at present levels.)

So my views have to do with the probabilities of achieving something like a 75% reduction in CO2 global output from current levels, when that output is currently increasing.

Come on now... this is what we call democracy in work. It takes huge amount of time but I would not have it any other way. The meetings makes it possible to get agreements further on to understand other demands, do more "research" at home get back and try to get a good outcome... I guess we will know in about 1-2 years what will happened.

"as they seem to be utterly pointless"

Does it matter?

"spending large amounts of money and emitting large amounts of CO2 in the process"

Even assuming that the CO2 emissions *may* cause an ecological problem, would they have spent any less money, and emitted any less CO2, had they spent the time doing something else?

NN,

About 80% reduction in emissions is the right order for stabilisation, but it depends on what you mean by "long term" and also depends rather critically on what the natural feedback might be (probably small but rather uncertain). I suspect the IPCC avoided discussion of this in order to avoid accusations of making inappropriate policy recommendations. I agree that such a large reduction is a long way away, but OTOH we can still take steps in the right direction.

JA, Agreed that we can take steps in the right direction, and there are a number of reasons to do so. But if you do the math on the likely trajectory of developing countries, and even the proposed 50% cutbacks in the developed countries over the discussed time periods the CO2 levels will get quite high. And we will get to find out what the climate sensitivity really is.

That goes back to my very first point which is that if we don't want to complete this experiment, then there either needs to be a major breakthrough on energy production, or we need to find a way to get CO2 out of the atmosphere.

When we talk about a new Manhattan Project these are the types of things that this would accomplish.

Nicolas Nierenberg | December 3, 2008 9:56 AM --- There are several ways to remove unwanted carbon from the active carbon cycle. I know of two or three which cost in the range of about $40 per tonne of carbon dioxide removed ($147 per tonne of pure carbon). I know of one or two which might possibly cost but $20--25 per tonne of carbon dioxide removed). I'm looking at another which might well be even less expensive.

The problem is that in 2007 CE we added about 10 GtC to the active carbon cycle; that's around 37 billion tonnes of carbon dioxide. Removing all of that is fairly big bucks!

[Thats in $. How much in CO2? -W]

DB, it is indeed! But intuitively I think we have a better shot at getting the cost of extraction down by two orders of magnitude than we have of reducing output sufficiently, or perhaps even significantly.

Since you have looked into it, do you think it is possible to reduce the costs to a level that would work?

Nicolas Nierenberg | December 4, 2008 11:59 PM --- Even $20 per tonne of CO2 removed would work if the world economy was willing to fork over a mere $740 billion per year. That's about 1.1% of last year's gross world product.

The current method I am studying still has too many unknowns to have any confidence that the cost is significantly less. It'll be some days yet.

William wrote "[Thats in $. How much in CO2? -W]" I fear I do not comprehend the question.

[How much CO2 does it cost to get rid of 1 unit of CO2? -W]

Actually DB this would be incredibly promising, if it is indeed possible. Can you give us a hint about this process?

To clarify William's point, what is the energy required for the carbon removal process, and where could it be located? What are the other components of the cost, and in manufacturing those components are there significant energy requirements or CO2 output as a side effect? Depending on where this process could be located, near hydroelectric, geothermal, or wind resources could produce the direct energy reqquired without additional CO2 being introduced.

Nicolas Nierenberg | December 6, 2008 1:15 PM --- What would? Around $20--25 per tonne of CO2 removed is not that difficult and, in principle, the fossil carbon added as CO2 would be negligibly small. In immediate practis, the equipment needed would consume fossil carbon to make, the mining, crushing and grinding would and the transportation would. Worse might be the required heating, but here solar thermal could well work.

Here aree some references.

Ex situ olivine weathering:

http://www.realclimate.org/index.php/archives/2008/03/air-capture/#comm…
ftp://ftp.geog.uu.nl/pub/posters/2008/Let_the_earth_help_us_to_save_the…
http://www.ecn.nl/docs/library/report/2003/c03016.pdf

See references 7, 8 and 9 in

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

Mine tailings:

http://adsabs.harvard.edu/abs/2005AGUFM.B33A1014W

The idea is to enhace the natural weathering of olivine by grining it into rock flour, then heating in a wet interior reactor (autoclave) until most of it is turned to carbonate, thus consuming atmopheric carbon. Since costs of mining, crushing and grinding are well known, I just plugged to in to obtain around $25 per tonne of carbon dioxide removed. However, the crushing and grinding costs are largely for the energy required, so wind or solar thermal might bring the cost down to just the mining and the (minimal) required transportation. I know of no way to significantly lower those costs.

The environmental costa are large open pit olivine mines and large piles of 'tailings', the reacted product. The only nice part about the latter is that it makes a very useful soil amendment, so maybe farmers will haul some of it away for free. Otherwise, just pile it up.

The entire process must be located right next to the olivine mine so that transportation costs are minimized. I suspect that a mixture of wind and solar thermal wold be adequate at most such tropical sites and some temperate ones.

In the future biodiesel can replace diesel, other non-fossil fuel sources of energy can be used to produce/maintain the necessary equipment.

The whole process of removing carbon dioxide can be made somewhat more efficient by providing a local source of extra CO2. An example is fermenting biomass to make biogasse + heat and then burning the biogasse for more heat (enough to generate electricity) plus a flue gas stream chock-a-block with CO2.